Department of Environment and Energy Engineering, Chonnam National University, Gwangju, 500-757, Republic of Korea.
Environ Sci Pollut Res Int. 2017 Mar;24(8):7177-7183. doi: 10.1007/s11356-016-8330-5. Epub 2017 Jan 17.
In several previous studies, the efficacy of various liming waste materials on the immobilization of heavy metals has been tested and it was found that soils contaminated with heavy metals can be stabilized using this technique. Since lime (CaO) has been identified as the main phase of calcined cockle shell (CCS), it was hypothesized that CCS could be used as a soil amendment to immobilize heavy metals in soil. However, to date, no studies have been conducted using CCS. In this study, the effectiveness of CCS powder on the immobilization of Cd, Pb, and Zn in mine tailing soil was evaluated. After 28 days of incubation, the treated soil samples were exposed to weathering (four cycles of freezing-thawing and four cycles of wetting-drying) for 8 days before being subjected to a leaching test. The results of this study revealed that the soil pH increased from 7.5 to 12.2 with the addition of 5% CCS. A similar soil pH was obtained when the soil was amended with 5% pure CaO. By leaching with 0.1 M HCl, extracted Cd, Pb, and Zn were reduced by up to 85, 85, and 91%, respectively. Therefore, CCS is suggested as a low-cost lime-based soil amendment for stabilizing heavy metals in abandoned mining sites.
在之前的几项研究中，已经测试了各种石灰废料固定重金属的效果，发现受重金属污染的土壤可以通过该技术进行稳定化处理。由于已经确定煅烧扇贝壳（CCS）的主要成分是石灰（CaO），因此假设 CCS 可以用作土壤改良剂来固定土壤中的重金属。然而，迄今为止，尚未使用 CCS 进行任何研究。在这项研究中，评估了 CCS 粉末对矿山尾矿土壤中 Cd、Pb 和 Zn 固定的有效性。经过 28 天的孵化，处理后的土壤样品在进行淋滤测试之前，先经历 8 天的风化（四个冻融循环和四个干湿循环）。研究结果表明，添加 5%CCS 可使土壤 pH 值从 7.5 增加到 12.2。当土壤用 5%纯 CaO 进行改良时，也可获得相似的土壤 pH 值。用 0.1M HCl 淋滤后，提取的 Cd、Pb 和 Zn 的去除率分别高达 85%、85%和 91%。因此，CCS 被建议作为一种低成本的基于石灰的土壤改良剂，用于稳定废弃矿山中的重金属。
