长江中下游浅水湖泊沉积物对磷的吸附特征

研究了长江中下游浅水湖泊1 1个沉积物对磷的吸附等温线及其吸附动力学,并分析了沉积物理化特征对磷吸附特征的影响,研究发现:①沉积物对磷酸盐的吸附主要在前1 0h内完成,在0.5h内吸附反应十分迅速,并逐渐达到吸附平衡;②沉积物本底吸附态磷与其有机质、CEC、总磷、无机磷、有机磷、Fe/Al 磷和总氮显著正相关;对磷酸盐的最大吸附量与其CEC和无机磷、有机质和总磷呈显著负相关;而总最大吸附磷量与其有机质、CEC、总磷、无机磷、有机磷、Fe/Al 磷和总氮含量呈显著正相关;③就目前长江中下游浅水湖泊的水质而言,其沉积物存在解析;沉积物对磷酸盐的吸附 解吸平衡浓度与其有机质,CEC ,总氮,总磷以及各形态磷含量均有显著的正相关关系.本研究条件下,即使是污染较为严重的湖泊,其沉积物也具有向上覆水体释磷酸盐的趋势.

Phosphate Adsorption Characteristics onto the Sediments from Shallow Lakes in the Middle and Lower Reaches of the Yangtze River

Adsorption isotherms and kinetics of phosphate onto the 11 sediments taken from shallow lakes in the middle and lower reaches of the Yangtze River were determined in laboratory, and the effect of physical and chemical properties of the sediments on its phosphate adsorption characteristics was also analyzed. The results indicate that: (1) The process of phosphate adsorption onto sediments mainly occurred within 0-10 h, the maximum adsorption rates occurred within 0-0.5 h, and then attends to a dynamic equilibrium; (2) Between the NAP and its organic matter, CEC, total phosphorus, inorganic phosphorus, organic phosphorus, Fe/Al-phosphorus and total nitrogen have remarkable positive correlation; between the maximum adsorption of phosphate and its CEC, inorganic phosphorus, organic matter and total phosphorus have remarkable negative correlation; between the total maximum adsorption of phosphate and its organic matter, CEC, total phosphorus, inorganic phosphorus, organic phosphorus, Fe/Al-phosphorus and total nitrogen have remarkable positive correlation; (3) As regards water quality of the shallow lakes in the middle and lower reaches of the Yangtze River at present, its sediment exists desorption. Between the adsorption-desorption equilibrium concentrations of phosphate onto the sediments and its organic matter, CEC, total nitrogen, the total phosphorus and the content of every form phosphorous have a remarkable positive correlation. Even the sediment from heavily polluted lake also has the tendency to release phosphate into the overlying water in this study.