Nitrogen-rich carbon nitrides are desired materials for base-catalysed transformations; however, their synthesis is challenging due to the volatile nature of N at high temperatures. Herein, we report on the temperature-controlled synthesis of ordered N-rich mesoporous carbon nitrides (MCNs) via pyrolysis of aminoguanidine by using SBA-15 as a hard template. The properties and the nitrogen content of the materials were tuned by varying the carbonization temperature in the range of 350¿500 °C. At 350 and 400 °C, higher amounts of N could be retained in the MCN framework with the predominant formation of C3N6 having a six-membered aromatic ring with diamino-s-tetrazine moiety, whereas C3N5 with 1-amino/imino-1,2,4-triazole moieties was produced at 450 and 500 °C. The base catalytic activity of MCNs in Knoevenagel condensation of benzaldehyde with malononitrile revealed that the MCN-400 exhibited the highest catalytic performance by displaying a 96.4 % product yield with toluene as a solvent. The superior catalytic activity of MCN-400 is attributed to high N content (62.6 wt%), high surface area (235 m2 g-1), and large pore volume (0.74 cm3 g-1). The optimum temperature for obtaining the highest yield of the products is 80 °C, and the catalyst showed good cycling stability for 5 consecutive cycles.

The development of versatile mesoporous silica nanomaterials (MSNSs) with suitable textural properties is essential for the targeted and precise delivery of therapeutic drugs for the treatment of various diseases. Especially, loading of highly toxic platinum-based drugs is essential to reduce their toxic side effects. However, loading platinum-based drugs such as carboplatin in high quantity in porous materials is extremely challenging owing to the high hydrophobicity and lack of functional groups for interacting with surfaces of MSNS. In this study, we report a facile synthesis of core-shell MSNS by employing a unique combination of triple surfactants - pluronic P123, cetyltrimethylammonium bromide (CTAB) and fluorocarbon-4 (FC-4) for targeted delivery of the carboplatin for the treatment of lung cancer. The highly hydrophobic FC-4 plays a vital role in tuning the self-assembly and thereby controls the size, morphology, textural properties and uniform pore size distribution of the MSNS. The optimised MSNS with the size range of 300¿320 nm, uniform size distribution, high surface area and ordered structure was successfully synthesised. A high drug loading of 26.7% was achieved on both bare and amine functionalised MSNS with a steady release of up to 60% and 37%, respectively, in PBS. The targeting efficiency of the folic acid functionalised particles was established by confocal microscopy, which showed higher cellular uptake of these particles in A549 cells. The high carboplatin loading and targeting ability resulted in high cytotoxicity from the folic acid functionalised and drug-loaded MSNS samples in PC9 cells compared to non-targeted and bare MSNS samples. Overall, this study proposes a new single-step synthesis of core-shell MSNS with high drug loading capacity that can be used to deliver drugs in treating different types of cancers.

We report on the catalytic activity of ordered mesoporous aluminosilicate, AlSBA-1 with 3D cage type porous structure, in the isopropylation of naphthalene (NP). The higher isopropylates: triisopropylnaphthalene (TriIPN) and tetraisopropylnaphthalene (TetIPN) isomers were formed over AlSBA-1 in addition to isopropylnaphthalene (IPN) and diisoprpylnaphthalene (DIPN) isomers. The higher isopropylates were started to form at 225 °C as primary products, which were produced by multi-step isopropylation from NP occurred during one stay on the catalytic site cooperated with the propene adsorbed neighbor acid sites. TriIPN isomers were composed of four isomers (1,3,7-. 1,3,5-, 1,3,6-, and 1,4,6-) formed from DIPN isomers. These formations of TriIPN isomers are controlled by the distribution of DIPN isomers. ß,ß-DIPN isomers lead to a,ß,ß-TriIPN isomers, and a,a-DIPN to a,a,ß-TriIPN, respectively. However, a,ß-DIPN isomers give both of a,a,ß- and a,ß,ß-TriIPN isomers depending on the reaction conditions. The distribution of TriIPN isomers is operated by their kinetic and thermodynamic properties. Bulky and unstable a,a,ß-TriIPN isomers (1,3,5- and 1,4,6-) were predominant at low temperatures, 175¿250 °C, and at low NP/Cat ratio at 250 °C, where the catalysis mainly proceeded under kinetic control. However, the formation of slim and stable a,ß,ß-TriIPN isomers (1,3,7- and 1,3,6-) increased with raising the temperatures, and was primary at 300 °C, where the catalysis occurred under thermodynamic control. From these results, it is concluded that the isopropylation of NP over AlSBA-1 occurs under kinetic and/or thermodynamically controls based on the reactivity of the reactants and the stability of the products, and no steric control concerns by mesopores.

Due to its high energy density and non-polluting combustion, hydrogen has emerged as one of the most promising candidates for meeting future energy demands and realising a C-free world. However, the wider application of hydrogen is restricted by issues related to the generation, storage, and utilisation. Hydrogen production using steam reforming leads to CO2 emissions, storage of hydrogen requires extreme conditions, and utilisation of hydrogen needs to be highly efficient. Solid materials, can play significant roles in hydrogen sector as these materials are appropriate for the effective generation, storage, and utilisation of hydrogen. Their physical, chemical, thermal, and electronic properties can be easily manipulated to enhance their efficiencies in all three areas. In this review, various materials are described for the photocatalytic, electrocatalytic, and photoelectrocatalytic production, physisorption- and chemisorption-based storage, and utilisation of hydrogen in fuel cells; moreover, chemical and ammonia syntheses and steelmaking have been comprehensively discussed. Detailed insights and relevant comparisons are provided to demonstrate the efficacies of the abovementioned materials in the hydrogen sector. This broad overview of materials development will promote the hydrogen economy and inspire researchers and policymakers to appreciate the roles of materials and invest more in their research and development.

In this paper, biocomposites were prepared with carrageenan/fish scale/allopurinol collagen by solution method. Carrageenan fish scale collagen and allopurinol were used at different ratio and the effect of varying the component ratio was investigated by studying the shape, morphology, thermal behavior, and drug release ability of the biocomposites. By varying the carrageenan/collagen ratio, the shape of the biocomposites can be modified. When high amount of carrageenan was used, biocomposites were obtained in film whereas higher content of collagen produced powder form of biocomposites. The characteristics of the biocomposites were studied by Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Thermal Gravimetric Analysis (TGA), and Differential Scanning Calorimetric (DSC) techniques. The drug (allopurinol) release ability of the biocomposites was evaluated with Ultraviolet¿Visible Spectroscopy (UV¿Vis). Biocomposites in the powder form are different from the biocomposites in the film form by having different shape, morphology, thermal behavior, and drug release ability. However, both are sensitive to pH of solution in drug release process. In addition, the cell toxicity of allopurinol and these biocomposites was evaluated with Vero cells by MTT method. The obtained results confirmed that the biocomposite materials in film shape are promising for the application in biomedicine.

We demonstrate a synthesis of copper nanoparticles decorated over nitrogen-doped mesoporous carbon with different N and Cu contents which exhibit conducting, redox, basic, adsorption, and excellent textural properties. These materials are prepared through a nanotemplating approach by simultaneously encapsulating sucrose, guanidine hydrochloride, and Cu(NO3)2 into the porous channels of mesoporous SBA-15 at a low carbonization temperature of 600 °C. The prepared materials exhibit an ordered mesoporous carbon framework with bimodal pores, decorated with nitrogen and Cu functionalities on the surface of the pores and in the wall structure. The presence of nitrogen functionalities in the porous carbon matrix not only helps to reduce the Cu ions but also stabilizes the nanoparticles and offers redox sites, which are beneficial for adsorption and electrochemical applications. The optimized sample exhibits the highest adsorption capacity of different gases such as CO2 ¿ 22.5 mmol/g at 273 K, H2 -13.5 mmol/g at 77 K at 30 bar and CH4 - 5 mmol/g at 298 K and 50 bar. We also demonstrate that the prepared material shows a high selectivity of adsorption towards CO2 in a mixture of CO2/H2 and CO2/CH4 and it also registers a high supercapacitance of 209 F g-1 at a current density of 1 A g-1 with excellent cyclic stability.

One of the key focuses of the agricultural industry for preventing the decline in crop yields due to pests is to develop effective, safe, green, and sustainable pesticide formulation. A key objective of industry is to deliver active ingredients (AIs) that have minimal off site migration and non-target activity. Nanoporous materials have received significant attention internationally for the efficient loading and controlled, targeted delivery of pesticides. This is largely made possible due to their textural features including high surface area, large pore-volume, and tunable pore size. Additionally, the easier manipulation of their surface chemistry and stability in different environments are added advantages. The unique features of these materials allow them to address the solubility of the active ingredients, their efficient loading onto the porous channels, and slow and controlled delivery over time. One of their major advantages is the wide range of materials that could be suitably designed via different approaches to either adsorb, encapsulate, or entrap the active ingredient. This review is a timely presentation of recent progress made in nanoporous materials and discusses critical aspects of pesticide formulation and delivery.

Anaerobic digestion (AD) is a well-known process with potential applications in the energy sector and waste management. The generation of digestate material during the AD process is considered a waste material. Although agriculture is a significant end-user of digestate, the surplus nutrient content, agricultural crop requirements, escalating transport costs, regulatory demands, and market acceptance constitute significant hurdles for utilizing digestate in agriculture alone. Many new innovative technologies are being developed as alternative approaches for digestate management and related options. Anaerobic digestate incorporates versatile characteristics including essential plant nutrients, enzymes, extracellular polysaccharides and trace elements. These properties give the AD digestate much application potential when combined with the appropriate treatments and valorization process. Microbial bioconversion, fermentation, hydrothermal carbonization, pyrolysis, Vacuum thermal stripping, Nijhuis Ammonium Recovery, Electrodialysis, Trans Membrane Chemi Sorption, Osmotic membrane bioreactor, chemical precipitation, Catalytic decomposition are the important processes commonly used to valorize the AD digestate. The AD digestate can be used as an organic amendment in agriculture, a substrate for algae cultivation, nitrogen and phosphorus extraction, energy production, synthesis of hydrochar and pyrochar for pollutants adsorption, energy storage and conversion, synthesis of various carbon and doped metal nanoparticles for photocatalytic activity and production of high-value chemicals. Among the multiple avenues open to applied research, some are entirely new. Hence, this review aims to incorporate recent research trends in AD digestate valorization, and subsequently generate knowledge on the preparation of novel products applicable to various sectors.

The isopropylation of naphthalene (NP) was carried out over a BEA zeolite (BEA38; SiO2/Al2O3 = 38) focused on the selectivities for diisopropylnaphthalene (DIPN) and triisopropylnaphthalene (TriIPN) isomers. The isopropylation gave possible eight DIPN isomers including ß,ß- (2,6- and 2,7-), a,ß- (1,3-, 1,6-, and 1,7-), and a,a- (1,4- and 1,5-). The catalysis over BEA works two types of controls: kinetic control operates to form predominantly bulky and unstable a,a-DIPN at low temperatures, and thermodynamic controls work for the predominant formation of the slim and stable ß,ß-DIPN at high temperatures, although the intermediately bulky and stable a,ß-DIPN are the major products through both controls. The enhanced selectivities for ß,ß-DIPN were observed at the early stages of the catalysis in the range of 200-300 °C, which operate under new type of thermodynamic control over fresh catalyst through thermodynamically preferred transition states; however, they decreased with the increase in the selectivities for a,a- and a,ß-DIPN, and converged after prolonged reaction period. The isopropylation of DIPN isomers gives TriIPN isomers: unstable and bulky 1,3,5- and 1,4,6-TriIPN with a,a,ß-substitution, and stable and slim 1,3,7- and 1,3,6-TriIPN with a,ß,ß-substitution. The low temperatures favor the former isomers, whereas the selectivity for the latter isomers increases with increasing reaction temperature. These results indicate that TriIPN isomers principally form under kinetic control at low temperatures, and thermodynamic controls participate in the catalysis at high temperatures. The selectivities for TriIPN isomers kept constant during the reaction at all temperatures: 200, 250, and 300 °C. The catalysis occurs inside the BEA channels and allow even the formation of bulky 1,3,5- and 1,4,6-TriIPN; however, all isomers cannot be isomerized to the others in the channels and on the external surfaces. Severe coke-deposition occurred during the catalysis, particularly in the early stages; however, the catalyst is recovered by the calcination with a small change in catalytic activity.

The isopropylation of naphthalene (NP) over USY zeolite (FAU06, SiO2/Al2O3 = 6) gave all eight possible diisopropylnaphthalene (DIPN) isomers: ß,ß- (2,6- and 2,7-), a,ß- (1,3-, 1,6-, and 1,7-), and a,a- (1,4- and 1,5-). The catalyses were operated under kinetic and/or thermodynamic controls depending on the reaction temperatures since the cavities of FAU topology are wide enough to form all DIPN isomers. Enhanced selectivities for ß,ß-DIPN were observed at the early stages at 200°C, 250°C, and 300°C although the selectivities decreased with the increasing periods, accompanying the increase in a,a- and a,ß-DIPN. The enhancement occurred under new types of thermodynamic controls through thermodynamically preferred transition states to ß,ß-DIPN. Triisopropylnaphthalene (TriIPN) isomers were also formed in the isopropylation. Unstable a,a,ß-TriIPN (1,4,6- and 1,3,5-) was predominantly formed at lower temperatures, however, decreased with the increased of stable a,ß,ß-TriIPN (1,3,6- and 1,3,7-) at higher temperatures. The predominant formation of 1,4,6-TriIPN was also observed in the initial stages in the range of 200°C, 250°C, and 300°C, as reaction period was increased, while the selectivity for the isomer was decreased with concomitant increase in the selectivities for the other isomers. These changes of the selectivities operated under kinetic and/or thermodynamic controls. Large cavities of the zeolite allowed the formation of all TriIPN isomers without steric restriction.

We report on the preparation of ordered mesoporous carbon nitrides (MCN) with a 3D porous structure, tuneable nitrogen contents and basicity and their basic catalytic activities on the Knoevenagel condensation of benzaldehyde with malononitrile. The chemical structure and the nitrogen contents of the materials are finely tuned with the simple adjustment of the calcination temperature from 350 to 550 °C. The samples prepared at 350 and 400 °C exhibit C3N5 structures with 1-amino/imino-1,2,4-triazole moieties, whereas the samples synthesised at 450, 500, and 550 °C possess C3N4 structures with 2-amino/imino-1,3,5-triazine moieties. The materials prepared at the temperature lower than 400 °C show much higher activity than those of the samples prepared at 450, 500 and 550 °C. The change in the catalytic activities of these materials is linked with the change of the structure, nitrogen contents and the functional groups on the surface of the materials prepared at different temperatures. CO2 temperature programme desorption study reveals that 1-amino/imino-1,2,4-triazole moieties in C3N5 samples provide high basicity due to the strain in 5-membered 1,2,4-triazole rings; however, the samples with 1,3,5-triazine moieties have limited basicity which significantly affects the catalytic activity of the material. The optimised C3N5 catalyst shows an enhanced catalytic activity when compared to other mesoporous basic catalysts and C3N4. It is also found that the optimised catalysts are highly stable and can be recycled several times and no major change in the activity is observed.

Aqueous film-forming foam, used in firefighting, and biowastes, including biosolids, animal and poultry manures, and composts, provide a major source of poly- and perfluoroalkyl substances (PFAS) input to soil. Large amounts of biowastes are added to soil as a source of nutrients and carbon. They also are added as soil amendments to improve soil health and crop productivity. Plant uptake of PFAS through soil application of biowastes is a pathway for animal and human exposure to PFAS. The complexity of PFAS mixtures, and their chemical and thermal stability, make remediation of PFAS in both solid and aqueous matrices challenging. Remediation of PFAS in biowastes, as well as soils treated with these biowastes, can be achieved through preventing and decreasing the concentration of PFAS in biowaste sources (i.e., prevention through source control), mobilization of PFAS in contaminated soil and subsequent removal through leaching (i.e., soil washing) and plant uptake (i.e., phytoremediation), sorption of PFAS, thereby decreasing their mobility and bioavailability (i.e., immobilization), and complete removal through thermal and chemical oxidation (i.e., destruction). In this review, the distribution, bioavailability, and remediation of PFAS in soil receiving solid biowastes, which include biosolids, composts, and manure, are presented.

Heteroatom doped nanomaterials are reported to be excellent electrodes for energy storage and conversion applications. However, the introduction of these heteroatoms in materials such as carbon nitride is quite challenging owing to the poor thermodynamic stability of these atoms in the carbon matrix. In this report, we demonstrate the single-step approach for the preparation of highly ordered nanoporous carbon oxynitride (O-MCN) materials with tailored pore sizes by employing carbohydrazide as a single C, N, O precursor using nano-templating approach. Experimental characterization of the O-MCN confirms oxygen doping in C-N framework. Density functional theory (DFT) calculations demonstrate that the O-MCN optimized with AB type bilayer structure can adsorb nine Li ions per unit cell with mild Li-ion binding energy value of 5.16 eV. The synthesized O-MCN materials are firstly applied in Li-ion batteries as anode materials. The optimized O-MCN displays 2.5 times higher reversible capacity than that of non-porous g-C3N4 with remarkable stability in the long run in the Li-ion battery.

Valorisation of food waste offers an economical and environmental opportunity, which can reduce the problems of its conventional disposal. Food waste is commonly disposed of in landfills or incinerated, causing many environmental, social, and economic issues. Large amounts of food waste are produced in the food supply chain of agriculture: production, post-harvest, distribution (transport), processing, and consumption. Food waste can be valorised into a range of products, including biofertilisers, bioplastics, biofuels, chemicals, and nutraceuticals. Conversion of food waste into these products can reduce the demand of fossil-derived products, which have historically contributed to large amounts of pollution. The variety of food chain suppliers offers a wide range of feedstocks that can be physically, chemically, or biologically altered to form an array of biofertilisers and soil amendments. Composting and anaerobic digestion are the main large-scale conversion methods used today to valorise food waste products to biofertilisers and soil amendments. However, emerging conversion methods such as dehydration, biochar production, and chemical hydrolysis have promising characteristics, which can be utilised in agriculture as well as for soil remediation. Valorising food waste into biofertilisers and soil amendments has great potential to combat land degradation in agricultural areas. Biofertilisers are rich in nutrients that can reduce the dependability of using conventional mineral fertilisers. Food waste products, unlike mineral fertilisers, can also be used as soil amendments to improve productivity. These characteristics of food wastes assist in the remediation of contaminated soils. This paper reviews the volume of food waste within the food chain and types of food waste feedstocks that can be valorised into various products, including the conversion methods. Unintended consequences of the utilisation of food waste as biofertilisers and soil-amendment products resulting from their relatively low concentrations of trace element nutrients and presence of potentially toxic elements are also evaluated.

Unresolved complex mixtures (UCMs) of hydrocarbons are the pollutants of serious concern commonly occurring in most of the environments contaminated with petroleum hydrocarbons. UCMs constitute a relatively unidentified group of compounds compared to the well-resolved hydrocarbons that could easily be identified by the modern chromatographic methods. UCMs that accumulate in the environment cause several toxicological effects of ecological significance, and indirectly affect the human health. Despite decades-long efforts to provide adequate information in this area of research, the fate and environmental impacts of UCMs of petroleum hydrocarbons are poorly understood. Techniques for extraction and analysis of UCMs in the environment are very important in their identification and quantification. Also, remediation of toxic UCMs of petroleum hydrocarbons is all the more essential. In fact, UCMs are often neglected in the risk assessments due to lack of proper identification methods and toxicity data. This critical review presents an overview of our current knowledge on the environmental occurrence, sources, separation, and identification methods for UCMs. The ecological toxicity of UCMs toward the biota and the strategies for remediation of the environments contaminated with UCMs have also been discussed in detail.

Chromium from tannery waste dump site causes significant environmental pollution affecting surrounding flora and fauna. The primary aims of this study were to survey vegetation, investigate the degree of soil pollution occurring near tannery waste dump site and make a systematic evaluation of soil contamination based on the chromium levels found in plants and earthworms from the impacted areas. This paper presents the pollution load of toxic heavy metals, and especially chromium, in 10 soil samples and 12 species of plants. Soil samples were analysed for heavy metals by using ICP-MS/ICP-OES method. Results indicated that Cr in soils exceeded soil quality guideline limits (SQGL). The total chromium present in the above ground parts of plants ranged from 1.7¿mg¿kg-1 in Casuarina sp.¿to 1007¿mg¿kg-1 in Sonchus asper. The Cr bioaccumulation in Eisenia fetida from tannery waste soil ranged from 5 to 194¿mg¿kg-1. The high enrichment factor of Cr in S. asper and bioaccumulation factor in earthworms indicate that there is a steady increase of toxic chromium risk in this area, which could be correlated with the past dumping activity. Emphasis needs to be put on control measures of pollution and remediation techniques in such areas to achieve an ecologically sustainable industrialisation.

Heavier fraction hydrocarbons (C15-C36) formed in soil after biotic and abiotic weatherings of engine oil are the continuing constraints in the bioremediation strategy, and their bioavailability remains a poorly quantified regulatory factor. In a microcosm study, we used two strains of Pseudomonas, P. putida TPHK-1 and P. aeruginosa TPHK-4, in strategies of bioremediation, viz., natural attenuation, biostimulation and bioaugmentation, for removal of weathered total petroleum hydrocarbons (TPHs) in soil contaminated long-term with high concentrations of engine oil (39,000¿41,000 mg TPHs kg-1 soil). Both the bacterial strains exhibited a great potential in remediating weathered hydrocarbons of engine oil. Addition of inorganic fertilizers (NPK), at recommended levels for bioremediation, resulted in significant inhibition in biostimulation/enhanced natural attenuation as well as bioaugmentation. The data on dehydrogenase activity clearly confirmed those of bioremediation strategies used, indicating that this enzyme assay could serve as an indicator of bioremediation potential of oil-contaminated soil. Extraction of TPHs from engine oil-contaminated soil with hydroxypropyl-ß-cyclodextrin (HPCD), but not 1-butanol, was found reliable in predicting the bioavailability of weathered hydrocarbons. Also, 454 pyrosequencing data were in accordance with those of bioremediation strategies used in the present microcosm study, suggesting the possible use of pyrosequencing in designing approaches for bioremediation.

Diesel is an important petroleum product, and a common pollutant in soil caused by leaks and accidental spills. Studies dealing with the ecotoxicity of diesel towards earthworms always relied on growth inhibition endpoint (EC50) values that were determined based on the spiked concentrations (nominal), ignoring the substantial portion of hydrocarbons volatilized from soil. In the present study we used, for the first time, the measured concentrations of total petroleum hydrocarbons (TPHs) from soil-applied diesel to assess earthworm (Eisenia fetida) survival, and the activities of dehydrogenase, urease and nitrification as indicators of soil health. The mortality endpoint (LC50) value for initially measured concentrations after exposure of earthworms to diesel for 28¿days was 916¿±¿10¿mg TPHs kg-1 soil which was equivalent to the nominal (initially added) concentration of 1426¿±¿19¿mg TPHs kg-1 soil. Morphological abnormalities such as clitella swelling and curling were noticed when the measured concentrations of diesel were more than 971¿mg¿kg-1 soil. Significant increases in activities of soil dehydrogenase (38¿58%) as well as urease were observed in the diesel-applied soil. Presence of earthworms further enhanced the activities of these soil enzymes. Nitrification was sensitive to application of diesel to soil, and it was inhibited in a dose-related manner even in the presence of earthworms. The differential response of the toxicity criteria to diesel-contaminated soil observed in the present study clearly warrants more studies involving several soil health parameters to arrive at a generalization of ecotoxicity of an environmental pollutant.

© 2016 American Institute of Chemical Engineers Soils contaminated with crude oil are rich sources of enzymes suitable for both degradation of hydrocarbons through bioremediation processes and improvement of crude oil during its refining steps. Due to the long term selection, crude oil fields are unique environments for the identificati on of microorganisms with the ability to produce these enzymes. In this metagenomic study, based on Hiseq Illumina sequencing of samples obtained from a crude oil field and analysis of data on MG-RAST, Actinomycetales (9.8%) were found to be the dominant microorganisms, followed by Rhizobiales (3.3%). Furthermore, several functional genes were found in this study, mostly belong to Actinobacteria (12.35%), which have a role in the metabolism of aliphatic and aromatic hydrocarbons (2.51%), desulfurization (0.03%), element shortage (5.6%), and resistance to heavy metals (1.1%). This information will be useful for assisting in the application of microorganisms in the removal of hydrocarbon contamination and/or for improving the quality of crude oil. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:638¿648, 2016.

We exposed the microalgal strain, Chlorella sp. MM3, to unused or used engine oil, or their water accommodated fractions (WAFs) to determine growth inhibition and response of antioxidant enzymes. Oil type and oil concentration greatly affected the microalgal growth. Used oil at 0.04¿% (0.4¿g L-1) resulted in 50¿% inhibition in algal growth, measured in terms of chlorophyll-a, while the corresponding concentration of unused oil was nontoxic. Similarly, used oil WAF showed significant toxicity to the algal growth at 10¿% level, whereas WAF from unused oil was nontoxic even at 100¿% concentration. Peroxidase enzyme in the microalga significantly increased with used oil at concentrations above 0.04¿g L-1 whereas the induction of superoxide dismutase and catalase was apparent only at 0.06¿g L-1. Activities of the antioxidant enzymes increased significantly when the microalga was exposed to 75 and 100¿% WAF obtained from used oil. The used oil toxicity on microalga could be due to the presence of toxic soluble mono- and polyaromatic compounds, heavy metals, and other compounds attained by the oil during its use in the motor engines.

Four bacterial strains, capable of degrading diesel oil, n-alkanes or hexadecane, were isolated from soils contaminated with petroleum oil and identified. Strains of Pseudomonas sp., Pseudomonas putida TPHK-1 and Pseudomonas aeruginosa TPHK-4, were more efficient in degrading high concentrations of the hydrocarbons than the other two strains, Stenotrophomonas maltophilia TPHK-2 and Acenitobacter sp. TPHK-3. P. putida TPHK-1 exhibited tolerance to very high concentrations of heavy metals such as cadmium, lead, zinc and copper. The innate ability of P. putida TPHK-1, as evidenced by the amplified genes alkB1 and alkB2 that encode alkane hydroxylases, and cat12o and cat23o coding for catechol dioxygenase, in degrading diesel oil in the presence of heavy metals is far greater than that of the strains reported in the literature. Heavy metal tolerance coupled with rapid degradation of hydrocarbons, even at high concentrations, suggests that P. putida TPHK-1 has a great potential in remediating soils contaminated with mixtures of hydrocarbons and heavy metals.

A study was conducted in the Department of Environmental Sciences, Tamil Nadu Agricultural University, Coimbatore, India, to transform the normal compost into bioactive compost, which has multiple benefits to the crop system. The key players in this transformation process were Azotobacter sp., Pseudomonas sp., Phosphobacteria sp. and the waste materials like poultry litter and spent wash. This enrichment process increases both the quality and nutrient content of the municipal solid waste compost significantly. A study was carried out to evaluate the effect of application of different levels of enriched municipal solid waste compost on the availability of the macronutrient content to the rice field soil. The effect of enriched compost on soil available nutrients was significant. The soil ammonium nitrogen and soil nitrate nitrogen content was found to be high in the plots where the enriched compost was applied along with inorganic fertilizer with the values of 38.87 mg kg-1 and 32.87 mg kg-1, respectively. In addition, the availability decreased towards crop growth. The soil available P and K were also increased with enriched compost application to about 22.46 kg ha-1 and 647 kg ha-1 compared with control values of 19.44 kg ha-1 and 518 kg ha-1, respectively. Both phosphorus and potassium content decreased towards advancement of crop growth. © 2007 Taylor & Francis.

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, India, to study the effect of Enriched Municipal Solid Waste Compost (EMSWC) application on growth, plant nutrient uptake and yield of rice in RBD during the year of 2004. The growth attributes viz., plant height, leaf area index, number of tillers and dry matter production differed significantly due to different treatments. These attributes increased significantly owing to the application of enriched compost, which has enhanced nutrient level, which leads to the continuous availability of nutrients in available form to the plants. The highest grain yield and straw yield were observed in the treatment combination of 25% of enriched compost and 75% of recommended dose of inorganic fertilizer (T5) with value of 5.22 and 8.65 t ha-1, respectively. Application of 5 t ha-1 enriched MSWC in combination with 25% N through inorganic fertilizer recorded grain yield of 4.33 t ha-1. The lowest grain yield (3.78 t ha-1) was recorded in treatment where the compost was applied alone. © 2007 Asian Network for Scientific Information.

A study was conducted in the Department of Environmental Science, Tamil Nadu Agricultural University, Coimbatore, to transform the normal compost into bioactive compost through the addition of various substrates, which has multiple benefits to the crop system. The key players in this transformation process were Azotobacter, Pseudomonas, Phosphobacteria, composted poultry litter, rock phosphate and diluted spent wash. This enrichment process has increased the nutritive value of compost. The highest nitrogen content (1.75%) and phosphorus content (1.16%) was observed in the treatment T5 (compost enriched with composted poultry litter, spent wash, microbial inoculants and rock phosphate). The beneficial microorganism viz., Azotobacter, Pseudomonas and Phosphobacteria population were higher in the treatment T5 where all the inputs (composted poultry litter, microbial consortium, rock phosphate and spent wash) were added to the compost. The plant growth promoters viz., IAA and GA content was more in the treatment applied with spent wash and microbial inoculum. Beneficial microorganisms, composted poultry litter, rock phosphate and diluted spent wash contributes maximum level of nutrients and growth promoters to the compost with small expenses. © 2007 Asian Network for Scientific Information.