磷石膏制备超微细硫酸钙晶须的除磷特性研究  

Study on phosphorus removal characteristics of ultrafine calcium sulfate whiskers prepared from phosphogypsum

作　　者：吕晴[1,2] 秦军 刘江[1] 邱学剑 杨靖[1] 陈梦瑜 LU Qing;QIN Jun;LIU Jiang;QIU Xue-jian;YANG Jing;CHEN Meng-yu(Key Laboratory of Karst Environment and Geohazard of Ministry of Natural Resources,Guizhou University,Guiyang 550025,China;College of Resource and Environmental Engineering,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学,自然资源部喀斯特环境与地质灾害重点实验室,贵州贵阳550025 [2]贵州大学资源与环境工程学院,贵州贵阳550025

出　　处：《应用化工》2020年第8期2018-2023,2044,共7页Applied Chemical Industry

基　　金：国家自然科学基金项目(21266005,51763002);贵州省科技厅联合基金项目(黔科合LH字[2014]7648)。

摘　　要：以磷石膏为原料,采用水热合成法经放大实验制备出超微细硫酸钙晶须(PUCSW),在研究PUCSW对废水中磷的吸附特性的基础上,结合FTIR、SEM、XRD和EDS等手段分析吸附前后PUCSW的结构和表面形貌,探讨吸附除磷机理。结果表明,碱性条件有利于PUCSW除磷,在pH=12时,PUCSW对磷的去除率达到最高,为100%;PUCSW对废水中磷的吸附符合准二级动力学方程,Langmuir模型能很好地描述磷在PUCSW上的吸附行为,理论饱和吸附量为117.6 mg/g,与实验测试值116.7 mg/g基本一致;制备的PUCSW含有结晶水,主要成分为半水硫酸钙,且结晶性良好,平均直径0.42μm,长径比45.17;PUCSW对废水中磷的吸附机理包括物理吸附和化学吸附,并以生成羟基磷酸钙沉淀和羟基配位交换的化学吸附为主。Ultrafine calcium sulfate whiskers were prepared from phosphogypsum(PUCSW)by enlarging hydrothermal synthesis method.On the basis of studying PUCSW adsorption characteristics of phosphorus in wastewater,the structures and surface morphology of PUCSW before and after adsorption were analyzed by FTIR,SEM,XRD and EDS,and the phosphorus-removal mechanism of PUCSW was discussed.The results showed that alkaline conditions were beneficial to phosphorus removal by PUCSW.At pH=12,the phosphorus-removal rate of PUCSW reaches 100%.The phosphorus-adsorption of PUCSW in wastewater conformed to quasi-second-order kinetics equation.The Langmuir model can well describe the adsorption behavior of phosphorus on PUCSW.The theoretical saturated adsorption capacity of phosphorus was 117.6 mg/g.The main component of PUCSW was calcium sulfate hemihydrate,which contained crystalline water and had good crystallinity with an average diameter of 0.42μm and a length-diameter ratio of 45.17.The phosphorus-adsorption mechanism of PUCSW included physical adsorption and chemical adsorption,and was mainly based on the chemical adsorption of calcium hydroxyphosphate precipitation and hydroxyl coordination exchange.

关 键 词：磷石膏 超微细硫酸钙晶须 除磷 吸附机理 

分 类 号：TQ126.3[化学工程—无机化工] TQ424.2