氧化剂强化光催化处理焦化废水研究

焦化废水污染物浓度高、生化降解难,利用纳米TiO2粉体,以紫外光(UV)为光源,进行了光催化处理焦化废水的试验研究,考察了TiO2用量、紫外光强度、焦化废水初始pH对COD和NH+4-N去除的影响;探讨了O2、O3、H2O2和Fenton试剂4种氧化剂与光催化的协同作用机理,分析了对COD和NH+4-N去除效果的影响,得出了最佳试验条件.结果表明,氧化剂与光催化协同作用使COD和NH+4-N的降解去除率得到了显著提高.在本试验条件下各氧化剂强化光催化对COD和NH+4-N去除率排序如下:TiO2+UV+Fenton＞TiO2+UV+O3＞TiO2+UV+H2O2＞TiO2+UV+O2＞TiO2+UV.

STUDY ON PHOTO-CATALYTIC TREATMENT OF COKING WASTEWATER WITH SEVERAL OXIDANTS

Coking wastewater has a lot of organic pollutants, and is hard to be biologically degraded. Photo-catalytic treatment of coking wastewater was examined by nanometer TiO_2under ultraviolet(UV). Effect of amount of TiO_2, irradiation intensity, initial pH value of coking wastewater on removal rates of COD and NH_4~+-N was investigated. The synergistic mechanisms of photo-catalysis with O_2, O_3, H_2O_2 or Fenton reagent were discussed. Effect on removal of COD and NH_4~+-N was analyzed, and the optimal conditions were obtained. Experimental results show that the removal rates of COD and NH_4~+-N greatly increased by photo-catalysis combined with oxidant. Under the experiment conditions, the order of removal rates of COD and NH_4~+-N by photo-catalysis with oxidant was:TiO_2+UV+Fenton>TiO_2+UV+O_3>TiO_2+UV+H_2O_2>TiO_2+UV+O_2>TiO_2+UV.