Effects of iron and organic matter on arsenic speciation in aquifer sediments of the oxbow lake wetland in the middle reaches of the Yangtze River
In this paper,taking the Tian-E-Zhou oxbow lake wetland in the middle reaches of the Yangtze River as the research object,the differences in arsenic and iron occurrence and organic matter composition of two typical borehole(C3 and C5)sediments in the inner and outer sides of the oxbow lake wetland were studied,and the effects of iron-carbon coupling on arsenic occurrence in the different sedimentary environ-ments of the inner and outer sides of the oxbow lake in the Tian-E-Zhou wetland were revealed by combi-ning the differences in the sedimentary environment of the inner and outer sides of the Tian-E-Zhou oxbow lake wetland.This study finds that the shallow sediments of borehole C3(0～＜10 m)on the outer side of oxbow lake wetland contain more arsenic strongly adsorbed on amorphous iron oxides and humus organic matter,and the inner borehole C5 sediments contain more arsenic bound to iron silicate which is unreactive.The lacustrine sedimentary environment with fine particle size and high weathering degree of the shallow sediments on the outer side of the oxbow lake wetland enriches clay minerals and As-Fe-OM,while the flu-vial sedimentary environment with coarse particle size and low weathering degree on the inner side of the oxbow lake wetland is not conducive to the enrichment of reactive arsenic,clay minerals and organic matter.
middle reaches of the Yangtze Riveroxbow lake wetlandsedimentarsenic speciationiron ox-ideorganic matter
万方数据
维普
