给水厂污泥制备高强度磷吸附剂研究

Preparation of high strength phosphorus adsorbent by water treatment residual

给水厂污泥对水体中的磷有良好的吸附作用,但其颗粒强度差,在水中易松散解体。为制备强度高,吸附容量大的吸附剂,以给水厂污泥为原料,添加硅酸盐水泥、生石灰和石膏,采用免烧法制备高强度颗粒状磷吸附剂,探究制备条件对吸附剂强度和吸附性能的影响。结果表明,随着pH增加,吸附剂对磷的吸附量先升后降,在pH值为5.0时,对磷的吸附量最大。磷在固相和液相之间的平衡分配符合Freundlich等温吸附模型,吸附剂表面的吸附位点分布是不均匀的,对磷的吸附介于单层与双层吸附之间。

Water treatment residual has good adsorption potential on phosphorus in water solution,but it is poor in strength and tends to disintegrate in water.In order to prepare strong adsorbent with high adsorption capacity,a method of preparing high strength granular phosphorus adsorbent by no-burn was investigated using water treatment residual as raw material with silicate cement,quicklime and gypsum.The preparation conditions of the adsorbent were determined by experiment,then the compressive strength and adsorption properties of the adsorbent were tested.The phosphorus adsorption capacity increased and then drcreased with pH increasing,the maximum adsorption capacity occurring at pH 5.0.The equilibrium partitioning of phosphate between the solid and liquid phases fitted the Freundlich adsorption isotherm,the distribution of adsorption sites on the adsorbent surface is heterogeneous and the adsorption of phosphorus possesses the pattern of monolayer and bilayer adsorption.