Fenton氧化处理颜料中间体生产废水的生化尾水

Treatment of biochemical effluent of pigment intermediate wastewater by Fenton oxidation process

颜料中间体生产废水的生化尾水的水质虽已达到园区污水处理厂的接管标准,但由于难降解有机物的残留,使得园区污水处理厂生化系统不能稳定运行。为寻求解决方法,采用Fenton氧化法对颜料中间体废水的生化尾水进行深度处理,通过正交试验和单因素试验,考察初始反应pH、H2O2投加量、摩尔比n(H2O2)∶n(Fe2+)和反应时间对废水化学耗氧量(COD)、紫外吸光度(UV254)和色度去除率的影响。结果表明:最佳反应条件为初始反应pH 4,30%H2O2投加量1 mL/L,n(H2O2)∶n(Fe2+)=5∶1,反应时间3 h,COD去除率可达46%,UV254去除率可达84%,色度去除率可达95%。根据实际工程应用,深度处理的药剂成本为2元/t废水,去除COD的成本为22.7元/kg。针对较难二次生化处理的废水先进行Fenton氧化预处理,提高其可生化性后,再与其他易生化处理的废水一同处理,既节省成本,又利于水质的稳定达标。

The quality of biochemical effluent of pigment intermediate wastewater had meet the connection standard of park sewage treatment plant, but because of refractory organic residues, the biochemical system could not stably be operated.To find a solution, the advanced treatment of biochemical effluent of pigment intermediate wastewater was carried out by Fenton oxidation process.An experimental design based on the orthogonal and single factor experiments was used to determine the optimal reaction conditions on the re- moval of chemical oxygen demand （ COD ）, ultra violet absorbance （ UV254 ） and colour, such as initial pH,the dosage of H2O2, the mole ratio of n（ H2O2） ：n（ Fez＋） and the reaction time.The best operating conditions were pH of 4,H2O2 of 1 mL/L,n（H2O2） ：n（Fe2＋） of 5：1 and the reaction time of 3 b.Under these conditions ,the removal rate of COD, UV254 and colour was 46% ,84% and 95%.According to the actual engineering application, the medicament cost was about 2 yuan per ton of wastewater, or 22. 7 yuan per kilo- gram of COD.The wastewater difficult to be treated by a secondary biochemical process was firstly pretreated by Fenton oxidation process to improve its biodegradability, and then treated by biochemical process, together with those having relatively high biodegradability.It could save cost and was favorable to the stabili- ty of the compliance of the water quality.