pH对红枫湖表层沉积物吸附与释放磷的影响

Effects of pH on Phosphorus Sorption and Desorption in the Surface Sediments of the Hongfeng Lake

为给进一步治理红枫湖提供参考资料,对沉积物中磷在大范围pH(2～12)下的吸附与释放特性进行了模拟试验。结果表明:红枫湖沉积物可溶性磷的存在形态包括有机磷、无机磷、铝/铁磷和钙磷等,铝/铁磷和钙磷为主要形态。红枫湖沉积物对磷的理论吸附量较大,说明,在上覆水含磷浓度较高的情况下,沉积物仍能吸附大量的磷污染物,在红枫湖水污染较轻的情况下,沉积物中的磷将释放,导致水体富营养化。pH对磷吸附的影响呈倒"U"型,对磷释放的影响呈"U"型,随着pH增大,磷的释放量也增大,这是由OH-交换能力的增强和红枫湖沉积物中可交换的铝/铁磷和钙磷含量较高所致。

The phosphorus sorption and desorption characteristics in the surface sediments（pH 2~12） were imitated in the laboratory to provide a reference for further managing Hongfeng Lake.The results showed that phosphorus in sediments of Hongfeng Lake included organic phosphorus,inorganic phosphorus,aluminum/iron bound phosphorous,calcium bound phosphorus and so on.Fe/Al-P and Ca-P were the two main fractions of P in the surface sediment of the Hongfeng Lake.The theoretical adsorbance was great which indicated that the sorption capacity of sediments of Hongfeng Lake were high,and the Hongfeng Lake sediments would be a source of phosphorus in the future.The pH effect on phosphorus sorption from sediments was reverse U-shaped,so phosphorus desorption from sediments increased with pH increasing,due to displacement of PO3-4adsorbed on sediment surfaces by OH-and the high content exchanged Fe/Al-P and Ca-P of the Hongfeng Lake sediments.