内循环BAF在高浓度含甲醛废水预处理中的应用研究

高浓度含甲醛废水环境危害性强,治理难度大。采用一种新型生物法水处理工艺—内循环BAF应用于高浓度含甲醛废水预处理研究中,考察了水力停留时间和甲醛浓度对处理效果的影响。研究结果发现:当HRT=10 h,循环比在30～40时,废水中甲醛含量由500mg/L提高到2 000 mg/L时,系统生化处理效果并未明显降低,甲醛的降解率达到90%～98%,COD降解率在90%以上,出水中甲醛的浓度维持在120 mg/L以下,很好地达到了预处理的目的。

APPLICATION RESEARCH ON THE PRETREATMENT OF HIGH CONCENTRATION FORMALDEHYDE-CONTAINING WASTEWATER BY INTERNAL CIRCULATION BIOLOGICAL AERATED FILTER

High concentration formaldehyde-containing wastewater,which is characterized by its great harm to environment,is difficult to treat.This paper introduces a new biological water treatment process called internal circulation biological aerated filter which is applied to the pretreatment of high concentration formaldehyde-containing wastewater.And it studies the impact of hydraulic retention time and formaldehyde content on treatment effect.The results show that under the conditions of HRT 10 h and circulation ratio 30—40,the formaldehyde content in wastewater increases from 500 mg/L to 2 000 mg/L.The biological treatment efficiency does not decrease significantly.The degradation rates of formaldehyde and COD are high up to 90—98% and 90% respectively and the formaldehyde content in effluent remains below 120mg/L,which achieves the goal of wastewater pretreatment well.