College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China.
College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China.
J Hazard Mater. 2018 Apr 15;348:109-116. doi: 10.1016/j.jhazmat.2018.01.024. Epub 2018 Jan 12.
Some rivers in China have been seriously contaminated due to the discharge of lead (Pb) smelting wastewater. In this study, biochar-supported nano-chlorapatite (BC-nClAP) was synthesized to immobilize Pb in contaminated sediment. The remediation effect of BC-nClAP on Pb-contaminated sediment was evaluated through batch experiments and the materials were characterized by x-ray diffraction, scanning electron microscope, Brunner-Emmet-Teller and electronic differential system. It was found that BC-nClAP can transform Pb effectively from labile fraction into stable fraction with a maximum transformation efficiency increasing to 94.1% after 30 days of treatment, and the stabilization efficiency of toxicity characteristic leaching procedure reached 100% only after 16 days of treatment. The content of available phosphorus (AP) in the sediments treated by BC-nClAP was much less than that treated by nClAP, which indicated a lower risk of eutrophication and suggested the dissolution-precipitation mechanism involved in Pb immobilization. BC-nClAP presented the best immobilization efficiency of Pb and the content of organic matters in BC-nClAP treated samples increased the most, thus the OM might play an important role during the Pb immobilization.
中国的一些河流由于铅（Pb）冶炼废水的排放而受到严重污染。在本研究中，合成了生物炭负载的纳米氯磷灰石（BC-nClAP）来固定污染沉积物中的 Pb。通过批实验评价了 BC-nClAP 对 Pb 污染沉积物的修复效果，并通过 X 射线衍射、扫描电子显微镜、Brunauer-Emmett-Teller 和电子差分系统对材料进行了表征。结果表明，BC-nClAP 可将 Pb 从活性态有效转化为稳定态，处理 30 天后最大转化效率增加到 94.1%，毒性特征浸出程序的稳定效率仅在处理 16 天后达到 100%。BC-nClAP 处理后的沉积物中有效磷（AP）含量明显低于 nClAP 处理后的沉积物，表明其富营养化风险较低，说明 Pb 固定涉及溶解-沉淀机制。BC-nClAP 对 Pb 的固定效率最高，且 BC-nClAP 处理样品中有机物的含量增加最多，因此 OM 在 Pb 固定过程中可能起重要作用。
