Zhang Yanfeng, Han Yuwei, Yang Jinxi, Zhu Lingyan, Zhong Wenjue
Tianjin Key Laboratory of Remediation & Pollution Control for Urban Ecological Environment, Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300351, China.
Tianjin Key Laboratory of Remediation & Pollution Control for Urban Ecological Environment, Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300351, China.
J Environ Sci (China). 2017 Dec;62:31-38. doi: 10.1016/j.jes.2017.08.002. Epub 2017 Aug 9.
The occurrence, toxicities, and ecological risks of five heavy metals (Pb, Cu, Cd, Zn and Ni) in the sediment of Taihu Lake were investigated in this study. To evaluate the toxicities caused by the heavy metals, the toxicities induced by organic contaminants and ammonia in the sediments were screened out with activated carbon and zeolite. The toxicities of heavy metals in sediments were tested with benthic invertebrates (tubificid and chironomid). The correlations between toxicity of sediment and the sediment quality guidelines (SQGs) derived previously were evaluated. There were significant correlations (p<0.0001) between the observed toxicities and the total risk quotients of the heavy metals based on SQGs, indicating that threshold effect level (TEL) and probable effect level (PEL) were reliable to predict the toxicities of heavy metals in the sediments of Taihu Lake. By contrast, the method based on acid volatile sulfides (AVS) and simultaneously extracted metals (SEM), such as ∑SEM/AVS and ∑SEM-AVS, did not show correlations with the toxicities. Moreover, the predictive ability of SQGs was confirmed by a total predicting accuracy of 77%. Ecological risk assessment based on TELs and PELs showed that the contaminations of Pb, Cu, Cd and Zn in the sediments of Taihu Lake were at relatively low or medium levels. The risks caused by heavy metals in the sediments of northern bay of the lake, which received more wastewater discharge from upper stream, were higher than other area of the lake.
本研究调查了太湖沉积物中五种重金属（铅、铜、镉、锌和镍）的存在情况、毒性及生态风险。为评估重金属引起的毒性，用活性炭和沸石筛选出沉积物中有机污染物和氨引起的毒性。用底栖无脊椎动物（颤蚓和摇蚊）测试沉积物中重金属的毒性。评估了沉积物毒性与先前推导的沉积物质量基准（SQGs）之间的相关性。观察到的毒性与基于SQGs的重金属总风险商之间存在显著相关性（p<0.0001），表明阈值效应水平（TEL）和可能效应水平（PEL）对于预测太湖沉积物中重金属的毒性是可靠的。相比之下，基于酸挥发性硫化物（AVS）和同步提取金属（SEM）的方法，如∑SEM/AVS和∑SEM-AVS，与毒性没有相关性。此外，SQGs的预测能力通过77%的总预测准确率得到证实。基于TELs和PELs的生态风险评估表明，太湖沉积物中铅、铜、镉和锌的污染处于相对较低或中等水平。该湖北部湾区沉积物中重金属造成的风险高于湖泊其他区域，该区域上游接纳了更多废水排放。
