TY - JOUR
ID - 10.1016/S1001-0742(11)61048-6
TI - Dynamics of arsenic in salt marsh sediments from Dongtan wetland of the Yangtze River estuary, China
AU - Yongjie Wang
AU - Limin Zhou
AU - Xiangmin Zheng
AU - Peng Qian and Yonghong Wu
VL - 24
IS - 12
PB -
SP - 2113
EP - 2121
PY -
JF - Journal of Environmental Sciences
JA - J. Environ. Sci.
UR - http://www.jesc.ac.cn/jesc_en/ch/reader/view_abstract.aspx?file_no=2012241210&flag=1
KW - arsenic;iron (hydr)oxides;salt marsh sediment;Spartina alterniflora;Yangtze River estuary
KW - arsenic;iron (hydr)oxides;salt marsh sediment;Spartina alterniflora;Yangtze River estuary
AB - The mobility and transformation of arsenic (As) in salt marsh sediments were investigated in Dongtan wetland of the Yangtze River estuary, China. As in surface water, pore water and the rhizosphere sediments were quantified. The microcosm incubation experiments were conducted during the flooding of the sediments to examine As dynamics that occurred during changing redox conditions. The concentrations of dissolved As in pore water (0.04-0.95 μmol/L) were significantly greater than that in surface water (0.03-0.06 μmol/L). Under anoxic conditions, the reactive As could be initially mobilized by the reductive dissolution of Fe(III) (hydr)oxides. Subsequently, most of the dissolved As was likely to be associated with secondary iron (hydr)oxide phases and remained in solid phases. The seasonal variability of acid volatile sulfide concentrations suggest the anoxic conditions are enhanced during summer by Spartina alterniflora compared to Phragmites australis and Scirpus mariqueter, causing a notable increase in As mobility. Generally, there was a typical variation in redox conditions with season in salt marsh sediments of Dongtan wetland, in which the dynamics of As mobility and transformation possibly were controlled by iron, and all of this could be significantly influenced by the rapid spread of S. alterniflora.
ER -