摘要
磷复肥和光伏产业发展排放大量氟硅酸钠生产废水,其中含有较高浓度硅酸盐、氟硅酸和F-,对环境存在潜在危害。为达标排放氟硅酸钠生产废水,进行电化学氧化法预处理研究。基于Box-Behnken设计(BBD)原理构建响应面模型,分析了电功率、极板间距、电流和反应时间对污染物去除效率的影响。极板间距为40 mm,pH为6.5,电流密度为40 mA/cm^(2),反应时间为1.5 h条件下氟硅酸钠废水COD去除率可以达到82.53%,F离子离解浓度达到44.2 mg/L,与模型预测值接近且效果最优。采用FTIR和XPS手段分析了电化学氧化处理前后废水中有机物官能团变化特性,结果显示:原水中C-C、C-OH和C=O类有机物官能团分别占比为79.8%、11.63%和8.54%,电化学处理后占比分别变化为91.3%、7.27%和1.41%,氟硅酸钠废水中的羟基碳和羰基碳类有机物的矿化,且相较C-C类有机物而言去除率更高。SEM分析显示电化学氧化处理后固形物样品的粒径较原样品的粒径变小4μm,分布更为均匀,比表面积增大。本项目研究为氟硅酸钠生产废水电化学氧化处理工艺开发提供指导,为氟硅酸钠废水管理提供借鉴。
The development of phosphatic compound fertilizer and photovoltaic industry discharges a large amount of sodium fluorosilicate wastewater,which contains high concentration of silicate,hexafluoro silicic acid and F ions,and is potentially harmful to the environment.In order to meet the latest strict discharge limitation in GB 31573-2015 for inorganic chemical industry,electrochemical pretreatment of sodium fluorosilicate production wastewater was studied.A response surface methodology was constructed based on the Box Behnken design(BBD)principle to analyze the effects of electrical power,pH,current,and reaction time on pollutant removal efficiency.Under the conditions of plate spacing of 40 mm,pH of 6.5,current density of 40mA/cm^(2),and reaction time of 1.5 h,the COD removal rate of sodium fluorosilicate wastewater can reach 82.53%,and the F ion dissociation concentration can reach 44.2 mg/L,which is close to the predicted value of the model and the effect is optimal.FTIR,XPS were used to analyze the change characteristics of key components before and after electrochemical treatment.The results showed that the proportions of C-C,COH and C=O organics in raw water were 79.8%,11.63%and 8.54%respectively,and the proportions after electrochemical treatment were 91.3%,7.27%and 1.41%respectively,indicating that the mineralization of hydroxyl carbon and carbonyl carbon organics in sodium fluorosilicate wastewater was higher than that of C-C organics.The particle size of the electrochemical sample decreased significantly by 4μm compared to the original sample,resulting in a more uniform distribution and an increase in specific surface area.The research of this project provides guidance for the development of chemical treatment process of sodium fluorosilicate production waste water,and provides reference for sodium fluorosilicate wastewater management.
作者
叶新合
刘军伟
策红军
王锐
YE Xinhe;LIU Junwei;CE Hongjun;WANG Rui(Zhengyang County Environmental Protection Bureau,Zhengyang 463600,China;Luoyang Green EPT Co.,Ltd.,Luoyang 471000,China;Luoyang Institute of Technology,Luoyang 471023,China)
出处
《水处理技术》
CAS
2024年第11期67-73,共7页
Technology of Water Treatment
基金
河南省科技攻关项目(222102320327)。
关键词
电化学氧化
氟硅酸钠废水
预处理
响应曲面法
electrochemical oxidation
sodium fluorosilicate wastewater
pre-treatment
response surface methodology
