Abstract:To investigate variation of methylmercury of the water-level-fluctuating zone in the Three Gorges Reservoir Area, dynamic changes of methylmercury contents and influencing factors were analyzed in soil and water by simulation experiment. The results showed that the methylmercury contents in soil initially increased but then decreased in both the flooding and drying process. Flooding could promote the transformation of inorganic mercury into organic forms. Methylmercury contents in soil increased with the number of wet-dry cycles. The average methylmercury content in soil during the second flooding phase was 22.13% higher than the first one, whereas the average methylmercury content increased by 58.17% in the second drying phase. The ratio of methylmercury to total mercury in soil during the second flooding phases was significantly higher than that during the first, and the alternate wet-dry environment was beneficial to mercury methylation. Methylmercury in soil was rapidly released into water, resulted in an obvious increase of methylmercury content in water. Methylmercury contents in water increased by 119.42% after the first flooding cycle and 334.72% after the second. The results showed that there was no correlation between methylmercury contents in water and methylmercury contents in soil. Methylmercury contents in soil were significantly affected by soil pH, organic matter content, Eh and soil moisture. Meanwhile, water pH, DO, DOM and temperature considerably influenced methylmercury contents in water.
张成, 宋丽, 王定勇, 孙荣国, 张金洋. 三峡库区消落带甲基汞变化特征的模拟[J]. 中国环境科学, 2014, 34(2): 499-504.
ZHANG Cheng, SONG Li, WANG Ding-Yong, SUN Rong-Guo, ZHANG Jin-Yang. Simulation on the variation characteristics of methylmercury of the water-level-fluctuating zone in the Three Gorges Area. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(2): 499-504.