基于SO_(4)^(·-)的高级氧化技术对低生化性废水的预处理研究

Research on pretreatment of low biochemical wastewater by advanced oxidation technology based on SO_(4)^(·-)

高级氧化法是处理低生化性废水的一种有前途的技术。采用亚铁离子活化过硫酸盐(Fe^(2+)/PS)体系预处理某低生化性制药废水。通过小试研究考察了pH、过硫酸钠、硫酸亚铁和PAC质量浓度对Fe^(2+)/PS体系处理效果的影响及各影响因素的最佳参数。结果表明,pH对Fe^(2+)/PS体系处理效果的影响最大,其次是硫酸亚铁质量浓度和过硫酸盐质量浓度,PAC质量浓度的影响可以忽略不计。综合考虑成本因素,各参数的最佳水平组合:pH≈7、硫酸亚铁、过硫酸钠、PAC质量浓度分别为1.0、0.3、0.03 g/L。通过ESR(电子自旋共振)测试和猝灭试验,确定反应体系中起主要降解作用的活性物种。结果表明,SO_(4)^(·-)活跃于Fe^(2+)/PS反应体系中,并在反应体系中起主要作用。通过中试研究考察了Fe^(2+)/PS反应体系处理前后废水COD、TOC、NH3-N的变化。研究表明,经过处理后的废水,COD去除率为50%,TOC去除率为67%,NH3-N去除率为30%,平均B/C从0.067提升到0.409。基于SO_(4)^(·-)的高级氧化技术是一种很好的低生化性高浓度有机废水预处理方法。

Advanced oxidation process is a promising choice for treating low biochemical wastewater.A low biochemical pharmaceutical wastewater was pretreated by ferrous ion activated persulfate(Fe^(2+)/PS)system.Through the bench scale test,the effects of pH,persulfate,ferrous sulfate and PAC mass concentration on the treatment of Fe^(2+)/PS system and the optimal parameters of each influencing factor were investigated.According to the experimental results,pH had the greatest impact on the treatment effect of the Fe^(2+)/PS system,followed by the mass concentration of ferrous sulfate and persulfate.The influence of PAC mass concentration could be ignored.Considering the cost factor comprehensively,the optimal combination of various parameters was pH≈7,ferrous sulfate,sodium persulfate and PAC mass concentrations of 1.0,0.3 and 0.03 g/L,respectively.The active species playing the main degradation role in the reaction system were identified through ESR(Electron Spin-Resonance Spectroscopy)testing and quenching experiments.The results indicated that SO_(4)^(·-)was active in the Fe^(2+)/PS reaction system and played a major degradation role in the reaction system.Through the pilot scale test,the changes of COD,TOC and NH3-N in wastewater before and after treatment by Fe^(2+)/PS reaction system were investigated.The study showed that the treated wastewater had about 50%COD removal rate,67%TOC removal rate,30%NH3-N removal rate,and the average B/C value increased from 0.067 to 0.409.The results showed that advanced oxidation technology based on SO_(4)^(·-)was a good pretreatment method for wastewater with low biochemical property and high organic concentration.