多级A/OVTBR组合工艺处理焦化废水

TREATMENT OF COKING WASTEWATER BY COMBINED VERTICAL TUBULANT BIOLOGICAL REACTOR PROCESS

采用水解酸化、多级A/O垂直折流生物膜反应器(vertical tubulant biological reactor,VTBR)、混凝和Fenton氧化组合技术对实际焦化废水进行处理。其中水解酸化预处理阶段提高了废水可生化性,混凝降低了生化处理的有机负荷,一级A/O VTBR以脱碳为主,二级A/O VTBR主要脱碳和脱氮,三级好氧VTBR强化对氨氮的去除,Fenton氧化则对生化出水进行深度处理。试验结果表明:在进水ρ(COD)为3 000～3 500 mg/L,ρ(BOD5)为1 212 mg/L,ρ(NH3-N)为109 mg/L条件下,保持好氧段ρ(DO)为3～7 mg/L,缺氧段ρ(DO)<1 mg/L,总停留时间HRT 56 h,该工艺对COD、BOD5、NH3-N的去除率分别为98%、99%、95%,出水达GB8978-1996《污水综合排放标准》中的一级排放标准。

A combination process of hydrolytic acidification,multilevel vertical tubulant biological reactor,coagulation and Fenton oxidation has been used for treating coking wastewater.The results show that under the conditions of the influent COD 3 000 ～ 3 500 mg /L,BOD51 212 mg /L,NH3-N 109 mg /L,dissolved oxygen in the aerobic reactor varied within 3 ～ 7 mg /L and in the anoxic reactor below 1 mg /L,hydraulic retention time 56 h,their average removal rates are 98%,99%,95%,respectively.The concentrations of the effluent COD and NH3-N meet the first-order of＂The Integrated Wastewater Discharge Standard＂（GB8978-1996）.