河口沉积物对砷的吸附性能及影响因素

对比分析了砷在辽东湾营口河口外侧近海域沉积物和河口内侧河流段沉积物上的含量和吸附行为,并探讨了主要影响因素.结果表明,海域沉积物和河流段沉积物中As含量分别为7.5和4.0 mg/kg,相对于As的效应临界浓度TEL值7.2 mg/kg,海域沉积物中有一定的As污染.河口外侧近海域沉积物由于铁锰铝等金属和有机质含量较高...

Adsorption of Arsenic in Estuarine Sediments and Its Influencing Factors

Arsenic concentrations and adsorption behavior on both estuarine marine sediment and estuarine river sediment of Liaodong Bay were compared.The influence of arsenic initial concentration,pH value and other ions in water on arsenic adsorption was studied.Results showed that the concentrations of As in sediments from estuarine marine sediment were 7.5 mg/kg which was higher than the threshold effect leve(l TEL),implying As contamination there.Higher adsorption capacity for As(Ⅲ) and As(V) was observed on the marine sediment which contained more organic matter and iron,manganese and aluminum metals.The amount of adsorption for As(Ⅲ) was higher than that for As(V) in both sediments.Adsorption kinetics for As(Ⅲ) and As(V) can be satisfactorily fitted by pseudo-first-order model.A modified Langmuir equation may describe well the As(Ⅲ) and As(V) adsorption on the samples.With the initial concentration of As(Ⅲ) and As(V) increased,adsorption capacity and rate of As(Ⅲ) and A(s V) rose.Best adsorption environment of As(Ⅲ) was acidic while As(V) was alkaline.The coexistence ions in water showed an obvious influence on the adsorption of arsenic in the sediments.