Moon Deok Hyun, Cheong Kyung Hoon, Koutsospyros Agamemnon, Chang Yoon-Young, Hyun Seunghun, Ok Yong Sik, Park Jeong-Hun
Department of Environmental Engineering, Chosun University, Gwangju, 501-759, Republic of Korea.
Department of Civil and Environmental Engineering, University of New Haven, West Haven, CT, 06516, USA.
Environ Sci Pollut Res Int. 2016 Feb;23(3):2362-70. doi: 10.1007/s11356-015-5456-9. Epub 2015 Sep 28.
A novel treatment mix was designed for the simultaneous immobilization of As, Cu, and Pb in contaminated soils using natural (waste oyster shells (WOS)) and industrial (coal mine drainage sludge (CMDS)) waste materials. The treatments were conducted using the standard U.S. sieve size no. 20 (0.85 mm) calcined oyster shells (COS) and CMDS materials with a curing time of 1 and 28 days. The As immobilization treatments were evaluated using the 1-N HCl extraction fluid, whereas the Pb and Cu immobilization treatments were evaluated using the 0.1-N HCl extraction fluid based on the Korean leaching standards. The treatment results showed that the immobilization of As, Cu, and Pb was best achieved using a combination mix of 10 wt% COS and 10 wt% CMDS. This treatment mix was highly effective leading to superior leachability reductions for all three target contaminants (>93 % for As and >99 % for Cu and Pb) for a curing period of 28 days. The X-ray absorption near-edge structure (XANES) results showed that As was present in the form of As(V) in the control sample and that no changes in As speciation were observed following the COS-CMDS treatments. The scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) sample treated with 10 wt% COS and 10 wt% CMDS indicated that As immobilization may be associated with the formation of Ca-As and Fe-As precipitates while Pb and Cu immobilization was most probably linked to calcium silicate hydrates (CSHs) and calcium aluminum hydrates (CAHs).
设计了一种新型处理混合物，用于使用天然（废弃牡蛎壳（WOS））和工业（煤矿排水污泥（CMDS））废料同时固定污染土壤中的砷、铜和铅。使用美国标准20号筛目（0.85毫米）煅烧牡蛎壳（COS）和CMDS材料进行处理，养护时间为1天和28天。根据韩国浸出标准，使用1-N盐酸萃取液评估砷的固定处理，而使用0.1-N盐酸萃取液评估铅和铜的固定处理。处理结果表明，使用10 wt% COS和10 wt% CMDS的组合混合物能最好地实现砷、铜和铅的固定。这种处理混合物非常有效，在28天的养护期内，对所有三种目标污染物的浸出性降低效果显著（砷>93%，铜和铅>99%）。X射线吸收近边结构（XANES）结果表明，对照样品中的砷以As(V)形式存在，COS-CMDS处理后未观察到砷形态的变化。用10 wt% COS和10 wt% CMDS处理的扫描电子显微镜（SEM）-能量色散X射线光谱（EDX）样品表明，砷的固定可能与Ca-As和Fe-As沉淀的形成有关，而铅和铜的固定很可能与硅酸钙水合物（CSHs）和钙铝水合物（CAHs）有关。
