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Dr Zhaohui Wang

ARC DECRA Fellow

School of Environmental and Life Sciences

Career Summary

Biography

Dr Zhaohui Wang received his PhD degree in Physical Chemistry (2009) from Institute of Chemistry, Chinese Academy of Sciences, China. He is currently a Senior Research Fellow at International Centre for Balanced Land Use at the University of Newcastle, Australia. Prior to this Dr Wang worked as an Associate Professor at College of Environmental Science and Engineering, Donghua University, China and as a Research Associate at Southern Cross GeoScience, Southern Cross University, Australia, respectively. His career has been dedicated to fundamental discovery on environmental chemistry of redox-active elements, focusing specifically on Fe, Cl and Cr cycles both in natural and engineered systems. Dr Wang is the (co)author of over 70 peer-reviewed journal articles and 4 book chapters. To date his publications have received over 2100 citations (Google Scholar), with an H-index of 22 (i10-index of 38). He has served as an Associate Editor for RSC Advances (Royal Society of Chemistry) and Current Catalysis (Bentham Science) since 2015.


Qualifications

  • PhD, Graduat University of Chinese Academy of Sciences

Keywords

  • Advanced oxidation processes
  • Chemical intermediates
  • Environmental catalysis
  • Environmental geochemistry
  • Environmental photochemistry
  • Environmental redox chemistry
  • Radical chemistry

Languages

  • Mandarin (Mother)
  • English (Fluent)

Fields of Research

Code Description Percentage
039901 Environmental Chemistry (incl. Atmospheric Chemistry) 50
040202 Inorganic Geochemistry 25
090409 Wastewater Treatment Processes 25

Professional Experience

UON Appointment

Title Organisation / Department
Senior Lecturer University of Newcastle
School of Environmental and Life Sciences
Australia

Grant Reviews

Year Grant Amount
2017 ARC FT DP DE
Aust Competitive - Commonwealth - 1CS, Aust Competitive - Commonwealth - 1CS
$1,000,000

Prestigious works

Year Commenced Year Finished Prestigious Work Role
2015 2018 Associate Editor RSC Editor
Edit

Publications

For publications that are currently unpublished or in-press, details are shown in italics.


Chapter (2 outputs)

Year Citation Altmetrics Link
2013 Wang Z, Chen C, Ma W, Zhao J, 'Sensitization of Titania Semiconductor: A Promising Strategy to Utilize Visible Light', Photocatalysis and Water Purification: From Fundamentals to Recent Applications 199-240 (2013)
DOI 10.1002/9783527645404.ch8
Citations Scopus - 7
2011 Wang Z, 'Photocatalytic Degradation of Organic Contaminants on Mineral Surface', Biophysico-Chemical Processes of Anthropogenic Organic Compounds in Environmental Systems, John Wiley & Sons, USA (2011)

Journal article (68 outputs)

Year Citation Altmetrics Link
2017 Fang C, Lou X, Huang Y, Feng M, Wang Z, Liu J, 'Monochlorophenols degradation by UV/persulfate is immune to the presence of chloride: Illusion or reality?', Chemical Engineering Journal, 323 124-133 (2017) [C1]

© 2017 Elsevier B.V.The efficiency and, accordingly, the success of the advanced oxidation processes (AOPs) has generally been evaluated on the basis of degradation kinetics. In ... [more]

© 2017 Elsevier B.V.The efficiency and, accordingly, the success of the advanced oxidation processes (AOPs) has generally been evaluated on the basis of degradation kinetics. In practice, chloride in saline wastewater is often found to inhibit degradation processes. Therefore its highly desirable to develop more effective processes which are not affected by chloride. In this study, no significant interference of chloride with monochlorophenols (MCPs, e.g. 2-CP, 3-CP and 4-CP) degradation by the UV photo-activated persulfate (UV/PS) process has been observed. This indicated the ¿illusion¿ that the UV/PS process might have been an appropriate technology working under saline conditions. To further evaluate its applicability, the generation of reaction intermediates, of adsorbable organic halogen (AOX) accumulation and of acute toxicity of MCPs in the UV/PS system were examined. In reality, several aromatic chlorinated compounds (number of chlorine atoms¿=2), such as dichlorophenols and 2,3,5,3',5'-pentachloro-biphenyl, were identified and quantified. An accumulation and relative increase of AOX with reaction time was observed in the UV/PS/Cl system. The acute toxicity tests with Photobacterium phosphoreum indicated that the inhibition effect of UV/PS reactions increased with reaction time regardless of the presence of chloride or not. The results of this study might be helpful for assessing the PS-based technologies for saline wastewater treatment.

DOI 10.1016/j.cej.2017.04.094
Citations Scopus - 2
2017 Wang Z, Sun L, Lou X, Yang F, Feng M, Liu J, 'Chemical instability of graphene oxide following exposure to highly reactive radicals in advanced oxidation processes.', JOURNAL OF COLLOID AND INTERFACE SCIENCE, 507 51-58 (2017) [C1]
DOI 10.1016/j.jcis.2017.07.105
2017 Lou X, Fang C, Geng Z, Jin Y, Xiao D, Wang Z, et al., 'Significantly enhanced base activation of peroxymonosulfate by polyphosphates: Kinetics and mechanism', CHEMOSPHERE, 173 529-534 (2017) [C1]
DOI 10.1016/j.chemosphere.2017.01.093
Citations Scopus - 3Web of Science - 1
2017 Fang C, Wang Z, Feng M, Huang Y, Yang F, Liu J, 'Trace bromide ion impurity leads to formation of chlorobromoaromatic by-products in peroxymonosulfate-based oxidation of chlorophenols', Chemosphere, 182 624-629 (2017) [C1]

© 2017 Elsevier Ltd Trace bromide (Br - ) released from industrial effluents or brominated compounds is able to directly react with peroxymonosulfate (PMS) to generate a series o... [more]

© 2017 Elsevier Ltd Trace bromide (Br - ) released from industrial effluents or brominated compounds is able to directly react with peroxymonosulfate (PMS) to generate a series of reactive oxidants which can oxidize and also halogenate organics. We report the identification and evolution of by-products during 2,4,6-trichlorophenol (TCP) degradation in the presence of PMS and trace Br - . The influencing factors, including Br - concentration and pH, were investigated. The depletion of TCP was accelerated with increasing trace Br - concentration (0¿0.2¿mM) and was affected by the initial pH (3.0¿7.0). The chlorinated and brominated compounds were identified in simulated wastewater during treatment with PMS. Notably, the potential formation of chlorobromoaromatic by-products was demonstrated for the first time in the presence of PMS and trace Br - . The possible reaction pathways of TCP and its derivatives are discussed. These findings have important implications for the future applications of PMS-based oxidation processes.

DOI 10.1016/j.chemosphere.2017.05.065
2017 Wang Z, Feng M, Fang C, Huang Y, Ai L, Yang F, et al., 'Both degradation and AOX accumulation are significantly enhanced in UV/peroxymonosulfate/4-chlorophenol/Cl- system: two sides of the same coin?', RSC ADVANCES, 7 12318-12321 (2017) [C1]
DOI 10.1039/c7ra01294b
Citations Scopus - 1Web of Science - 1
2017 Huang Y, Wang Z, Liu Q, Wang X, Yuan Z, Liu J, 'Effects of chloride on PMS-based pollutant degradation: A substantial discrepancy between dyes and their common decomposition intermediate (phthalic acid)', Chemosphere, 187 338-346 (2017) [C1]

© 2017 Elsevier Ltd A considerable effort has been devoted to elucidating the roles of chloride in oxidative degradation and chlorination of dyes. However, few investigations are... [more]

© 2017 Elsevier Ltd A considerable effort has been devoted to elucidating the roles of chloride in oxidative degradation and chlorination of dyes. However, few investigations are available on kinetic analysis and transformation pathways of secondary degradation byproducts of dyes in saline wastewater treatment. Here the impact of chlorine on the degradation rate of phthalic acid, a typical dye degradation intermediate, by the Co 2+ /peroxymonosulfate (PMS) process was examined. Degradation efficiency, intermediate products, AOX (adsorbable organic halogen) formation and mineralization were considered. An overall negative impact was observed within the concentration of Cl - up to 100 mM, differing from the dual effect of chloride on dye degradation process as previously observed. The presence of high levels of Cl - led to a low production of AOX and a reduction of the formation of chlorinated by-products. The mineralization was also restrained when the Cl - concentration was increased. Degradation pathways for these processes are proposed. These findings provide valuable information about the degradation pathways of dyes and about the formation mechanism of chlorinated by-products in industrial saline wastewater treatment.

DOI 10.1016/j.chemosphere.2017.08.120
2017 Li S, Hu S, Jiang W, Liu Y, Liu J, Wang Z, 'Synthesis of n-type TaON microspheres decorated by p-type Ag
DOI 10.1016/j.mcat.2017.03.027
Citations Scopus - 3
2017 Li S, Hu S, Jiang W, Liu Y, Liu J, Wang Z, 'Facile synthesis of flower-like Ag3VO4/Bi2WO6 heterojunction with enhanced visible-light photocatalytic activity', Journal of Colloid and Interface Science, 501 156-163 (2017) [C1]
DOI 10.1016/j.jcis.2017.04.057
Citations Scopus - 7
2017 Choppala G, Bush R, Moon E, Ward N, Wang Z, Bolan N, Sullivan L, 'Oxidative transformation of iron monosulfides and pyrite in estuarine sediments: Implications for trace metals mobilisation', Journal of Environmental Management, 186 158-166 (2017) [C1]
DOI 10.1016/j.jenvman.2016.06.062
Citations Scopus - 2Web of Science - 2
Co-authors Richard Bush, Nanthi Bolan
2017 Wang Z, Ai L, Huang Y, Zhang J, Li S, Chen J, Yang F, 'Degradation of azo dye with activated peroxygens: When zero-valent iron meets chloride', RSC Advances, 7 30941-30948 (2017) [C1]
DOI 10.1039/c7ra03872k
Citations Scopus - 2
2017 Huang Y, Yang F, Ai L, Feng M, Wang C, Wang Z, Liu J, 'On the kinetics of organic pollutant degradation with Co2+/peroxymonosulfate process: When ammonium meets chloride', CHEMOSPHERE, 179 331-336 (2017) [C1]
DOI 10.1016/j.chemosphere.2017.03.110
2017 Wang Z, Sun H, 'Nanoscale in photocatalysis', Nanomaterials, 7 (2017)
DOI 10.3390/nano7040086
2017 Li S, Hu S, Xu K, Jiang W, Liu J, Wang Z, 'A Novel Heterostructure of BiOI Nanosheets Anchored onto MWCNTs with Excellent Visible-Light Photocatalytic Activity', NANOMATERIALS, 7 (2017) [C1]
DOI 10.3390/nano7010022
Citations Scopus - 3Web of Science - 1
2016 Fang C, Xiao D, Liu W, Lou X, Zhou J, Wang Z, Liu J, 'Enhanced AOX accumulation and aquatic toxicity during 2,4,6-trichlorophenol degradation in a Co(II)/peroxymonosulfate/Cl
DOI 10.1016/j.chemosphere.2015.11.030
Citations Scopus - 15Web of Science - 13
2016 Jiang B, Wang X, Liu Y, Wang Z, Zheng J, Wu M, 'The roles of polycarboxylates in Cr(VI)/sulfite reaction system: Involvement of reactive oxygen species and intramolecular electron transfer', Journal of Hazardous Materials, 304 457-466 (2016) [C1]
DOI 10.1016/j.jhazmat.2015.11.011
Citations Scopus - 10Web of Science - 10
2016 Zhou J, Xiao JH, Fang CL, Xiao DX, Guo YG, Lou XY, et al., 'Degradation kinetics and mechanisms of chloronitrophenol in UV/PMS system', Zhongguo Huanjing Kexue/China Environmental Science, 36 66-73 (2016)

© 2016, Chinese Society for Environmental Sciences. All right reserved. The efficient removal of 4-chloro-2-nitrophenol (4C2NP) in ultraviolet (UV)/peroxymonosulfate (PMS) oxidat... [more]

© 2016, Chinese Society for Environmental Sciences. All right reserved. The efficient removal of 4-chloro-2-nitrophenol (4C2NP) in ultraviolet (UV)/peroxymonosulfate (PMS) oxidation system was investigated. The effects of pH, PMS dosage and concentrations of 4C2NP, chloride and nitrate ions on the degradation efficiency of 4C2NP were evaluated. No significant differences in 4C2NP degradation rate were observed at pH 2.0~5.0, but a further increase in pH value would inhibit the substrate decomposition. In addition, PMS dosage positively correlated with degradation rates of 4C2NP, while 4C2NP concentration had a negative effect. A typical dual effect of chloride concentrations on the 4C2NP degradation kinetics was observed, whereas the increasing concentrations of nitrate showed an indistinctively inhibitory effect on 4C2NP degradation. Dechlorination and denitration were the dominant degradation pathways during the oxidative degradation of 4C2NP, followed by the formation of chloride and nitrate ions. The released chloride from chloro groups would be involved in re-chlorination through radical reactions. Nitro groups released would be oxidized to stable nitrate, preventing re-nitration. Degradation mechanism of 4C2NP in a UV/PMS system was proposed based on intermediates identified.

Citations Scopus - 3
2016 Liu W, Fang C, Huang Y, Ai L, Yang F, Wang Z, Liu J, 'Is UV/Ce(IV) process a chloride-resistant AOPs for organic pollutants decontamination?', RSC Advances, 6 93558-93563 (2016) [C1]

© The Royal Society of Chemistry 2016. Most of the current advanced oxidation processes (AOPs) are vulnerable to the presence of chloride in saline wastewater treatment because c... [more]

© The Royal Society of Chemistry 2016. Most of the current advanced oxidation processes (AOPs) are vulnerable to the presence of chloride in saline wastewater treatment because chloride not only affects the degradation kinetics but also probably leads to absorbable organic halogen (AOX) formation. Here we report an UV/Ce(iv) process can efficiently oxidize organic pollutants such as Acid Orange 7, even in the presence of chloride. Fluorescent probe technology suggests hydroxyl radicals were generated in UV/Ce(iv) process, but not in UV/Ce(iv)/Cl - system. In the presence of chloride, Ce(iv)-chloride complex was formed, which can directly oxidize dyes or g enerate reactive oxygen species by chlorine activation. Although degradation and mineralization rates of dyes were still inhibited to some extents by large amounts of chloride, but negligible AOX was generated. Therefore, UV/Ce(iv) process can be recommended as an alternative AOPs when treating acidic saline wastewater.

DOI 10.1039/c6ra21682j
Citations Scopus - 1Web of Science - 1
2016 Li X, Wang Z, Zhang B, Rykov AI, Ahmed MA, Wang J, 'FexCo3-xO4 nanocages derived from nanoscale metal-organic frameworks for removal of bisphenol A by activation of peroxymonosulfate', APPLIED CATALYSIS B-ENVIRONMENTAL, 181 788-799 (2016)
DOI 10.1016/j.apcatb.2015.08.050
Citations Scopus - 53Web of Science - 46
2016 Lou X, Xiao D, Fang C, Wang Z, Liu J, Guo Y, Lu S, 'Comparison of UV/hydrogen peroxide and UV/peroxydisulfate processes for the degradation of humic acid in the presence of halide ions', ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 23 4778-4785 (2016)
DOI 10.1007/s11356-015-5232-x
Citations Scopus - 6Web of Science - 5
2016 Huang Y, Wang Z, Fang C, Liu W, Lou X, Liu J, 'Importance of reagent addition order in contaminant degradation in an Fe(II)/PMS system', RSC ADVANCES, 6 70271-70276 (2016)
DOI 10.1039/c6ra14081e
Citations Web of Science - 3
2015 Jiang B, Liu Y, Zheng J, Tan M, Wang Z, Wu M, 'Synergetic Transformations of Multiple Pollutants Driven by Cr(VI)-Sulfite Reactions', Environmental Science and Technology, 49 12363-12371 (2015) [C1]

© 2015 American Chemical Society. Reduction of Cr(VI) is often deemed necessary to detoxify chromium contaminants; however, few investigations utilized this reaction for the purp... [more]

© 2015 American Chemical Society. Reduction of Cr(VI) is often deemed necessary to detoxify chromium contaminants; however, few investigations utilized this reaction for the purpose of treating other industrial wastewaters. Here a widely used Cr(VI)-sulfite reaction system was upgraded to simultaneously transform multiple pollutants, namely, the reduction of Cr(VI) and oxidation of sulfite and other organic/inorganic pollutants in an acidic solution. As(III) was selected as a probe pollutant to examine the oxidation capacity of a Cr(VI)-sulfite system. Both ¿ OH and SO 4 ¿- were considered as the primary oxidants for As(III) oxidation, based on the results of electron spin resonance, fluorescence spectroscopy, and specific radicals quenching. As(III)-scavenging, oxidative radicals greatly accelerated Cr(VI) reduction and simultaneously consumed less sulfite. In comparison with a Cr(VI)-H 2 O 2 system with 50 µM Cr(VI), Cr(VI), the sulfite system had excellent performance for both As(III) oxidation and Cr(VI) reduction at pH 3.5. Moreover, in this escalated process, less sulfite was required to reduce Cr(VI) than the traditional Cr(VI) reduction by sulfite process. This effectively improves the environmental compatibility of this Cr(VI) detoxification process, alleviating the potential for SO 2 release and sulfate ion production in water. Generally, this study provides an excellent example of a "waste control by waste" strategy for the detoxification of multiple industrial pollutants.

DOI 10.1021/acs.est.5b03275
Citations Scopus - 23Web of Science - 22
2015 Wang Z, Xiao D, Bush RT, Liu J, 'Coprecipitated arsenate inhibits thermal transformation of 2-line ferrihydrite: Implications for long-term stability of ferrihydrite', Chemosphere, 122 88-93 (2015) [C1]

© 2014 Elsevier Ltd. 2-line ferrihydrite, a ubiquitous iron oxy-hydroxide found in natural and engineered systems, is an efficient sink for the toxic metalloids such as arsenic. ... [more]

© 2014 Elsevier Ltd. 2-line ferrihydrite, a ubiquitous iron oxy-hydroxide found in natural and engineered systems, is an efficient sink for the toxic metalloids such as arsenic. While much is known of the excellent capacity of ferrihydrite to coprecipitate arsenate, there is little information concerning the long-term stability of arsenate-accumulated ferrihydrite. By thermal treatment methodology, the expedited transformation of ferrihydrite in the presence of coprecipitated arsenate was studied at varying As/Fe ratios (0-0.5) and different heating temperature (40, 300, 450, 600. °C). Pure and transformed minerals were characterized by thermogravimetry (TG), X-ray diffraction (XRD), Electron Spin Resonance (ESR), Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform Infrared Spectroscopy (FTIR). Arsenate was found to retard the thermal transformation of ferrihydrite. The extents of ferrihydrite transformation to hematite decreased with increasing As/Fe ratios, but increased at a higher heating temperature. It is predicted that the coprecipitated arsenate can stabilize the amorphous iron oxides against the transformation to more crystalline solids. Arsenate concentration appears to play an important role in this predicted long-term stability.

DOI 10.1016/j.chemosphere.2014.11.017
Citations Scopus - 8Web of Science - 7
Co-authors Richard Bush
2015 Zhou J, Xiao J, Xiao D, Guo Y, Fang C, Lou X, et al., 'Transformations of chloro and nitro groups during the peroxymonosulfate-based oxidation of 4-chloro-2-nitrophenol', Chemosphere, 134 446-451 (2015) [C1]

© 2015 Elsevier Ltd. Dechlorination and denitration are known to occur during the oxidative degradation of chloronitroaromatic compounds, but the possibility of re-chlorination a... [more]

© 2015 Elsevier Ltd. Dechlorination and denitration are known to occur during the oxidative degradation of chloronitroaromatic compounds, but the possibility of re-chlorination and re-nitration of chloro and nitro groups is not assessed despite of its importance in evaluating the applicability of advanced oxidation processes (AOPs). In this study, transformation of chloro and nitro groups in degradation of 4-chloro-2-nitrophenol (4C2NP) by sulfate radical generated via Co-mediated peroxymonosulfate activation was investigated. Both chloride and nitrate ions were found as the main inorganic products of chloro and nitro groups in 4C2NP, but their levels were much lower than that of degraded parent 4C2NP. A typical dual effect of chloride on the 4C2NP degradation kinetics was observed, whereas no measurable influence was found for addition of low level nitrate. Re-chlorination took place, but re-nitration was not verified because several polychlorophenols but none of polynitrophenols were detected. The specific degradation mechanism involved in the transformation of nitro group and chloro group was proposed.

DOI 10.1016/j.chemosphere.2015.05.027
Citations Scopus - 23Web of Science - 19
2015 Li J, Luo G, Gao J, Yuan S, Du J, Wang Z, 'Quantitative evaluation of potential ecological risk of heavy metals in sewage sludge from three wastewater treatment plants in the main urban area of Wuxi, China', Chemistry and Ecology, 31 235-251 (2015)

© 2014, © 2014 Taylor & Francis. In this study, the potential ecological risks and eco-toxicity of heavy metals (Cu, Pb, Zn, Ni, Cd, Cr, As and Hg) in sewage sludge were q... [more]

© 2014, © 2014 Taylor & Francis. In this study, the potential ecological risks and eco-toxicity of heavy metals (Cu, Pb, Zn, Ni, Cd, Cr, As and Hg) in sewage sludge were quantitatively evaluated. Sewage sludge samples were collected from three wastewater treatment plants in Wuxi city during five years from 2009 to 2013. The levels of the eight metals temporally varied. The contents of Zn and Cu in the tested sewage sludge were the highest, followed by Cr, Ni, Pb and As, and the contents of Cd and Hg were the least. The Community Bureau of Reference (BCR) sequential extraction results showed that Zn, Ni and Cd had the highest mobilisation potential, while Cu, Pb, Cr and Hg were not stabilised and would release to the environment under oxidising conditions. The removal efficiency of Cu and Cr was higher than 70%, while that of As, Cd and Hg was less than other heavy metals. The overall potential ecological risk index (RI) of heavy metals in sewage sludge was 1376.34, revealing very high risk. However, the environmental risk values based on the index of geo-accumulation (I < inf > geo < /inf > ) and risk assessment code (RAC) were both low. Cd contamination is the major concern while the treated sewage sludge is used for agricultural purposes.

DOI 10.1080/02757540.2014.961439
Citations Scopus - 3Web of Science - 9
2015 Jiang B, Guo J, Wang Z, Zheng X, Zheng J, Wu W, et al., 'A green approach towards simultaneous remediations of chromium(VI) and arsenic(III) in aqueous solution', Chemical Engineering Journal, 262 1144-1151 (2015)

© 2014 Elsevier B.V. In this study, the applicability of glow discharge plasma for simultaneous redox transformations of Cr(VI) and As(III) was evaluated in aqueous solution. The... [more]

© 2014 Elsevier B.V. In this study, the applicability of glow discharge plasma for simultaneous redox transformations of Cr(VI) and As(III) was evaluated in aqueous solution. The results showed that there was a beneficially synergistic effect between Cr(VI) reduction and As(III) oxidation. The presence of Cr(VI) can significantly enhance As(III) oxidation, whereas a slight increase for Cr(VI) reduction mediated by As(III) was observed. The added ethanol or dicarboxylic acids can increase the Cr(VI) reduction with different mechanisms, but significantly retard As(III) oxidation. The conversions of both As(III) and Cr(VI) can also be effectively increased from 96% to 100% and 53% to 77%, respectively, by increasing the voltage input from 530 to 600V. Cr(VI) reduction proceeded more rapidly, approximately 96% at pH 2.0, while As(III) oxidation was depressed under acidic conditions, only 70% at pH 2.0. And the optimal pH value for As(V) formation facilitated by Cr(VI) is 7.0. H 2 O 2 generated in-situ in glow discharge plasma can reduce Cr(VI) and produce highly oxidizing OH that was responsible for As(III) oxidation. Reaction between As(III) and OH in turn partially avoided the re-oxidation of Cr(III) by OH to Cr(VI), thus facilitating the net conversion of Cr(VI). Our study demonstrated the feasibility of GDP for the coconversion of As(III) and Cr(VI), holding a great promise for real-world wastewater remediation.

DOI 10.1016/j.cej.2014.10.064
Citations Scopus - 15Web of Science - 10
2015 Xiao D, Lou X, Liu R, Guo Y, Zhou J, Fang C, et al., 'Fe-catalyzed photoreduction of Cr(VI) with dicarboxylic acid (C<inf>2</inf>¿C<inf>5</inf>): divergent reaction pathways', Desalination and Water Treatment, 56 1020-1028 (2015)

© 2014 Balaban Desalination Publications. All rights reserved. Reduction of carcinogenic hexavalent chromium (Cr(VI)) by ferrous iron (Fe(II)) to essentially nontoxic trivalent c... [more]

© 2014 Balaban Desalination Publications. All rights reserved. Reduction of carcinogenic hexavalent chromium (Cr(VI)) by ferrous iron (Fe(II)) to essentially nontoxic trivalent chromium (Cr(III)) is a simple and effective method for Cr(VI) decontamination. In this study, the photoreduction efficacy of Cr(VI) in acidic Fe(III)/Fe(II) solutions was examined in the presence of dicarboxylic acids (DCA) (i.e. oxalic acid (Oxal), malonic acid (Mal), succinic acid (Suc), and glutaric acid (Glu)). Rates of Cr(VI) reduction under UV irradiation depend on the photochemistry of Fe(III)/Fe(II) complexes with DCA, following the order of Oxal > Suc ¿ Glu > Mal. Fe(III)-oxalato complexes are favorable for transforming Cr(VI) due to the formation of relative abundance of Fe(II) and reductive radicals such as (Formula presented.) , (Formula presented.) after photoreaction, whereas Fe(III)-Mal complexes upon UV irradiation generate the lowest amount of Fe(II) among all the Fe-DCA complexes, and thus have poor capacity for Cr(VI) reduction. The effects of Suc and Glu on the Cr(VI) reduction are insignificant since the Fe(III)-OH complexes are still the main Fe(III) species due to their weak chelating abilities with Fe(III). This work has important implications for selecting the favorable ligands of Fe(III) for light-induced Cr(VI) transformation and designing the methods for treating wastewater with low-molecular-weight acids and Cr(VI).

DOI 10.1080/19443994.2014.941309
2015 Ramjaun SN, Wang Z, Yuan R, Liu J, 'Can electrochemical oxidation techniques really decontaminate saline dyes wastewater?', Journal of Environmental Chemical Engineering, 3 1648-1653 (2015)

© 2015 Elsevier Ltd. All rights reserved. Formation of toxic chlorinated organic byproducts is of great concern when selecting electrochemical oxidation (EO) as decontamination t... [more]

© 2015 Elsevier Ltd. All rights reserved. Formation of toxic chlorinated organic byproducts is of great concern when selecting electrochemical oxidation (EO) as decontamination technology for saline dye wastewater, but still not verified. To test the applicability of EO, methyl orange (MO) was used as a model dye for anodic contact glow discharge electrolysis (CGDE) and conventional electrolysis (CE) in the presence of chloride. The degradation kinetics and organic intermediates were analyzed. In the presence of chloride, the rates of dye degradation were significantly increased as CGDE and CE were applied. CE resulted in higher mineralization efficiency than CGDE which needs much energy input. Several refractory chlorinated aromatic and even aliphatic compounds were identified during MO degradation, as well as the other anthraquinone dye, alizarin red S (AR). Therefore, the issues of toxic chlorinated byproducts and energy cost should be preferentially evaluated prior to the selection of EO technologies.

DOI 10.1016/j.jece.2015.06.006
Citations Scopus - 5
2014 Wang Z, Bush RT, Sullivan LA, Chen C, Liu J, 'Selective oxidation of arsenite by peroxymonosulfate with high utilization efficiency of oxidant', Environmental Science and Technology, 48 3978-3985 (2014)

Oxidation of arsenite (As(III)) is a critical yet often weak link in many current technologies for remediating contaminated groundwater. We report a novel, efficient oxidation rea... [more]

Oxidation of arsenite (As(III)) is a critical yet often weak link in many current technologies for remediating contaminated groundwater. We report a novel, efficient oxidation reaction for As(III) conversion to As(V) using commercial available peroxymonosulfate (PMS). As(III) is rapidly oxidized by PMS with a utilization efficiency larger than 90%. Increasing PMS concentrations and pH accelerate oxidation of As(III), independent to the availability of dissolved oxygen the addition of PMS enables As(III) to oxidize completely to As(V) within 24 h, even in the presence of high concentrations of radical scavengers. On the basis of these observations and theoretical calculations, a two-electron transfer (i.e., oxygen atom transfer) reaction pathway is proposed. Direct oxidation of As(III) by PMS avoids the formation of nonselective reactive radicals, thus minimizing the adverse impact of coexisting organic matter and maximizing the utilization efficiency of PMS therefore, this simple approach is considered a cost-effective water treatment method for the oxidation of As(III) to As(V). © 2014 American Chemical Society.

DOI 10.1021/es405143u
Citations Scopus - 27Web of Science - 25
Co-authors Richard Bush
2014 Liu R, Guo Y, Wang Z, Liu J, 'Iron species in layered clay: Efficient electron shuttles for simultaneous conversion of dyes and Cr(VI)', Chemosphere, 95 643-646 (2014)

The simultaneous reduction of Chromium(VI) (Cr(VI)) and oxidation of cationic dyes in dispersions of Montmorillonite K10 (MK10) were examined under visible irradiation (¿ 420 nm)... [more]

The simultaneous reduction of Chromium(VI) (Cr(VI)) and oxidation of cationic dyes in dispersions of Montmorillonite K10 (MK10) were examined under visible irradiation (¿ 420 nm). The iron species (i.e. iron oxides, structural iron and exchangeable interlayer iron) in layered clays are active for catalytically reducing Cr(VI) by using Malachite green (MG) and Rhodamine B (RhB) as the electron donors. Molecular oxygen does not have a significant effect on clay-catalyzed Cr(VI) reduction, but is important for oxidative degradation of dye pollutants. MK10 catalysts are stable and reusable, and are therefore considered as a promising naturally-abundant material for decontamination of dye and heavy metals. © 2013 Elsevier Ltd.

DOI 10.1016/j.chemosphere.2013.09.055
Citations Scopus - 12Web of Science - 11
2014 Xiao D, Guo Y, Lou X, Fang C, Wang Z, Liu J, 'Distinct effects of oxalate versus malonate on the iron redox chemistry: Implications for the photo-Fenton reaction', Chemosphere, 103 354-358 (2014)

The dicarboxylic acids oxalate (Oxal) and malonate (Mal) are frequently detected as the final low-molecular-weight organic acids during oxidative degradation of aromatic compounds... [more]

The dicarboxylic acids oxalate (Oxal) and malonate (Mal) are frequently detected as the final low-molecular-weight organic acids during oxidative degradation of aromatic compounds. Here a distinct effect of Oxal versus Mal on iron-based photocatalytic technologies was reported by testing the degradation efficiency of the dye rhodamine B. The rates of dye degradation in irradiated Fe(III) solutions depended on Fe(III/II) speciation, photoreactivities of Fe complexes and reactivities of Fe(II) complexes with H 2 O 2 . Photolysis of the Fe(III)-oxalato complex was favorable due to the formation of O2-, HO2 and OH for oxidizing the dye; however, an excess of H 2 O 2 could quench the excited state of ferrioxalate, decreasing the degradation efficiency. In contrast, activities of UV/Fe(III) in the presence of Mal were significantly diminished because Fe(III)-Mal complexes, with much lower quantum yield of Fe(II) from photoreduction, dominated Fe(III) speciation. The results provide data for an understanding of the mechanism of iron redox (photo)chemistry mediated by diacids, which will aid in selecting appropriate Fe ligands, screening photo-Fenton conditions and designing UV/Fe(III) treatability. © 2013 Elsevier Ltd.

DOI 10.1016/j.chemosphere.2013.11.069
Citations Scopus - 8Web of Science - 7
2014 Yuan R, Wang Z, Hu Y, Wang B, Gao S, 'Probing the radical chemistry in UV/persulfate-based saline wastewater treatment: Kinetics modeling and byproducts identification', Chemosphere, 109 106-112 (2014)

The effect of Cl - on the oxidative degradation of Acid Orange 7 (AO7) was investigated in UV/S 2 O 8 2- system to elucidate the chlorination pathways in saline wastewaters. Low... [more]

The effect of Cl - on the oxidative degradation of Acid Orange 7 (AO7) was investigated in UV/S 2 O 8 2- system to elucidate the chlorination pathways in saline wastewaters. Lower amount of Cl - as well as Br - enhanced the decoloration of AO7, but such promotion effect reduced gradually with the increasing halide ion dosage. The dye mineralization was found to be inhibited by Cl - , especially under acidic conditions. Results of kinetics modeling demonstrated that the fraction of different oxidizing radicals largely depended on the content of Cl - . At the initial pH of 6.5, Cl 2 - was much more abundant than SO 4 - . The significance of Cl 2 - for AO7 degradation increased with the increasing Cl - concentration and overwhelmed that of SO 4 - at [Cl - ] > 1mM. Without Cl - , SO 4 - was the predominant radical for AO7 degradation under acidic conditions, while OH prevailed gradually at higher pH. Under high salinity conditions, more OH can be formed and contributed to the dye degradation especially in alkaline medium, leading to higher destruction efficiency of AO7. Several chlorinated byproducts were detected in the presence of chloride ions, and SO 4 - /Cl 2 - -based degradation pathways of AO7 were proposed. This work provides further understanding of the complex reaction mechanisms for SO 4 - -based advanced oxidation processes in chloride-rich environments. © 2014 Elsevier Ltd.

DOI 10.1016/j.chemosphere.2014.03.007
Citations Scopus - 29Web of Science - 29
2014 Lou X, Wu L, Guo Y, Chen C, Wang Z, Xiao D, et al., 'Peroxymonosulfate activation by phosphate anion for organics degradation in water', Chemosphere, 117 582-585 (2014) [C1]

© 2014 Elsevier Ltd. Activation of peroxygens is a critical method to generate oxidative species, but often consumes additional chemical reagents and/or energy. Here we report a ... [more]

© 2014 Elsevier Ltd. Activation of peroxygens is a critical method to generate oxidative species, but often consumes additional chemical reagents and/or energy. Here we report a novel and efficient activation reaction for peroxymonosulfate (PMS) by phosphate anions (PBS). The PBS/PMS coupled system, at neutral pH, is able to decompose efficiently even mineralize a variety of organic pollutants, such as Acid Orange 7, Rhodamine B and 2,4,6-trichlorophenol. In contrast, no measurable degradation was observed when the PMS was replaced by other peroxygens (i.e. hydrogen peroxide and peroxydisulfate). Both PMS and PBS are indispensable for the oxidative degradation of pollutants. Increasing pH and concentrations of PMS and PBS significantly accelerate the degradation of organics. It is proposed that OH would be the major radical for contamination degradation at pH 7.0 through the radical quenching experiments. This work provides a new way of PMS activation for decontamination at neutral pH, in particular for phosphate-rich wastewater treatment.

DOI 10.1016/j.chemosphere.2014.09.046
Citations Scopus - 27Web of Science - 20
2014 Wang H, Zhang L, Chen Z, Hu J, Li S, Wang Z, et al., 'Semiconductor heterojunction photocatalysts: Design, construction, and photocatalytic performances', Chemical Society Reviews, 43 5234-5244 (2014)

Semiconductor-mediated photocatalysis has received tremendous attention as it holds great promise to address the worldwide energy and environmental issues. To overcome the serious... [more]

Semiconductor-mediated photocatalysis has received tremendous attention as it holds great promise to address the worldwide energy and environmental issues. To overcome the serious drawbacks of fast charge recombination and the limited visible-light absorption of semiconductor photocatalysts, many strategies have been developed in the past few decades and the most widely used one is to develop photocatalytic heterojunctions. This review attempts to summarize the recent progress in the rational design and fabrication of heterojunction photocatalysts, such as the semiconductor-semiconductor heterojunction, the semiconductor-metal heterojunction, the semiconductor-carbon heterojunction and the multicomponent heterojunction. The photocatalytic properties of the four junction systems are also discussed in relation to the environmental and energy applications, such as degradation of pollutants, hydrogen generation and photocatalytic disinfection. This tutorial review ends with a summary and some perspectives on the challenges and new directions in this exciting and still emerging area of research. This journal is © the Partner Organisations 2014.

DOI 10.1039/c4cs00126e
Citations Scopus - 625Web of Science - 603
2014 Wang Z, Liu J, 'New insight into photochemical oxidation of Fe(II): The roles of Fe(III) and reactive oxygen species', Catalysis Today, 224 244-250 (2014)

Photooxidation of Fe(II) at acidic pH occurs in photocatalytic processes of Fe(III) species, but its reaction mechanism is not well understood. The kinetics of Fe(II) oxidation in... [more]

Photooxidation of Fe(II) at acidic pH occurs in photocatalytic processes of Fe(III) species, but its reaction mechanism is not well understood. The kinetics of Fe(II) oxidation in irradiated aqueous solutions at pH 3.0 have been investigated in terms of kinetic modeling approach, rate constant estimation and the significance of various oxidation pathways. Fe(II) oxidation kinetics strongly rely on the availability of UV light, Fe(III) ions and oxygen. The presence of a portion of Fe(III) in Fe(II)-containing solutions favors the rapid oxidation of Fe(II). At high concentration of Fe(II), excitation of Fe(III) species may be quenched by Fe(II) in deaerated systems or may sensitize Fe(II) oxygenation under oxic conditions. By incorporation of this photosensitization pathway, the established model in this study is shown to be able to adequately describe the oxidation of Fe(II) at pH 3.0. Sensitivity analysis indicates that photolysis of Fe(III) species is critically important for overall Fe(II) oxidation kinetics. Fe(III)-catalyzed oxygenation of Fe(II), and oxidation of Fe(II) by HO 2 and OH also exerts a marked impact on the oxidation of Fe(II). Therefore, Fe(III)-catalyzed oxygen activation and their secondary reactive oxygen species (ROS) account for the oxidation kinetics of Fe(II) at acidic pH. © 2013 Elsevier B.V.

DOI 10.1016/j.cattod.2013.09.063
Citations Scopus - 2Web of Science - 2
2014 Wang Z, Xiao D, Liu R, Guo Y, Lou X, Liu J, 'Fenton-like degradation of reactive dyes catalyzed by biogenic jarosite', Journal of Advanced Oxidation Technologies, 17 104-108 (2014)

A kind of Fe mineral-biogenic jarosite was prepared by biooxidation of Fe 2+ using Acidithiobacillus ferrooxidans. Decolorization of reactive dyes, Reactive Blue 19 (RB) and Reac... [more]

A kind of Fe mineral-biogenic jarosite was prepared by biooxidation of Fe 2+ using Acidithiobacillus ferrooxidans. Decolorization of reactive dyes, Reactive Blue 19 (RB) and Reactive Orange 1 (RO), were conducted using asprepared jarosite as a catalyst in the presence of H 2 O 2 via a Fenton-like reaction process. The experimental results indicated that jarosite can serve as an efficient Fe catalyst to initiate Fenton-like reaction in the process of dye decolorization. 98% of decolorization efficiency of RB was achieved within 105 min of reaction time by using 5 mM H 2 O 2 and 1 g/L jarosite catalyst at pH 5.0. The current investigation may provide a practical and costseffective way using biogenic Fe minerals for remediation of wastewater contaminated with industrial colorants. © 2014 Science & Technology Network, Inc.

Citations Scopus - 5Web of Science - 5
2014 Guo Y, Zhou J, Lou X, Liu R, Xiao D, Fang C, et al., 'Enhanced degradation of Tetrabromobisphenol A in water by a UV/base/persulfate system: Kinetics and intermediates', Chemical Engineering Journal, 254 538-544 (2014)

Tetrabromobisphenol A (TBBPA), one of the most frequently used brominated flame retardants (BFRs), is only soluble in strongly alkaline solutions where most advanced oxidation pro... [more]

Tetrabromobisphenol A (TBBPA), one of the most frequently used brominated flame retardants (BFRs), is only soluble in strongly alkaline solutions where most advanced oxidation processes (AOPs) are inefficient or in organic solvents. It is highly desirable to develop an environmentally friendly cleanup technology for TBBPA which operates at alkaline pH without the need of organic solvents to enhance its solubility in water. In this study a favorable UV/base/persulfate (PS) system for rapid degradation of TBBPA in aqueous solution is reported. Increases of initial pH and PS concentrations have positive effects on the degradation of TBBPA and a high initial TBBPA concentration has a negative influence. The addition of Br - has a negligible effect on the degradation of TBBPA. The low TOC removal and degradation intermediates of TBBPA identified by GC-MS suggested that TBBPA was degraded via the cleavage between the isopropyl group and one of the benzene rings rather than complete debromination and degradation. The present study provides a simple and green approach to detoxify TBBPA in water rather than using toxic organic solvents. © 2014 Elsevier B.V.

DOI 10.1016/j.cej.2014.05.143
Citations Scopus - 26Web of Science - 25
2014 Liu R, Xiao D, Guo Y, Wang Z, Liu J, 'A novel photosensitized Fenton reaction catalyzed by sandwiched iron in synthetic nontronite', RSC Advances, 4 12958-12963 (2014)

The conventional photo-Fenton reaction often suffers from the constraints of operation pH, low iron loading, ultraviolet availability in solar light and instability of iron-based ... [more]

The conventional photo-Fenton reaction often suffers from the constraints of operation pH, low iron loading, ultraviolet availability in solar light and instability of iron-based catalysts. Here we report a novel heterogeneous Fenton reaction which works with a dye-photosensitized structural Fe(iii)/Fe(ii) redox cycling mechanism. The synthesized nontronite catalyst (NAU) was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS) analysis, and thermal gravimetric analysis (TG). NAU exhibited excellent catalytic activity over a wide pH range (3.0-8.0) for highly efficient degradation of Rhodamine B by hydrogen peroxide (H 2 O 2 ) under visible light irradiation (¿ > 420 nm). The excited dye molecule donates electrons to structural iron sandwiched in NAU which further catalyzes H 2 O 2 to generate highly reactive OH radicals. This iron-rich clay mineral (total Fe, 24.4 wt%) is chemically and mechanically stable. There are no measurable iron leaching, nor any noticeable loss of activity and damage to the clay structure observed after 6 recycles. Therefore, NAU clay has outstanding merits for the practical treatment of organic dye pollutants at large scale. This journal is © the Partner Organisations 2014.

DOI 10.1039/c3ra47359g
Citations Scopus - 8Web of Science - 9
2014 Wang Z, 'Probing the importance of planar surfaces and crystal edges for electron transfer within iron-bearing clays', RSC Advances, 4 31476-31480 (2014)

We demonstrated the importance of basal planes and crystal edge for electron transfer within montmorillonite (MK10) and nontronite (NAu-2) by a facile dye-sensitized photoreductio... [more]

We demonstrated the importance of basal planes and crystal edge for electron transfer within montmorillonite (MK10) and nontronite (NAu-2) by a facile dye-sensitized photoreduction method. It was found that not all structural Fe in the clay matrix was redox-active. The results are vital to the utilization of naturally abundant clays in environmental redox chemistry. This journal is © the Partner Organisations 2014.

DOI 10.1039/c4ra04521a
Citations Scopus - 1Web of Science - 2
2014 Wang Z, Xiao D, Liu J, 'Diverse redox chemistry of photo/ferrioxalate system', RSC Advances, 4 44654-44658 (2014)

© 2014 the Partner Organisations. The diverse redox processes of the photo/ferrioxalate system (PFS) were investigated by varying the concentrations of Fe(iii), oxalate and oxyge... [more]

© 2014 the Partner Organisations. The diverse redox processes of the photo/ferrioxalate system (PFS) were investigated by varying the concentrations of Fe(iii), oxalate and oxygen. Photoreactivity of PFS is determined by the prevalence of the most photolabile Fe(iii) and abundance of Fe(iii) and oxalate, which is critical for the operation optimization of PFS in wastewater treatment.

DOI 10.1039/c4ra07153k
Citations Scopus - 2Web of Science - 2
2014 Zhou S, Li Y, Chen J, Liu Z, Wang Z, Na P, 'Enhanced Cr(vi) removal from aqueous solutions using Ni/Fe bimetallic nanoparticles: Characterization, kinetics and mechanism', RSC Advances, 4 50699-50707 (2014)

© the Partner Organisations 2014. In this study, Ni/Fe bimetallic nanoparticles were prepared by a liquid-phase chemical reduction method and characterized by scanning electron m... [more]

© the Partner Organisations 2014. In this study, Ni/Fe bimetallic nanoparticles were prepared by a liquid-phase chemical reduction method and characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) with image mapping, transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The as-prepared Ni/Fe material was applied to remove Cr(vi) via a coupled adsorption/reduction process. It was found that Cr(vi) removal followed pseudo-second-order reaction kinetics. Acidic pH favored the efficient removal of Cr(vi) due to the abundance of reactive H species that were mediated by the Ni catalyst. XPS studies demonstrated that Cr(vi) removal on the surface of the bimetallic nanoparticles was a synergistic adsorption and reduction process. The introduction of nickel to nZVI not only controls iron passivation but also facilitates the efficient flow of electron transfer between iron and Cr(vi), and thus the efficient reduction of Cr(vi) to Cr(iii). Hydroxylated Cr(OH) 3 and co-precipitation of Cr x Fe 1-x (OH) 3 were the final products of Cr(vi) removal by the Ni/Fe material. This journal is

DOI 10.1039/c4ra08754b
Citations Scopus - 14
2013 Wang Z, Bush RT, Sullivan LA, Liu J, 'Simultaneous redox conversion of chromium(VI) and arsenic(III) under acidic conditions', Environmental Science and Technology, 47 6486-6492 (2013)

Arsenic and chromium are often abundant constituents of acid mine drainage (AMD) and are most harmful as arsenite (As(III)) and hexavalent (Cr(VI)). To simultaneously change their... [more]

Arsenic and chromium are often abundant constituents of acid mine drainage (AMD) and are most harmful as arsenite (As(III)) and hexavalent (Cr(VI)). To simultaneously change their oxidation state from As(III) to As(V), and Cr(VI) to Cr(III), is a potentially effective and attractive strategy for environmental remediation. The coabundance of As(III) and Cr(VI) in natural environments indicates their negligible direct interaction. The addition of H 2 O 2 enables and greatly accelerates the simultaneous oxidation of As(III) and reduction of Cr(VI). These reactions are further enhanced at acidic pH and higher concentrations of Cr(VI). However, the presence of ligands (i.e., oxalate, citrate, pyrophosphate) greatly retards the oxidation of As(III), even though it enhances the reduction of Cr(VI). To explain these results we propose a reaction mechanism where Cr(VI) is primarily reduced to Cr(III) by H 2 O 2 , via the intermediate tetraperoxochromate Cr(V). Cr(V) is then involved in the formation of ¿ OH radicals. In the presence of ligands, the capacity of Cr(V) to form ¿ OH radicals, which are primarily responsible for As(III) oxidation, is practically inhibited. Our findings demonstrate the feasibility for the coconversion of As(III) and Cr(VI) in AMD and real-world constraints to this strategy for environmental remediation. © 2013 American Chemical Society.

DOI 10.1021/es400547p
Citations Scopus - 23Web of Science - 22
Co-authors Richard Bush
2013 Guo Y, Lou X, Fang C, Xiao D, Wang Z, Liu J, 'Novel photo-sulfite system: Toward simultaneous transformations of inorganic and organic pollutants', Environmental Science and Technology, 47 11174-11181 (2013)

An efficient and green advanced oxidation process (i.e., photo-sulfite reaction) for the simultaneous oxidation of sulfite and organic pollutants in water is reported. The photo-s... [more]

An efficient and green advanced oxidation process (i.e., photo-sulfite reaction) for the simultaneous oxidation of sulfite and organic pollutants in water is reported. The photo-sulfite system (UV-Fe(III)-sulfite) is based on the Fe-catalyzed sulfite oxidation and photochemistry of Fe(III) species. SO 4 ¿- and ¿ OH radicals were identified in the photo-sulfite system with radical scavenging experiments using specific alcohols. This novel technology was consistently proven to be more favorable than the alternative Fe(III)-sulfite systems for the degradation of 2,4,6-trichlorophenol (2,4,6-TCP) and other organic pollutants at all conditions tested. The reactivity of photo-sulfite system was sustained due to the spontaneous switch of photoactive species from Fe(III)-sulfito to Fe(III)-hydroxo complexes with the depletion of sulfite and the decrease in pH. In contrast, in the absence of light the performance of the Fe(III)-sulfite system was greatly diminished after the consumption of sulfite. The formation of the Fe(III)-sulfito complex is a necessary step for initiating the photo-sulfite reaction. Inhibition of the oxidation of 2,4,6-TCP and methyl orange (MO) was observed in the presence of ligands that can stabilize one or more of the reactants: Fe(III), Fe(II), or sulfite. Our study provides a new facile route for the generation of SO 4 ¿- and simultaneous removal of organic and inorganic pollutants. © 2013 American Chemical Society.

DOI 10.1021/es403199p
Citations Scopus - 30Web of Science - 30
2013 Wang Z, Bush RT, Liu J, 'Arsenic(III) and iron(II) co-oxidation by oxygen and hydrogen peroxide: Divergent reactions in the presence of organic ligands', Chemosphere, 93 1936-1941 (2013)

Iron-catalyzed oxidation of As(III) to As(V) can be highly effective for toxic arsenic removal via Fenton reaction and Fe(II) oxygenation. However, the contribution of ubiquitous ... [more]

Iron-catalyzed oxidation of As(III) to As(V) can be highly effective for toxic arsenic removal via Fenton reaction and Fe(II) oxygenation. However, the contribution of ubiquitous organic ligands is poorly understood, despite its significant role in redox chemistry of arsenic in natural and engineered systems. In this work, selected naturally occurring organic ligands and synthetic ligands in co-oxidation of Fe(II) and As(III) were examined as a function of pH, Fe(II), H 2 O 2 , and radical scavengers (methanol and 2-propanol) concentration. As(III) was not measurably oxidised in the presence of excess ethylenediaminetetraacetic acid (EDTA) (i.e. Fe(II):EDTA < 1:1), contrasting with the rapid oxidation of Fe(II) by O 2 and H 2 O 2 at neutral pH under the same conditions. However, partial oxidation of As(III) was observed at a 2:1 ratio of Fe(II):EDTA. Rapid Fe(II) oxidation in the presence of organic ligands did not necessarily result in the coupled As(III) oxidation. Organic ligands act as both iron speciation regulators and radicals scavengers. Further quenching experiments suggested both hydroxyl radicals and high-valent Fe species contributed to As(III) oxidation. The present findings are significant for the better understanding of aquatic redox chemistry of iron and arsenic in the environment and for optimization of iron-catalyzed arsenic remediation technology. © 2013 Elsevier Ltd.

DOI 10.1016/j.chemosphere.2013.06.076
Citations Scopus - 11Web of Science - 11
Co-authors Richard Bush
2013 Lou XY, Guo YG, Xiao DX, Wang ZH, Lu SY, Liu JS, 'Rapid dye degradation with reactive oxidants generated by chloride-induced peroxymonosulfate activation', Environmental Science and Pollution Research, 20 6317-6323 (2013)

Transition-metal is known to catalyze peroxymonosulfate (PMS) decomposition to produce sulfate radicals. Here we report reactions between PMS and chloride, without a need of trans... [more]

Transition-metal is known to catalyze peroxymonosulfate (PMS) decomposition to produce sulfate radicals. Here we report reactions between PMS and chloride, without a need of transition metals, also can be used to degrade organic dye pollutant (Rhodamine B, (RhB)). Some important operating parameters, such as dosages of PMS and Cl - , pH of solution, temperature, ionic strength, and several common cations, were systematically investigated. Almost complete decoloration of RhB was achieved within 5 min ([PMS] = 0.5 mM, [Cl - ] = 120 mM, and pH 3.0), and RhB bleaching rate increased with the increased dosages of both PMS and chloride ion, following the pseudo-first-order kinetic model. However, the total organic carbon (TOC) removal results demonstrated that the decoloration of RhB was due to the destruction of chromophore rather than complete degradation. RhB decoloration could be significantly accelerated due to the high ionic strength. Increasing of the reaction temperature from 273 K to 333 K was beneficial to the RhB degradation, and the activation energy was determined to be 32.996 kJ/mol. Bleaching rate of RhB with the examined cations increased with the order of NH 4 + < Na + < K + < Al 3+ < Ca 2+ < Mg 2+ . Some major degradation products of RhB were identified by GC-MS. The present study may have active technical implications for the treatment of dyestuff wastewater in practice. © 2013 Springer-Verlag Berlin Heidelberg.

DOI 10.1007/s11356-013-1678-x
Citations Scopus - 19Web of Science - 16
2013 Guo YG, Huang P, Zhang WG, Yuan XW, Fan FX, Wang HL, et al., 'Leaching of heavy metals from Dexing copper mine tailings pond', Transactions of Nonferrous Metals Society of China (English Edition), 23 3068-3075 (2013)

The wastewater source of 4# tailing pond in Dexing copper mine consists of alkaline flotation pulp and acid mine drainage (AMD) from the nearby opencast mine. Therefore, the heavy... [more]

The wastewater source of 4# tailing pond in Dexing copper mine consists of alkaline flotation pulp and acid mine drainage (AMD) from the nearby opencast mine. Therefore, the heavy metals in tailing ore are very likely to be released due to acidification from AMD. The leaching behaviors of Zn, Cu, Fe and Mn in mine tailings from Dexing copper mine were investigated by a series of laboratory batch experiments. The effectcs of pH, temperature, particle size and contact time on the leachability of such heavy metals were examined. It was evident that Zn, Cu, Fe and Mn were major heavy metals in the tailings while gangue minerals like quartz were major constituents in examined tailings. The tailing dissolution reaction was controlled by the acid, whose kinetics could be expressed according to the heterogeneous reaction models and explained by a shrinking core model with the surface chemical reaction as the rate-controlling step. The leachability of all metals examined depended on pH and contact time. The batch studies indicated that the maximum leaching ratios of Zn, Cu, Fe and Mn at pH 2.0 were 5.4%, 5.8%, 11.1% and 34.1%, respectively. The dissolubility of all metals examined was positively correlated to the temperatures. The particle size would not change dissolution tendency of those heavy metals, but decrease the concentrations of leached heavy metals. © 2013 The Nonferrous Metals Society of China.

DOI 10.1016/S1003-6326(13)62835-6
Citations Scopus - 21
2013 Xu L, Yuan R, Guo Y, Xiao D, Cao Y, Wang Z, Liu J, 'Sulfate radical-induced degradation of 2,4,6-trichlorophenol: A de novo formation of chlorinated compounds', Chemical Engineering Journal, 217 169-173 (2013)

The degradation of 2,4,6-trichlorophenol (TCP) by sulfate radical generated via Co(II)-mediated activation of peroxymonosulfate (PMS) was examined. The influencing factors, such a... [more]

The degradation of 2,4,6-trichlorophenol (TCP) by sulfate radical generated via Co(II)-mediated activation of peroxymonosulfate (PMS) was examined. The influencing factors, such as substrate concentration and pH were investigated. The initial pH and its adjustment orders significantly affected the TCP degradation and mineralization. Several chlorinated products were detected, as well as some carboxylic acids, such as glycolic acid and oxalic acid. Many polychlorinated (chlorine atom number =3) aromatics (e.g. 2,4,5-trichlorophenol, 2,3,4,6-tetrachlorophenol, 2,3,5,6-tetrachloro-1,4-benzenediol) and even their ring-opening products (e.g. 2,4-dichloro-5-oxo-2-hexenedioic acid, 1,1,3,3-tetrachloro-2-propanone) were identified, indicating a de novo formation mechanism of organohalogens may be involved in TCP degradation. The released chlorine atoms from TCP and/or dichloride radicals activated by sulfate radicals played an important role. This finding may have significant scientific and technical implications for utilizing Co/PMS reagent to detoxify chlorinated pollutants. © 2012 Elsevier B.V.

DOI 10.1016/j.cej.2012.11.112
Citations Scopus - 37Web of Science - 35
2013 Guo Y-G, Huang P, Zhang W-G, Yuan X-W, Fan F-X, Wang H-L, et al., 'Leaching of heavy metals from Dexing copper mine tailings pond', TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA, 23 3068-3075 (2013)
DOI 10.1016/S1003-6326(1362835-6
Citations Web of Science - 15
2012 Guo Y, Lou X, Xiao D, Xu L, Wang Z, Liu J, 'Sequential reduction-oxidation for photocatalytic degradation of tetrabromobisphenol A: Kinetics and intermediates', Journal of Hazardous Materials, 241-242 301-306 (2012)

CBr bond cleavage is considered as a key step to reduce their toxicities and increase degradation rates for most brominated organic pollutants. Here a sequential reduction/oxidati... [more]

CBr bond cleavage is considered as a key step to reduce their toxicities and increase degradation rates for most brominated organic pollutants. Here a sequential reduction/oxidation strategy (i.e. debromination followed by photocatalytic oxidation) for photocatalytic degradation of tetrabromobisphenol A (TBBPA), one of the most frequently used brominated flame retardants, was proposed on the basis of kinetic analysis and intermediates identification. The results demonstrated that the rates of debromination and even photodegradation of TBBPA strongly depended on the atmospheres, initial TBBPA concentrations, pH of the reaction solution, hydrogen donors, and electron acceptors. These kinetic data and byproducts identification obtained by GC-MS measurement indicated that reductive debromination reaction by photo-induced electrons dominated under N 2 -saturated condition, while oxidation reaction by photoexcited holes or hydroxyl radicals played a leading role when air was saturated. It also suggested that the reaction might be further optimized for pretreatment of TBBPA-contaminated wastewater by a two-stage reductive debromination/subsequent oxidative decomposition process in the UV-TiO 2 system by changing the reaction atmospheres. © 2012 Elsevier B.V.

DOI 10.1016/j.jhazmat.2012.09.044
Citations Scopus - 22Web of Science - 21
2012 Wang ZH, Xie XH, Liu JS, 'Experimental measurements of short-term adsorption of Acidithiobacillus ferrooxidans onto chalcopyrite', Transactions of Nonferrous Metals Society of China (English Edition), 22 442-446 (2012)

The influencing factors in adsorption such as adsorption time, pulp concentration, bacterial concentration, pH as well as ionic strength were investigated to explore the relations... [more]

The influencing factors in adsorption such as adsorption time, pulp concentration, bacterial concentration, pH as well as ionic strength were investigated to explore the relationship among them and bacterial adsorption. The adsorption was a rapid process for bacterial adhesion to chalcopyrite. The extent of adsorption increased with increasing initial bacterial concentration and pulp concentration. The optimal pH for Acidithiobacillus ferrooxidans adsorption onto chalcopyrite surfaces was in the range of pH 1-3. The increase of ionic strength led to decrease in bacterial adsorption, which can be well explained by electric double layer theory. The adsorption behavior appeared to be controlled by both hydrophobic and electrostatic interactions at the interface of bacteria and mineral. © 2012 The Nonferrous Metals Society of China.

DOI 10.1016/S1003-6326(11)61196-5
Citations Scopus - 8Web of Science - 6
2012 Wang Z, Song W, Ma W, Zhao J, 'Environmental photochemistry of iron complexes and their involvement in environmental chemical processes', Progress in Chemistry, 24 423-432 (2012)

Iron is one of the most abundant metals in the continental crust, while most of dissolved iron is complexed with organic ligands. The irradiated iron complexes in the environment ... [more]

Iron is one of the most abundant metals in the continental crust, while most of dissolved iron is complexed with organic ligands. The irradiated iron complexes in the environment undergo direct photolysis and secondary (photo)chemical reactions, generating Fe(II), organic radicals and some reactive oxygen species (ROS). Environmental photochemistry of iron complexes can greatly affect ROS dynamics, organics degradation and redox cycling of other elements. Therefore, it is becoming a hot topic in the international field of environmental sciences research. This review firstly summarizes three types of iron complexes including inorganic Fe complexes, simple organic Fe complexes and macrocyclic organic Fe complexes, and photoreduction mechanisms of iron complexes. Secondly, the potential oxidants of Fe(II) in acidic aquatic environment are introduced. The oxidation kinetics, possible reaction mechanism and influencing factors (such as dissolved oxygen concentration, pH, ionic strength, temperature and natural organic matters concentrations) of (photo)chemical oxidation of Fe(II) are elucidated. This review also highlights recent findings in the study of environmental processes involving iron photochemistry. Finally, the future prospects in this field are discussed based on the current status.

Citations Scopus - 5
2012 Yuan R, Ramjaun SN, Wang Z, Liu J, 'Photocatalytic degradation and chlorination of azo dye in saline wastewater: Kinetics and AOX formation', Chemical Engineering Journal, 192 171-178 (2012)

Chloride ion as one of the major salt components in dyestuff wastewaters can greatly affect the homogenous OH radical-based advanced oxidation processes (AOPs), but little inform... [more]

Chloride ion as one of the major salt components in dyestuff wastewaters can greatly affect the homogenous OH radical-based advanced oxidation processes (AOPs), but little information is available now for heterogeneous AOPs like UV/TiO 2 under similar conditions. Here the effects of chloride on kinetics and reaction intermediates of dye degradation in heterogeneous photocatalysis were examined. The dye degradation efficiency in UV/TiO 2 process was investigated as a function of a wide range of salinity and pH. The chloride ion was found to have a dual effect on both the dye decoloration and mineralization in UV/TiO 2 system due to different mechanisms involved. Higher Cl - concentration would inhibit dye degradation, especially in acidic medium. AOX (halogenated organic compounds adsorbable on activated carbon) generated increased with the increasing content of chloride ion present in the solution. Several toxic chlorinated byproducts were firstly identified during the dye degradation in UV/TiO 2 process using GC-MS method and possible decomposition pathways were proposed. These findings may have significant technical implications for optimizing the photochemical technologies in salt-rich wastewater treatment. © 2012 Elsevier B.V.

DOI 10.1016/j.cej.2012.03.080
Citations Scopus - 51Web of Science - 51
2012 Yuan R, Ramjaun SN, Wang Z, Liu J, 'Concentration profiles of chlorine radicals and their significances in ¿OH-induced dye degradation: Kinetic modeling and reaction pathways', Chemical Engineering Journal, 209 38-45 (2012)

In order to further understand the mechanism details during saline wastewater treatment by ¿ OH-based advanced oxidation processes (AOPs), the degradation efficiency of an azo d... [more]

In order to further understand the mechanism details during saline wastewater treatment by ¿ OH-based advanced oxidation processes (AOPs), the degradation efficiency of an azo dye Acid Orange 7 (AO7) in UV/H 2 O 2 process was investigated as a function of a wide range of salinity and pH. Kinetic modeling results demonstrated that the inhibitory effect of Cl - on AO7 degradation observed in the laboratory experiments could be attributed to both scavenging effect of Cl - on ¿ OH and the much lower reactivity of chlorine radicals formed, although the chlorine radicals may be more abundant than ¿ OH. Such retardation behavior was favored under acidic conditions due to a lower yield of ¿ OH generated by the dissociation of ClOH ¿- to ¿ OH and Cl - . Traces of Br - had a greater inhibitory effect on AO7 bleaching rate than Cl - . AOX (halogenated organic compounds adsorbable on activated carbon) was found to increase with the increasing content of Cl - . Based on the intermediate products and especially several toxic halogenated byproducts identified by GC-MS, the possible degradation pathways of saline dyeing wastewater were proposed. © 2012 Elsevier B.V.

DOI 10.1016/j.cej.2012.07.127
Citations Scopus - 20Web of Science - 18
2012 Wang Z, Chen C, Ma W, Zhao J, 'Photochemical coupling of iron redox reactions and transformation of low-molecular-weight organic matter', Journal of Physical Chemistry Letters, 3 2044-2051 (2012)

The photoreactions between Fe(III)/Fe(II) and low-molecular-weight organic matter (LMWOM) under solar irradiation have significant implications for many biogeochemical cycles on t... [more]

The photoreactions between Fe(III)/Fe(II) and low-molecular-weight organic matter (LMWOM) under solar irradiation have significant implications for many biogeochemical cycles on the Earth and for the fates of environmental pollutants. In this Perspective, we focus on several fundamental aspects of the photochemical processes that couple the redox cycling of iron species and transformation of organic substrates. The primary photoprocesses (e.g., intramolecular electron transfer or photodissociation) are first highlighted by introducing the recently disputed observations on the photolysis of ferrioxalate complexes. The effects of LMWOM and its daughter radicals on the photochemical redox cycling of iron species are discussed with special attention given to the example of Fe-malonate complexes. These processes and mechanisms would provide us some refreshed understanding of environmental photochemistry of LMWOM and the iron species and would be helpful for our assessment of photochemical decontamination of organic pollutants. © 2012 American Chemical Society.

DOI 10.1021/jz3005333
Citations Scopus - 13Web of Science - 13
2012 Wang Z, Song W, Ma W, Zhao J, 'Environmental Photochemistry of Iron Complexes and Their Involvement in Environmental Chemical Processes', PROGRESS IN CHEMISTRY, 24 423-432 (2012)
Citations Web of Science - 5
2011 Ramjaun SN, Yuan R, Wang Z, Liu J, 'Degradation of reactive dyes by contact glow discharge electrolysis in the presence of Cl

The plasma generated around the anode during contact glow discharge electrolysis (CGDE) is a rich source of hydroxyl (OH) radicals that can efficiently degrade organic contaminant... [more]

The plasma generated around the anode during contact glow discharge electrolysis (CGDE) is a rich source of hydroxyl (OH) radicals that can efficiently degrade organic contaminants in aqueous solutions. The degradation of textile azo dyestuffs, Reactive Yellow 176 (Y3RS), Reactive Red 239 (R3BS) and Reactive Black 5 (B5), by anodic CGDE was investigated in the presence of chloride (Cl - ) ions. The degradation kinetics of the dyes was dependent on the concentration of Cl - ions and on the respective dye being treated. R3BS degradation was inhibited by Cl - ions in the range of 0-0.01 M. When the Cl - ion concentration was less than 0.02 M, the dyes followed pseudo first-order degradation kinetics. For concentrations greater than 0.02 M, the degradation of Y3RS and B5 was significantly enhanced compared to the degradation of R3BS and deviated from first-order reaction kinetics. The presence of Cl - ions (0.03 M) did not appear to improve dye mineralization but resulted in the formation of adsorbable organic halogens (AOX). The results indicated that the AOX could be abated with prolonged electrolytic treatment. This observation is significant for the assessment of the environmental impact of this technology for wastewater treatment. © 2011 Elsevier Ltd. All rights reserved.

DOI 10.1016/j.electacta.2011.09.052
Citations Scopus - 17Web of Science - 16
2011 Wang Z, Yuan R, Guo Y, Xu L, Liu J, 'Effects of chloride ions on bleaching of azo dyes by Co2+/oxone regent: Kinetic analysis', Journal of Hazardous Materials, 190 1083-1087 (2011)

Orange II (Org II), one of the most common used azo dyes, was taken as a model to investigate the effects of chloride ion on dye decoloration in cobalt/peroxymonosulfate (Co/PMS) ... [more]

Orange II (Org II), one of the most common used azo dyes, was taken as a model to investigate the effects of chloride ion on dye decoloration in cobalt/peroxymonosulfate (Co/PMS) system. A significant decrease in the rate of Org II decoloration was observed upon addition of Cl - (0.05-10mM), but further addition of Cl - ( > 50mM) apparently accelerated dyes degradation. This dual effect of chloride on dyes bleaching was also observed as other halide ions (e.g. Br - , I - ) or other azo dyes were present in Co/PMS system. In the Co-free PMS solutions, the observed first-order rate constant always exponentially increased with the chloride content. The reactive chlorine species generated from chloride oxidation by PMS should be responsible for this non-radical mechanism for dye decoloration, however, these rapid decoloration of Org II as chloride ion was present, did not readily lead to much mineralization. Therefore, this finding may have significant technical implications for utilizing Co/PMS regent to detoxify chloride-rich azo dyes wastewater. © 2011 Elsevier B.V.

DOI 10.1016/j.jhazmat.2011.04.016
Citations Scopus - 87Web of Science - 80
2011 Yuan R, Ramjaun SN, Wang Z, Liu J, 'Effects of chloride ion on degradation of Acid Orange 7 by sulfate radical-based advanced oxidation process: Implications for formation of chlorinated aromatic compounds', Journal of Hazardous Materials, 196 173-179 (2011)

Sodium chloride is a common salt used during textile wet processes. Here a dual effect of chloride (i.e. inhibitory and accelerating effect) on azo dye (Acid Orange 7, AO7) degrad... [more]

Sodium chloride is a common salt used during textile wet processes. Here a dual effect of chloride (i.e. inhibitory and accelerating effect) on azo dye (Acid Orange 7, AO7) degradation in an emerging cobalt/peroxymonosulfate (Co/PMS) advanced oxidation process (AOP) was reported. Compared to OH-based AOPs, high concentrations of chloride ( > 5mM) can significantly enhance dye decoloration independent of the presence of the Co 2+ catalyst, but did greatly inhibit dye mineralization to an extent which was closely dependent upon the chloride content. Both UV-vis absorbance spectra and AOX determination indicated the formation of some refractory byproducts. Some chlorinated aromatic compounds, including 3-chloroisocoumain, 2-chloro-7-hydroxynaphthalene, 1,3,5-trichloro-2-nitrobenzene and tetrachlorohydroquione, were identified by GC-MS measurement in both Co/PMS/Cl - and PMS/Cl - reaction systems. Based on those experimental results, two possible branched (SO 4 - radical-based and non-radical) reaction pathways are proposed. This is one of the very few studies dealing with chlorinated organic intermediates formed via chlorine radical/active chlorine species (HOCl/Cl 2 ) attack on dye compounds. Therefore, this finding may have significant technical implications for utilizing Co/PMS regent to detoxify chloride-rich azo dyes wastewater. © 2011 Elsevier B.V.

DOI 10.1016/j.jhazmat.2011.09.007
Citations Scopus - 153Web of Science - 136
2011 Wang ZH, Xie XH, Liu JS, 'Numerical modeling of potential profiles in electrical double layer of Acidithiobacillus ferrooxidans cell surface', Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals, 21 1485-1490 (2011)

The surface charge density, space charge density, surface potential (f 0 ) and Donnan potential (f Don ) on the surface of Acidithiobacillus ferrooxidans cultivated with elemental... [more]

The surface charge density, space charge density, surface potential (f 0 ) and Donnan potential (f Don ) on the surface of Acidithiobacillus ferrooxidans cultivated with elemental sulfur (S-A.ferrooxidans) were calculated by numerical simulation using the ion-impenetrable and ion-penetrable models. Zeta potential measurement show that the isoelectric point (IEP) of S-A.ferrooxidans is higher than that of bacterium cultured with Fe 2+ . It is concluded from fitting data by ionizable surface group model that S-A.ferrooxidans surface probably consists of much proteins, the ionization of amino group of which causes higher IEP ( > 2). The ion-penetrable model reveals that f 0 and f Don decrease rapidly at pH < 5 but hardly change when pH is 6-7. The thickness of electrical double layer of S-A.ferrooxidans is estimated as 5 nm. The electrical double layer of bacterial cell surface may have significant implications for ions transfer and nutrient transport, but their interaction is unfavorable for bacterial aggration.

Citations Scopus - 1
2011 Wang Z, Ma W, Chen C, Ji H, Zhao J, 'Probing paramagnetic species in titania-based heterogeneous photocatalysis by electron spin resonance (ESR) spectroscopy-A mini review', Chemical Engineering Journal, 170 353-362 (2011)

Many paramagnetic species such as active surface sites, reactive oxygen species (ROS) and organic radicals derived from the photodegradation of organics were involved in the heter... [more]

Many paramagnetic species such as active surface sites, reactive oxygen species (ROS) and organic radicals derived from the photodegradation of organics were involved in the heterogeneous photocatalysis. Identification and characterization of these paramagnetic species are essentially conducted using electron spin resonance (ESR) techniques, which can provide a detailed understanding of the radical composition and structure on the basis of the unique feature of g, hyperfine, and superhyperfine tensors for each kind of radicals of interest. In the present review, the basic theoretical principles of the ESR technique and its application in the field of TiO 2 -based heterogeneous photocatalysis are generally summarized. Two experimental approaches typical of ESR-direct monitoring of paramagnetic species or sites and spin-trapping technique have been described with particular attention to the choices of spin traps. The general features of the ESR spectra of photoinduced charges, inorganic and organic radicals in photocatalytic events are presented and discussed. In addition, some remarks will be made about the use of ESR in revealing the origin of enhanced photocatalytic activities in the mixed phase titania (P25) and visible-light-response N-doped TiO 2 . © 2010 Elsevier B.V.

DOI 10.1016/j.cej.2010.12.002
Citations Scopus - 101Web of Science - 96
2011 Chen X, Ma W, Li J, Wang Z, Chen C, Ji H, Zhao J, 'Photocatalytic Oxidation of Organic Pollutants Catalyzed by an Iron Complex at Biocompatible pH Values: Using O-2 as Main Oxidant in a Fenton-like Reaction', JOURNAL OF PHYSICAL CHEMISTRY C, 115 4089-4095 (2011)
DOI 10.1021/jp110277k
Citations Web of Science - 24
2010 Wang Z, Chen X, Ji H, Ma W, Chen C, Zhao J, 'Photochemical cycling of iron mediated by dicarboxylates: special effect of malonate.', Environ Sci Technol, 44 263-268 (2010)
DOI 10.1021/es901956x
Citations Web of Science - 23
2010 Wang Z, Xie X, Xiao S, Liu J, 'Comparative study of interaction between pyrite and cysteine by thermogravimetric and electrochemical techniques', Hydrometallurgy, 101 88-92 (2010)

Adsorption mechanism of l-cysteine on pyrite was investigated by thermogravimetric and electrochemical techniques. TG curves provided the direct evidence for chemisorption of cyst... [more]

Adsorption mechanism of l-cysteine on pyrite was investigated by thermogravimetric and electrochemical techniques. TG curves provided the direct evidence for chemisorption of cysteine on pyrite surface. Once cysteine adsorbed to pyrite surface, E corr (corrosion potential) sharply lowered whereas I corr (corrosion current) increased rapidly. Pyrite became more susceptible to be oxidized even at lower potential as cysteine was added. However, the mechanism for pyrite oxidation does not fundamentally change, although cysteine can obviously accelerate oxidation rate of pyrite. These findings have important implications for understanding the mechanism of bacterial adhesion to pyrite and even metal sulfide bioleaching. © 2009 Elsevier B.V. All rights reserved.

DOI 10.1016/j.hydromet.2009.11.015
Citations Scopus - 7Web of Science - 7
2010 Wang Z, Xie X, Xiao S, Liu J, 'Adsorption behavior of glucose on pyrite surface investigated by TG, FTIR and XRD analyses', Hydrometallurgy, 102 87-90 (2010)

The interaction of glucose with pyrite has been investigated by a series of surface analyses, such as amounts adsorbed, TG, FTIR and XRD measurements. The adsorption experiment re... [more]

The interaction of glucose with pyrite has been investigated by a series of surface analyses, such as amounts adsorbed, TG, FTIR and XRD measurements. The adsorption experiment reveals that glucose would rapidly adsorb on the pyrite surface within 60 min. However, physical adhesion characterized as multi-molecular layer adsorption may occur based on adsorption isotherm type. All results obtained by TG and FTIR suggest that no adsorption took place after several times of washing. XRD results indicate that crystal structure of pyrite was not obviously destructed after glucose was added. The interplane distances of (111), (400) after interaction between glucose and pyrite were widened, which showed the similar manner with that of before interaction. All these convincing data imply that physical adsorption predominantly governs the interaction of glucose on pyrite. © 2010 Elsevier B.V. All rights reserved.

DOI 10.1016/j.hydromet.2010.01.004
Citations Scopus - 8Web of Science - 6
2009 Wang Z, Ma W, Chen C, Zhao J, 'Light-assisted decomposition of dyes over iron-bearing soil clays in the presence of H2O2', JOURNAL OF HAZARDOUS MATERIALS, 168 1246-1252 (2009)
DOI 10.1016/j.jhazmat.2009.02.160
Citations Web of Science - 28
2008 Wang Z, Ma W, Chen C, Zhao J, 'Photochemical coupling reactions between Fe(III)/Fe(II), Cr(VI)/Cr(III), and polycarboxylates: Inhibitory effect of Cr species', Environmental Science and Technology, 42 7260-7266 (2008)

The roles of chromium species on photochemical cycling of iron and mineralization of polycarboxylates are examined in the presence of Cr(VI) or Cr(III) at pH 2.2-4.0. Under UV irr... [more]

The roles of chromium species on photochemical cycling of iron and mineralization of polycarboxylates are examined in the presence of Cr(VI) or Cr(III) at pH 2.2-4.0. Under UV irradiation, Cr(III) altered the redox equilibrium of iron species, leading to the shift of the photosteady state toward Fe(II). After a longer time of illumination, total organic carbon (TOC) approached a steady state in the presence of Cr(III) or Cr(VI), whereas oxalate was thoroughly mineralized in the absence of Cr species. The TOC of steady state was closely related to the kind of polycarboxylates, Cr species dosages, pH and O 2 atmosphere, but hardly affected by more addition of Fe(III). ESI-MS data indicates that several Cr-oxalate complexes formed in the photochemical reactions, which are responsible for protecting oxalate against further oxidation. A mechanism is proposed for the inhibitory effect of Cr species on oxidation of oxalate and Fe(II). The present study may provide a new insight into the dual environmental effects induced by Cr contaminants especially at heavily chromium-contaminated and dissolved organic matter (DOM)-rich sites. © 2008 American Chemical Society.

DOI 10.1021/es801379j
Citations Scopus - 27Web of Science - 26
2006 Liu J-S, Wang Z-H, Chen H, Zhang Y-H, 'Interfacial electrokinetic characteristics before and after bioleaching microorganism adhesion to pyrite', TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA, 16 676-680 (2006)
DOI 10.1016/S1003-6326(06)60120-9
Citations Web of Science - 3
2006 Liu J-S, Wang Z-H, Li B-M, Zhang Y-H, 'Interaction between pyrite and cysteine', TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA, 16 943-946 (2006)
DOI 10.1016/S1003-6326(06)60356-7
Citations Web of Science - 11
2004 Liu JS, Xia HB, Wang ZH, Hu YH, 'Bacterial oxidation activity in heap leaching', JOURNAL OF CENTRAL SOUTH UNIVERSITY OF TECHNOLOGY, 11 375-379 (2004)
DOI 10.1007/s11771-004-0078-2
Citations Web of Science - 3
Show 65 more journal articles

Conference (1 outputs)

Year Citation Altmetrics Link
2013 Yuan R, Wang Z, Liu J, 'Application of advanced oxidation processes in treatment of high salinity organic wastewater: Kinetics and AOX formation', ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, New Orleans, LA (2013)
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Research Supervision

Number of supervisions

Completed0
Current1

Total current UON EFTSL

PhD0.8

Current Supervision

Commenced Level of Study Research Title Program Supervisor Type
2017 PhD The Degradation Process of the Phenicol Antibiotics by the Advanced Oxidation Method. PhD (Environmental Sc), Faculty of Science, The University of Newcastle Co-Supervisor
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Research Collaborations

The map is a representation of a researchers co-authorship with collaborators across the globe. The map displays the number of publications against a country, where there is at least one co-author based in that country. Data is sourced from the University of Newcastle research publication management system (NURO) and may not fully represent the authors complete body of work.

Country Count of Publications
China 68
Australia 22
Egypt 1
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Dr Zhaohui Wang

Position

ARC DECRA Fellow
School of Environmental and Life Sciences
Faculty of Science

Contact Details

Email zhaohui.wang@newcastle.edu.au
Phone (02) 4913 8082
Links Personal Blogs
Google+

Office

Room NIER C 132
Building NIER C.
Location Callaghan
University Drive
Callaghan, NSW 2308
Australia
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