【摘要】 以Bi（NO₃）₃·5H₂O和Na₂WO₃·2H₂O为原料,EDTA为络合剂,辅助水热法合成Bi₂WO₆光催化剂,采用X射线衍射（XRD）、扫描电镜（SEM）、拉曼光谱（Raman）、紫外—可见漫反射光谱（DRS）等测试手段对产品进行表征。同时,在Bi₂WO₆光催化降解制革废水反应中考察了催化剂投加量、空气通入量、溶液pH值、双氧水用量及光照强度对制革废水COD_cr去除率的影响。结果表明,Bi₂WO₆光催化剂的结晶度良好,具有Bi₂WO₆特征峰,为规则方形花状Bi₂WO₆,其带隙能为2.696eV。Bi₂WO₆能有效降解制革废水中的有机物质,废水的COD_cr去除率显著提高。通过正交实验确定了降解制革废水最佳工艺条件为:Bi₂WO₆光催化剂的投加量为2.0g/L,自然pH值,体积分数2%H₂O₂,空气通入量为中档,灯液光照距离为11cm,可见光照射3.0h。该条件下,制革废水的脱色率和COD_cr去除率分别达到91.5%和92.6%,达到了国家相关排放标准。Bi₂WO₆晶体的可见光催化降解制革废水过程符合一级反应速率动力学方程。更多还原

【Abstract】 Using Bi（NO₃）₃ ·5H₂O and Na₂WO₃ ·2H₂O as raw materials,Bi₂WO₆ was successfully synthesized by hydrothermal method with ethylenediamine tetraacetic acid（EDTA）as the chelating agent.The properties of the as-prepared samples were investigated by XRD,SEM,Raman and UV-vis DRS tests.The as-prepared products were used to photodegrade tannery wastewater.The effects of dosage of Bi₂WO₆ photocatalyst,air flow rate,pH of wastewater,H₂O₂ dosage and the illumination intensity on the wastewater degradation were investigated in detail.The results showed that highly crystallinity square flower-like Bi₂WO₆ with its band gap of 2.696 eV could be obtained via a hydrothermal route assisted by EDTA.The Bi₂WO₆ could effectively degrade the hardly-degraded organic pollutants,and the COD_crremoval rate increased significantly.The optimum conditions of treatment of tannery wastewater were natural pH value,Bi₂WO₆ of 2g/L,H₂O₂ of 2%,amount of air of mid-range,distance of light liquid light of 11 cm,reaction time of 3.0 h.Under the optimal conditions,the decolorization rate and COD_crremoval rate were 91.5% and 92.6%.The dynamic behavior of Bi₂WO₆ photocatalyst degrading the molasses fermentation wastewater agrees with the firstorder rate dynamic equation.更多还原