Immobilization of lead in contaminated firing range soil using biochar

Abstract

Soybean stover-derived biochar was used to immobilize lead (Pb) in military firing range soil at a mass application rate of 0 to 20 wt.% and a curing period of 7 days. The toxicity characteristic leaching procedure (TCLP) was performed to evaluate the effectiveness of the treatment. The mechanism responsible for Pb immobilization in military firing range soil was evaluated by scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) and x-ray absorption fine structure (XAFS) spectroscopy analyses. The treatment results showed that TCLP Pb leachability decreased with increasing biochar content. A reduction of over 90 % in Pb leachability was achieved upon treatment with 20 wt.% soybean stover-derived biochar. SEM-EDX, elemental dot mapping and XAFS results in conjunction with TCLP leachability revealed that effective Pb immobilization was probably associated with the pozzolanic reaction products, chloropyromorphite and Pb-phosphate. The results of this study demonstrated that soybean stover-derived biochar was effective in immobilizing Pb in contaminated firing range soil.

Can Biochar Come to the Rescue of Coastal Barren Species? A Controlled Study Reports on the Impact of Biochar Amendment on Their Survival

“…Perhaps the issue that is most central to the potential value of biochar as an ecological tool lies in determining whether biochar benefits will extend survival of other species in other plant communities or, for example, in disturbed plant communities such as those found on former military firing ranges (Moon et al 2013;Uchimiya and Bannon, 2013) where mitigation is an additional concern. If biochar can be shown to improve soil fertility and enhance plant physiological response even after anthropogenic disturbance, perhaps it can play a rescue role in revitalization efforts to reverse habitat loss in the Northeast U.S. (Foster and Motzkin 2003).…”

Salisbury biochar did not affect the mobility or speciation of lead in kaolin in a short-term laboratory study

“…Sequential extraction based on [14,16,17] was used to determine the different geochemical phases (speciation) of Pb 2+ present in the soils. The details of the procedure can be found in a previous study [6].…”

“…Therefore, the impact of biochar on immobilisation of heavy metals in clay-rich soils is worth being investigated. However, the majority of studies to date have investigated the performance of biochar in sanddominated soils, as indicated in Table S1 [3, [10][11][12][13][14]. Studies that applied biochar on clay-rich soils are very limited, leading to a poor understanding of the performance of biochar on clay soils contaminated with heavy metals and the remediation mechanisms involved.…”

Lead Stabilization in Soil Amended with Lime Waste: An Extended X-ray Absorption Fine Structure (EXAFS) Investigation

“…이와 함께 비산재, 고로슬 래그, 굴껍질 등의 폐석회물질을 사용하여 토양 pH를 상승 시켜 토양에 의한 중금속 흡착 및 수산화물 등으로의 침전 을 증대하여 중금속을 안정화하는 방법이 있다 (Kostarelos et al, 2006;Lee et al, 2009;Ok et al, 2011b;Zhao and Masaihiko, 2007). 최근에는 바이오차 (biochar)를 오염토 양에 처리함으로써 중금속을 안정화하고 토양질을 개선하 는 방법도 주목을 받고 있다 (Ahmad et al, 2012b;2014a;2014b;Almaroai et al, 2014;Awad et al, 2012;Mohan et al, 2014;Moon et al, 2013). (Ahmad et al, 2012a;Hashimoto et al, 2010;Ippolito et al, 2012;Moon et al, 2011).…”