摘要：

采用UV/Fe-EDTA/H₂O₂体系预处理皮革废水,考察了初始pH、反应时间、H₂O₂和Fe-EDTA投量对COD去除率的影响,测定了处理过程中B/C变化,同时与UV/Fenton法进行了比较。结果表明:UV/Fenton法的最佳工艺条件为FeSO₄25mmol/L、H₂O₂300mmol/L、pH=5。加入EDTA后,反应的最佳初始pH碱移,UV/Fe-EDTA/H₂O₂体系于pH为8.0时,反应10minCOD去除率可达51.9%,而pH为5.0时UV/Fenton体系处理10min后COD去除率仅37.9%。对比降解效果,UV单独作用效果不理想,60min后COD去除率仅25%。引入UV后,Fenton法处理效果提高,60min后COD去除率由37.0%提高至59.3%,加入EDTA后最终COD去除率与UV/Fenton法接近。经光照处理的废水B/C呈先降后升趋势,经UV/Fenton处理后,原水B/C由0.3提高至0.35,经UV/Fe-EDTA/H₂O₂处理的废水最终B/C略有降低。

关键词: 光氧化技术, 皮革废水, 可生化性

Abstract:

An advanced oxidation process applying EDTA in UV/Fenton system has been used for degrading the pollutants contained in tannery wastewater. The effect of initial pH,H₂O₂ and Fe-EDTA dosage are investigated and the biodegradability changes of the pretreatment system of UV/Fenton and UV/Fe-EDTA/H₂O₂ are compared. The results show that the best conditions are as follows:FeSO₄ 25 mmol/L,H₂O₂ 300 mmol/L,pH=5. After adding EDTA,the best initial pH moves towards alkaline. When the pH is 8.0,UV/Fe-EDTA/H₂O₂ reacts for 10 min,the COD removal rate can reach 51.9%,while the pH is 5.0,after being treated by UV/Fenton process for 10 min,the COD removal rate is only 37.9%. Various degrading efficiencies are compared. The results show that when UV is used alone,the result is not so good. After 60 min,the COD removal rate is only around 25%. After introducing UV,the treatment efficiency of Fenton process is obviously improved:in 60 min increasing from 37% to 59.3%. After adding EDTA,the final COD removal rate is similar to the efficiency of UV/Fenton process. The radiated wastewater B/C appears increasing first then decreasing afterwards. After being treated by UV/Fenton process,the raw water improves from 0.3 to 0.35. After being treated by UV/Fe-EDTA/H₂O₂,it declines a little.

Key words: photooxidation process, tannery wastewater, biodegradability

中图分类号: 

• X703.1