改性方解石的除磷能力研究

Study on the capacity of modified particles calcite for phosphorus removal

选用颗粒方解石,对其表面进行改性,便于磷在其表面的吸附、结晶、沉淀,形成永久性固态磷,加速磷的自然沉淀过程。考察了改性的最佳条件和改性方解石除磷的影响因素。结果表明,方解石的最佳改性条件:改性液TP、Ca2+、HCO-3分别为93.00、120.00、244.00 mg/L,浸泡时间2d;改性方解石具有持续的除磷能力,在实验前76h的平均除磷速率为0.053 0mg/(g·d),而稳定阶段的除磷速率为0.021 4mg/(g·d);待处理水样的Ca2+浓度对改性方解石的除磷效果有较大影响,Ca2+为120.00mg/L时除磷效果最好,碱度对除磷效果的影响很小;pH≤7.30,投加改性方解石系统中磷的去除以改性方解石表面Ca-P结晶为主,而当pH≥8.15时,溶液中发生Ca-P沉淀,而Ca-P结晶逐步减少;水温对改性方解石的除磷效果具有显著影响。

In order to improve the capacity of particles calcite for phosphorus removal,the particles calcite was modified by soaking in high concentrate phosphorus and calcium solution.The modification process was benefit to the adsorption,crystallization and precipitation of phosphorus on calcite,and could accelerate the natural precipitation of phosphorus in the solution.The optimum conditions for calcite modification as well as the influencing factors of phosphorus removal were investigated.Results showed that the optimum modification conditions were TP,Ca^2＋,HCO3^-concentrations f 93.00,120.00,244.00mg/L,immersion time of 2days.The modified calcite had sustainable phosphorus removal capacity,the average phosphorus removal rate for first 76 hwas 0.053 0mg/（g·d）,and the stable phosphorus removal capacity was 0.021 4mg/（g·d）.Ca^2＋had relative high influence on phosphorus removal,while the influence of alkalinity was small.When the solution pH was less than 7.30,phosphorus was mainly removed by Ca-P crystallization on the surface of modified calcite,when the solution pH≥8.15,the crystallization of Ca-P was gradually reduced,and most of phosphorus was removed by precipitation with Ca.Water temperature had significant effect on phosphorus removal by modified calcite.