Wang Haotian, Liu Ruimin, Wang Qingrui, Xu Fei, Men Cong, Shen Zhenyao
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 100875, China.
Mar Pollut Bull. 2016 Dec 15;113(1-2):125-131. doi: 10.1016/j.marpolbul.2016.08.076. Epub 2016 Sep 12.
The bioavailability and risk assessment of As were studied in sediments of the Yangtze River estuary (YRE). Results showed that residual fractions dominated the As partition (>85%), which attenuated overall bioavailability. After the residual fraction, As mainly partitioned into the Fe-Mn oxides fraction (3.16-4.22%). Arsenic bound to Fe-Mn oxides was higher in wet seasons. The carbonate fraction was minimal, which may result from the negative state presence of As in sediments. According to the risk assessment code, the YRE was classified as low risk. Additionally, the reduction of As(V) to As(III) may occur due to the reducing condition in wet seasons. Considering As(III) is more toxic and mobile, As bound to the exchangeable and Fe-Mn oxides fractions may have more potential ecological risk. Thus, the speciation and fraction should be both considered on the ecological risk of As in sediments of the YRE.
对长江河口（YRE）沉积物中砷的生物有效性和风险评估进行了研究。结果表明，残渣态在砷的分配中占主导地位（>85%），这降低了总体生物有效性。在残渣态之后，砷主要分配到铁锰氧化物态（3.16 - 4.22%）。与铁锰氧化物结合的砷在湿润季节含量更高。碳酸盐态含量最低，这可能是由于沉积物中砷呈负价态所致。根据风险评估代码，长江河口被归类为低风险。此外，由于湿润季节的还原条件，可能会发生五价砷还原为三价砷的情况。考虑到三价砷毒性更大且迁移性更强，与可交换态和铁锰氧化物态结合的砷可能具有更大的潜在生态风险。因此，在评估长江河口沉积物中砷的生态风险时，应同时考虑其形态和赋存形态。
