多羧酸改良硫代光-Fenton处理有机染料废水

Degradation of organic dye wastewater using polycarboxylic acid modified SR-Photo-Fenton

使用EDDS(乙二胺二琥珀酸)螯合Fe(Ⅲ),在光照过程中活化过硫酸盐/亚硫酸盐产生硫酸根自由基,并用于处理水体中的染料橙黄Ⅱ,考察过硫酸盐/亚硫酸盐初始浓度,Fe(Ⅲ)-EDDS初始浓度以及溶液初始pH对橙黄Ⅱ降解效果的影响,并获得处理效果较好的优化体系。结果表明,Na_2SO_3-Fe(Ⅲ)-EDDS体系中,[Na_2SO_3]=5 mmol·L^(-1),[Fe(Ⅲ)-EDDS]=0.05 mmol·L^(-1),pH=3.0时,60 min内橙黄Ⅱ降解效率达98%;Na_2S_2O_8-Fe(Ⅲ)-EDDS体系中,[Na_2S_2O_8]=10 mmol·L^(-1),[Fe(Ⅲ)-EDDS]=0.50 mmol·L^(-1),pH=7.0时,120 min内橙黄Ⅱ降解效率达99%。两个体系中,Fe(Ⅲ)-EDDS均存在最佳浓度,增大或减小均导致效率降低。Na_2SO_3-Fe(Ⅲ)-EDDS体系中,溶液初始pH越大,橙黄Ⅱ降解效率越低。Na_2S_2O_8-Fe(Ⅲ)-EDDS体系中,pH高于或低于7.0时橙黄Ⅱ降解效率均降低。Na_2SO_3-Fe(Ⅲ)-EDDS体系中,亚硫酸钠浓度越大橙黄Ⅱ降解效率越高。Na_2S_2O_8-Fe(Ⅲ)-EDDS体系中,过硫酸钠存在最佳浓度,增大或减小均导致降解效率降低。

This study was designed to investigate the degradation performance of acid orange Ⅱ in a persulfate or sulfite modified photo-Fenton system using EDDS （N,N＇-ethylenediamine disuccinic acid） as the complexing agent of Fe（ Ⅲ ）. The effects of initial pH ,and the concentration of persulfate or sulfite and Fe（ Ⅲ ） -EDDS,were investigated and the optimal system for acid orange Ⅱ degradation was obtained. According to the results,under the conditions of 5 mmol · L^-1 Na2SO3 and 0.05 mmol · L^-1 Fe（ Ⅲ ）-EDDS in a Na2SO3-Fe（ Ⅲ ）-EDDS sys- tem,the removal efficiency of acid orange Ⅱ reached 98% at pH 3.0 after 60 min of degradation. While in the Na2S2Os-Fe（ Ⅲ ）-EDDS system,under the conditions of 10 mmol · L^-1 Na2S20s and 0.50 mmol · L^-1 Fe（Ⅲ ） - EDDS,acid orange Ⅱ removal efficiency was 99% at pH 7.0 after 120 min of degradation. It was observed that there is an optimum concentration of Fe（ Ⅲ ）-EDDS for orange Ⅱ degradation in both systems. The degradation rate of acid orangeⅡ declined with increase in the initial pH in the Na2SO3-Fe （ Ⅲ）-EDDS system. For the Na2S2O8-Fe（ Ⅲ）-EDDS system,the degradation rate of orange Ⅱ decreased when the pH was higher or lower than 7.0. In the Na2SO3-Fe（ Ⅲ ）-EDDS system,the degradation rate of acid orange Ⅱ increased with increase in the concentration of Na2SO3 ,and in the Na2S2O8-Fe（ Ⅱ ）-EDDS system,it had an optimum pH. Either increase or decrease of the concentration led to decrease of the degradation efficiency.