MIEX和PAC对微污染水源水的水质净化效果比较

摘要

研究了MIEX和PAC两种水处理吸附剂对微污染水源水的水质净化性能。实验分别考察了MIEX和PAC对DOC和UV254的去除效率，并通过凝胶渗透色谱和三维荧光光谱分析，研究了MIEX和PAC对不同相对分子质量区间以及不同种类有机物的去除规律。在正常的吸附剂投加量下（MIEX=5～8 ml·L−1，PAC=30～50 mg·L−1），MIEX对DOC和UV254的平均去除率比PAC高23%和20%。但随着吸附剂投加量的增加，两者去除效率差别逐渐减小，MIEX对DOC和UV254的最大去除率仅比PAC高6%～8%。与PAC相比，MIEX去除的有机物相对分子质量分布范围更广，特别是对中等分子量（5000～50000）有机物，其去效率明显高于PAC。MIEX对腐殖酸和富里酸类有机物的去除率略高于PAC，而对蛋白质类有机物的去除率则远高于PAC。动力学分析表明， MIEX和PAC对DOC的吸附去除过程符合准二级动力学，MIEX对有机物的吸附速率是PAC的40倍左右。%Purification performance on micropolluted source water by magnetic ion exchange resin (MIEX) and powder activated carbon (PAC) was studied in this paper. Removal efficiencies of DOC and UV254 by MIEX and PAC were compared, respectively. The effluents of MIEX and PAC treatment were analyzed through gel permeation chromatography (GPC) and three-dimensional fluorescence spectroscopy (3DEEM). The removal characteristics of organic pollutants with different relative molecular weights and composition were discussed. The results showed that under the normal dosages of the both absorbents (where MIEX was 5—8 ml·L−1 and PAC was 30—50 mg·L−1), the average removal efficiencies of DOC and UV254 by MIEX treatment were 23% and 20% higher than that by PAC treatment, respectively. However, with increasing absorbent dosages, the maximum removals of DOC and UV254 for MIEX were only 6%—8% higher than that for PAC. Compared with PAC treatment, organic pollutants with wider range of relative molecular weight distribution was removed by MIEX treatment. In the range of 5000—50000, MIEX had a more excellent removal performance than PAC. On the other hand, a slightly higher removal of humic acid and fulvic acid was obtained for MIEX than PAC, but the removal of protein by MIEX was significantly higher than that by PAC. Kinetic analysis suggested that the adsorption process of both MIEX and PAC fitted the pseudo-second-order model, and the adsorption rate of MIEX was about 40 times higher than PAC.