PAC四级逆流吸附/微滤组合工艺处理二级出水

Treatment of Secondary Effluent by Combined Process of PAC Four-stage Countercurrent Adsorption and Microfiltration

研究了粉末活性炭(PAC)对城镇污水处理厂二级出水中有机物的吸附特性,分别以DOC和UV254表征的有机物均较好地符合Langmuir吸附等温式,60 min基本可达到吸附平衡。基于Langmuir吸附等温式,提出了PAC四级逆流吸附/微滤组合工艺处理二级出水中有机物的计算方法,可用于预测PAC投量以及处理出水中的有机物浓度。验证试验表明,当DOC去除率为50%时,组合工艺出水DOC和UV_(254)浓度的计算值和实测值的相对误差分别为1.7%和4.9%。另外,PAC四级逆流吸附/微滤组合工艺可节约一定量的PAC,当DOC去除率为50%时,四级逆流吸附所需的PAC投量分别为二级逆流吸附和单级吸附的89.4%和68.3%。

The jar test was conducted to study the adsorption behavior of powdered activated carbon （PAC） on organics in the secondary effluent from a municipal wastewater treatment plant. The ad- sorption process characterized by DOC or UV254 fitted well with Langmuir adsorption isotherm, with approximate 60 min for equilibrium. Based on Langmuir adsorption isotherm, the calculation method of the combined process of PAC four-stage countercurrent adsorption and microfiltration for removing organics in the secondary effluent was put forward, and it could be used to predict the dosage of PAC and the concentration of organics in treated effluent. The validation results indicated that when the removal rate of DOC was 50%, the relative errors of calculated and measured values of DOC and UV254 in the effluent were 1.7% and 4.9%, respectively. Additionally, the dosage of PAC could be saved for the treatment of secondary effluent. When the removal rate of DOC was 50%, the dosage of PAC demanded by four-stage countercurrent adsorption was 89.4% and 68.3 % of second-stage countercurrent adsorption and singlestage adsorption, respectively.