某化工园区污水处理厂Fenton处理方案的比较研究

利用GC-MS分析了某化工园区污水厂一期（化工）进水中的有机物组分，并通过活性污泥呼吸抑制实验评估其微生物毒性及对现有生化处理系统的影响。在此基础上，对Fenton试剂后置深度处理和前置预处理2个方案开展比较研究。结果表明，一期进水含多种难降解有机物，对生活污泥表现出微生物毒性，但对园区污水厂污泥无明显呼吸抑制作用。Fenton试剂后置处理生化出水，当进水COD-1，在pH为3.5左右，H2O2投加量为5 mmol·L-1，Fe2+/H2O2摩尔比为1：2的条件下，出水COD可稳定低于60 mg·L-1，处理成本不含污泥处置费低于1.8元·t-1水，难降解组分从18种减少为4种。而Fenton试剂前置预处理化工废水时，废水B/C在几种Fenton药剂组合下均未能达到0.3以上，无法得到理想的可生化性提高效果。因此推荐该化工园区污水厂采用Fenton试剂后置处理工艺为主的提标改造方案。

Comparative study of Fenton process in a chemical industry park wastewater treatment plant

The refractory organics in the chemical influent from a chemical industry park wastewater treatment plant were analyzed by GC-MS. An activated sludge respiration inhibition test was used to evaluate the microbial toxicity of the wastewater and its effect on the biochemical treatment system. Based on this information, a comparative study of the pre- and post-Fenton process was developed. The results show that the chemical influent contains a variety of refractory organics, which reveal microbial toxicity to the municipal sludge, whereas there were no obvious inhibitory effects to the sludge from the plant. When the COD was below 125 mg·L-1 in the biochemical effluent, the post-Fenton processed effluent COD was consistently lower than 60 mg·L-1, with a processing cost of under RMB 1.8 yuan·t-1 (sludge disposal cost was not included). The optimal conditions were a pH of 3.5, H2O2 dosage of 5 mmol·L-1, and Fe2+/H2O2 ratio of 1:2. The number of recalcitrant components was reduced from 18 to 4. On the contrary, when the Fenton reagent was used for pretreatment, the B/C failed to reach 0.3 for several dosage combinations, illustrating an unsatisfactory improvement in biodegradability. Accordingly, the post-Fenton process is recommended as the proper method to apply to further transformation projects of the chemical industry park wastewater treatment plant.