石灰铝盐沉淀法去除稻瘟灵废水中氯离子的研究

Research on the Removal of Chloride Ion from Isoprothiolane Wastewater by Lime Aluminum Salt Precipitation Method

采用石灰铝盐沉淀法处理稻瘟灵生产废水,生成钙铝氯沉淀物以达到去除氯离子的效果。通过单因素实验研究了pH值、反应时间、反应温度、转速、药品配比及加药方式等试验条件对氯离子去除效果的影响,确定主要影响因素和较佳反应条件。选取单因素试验得到的对氯离子去除率影响较大三个主要因素(反应时间、药品配比和转速)做三因素正交实验。通过三因素三水平正交实验分析,确定了药品配比是显著影响因素,并得到去除率稻瘟灵废水中氯离子的最优工艺条件:反应时间为2.5 h,n[Cl^-]∶n[Al^(3+)]∶n[Ca^(2+)]=1∶3∶6,转速400 r/min,在此条件下,氯离子去除率为80.95%。对反应生成的沉淀物采用扫描电镜(SEM)和X射线衍射(XOD)进行形貌和结构分析,结果表明,反应生成的沉淀产物为弗氏盐,具有层状结构,主要成分为Ca_4Al_2Cl_2(OH)_(12),沉淀物结晶度高、粒度较大。

The wastewater from isoprothiolane production is treated by lime aluminum salt precipitation method to produce calcium aluminum chloride precipitate to remove chloride ion.The effects of pH value,reaction time,temperature,rotation speed,drug ratio and dosing method on the removal efficiency of chloride ion are studied by single factor experiment,and the main influencing factors and better reaction conditions are determined.Three main factors(reaction time,drug ratio and rotational speed)are selected to do the orthogonal experiment.Through three factors and three levels of orthogonal experimental analysis,it is determined that the ratio of drugs is a significant factor,and the optimal technological conditions for the removal rate of chloride ion in the isoprothiolane wastewater are obtained:the reaction time is 2.5h,n[Cl-]∶n[Al 3+]∶n[Ca 2+]=1∶3∶6,and the rotational speed is 400 r/min.Under these conditions,the removal rate of chloride ion is 80.95%.SEM and XOD are used to analyze the morphology and structure of the precipitate.The results show that the precipitate is Freund's salt with layered structure,and the main component is Ca 4Al 2Cl 2(OH)12.The precipitate has high crystallinity and large particle size.