湖泊沉积物对N和P的吸附特性及影响因素研究

Adsorptive Characteristic of Nutrient Elements and Influential Factors in Taihu Lake Sediment

以太湖沉积物为悬浮颗粒物(SPM)材料,进行了SPM对磷酸盐(PO_4-P)、氨氮(NH_4-N)、硝酸盐氮(NO_3-N)的吸附特性及其影响因素的试验研究。结果显示,SPM对PO_4-P和NH_4-N的吸附分别在5h和2h达到稳态,之后基本处于一种动态平衡。SPM对NO_3-N的吸附量很小甚至出现负吸附。pH对SPM吸磷作用影响显著,随着pH值的上升吸附量下降。盐度、[NO_3^-]和[NH_4^-]对PO-P的吸附有抑制作用,而犤Ca^(2+)犦对PO-P的吸附影响分为2部分,在低浓度下抑制,在高浓度下有促进;[Ca^(2+)]和盐度对NH_4-N的吸附都有抑制作用。

Adsorptive characteristic of phosphate (PO4- P), nitrate (NO3- N), ammonia( NH4- N) on suspended particular matter( SPM) of sediment in Taihu Lake were analyzed in laboratory. The results indicated that process of sorption of both PO4- P and NH4- N on SPM mainly occurred within 0～ 5 and 0～ 2 hours, respectively, and then reached a dynamic equilibrium. The sorption of NO3- N was either little or negative sorption occurred at the certain points on SPM. pH values had great influences on the sorption of P, with the sorption ability declining gradually as the increasing pH values. High initial salinity and concentration of restrained the P- sorption. The influence of Ca2+ on P- sorption may be divided into two patterns: restraining at low concentration and promoting at high concentration. Elevated salinity and Ca2+ restrained NH4- N sorption.