Total and Methylmercury of Suaeda heteroptera Wetland Soil Response to a Salinity Gradient Under Wetting and Drying Conditions.

Total and Methylmercury of Suaeda heteroptera Wetland Soil Response to a Salinity Gradient Under Wetting and Drying Conditions. Bull Environ Contam Toxicol. 2020 May 19;: Authors: Li H, Zheng D, Zhang X, Niu Z, Ma H, Zhang S, Wu C Abstract Mercury (Hg) methylation could occur in freshwater ecosystems with low or high salinity. However, few studies are available about the effects of salinity change on mercury(Hg) release and methylation. In-situ experiments using Suaeda heteroptera wetland soil column from the Liaohe estuary were performed to decipher how total mercury (THg) and methylmercury (MeHg) contents change under fluctuant salinity and wet and dry soil conditions. Salinity gradients were set to 0.50% (S1), 1.00% (S2), 1.50% (S3) and 1.80% (S4), and pure deionized water was used as a blank control (CK). Wet and dry soil conditions were set to full inundation condition (WD1) and naturally dried treatment (WD2). Results indicated that the highest THg and MeHg contents were found in surface and bottom soil when water salinity treatment was CK under WD1. THg and MeHg decreased with salinity under WD1. THg contents in overlying water varied from 0.854 to 1.243 µg L-1 under WD1 treatments and increased with salinity change. When under WD2 treatment, THg contents in both soil layers gradually decreased with rising salinity. Meanwhile, MeHg contents in both soil layers reached the lowest level at CK (1.666 μg kg-1and 2.520 μg kg-...
Source: Bulletin of Environmental Contamination and Toxicology - Category: Environmental Health Authors: Tags: Bull Environ Contam Toxicol Source Type: research