溶解氧对催化铁内电解法预处理混合废水的影响

INFLUENCE OF DISSOLVED OXYGEN ON THE PRETREATMENT OF MIXED WASTEWATER BY CATALYZED IRON INTERNAL ELECTROLYSIS PROCESS

采用内循环、微曝气和强曝气催化铁内电解法处理难降解混合废水,中试结果表明,在缺氧(DO<0.4mg/L)和微氧(DO≈1.2mg/L)条件下,混合废水经催化铁预处理后其BOD5/COD值从0.13和0.12分别提高到0.32和0.28,平均TP去除率分别达到29.3%和36.1%,而且出水铁离子浓度在15～30mg/L范围内,可有效提高后续活性污泥浓度,改善污泥稳定性、以及混合液分离效果。在好氧(DO>4.5mg/L)条件下,催化铁内电解法对混合废水可起到强化混凝作用,其对COD和TP的平均去除率高达37.5%和65.9%,但铁铜滤料消耗大,强度变差,而且出水铁离子浓度达100mg/L之多,对生物处理工艺产生不利影响。

Internal reflux, micro-aeration and macro-aeration catalyzed iron internal electrolysis （CIIE） processes were used for pretreatment of diffi- cult-to-degrade mixed wastewater. The pilotscale test results showedthat ratio of BOD5/CODcr increased respectively from 0.13 and 0.12 to 0.32 and 0.28 atter the pretreatment of the mixed wastewater by the CIIE process under the conditions of anoxic （DO〈0.4mg/L） and micro-oxygen （DO=1.2mg/L）, and the average removal rate of TP came up to 29.3% and 36.1% respectively, moreover, the total Fe content in the effluent of CIIE process is in the range of 15-30mg/L, which enhanced the activated sludge concentration in the subsequent biological treatment process, improved the sludge sta- bility and the separation effect of mixture. Under aerobic condition of DO〉4.5mg/L, the CIIE process could serve enhanced coagulation for the mixed wastewater, so that the average removal rate of COD and TP came up to 37.5% the Fe/cu fillings had greater consumption, and its strength got poor, moreover, the concentration of iron ions in the effluent was ashigh as 100mg/L, having adverse influence on biological treatment process.