类镁铝水滑石吸附水中磷的机制研究  

Study on the Mechanism of Phosphorus Adsorption from Water by Magnesium-Like Aluminum Hydrotalcite

作　　者：陈超 CHEN Chao(Shanghai Electromechanical Design and Research Institute Co.Ltd.,Shanghai 200000,China)

机构地区：[1]上海市机电设计研究院有限公司,上海200000

出　　处：《工程建设与设计》2023年第12期94-97,共4页Construction & Design for Engineering

摘　　要：城镇生活污水经传统二级处理后,其出水中磷浓度难以达到GB18918—2002《城镇污水处理厂污染物排放标准》中规定的一级A标准,本研究以处理污水处理厂二级出水中磷为目的,研究考察了制备的镁铝水滑石对溶液中磷酸根的吸附效果,使用准一级、准二级、Elovich动力学方程对其吸附过程进行模拟。结果表明,Mg∶Al=3∶1的水滑石材料吸附效率和吸附量都要高于其他材料,对磷的去除率在95%以上,其吸附动力学符合准二级吸附动力学方程。两种文石型碳酸钙吸附效率略低于镁铝水滑石,也符合二级吸附动力学方程。镁铝铁三元水滑石吸附效率最低,符合一级动力学方程。之后讨论了Mg-Al水滑石对磷酸根的吸附方式主要有表面静电吸附、配位络合、阴离子交换等。以污水处理厂二级出水为实验对象的研究表明,溶液中的磷酸根浓度在1 min左右已经降到了检出限(0.01mg/L)以下。综合分析,Mg-Al水滑石对磷酸根吸附量大、吸附速率高,在污水深度除磷领域有较好的应用前景。After traditional secondary treatment of urban domestic sewage,the phosphorus concentration in the effluent is difficult to reach the first level A standard specified in the GB 18918-2002 Pollutant Discharge Standard for Urban Sewage Treatment Plants.This study aims to treat phosphorus in the secondary effluent of sewage treatment plants and investigates the adsorption effect of prepared magnesium aluminum hydrotalcite on phosphate ions in solution.The adsorption process is simulated using quasi first,quasi second,and Elovich kinetic equations.The results show that the adsorption efficiency and amount of Mg:Al=3:1 hydrotalcite material are higher than other materials,and the phosphorus removal rate is above 95%.Its adsorption kinetics comply with the quasi second-order adsorption kinetics equation.The adsorption efficiency of two types of aragonite type calcium carbonate is slightly lower than that of magnesium aluminum hydrotalcite,which also conforms to the second-order adsorption kinetics equation.The adsorption efficiency of magnesium aluminum iron ternary hydrotalcite is the lowest,which conforms to the first order kinetic equation.Afterwards,it was discussed that the adsorption methods of Mg-Al hydrotalcite for phosphate ions mainly include surface electrostatic adsorption,coordination complexation,anion exchange,etc.The study using the secondary effluent ofa sewage treatment plant as the experimental object shows that the concentration of phosphate ions in the solution has dropped below the detection limit(0.01 mg/L)within about 1 minute.Overall analysis shows that Mg-Al hydrotalcite has a large adsorption capacity and high adsorption rate for phosphate ions,and has good application prospects in the field ofdeep phosphorus removal of wastewater.

关 键 词：MG-AL水滑石 吸附 磷酸根 

分 类 号：X52[环境科学与工程—环境工程]