纳米TiO2胶体絮凝-光催化氧化-砂滤深度处理造纸废水研究

研究了纳米TiO₂胶体絮凝-光催化氧化-砂滤深度处理造纸废水的效果。分析了絮凝剂的选择和用量、光催化剂用量、光催化时间和外加氧化剂等对废水COD_Cr去除效果的影响；研究证实了样品中残留微量纳米TiO₂胶体对COD_Cr测定的影响，并利用砂滤除去。实验结果表明，以用量为0.01%(相对于废水质量，下同)的纳米TiO₂胶体为絮凝剂对经序列间歇式活性污泥法（SBR）处理后的造纸废水进行处理，在光催化剂用量（质量分数）0.05%，曝气并紫外光照射2 h时，沉降后的上层液体经过砂滤，废水COD_Cr从210 mg/L降到43.0 mg/L。

Advanced Treatment of Paper-making Wastewater Using Nano-TiO2Colloid Coagulation, Photocatalyzed Oxidation and Sand Filtration Processes

In this article, advanced treatment of paper-making wastewater by nano-TiO₂ colloid coagulation, photocatalyzed oxidation and sand filtration was studied. The experimental such as the types and dosage of coagulatants, dosage of photocatalysts, illumination time and external oxidants were investigated. The results indicated that residual nano-TiO₂ which can be removed by sand filtration will affect the determined COD_Cr value. When the wastewater was pretreated by using 0.01% (on wastewater weight) nano-TiO₂ as a coagulatant, then further treated by UV irradiation for 2 hours with using 0.05% nano-TiO₂ as photocatalyst and under aeration, the upper water after sedimentation passed through sand filtration, the COD_Cr of the final effluent decreased from 210 mg/L to 43mg/L.