方解石粉钝化太湖水中磷的能力及影响因素

Capacity and factors affecting phosphorus immobilization in Taihu Lake by calcite powder

利用轻质、重质和纳米方解石粉进行了去除太湖水中磷的实验研究,单位重量方解石粉除磷量与溶液中磷浓度正相关,轻质和重质方解石粉除磷规律符合Langmuir吸附等温式,极限除磷量分别为0.387 mg/g和0.351 mg/g,纳米方解石粉除磷规律符合Freundlich吸附等温式。方解石粉BET比表面积是影响方解石粉除磷能力的主要因素,可作为衡量方解石粉除磷能力的指标。当碱度在6 mmol/L以内变化时,对方解石粉除磷能力影响很小,当碱度大于6 mmol/L时,方解石粉除磷能力下降。增加原水Ca2+离子浓度和pH值能提高方解石粉除磷能力。

Light-weight,heavy-weight and nano-calcite powder were used to remove phosphorus from Taihu Lake water in lab.The quantity of phosphorus removed by unit calcite powder was positively related to the phosphorus concentration in water.The capacity of light-weight and heavy-weight calcite powder to remove phosphorus fits Langmuir adsorption equation and the maximal capacity is 0.387 mg/g and 0.351 mg/g,respectively.The capacity of nano-calcite powder to remove phosphorus fits Freundlich adsorption equation.The BET specific surface area is the dominating factor affecting calcite powder to remove phosphorus,and can be used as an indicator measuring the capacity of calcite powder to remove phosphorus.Alkalinity has little effect on calcite powder to remove phosphorus when alkalinity is less than 6 mmol/L,while the capacity of calcite powder to remove phosphorus decrease when alkalinity is more than 6 mmol/L.The capacity of calcite powder to remove phosphorus increases with the increasing in pH and Ca2＋ concentrtion.