在室内模拟扰动条件下,研究了桑沟湾养殖水域表层沉积物对磷酸盐的吸附动力学及其吸附等温线,探讨了磷酸盐的吸附-解吸平衡质量浓度以及沉积物的源汇角色.结果表明,沉积物对磷酸盐的吸附主要发生在0--0.5 h,吸附平衡时间约为6h,吸附动力学方程符合修正的Elovich模型,回归方程为:Q=85.536+35.512 lnt(R^2=0.960 2);低浓度条件下沉积物对磷酸盐的吸附等温线呈线性,线性方程为:Q=265.04ce-7.46(R^2=0.965),高浓度条件下沉积物对磷酸盐的吸附等温线符合Langmuir模型(R^2=0.989);沉积物中本底吸附态磷为7.46μg/g,对磷的最大吸附量Qmax为769.23μg/g;沉积物对磷酸盐的吸附-解吸平衡质量浓度EPC0为0.028 mg/L,结合该区域水体磷酸盐含量情况,初步推断该区域的沉积物大多数时间充当的是磷源的角色.
Phosphate adsorption characteristics onto surface sediments from aquaculture area in Sungo bay were studied in laboratory simulating condition, and phosphate adsorption-desorption equilibrium mass concentration was also analyzed. The results showed that the process of phosphate adsorption onto sediments mainly occurred within 0.5 h, and attended to dynamic equilibrium after 6 h. Adsorption kinetics were fitted to modified Elovich model which can be expressed by Q = 85.536 + 35.512 lnt (R2 = 0.9602). Under low initial phosphate concentration condition, the adsorption isotherm curves were fitted to linear equation Q = 265.04 Ce- 7.46 ( R^2E = 0. 965 ), while under high initial phosphate concentration condition, the adsorption isotherm curves were fitted to Langmuir equation (R^2 = 0.989). The native adsorbed phosphorus was 7.46μg/g and the maximum adsorption capacity was 769.23 μg/g. The phosphate adsorption-desorption equilibrium mass concentration was 0.028 mg/L, which indicated that the sediments played the source role in most time in this area based on the phosphate concentration in water body.