污泥基催化剂强化臭氧深度处理煤制气废水中试性能

为解决煤制气废水生化处理后出水仍含有大量有毒和难降解污染物,对环境产生严重污染的问题,以污水污泥为原料制备污泥基活性炭,采用浸渍法将其负载过渡金属锰和铁的氧化物(主要为Mn_3O_4和Fe_3O_4,负载量分别为15.52%和7.45%),制备比表面积分别为327.5和339.1 m~2/g的臭氧催化剂.中试实验结果表明,催化剂的使用显著提高臭氧氧化废水污染物的效能,处理后出水COD、TOC、总酚和氨氮质量浓度分别为41~43,19~20,0.6~0.9和4.3~4.5 mg/L,均达到城镇污水处理厂污染物排放一级A标准;在最佳的臭氧投加量18 g/h条件下,催化剂的使用将臭氧利用率提高40%,达1.24 mg/mg(以COD计),显著降低工艺运行成本;相比新鲜的催化剂,连续50次的催化臭氧氧化运行,COD去除率仅下降5.2%.催化剂具有良好的稳定性,制备成本仅为5 000元/t.制备的臭氧催化剂具有性能高效稳定、经济节约和可持续发展的技术优势,适用于强化臭氧深度处理煤制气废水.

Advanced treatment of coal gasification wastewater using catalytic ozonation by sewage sludge based activated carbon as catalysts in pilot-scale

In order to solve the biologically pretreated coal gasification wastewater (CGW) still contained a large number of toxic and refractory compounds, posing great hazard to the environment, sludge based activated carbon was prepared from the sewage sludge produced during gasification wastewater (CGW) treatment via the loading process of manganese and ferric oxides (main Mn₃O₄ and Fe₃O₄, loading dose of 15.52% and 7.45%, respectively), and the zone catalysts exhibited a specific surface area of 327.5 and 339.1 m²/g. Pilot-scale tests demonstrated that the additive of the prepared catalysts significantly improved the removal efficiency of pollutants during ozonation treatment, with an effluent COD, TOC, total phenols and NH₄+-N concentrations of 41-43, 19-20, 0.6-0.9 and 4.3-4.5 mg/L, respectively, can meet class-I criteria of the Integrated Wastewater Discharge Standard. Moreover, utilization rate of ozone with catalysts additive (1.24 mg/mg) increased 40% as compared with the test only with ozone additive, would significantly save the operation cost. In comparison with the fresh catalysts, COD removal efficiency only decreased by 5.2% after 50th successive catalytic ozonation. The cost of catalysts production was about 5 000 RMB/t average. Overall, efficient, stable, economical and sustainable characteristics of the prepared catalysts made it suitable for advanced treatment of CGW.