Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029, China.
J Zhejiang Univ Sci B. 2010 Mar;11(3):177-89. doi: 10.1631/jzus.B0900291.
A treatability study of industrial wastewater containing chlorinated nitroaromatic compounds (CNACs) by a catalytic ozonation process (COP) with a modified Mn/Co ceramic catalyst and an aerobic sequencing batch reactor (SBR) was investigated. A preliminary attempt to treat the diluted wastewater with a single SBR resulted in ineffective removal of the color, ammonia, total organic carbon (TOC) and chemical oxygen demand (COD). Next, COP was applied as a pretreatment in order to obtain a bio-compatible wastewater for SBR treatment in a second step. The effectiveness of the COP pretreatment was assessed by evaluating wastewater biodegradability enhancement (the ratio of biology oxygen demand after 5 d (BOD(5)) to COD), as well as monitoring the evolution of TOC, carbon oxidation state (COS), average oxidation state (AOS), color, and major pollutant concentrations with reaction time. In the COP, the catalyst preserved its catalytic properties even after 70 reuse cycles, exhibiting good durability and stability. The performance of SBR to treat COP effluent was also examined. At an organic loading rate of 2.0 kg COD/(m(3)xd), with hydraulic retention time (HRT)=10 h and temperature (30+/-2) degrees C, the average removal efficiencies of NH(3)-N, COD, BOD(5), TOC, and color in a coupled COP/SBR process were about 80%, 95.8%, 93.8%, 97.6% and 99.3%, respectively, with average effluent concentrations of 10 mg/L, 128 mg/L, 27.5 mg/L, 25.0 mg/L, and 20 multiples, respectively, which were all consistent with the national standards for secondary discharge of industrial wastewater into a public sewerage system (GB 8978-1996). The results indicated that the coupling of COP with a biological process was proved to be a technically and economically effective method for treating industrial wastewater containing recalcitrant CNACs.
采用改性 Mn/Co 陶瓷催化剂的催化臭氧氧化工艺(COP)与好氧序批式反应器(SBR)对含有氯代硝基芳烃化合物(CNACs)的工业废水进行了可处理性研究。初步尝试用单个 SBR 处理稀释废水,结果表明去除颜色、氨、总有机碳(TOC)和化学需氧量(COD)的效果不佳。接下来,将 COP 用作预处理,以便在第二步中用 SBR 处理生物相容的废水。通过评估废水生物降解性增强(5 天后生物需氧量(BOD5)与 COD 的比值)以及监测 TOC、碳氧化态(COS)、平均氧化态(AOS)、颜色和主要污染物浓度随反应时间的变化来评估 COP 预处理的效果。在 COP 中,即使经过 70 次重复使用,催化剂仍保持其催化性能,表现出良好的耐用性和稳定性。还考察了 SBR 处理 COP 出水的性能。在有机负荷率为 2.0kg COD/(m3·d)、水力停留时间(HRT)=10h 和温度(30±2)℃的条件下,在 COP/SBR 耦合工艺中,NH3-N、COD、BOD5、TOC 和颜色的平均去除率分别约为 80%、95.8%、93.8%、97.6%和 99.3%,平均出水浓度分别为 10mg/L、128mg/L、27.5mg/L、25.0mg/L 和 20 倍,均符合《污水排入城镇下水道水质标准》(GB 8978-1996)中工业废水排入城镇下水道的二级标准。结果表明,COP 与生物工艺的耦合被证明是处理含有难处理 CNACs 的工业废水的一种技术上和经济上有效的方法。