电解催化氧化法处理毒死蜱废水的研究

Study on electrochemical enhanced catalytic oxidation reaction for chlorpyrifos production wastewater treatment

采用电解氧化和Fenton技术耦合的电解催化氧化法对毒死蜱废水进行处理,考察了该法对毒死蜱废水的处理效果和出水的生化性能。结果表明:采用H_2O_2溶液用量逐步增加的方式,经过420 min电解催化氧化反应,废水CODCr仅由初始的7 920 mg/L降至5 880 mg/L,反映出毒死蜱废水的难降解特性。电解氧化单独处理毒死蜱废水时,在初始20 min内CODCr迅速下降,削减量为1 892 mg/L,随后CODCr变化不大;反应至80 min时,随着Fenton氧化反应的加入,废水CODCr开始逐步下降,有机物得到进一步降解。结合电解催化氧化出水的可生物降解CODCr(BCODCr)和废水处理要求(生化出水预期CODCr为500~600 mg/L,满足DB 33/923—2014《生物制药工业污染物排放标准》排放限值),将其分别稀释3和4倍后进行好氧生化试验,反应动力学常数分别为383.4和298.3 min-1,该好氧生化反应过程可能更多受浓度控制而非毒性抑制。电解催化氧化出水稀释3倍后进行21 d水解酸化-好氧连续流试验,出水CODCr为512~673 mg/L,去除率基本保持在60%以上;出水TP浓度后期稳定在20~30 mg/L,去除率在45%左右;出水NH3-N浓度为2.8~5.3 mg/L,去除率可达95%以上。

Electrochemical enhanced catalytic oxidation method,which combined electrolytic reaction with Fentonreaction,was used for the treatment of chlorpyrifos production wastewater. The removal efficiency of chlorpyrifosproduction wastewater by this method was investigated and compared with that using electrolytic reaction. Thebiodegradability of the effluent from electrochemical enhanced catalytic oxidation reaction was also studied. Theresults showed that with the gradual increase of the dose of H2 O2 solution,the CODCronly decreased from initial7 920 mg？L to 5 880 mg？L in 420 min after electrochemical enhanced catalytic oxidation reaction,which indicatedthat chlorpyrifos production wastewater is indeed refractory. In the sole electrolytic oxidation treatment,the CODCrdecreased sharply in the first 20 min,with a reduction of 1 892 mg？L,then the CODCrvalue kept stable. But itstarted to decrease gradually in the later 80 min of coupled reaction with Fenton oxidation,which showed that theorganics in the wastewater were further degraded. Combining the requirement of biodegradability of electrochemicalenhanced catalytic oxidation effluent and the wastewater treatment,which demands effluent CODCrof 500600,mg？L,the effluent from electrochemical enhanced catalytic oxidation reaction was diluted by 3 times and 4 timesrespectively to perform aerobic biodegradation experiment. The reaction kinetics constant was 383. 4 and 298. 3min - 1respectively,indicating that the biochemical reaction process was more controlled by the CODCrconcentrationrather than the chemical toxicity of the effluent. Experiment on the hydrolytic acidificationaerobic reaction processfor the treatment of effluent from electrochemical enhanced catalytic oxidation reaction was conducted,and it turnedout that the removal rate of CODCrremained at above 60% （ CODCr512673 mg？L） ,while that of TP isapproximately 45% （ TP 2030 mg？L） ,and the removal rate of ammonia nitrogen went up to 95% （ NH3 N 2. 85. 3 mg？L）in 21day period.