Dr Peter Sanderson

© 2018 by Taylor & Francis Group, LLC. Spoil to Soil: Mine Site Rehabilitation and Revegetation presents both fundamental and practical aspects of remediation and revegetation of mine sites. Through three major themes, it examines characterization of mine site spoils; remediation of chemical, physical and biological constraints of mine site spoils, including post mine-site land-use practices; and revegetation of remediated mine site spoils. Each theme includes chapters featuring case studies involving mine sites around the world. The final section focuses specifically on case studies with successful mine site rehabilitation. The book provides a narrative of how inert spoil can be converted to live soil. Instructive illustrations show mine sites before and after rehabilitation. The purpose of this book is to provide students, scientists, and professional personnel in the mining industry sensible, science-based information needed to rehabilitate sustainably areas disturbed by mining activities. This book is suitable for undergraduate and graduate students majoring in environmental, earth, and soil sciences; environmental and soil scientists; and mine site environmental engineers and regulators

© 2018 by Taylor & Francis Group, LLC. The Australian beef cattle industry is one of the most efficient and ranks third largest in beef export in the world, contributing 4% of beef supply. As on 2013, the meat value produced from beef cattle, in Australia is estimated to be $12.3 billion (Fastfacts, 2013). Beef cattle production ranges from intensive farms on fertile lands to extensive range lands. With the increase in human population and increase in affordability of meat-based food, the demand for beef cattle is also increasing

© 2018 by Taylor & Francis Group, LLC. ¿Mining¿ refers to the excavation of economically important resources from terrestrial landmasses, thereby generating a large quantity of valuable precursors for commercial and industrial activities. Mineral products such as coal, aluminum, copper, iron, gold, and mineral sand are examples from the mining industry. Though mining advances global economic prosperity, this industry severely disturbs the land, water resources, and the environment (Figure 4.1). Mined waste materials such as tailings, subsoils, oxidized wastes, and fireclay are the main causes for land disturbance. Presence of potentially hazardous substances such as heavy metals in elevated concentrations in the mined waste materials has caused land contamination. Poor soil characteristics such as low-level organic matter and poor soil texture and structure have resulted in deterioration of the land, adversely affecting the establishment of plants and soil microbial flora and fauna (Boyer et al. 2011, Johnson 2003, Larney and Angers 2012, Sopper 1992). Disturbed mine sites are known to contaminate water resources 60 61in many countries, mainly from acid mine drainage (Bolan et al. 2003, Lindsay et al. 2015, Taylor et al. 1997). Therefore, these sites need to be rehabilitated to minimize potential environmental consequences, thereby enhancing their utilization. Revegetation of mine sites is one of the potential strategies that can be applied to improve these disturbed land masses. Here, infertile soil properties are improved by a series of processes such as land application of biowastes

© 2018 by Taylor & Francis Group, LLC. Soils are a prime and very important natural resource, and soil fertility is a major concern for sustainable agriculture and economic development of any country. In recent decades, problems of contaminated land sites, water bodies, groundwater, and air worldwide have increased manyfold due to anthropogenic activities. Mining is one of the anthropogenic activities that cause pollution problems in, around, and outside of mining areas. It results in the mobilization of metals and organic and inorganic substances into the environment, which causes pollution of air, soils, sediments, vegetation, and surface and groundwater. It also increases the morbidity and mortality of plant and animal species and results in the loss of visual, aesthetic characteristics of landscapes (Bolan et al. 2003; Pavli et al. 2015)

© 2018 by Taylor & Francis Group, LLC. Degradation of land resources as a result of mining activities poses serious threat to the environment. It has been estimated that around 0.4 × 106km2area of land is impacted by mining activities around the world (Hooke and Martín-Duque 2012). Unfortunately, a significant percentage of this area has never been reclaimed, which poses health risks to ecosystems and humans. Often, these wastes contain hazardous substances such as heavy metals, organic contaminants, radionuclides, and crushed limestone, where the latter could become a potential source of atmospheric CO2emission. Thus, they not only pose serious risk to the groundwater and surface water, but also to the atmosphere (Wijesekara et al. 2016). In order to tackle the issues related to mine wastes and manage the affected sites sustainably, an appropriate physical, chemical, and biological characterization of waste materials becomes very prudent. Due to the lack of both above- and below-ground biodiversity, mine waste sites are very poor in organic matter content. This in return leads to poor seed germination, plant growth, and vegetation establishment. In many cases, the associated toxic contaminants also seriously compromise the soil health, microbial life, and plant growth (Castillejo and Castelló 2010, Larney and Angers 2012). This chapter describes the physicochemical characteristics of mine wastes, including spoil, tailings, and overburden, by underpinning their source-property relationships. The value of readily available biowaste resources, including biosolids, composts, and manures, in improving such physicochemical properties of mining-impacted soils/sites is also discussed

© 2018 by Taylor & Francis Group, LLC. Historically, mining of metalliferous ore bodies was a relatively dispersed activity, with numerous small mines occurring throughout many western countries including the United States, the United Kingdom, and Australia (Soucek et al. 2000, Grant et al. 2002, Mayes et al. 2009). Many metalliferous mine sites began operation in the late eighteenth and early nineteenth centuries and were abandoned in most instances before the environmental movement in Western countries. As such, there was very little recognition of the potential impacts caused by the dispersal of metal toxicants such as arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) into the surrounding environments from these sites. Many of these contaminants are cariogenic in humans (e.g., As), cause a range of human health-related impacts (Pb, Cd), and are toxic to ecological receptors in nearby streams and surrounding terrestrial environments (Cu, Zn, Mn, Ni). As a result of the lack of regard for potential impacts, much of the mining waste was discarded carelessly throughout mining sites, and in some cases, directly into nearby watercourses

© 2018 by Taylor & Francis Group, LLC. In the era of global competition, mineral exploitation has been significantly increased resulting in pressure on the environment in the form of massive deforestation, soil pollution, and erosion. Despite global economic importance, mineral industries have adversely affected the ecosystems across the world. The impact of mine waste in soil depends on its type and composition, commodity being mined, type of ore, and technologies used to process the ore. Mining types and activities are several, which include surface mining, underground mining, openpit mining, in situ mining, pillar mining, slope mining, block caving, and quarrying. And thus mine waste materials vary in their physical and chemical composition and potential for soil contamination. The different 96types of mine waste materials are overburden, waste rock, tailings, slags, mine water, sludge, and gaseous wastes. Overburden includes the soil and rock that are removed to gain access to the ore deposits at openpit mines. It is usually dumped on the surface at mine sites where it will not hinder further expansion of the mining operation. Waste rock contains minerals in concentrations considered too low to be extracted at a profit. It is often stored in heaps on the mine site. Tailings are finely ground rock and mineral waste products of mineral processing operations. They also contain leftover processing chemicals, and usually are deposited in the form of water-based slurry into tailings ponds. Slags are nonmetallic by-products from metal smelting. Mine water is produced in a number of ways at mine sites and varies in its quality and potential for environmental contamination. Sludge is produced at active water treatment plants used at some mine sites and consists of the solids that have been removed from the water as well as any chemicals. Gaseous wastes are produced during high-temperature chemical processing such as smelting, and consist of particulate matter and oxides of sulfur

© 2017 Elsevier Ltd Shooting range soils contain mixed heavy metal contaminants including lead (Pb), cadmium (Cd), and zinc (Zn). Phosphate (P) compounds have been used to immobilize these metals, particularly Pb, thereby reducing their bioavailability. However, research on immobilization of Pb's co-contaminants showed the relative importance of soluble and insoluble P compounds, which is critical in evaluating the overall success of in situ stabilization practice in the sustainable remediation of mixed heavy metal contaminated soils. Soluble synthetic P fertilizer (diammonium phosphate; DAP) and reactive (Sechura; SPR) and unreactive (Christmas Island; CPR) natural phosphate rocks (PR) were tested for Cd, Pb and Zn immobilization and later their mobility and bioavailability in a shooting range soil. The addition of P compounds resulted in the immobilization of Cd, Pb and Zn by 1.56¿76.2%, 3.21¿83.56%, and 2.31¿74.6%, respectively. The reactive SPR significantly reduced Cd, Pb and Zn leaching while soluble DAP increased their leachate concentrations. The SPR reduced the bioaccumulation of Cd, Pb and Zn in earthworms by 7.13¿23.4% and 14.3¿54.6% in comparison with earthworms in the DAP and control treatment, respectively. Bioaccessible Cd, Pb and Zn concentrations as determined using a simplified bioaccessibility extraction test showed higher long-term stability of P-immobilized Pb and Zn than Cd. The differential effect of P-induced immobilization between P compounds and metals is due to the variation in the solubility characteristics of P compounds and nature of metal phosphate compounds formed. Therefore, Pb and Zn immobilization by P compounds is an effective long-term remediation strategy for mixed heavy metal contaminated soils.

© 2016 Elsevier Ltd. The stabilisation of Pb in the soil by phosphate is influenced by environmental conditions and physicochemical properties of the soils to which it is applied. Stabilisation of Pb by phosphate was examined in four soils under different environmental conditions.The effect of soil moisture and temperature on stabilisation of Pb by phosphate was examined by measurement of water extractable and bioaccessible Pb, sequential fractionation and X-ray absorption spectroscopy. The addition of humic acid, ammonium nitrate and chloride was also examined for inhibition or improvement of Pb stability with phosphate treatment.The effect of moisture level varied between soils. In soil MB and DA a soil moisture level of 50% water holding capacity was sufficient to maximise stabilisation of Pb, but in soil TV and PE reduction in bioaccessible Pb was inhibited at this moisture level. Providing moisture at twice the soil water holding capacity did not enhance the effect of phosphate on Pb stabilisation. The difference of Pb stability as a result of incubating phosphate treated soils at 18 °C and 37 °C was relatively small. However wet-dry cycles decreased the effectiveness of phosphate treatment. The reduction in bioaccessible Pb obtained was between 20 and 40% with the most optimal treatment conditions. The reduction in water extractable Pb by phosphate was substantial regardless of incubation conditions and the effect of different temperature and soil moisture regimes was not significant.Selective sequential extraction showed phosphate treatment converted Pb in fraction 1 (exchangeable, acid and water soluble) to fraction 2 (reducible). There were small difference in fraction 4 (residual) Pb and fraction 1 as a result of treatment conditions. X-ray absorption spectroscopy of stabilised PE soil revealed small differences in Pb speciation under varying soil moisture and temperature treatments. The addition of humic acid and chloride produced the greatest effect on Pb speciation in phosphate treated soils.

This study aims to examine the effectiveness of amendments for risk-based land management of shooting range soils and to explore the effectiveness of amendments applied to sites with differing soil physiochemical parameters. A series of amendments with differing mechanisms for stabilisation were applied to four shooting range soils and aged for 1¿year. Chemical stabilisation was monitored by pore water extraction, toxicity characteristic leaching procedure (TCLP) and the physiologically based extraction test (PBET) over 1¿year. The performance of amendments when applied in conditions reflecting field application did not match the performance in the batch studies. Pore water-extractable metals were not greatly affected by amendment addition. TCLP-extractable Pb was reduced significantly by amendments, particularly lime and magnesium oxide. Antimony leaching was reduced by red mud but mobilised by some of the other amendments. Bioaccessible Pb measured by PBET shows that bioaccessible Pb increased with time after an initial decrease due to the presence of metallic fragments in the soil. Amendments were able to reduce bioaccessible Pb by up to 50¿%. Bioaccessible Sb was not readily reduced by soil amendments. Soil amendments were not equally effective across the four soils. © 2013 Her Majesty the Queen in Right of Australia.

Shooting ranges have come under increased scrutiny in recent years as a potential source of contamination owing to the high loading of lead in the soil. Stabilization by the addition of chemical amendments has been examined as a viable risk-based approach to managing shooting range contamination. Amendments have been shown to immobilize metals to varying degrees, determined by the target contaminant, the amendment used, soil properties, and the reaction kinetics in the contaminated soil and amendment system. Field scale evaluation of the effectiveness of chemical amendments for the stabilization of metal contaminants in shooting range soil is limited. Doubt remains over effectiveness and long-term stability under the varying conditions found in the field, which affect the kinetics of immobilization and dissolution in amended soil. © 2012 American Society of Civil Engineers.