Liao Jianbo, Ru Xuan, Xie Binbin, Zhang Wanhui, Wu Haizhen, Wu Chaofei, Wei Chaohai
The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Guangzhou Municipal Engineering Group Co., Ltd., Guangzhou 510060, PR China.
Ecotoxicol Environ Saf. 2017 Jul;141:75-84. doi: 10.1016/j.ecoenv.2017.03.009. Epub 2017 Mar 19.
To date, there is a lack of a comprehensive research on heavy metals detection and ecological risk assessment in river water, sediments, pore water (PW) and suspended solids (SS). Here, the concentrations of heavy metals, including Cu, Zn, Mn, Cd, Pb and As, and their distribution between the four phases was studied. Samples for analysis were taken from twelve sites of the Hengshi River, Guangdong Province, China, during the rainy and dry seasons. A new comprehensive ecological risk index (CERI) based on considering metal contents, pollution indices, toxicity coefficients and water categories is offered for prediction of potential risk on aquatic organisms. The results of comprehensive analysis showed that the highest concentrations of Cu, Zn and Mn of 6.42, 87.17 and 98.74mg/L, respectively, in PW were comparable with those in water, while concentrations of Cd, Pb and As of 609.5, 2757 and 96.38μg/L, respectively, were 2-5 times higher. The sum of the exchangeable and carbonate fractions of target metals in sediments followed the order of Cd > Mn > Zn > Pb > Cu > As. The distribution of heavy metals in phases followed the order of sediment > SS > water > PW, having the sum content in water and PW lower than 2% of total. The elevated ecological risk for a single metal and the phase were 34,585 for Cd and 1160 for water, respectively, implied Cd as a priority pollutant in the considered area. According to the CERI, the maximum risk value of 769.3 was smaller than 1160 in water, but higher than those in other phases. Out of considering the water categories and contribution coefficients, the CERI was proved to be more reliable for assessing the pollution of rivers with heavy metals. These results imply that the CERI has a potential of adequate assessment of multi-phase composite metals pollution.
迄今为止，针对河流水体、沉积物、孔隙水（PW）和悬浮固体（SS）中的重金属检测及生态风险评估，尚缺乏全面的研究。在此，对包括铜（Cu）、锌（Zn）、锰（Mn）、镉（Cd）、铅（Pb）和砷（As）在内的重金属浓度及其在这四个相之间的分布进行了研究。在雨季和旱季期间，从中国广东省横石河的12个采样点采集了用于分析的样本。提出了一种基于金属含量、污染指数、毒性系数和水体类别考虑的新综合生态风险指数（CERI），用于预测对水生生物的潜在风险。综合分析结果表明，孔隙水中铜、锌和锰的最高浓度分别为6.42、87.17和98.74mg/L，与水体中的浓度相当，而镉、铅和砷的浓度分别为609.5、2757和96.38μg/L，高出2至5倍。沉积物中目标金属的可交换态和碳酸盐态含量之和顺序为：镉＞锰＞锌＞铅＞铜＞砷。重金属在各相中的分布顺序为：沉积物＞悬浮固体＞水体＞孔隙水，水体和孔隙水中的总含量低于总量的2%。单一金属和相的生态风险升高值分别为：镉为34585，水体为1160，这表明镉是该研究区域的首要污染物。根据CERI，最高风险值769.3低于水体中的1160，但高于其他相中的值。考虑到水体类别和贡献系数，CERI被证明在评估河流重金属污染方面更可靠。这些结果表明，CERI在评估多相复合金属污染方面具有潜力。
