好氧-SNAD-MBBR工艺处理煤气化废水

研究了同步亚硝化、厌氧氨氧化和反硝化(SNAD)-生物移动床(MBBR)工艺对煤气化废水脱氮的处理效果。结果表明,通过控制低DO含量和低污泥停留时间(SRT)的方法防止了好氧反应器中硝化菌的积累,为后续SNAD反应器提供了合适的进水。煤气化废水经好氧反应器去除COD后进入SNAD MBBR进行脱氮,控制SNAD反应器温度为30~33℃,DO的质量浓度为0.5~0.8 mg/L,pH为7.5~7.7,HRT为24 h。TN去除率达到90.7%,出水TN、NH4+-N的质量浓度分别低于20、5 mg/L,COD去除率达到89.6%,出水COD低于60 mg/L。运行25 d后,SNAD反应器中厌氧氨氧化菌的种类由接种时的Candidatus Brocadia变为Candidatus Kuenenia。

Treatment of Coal Gasification Wastewater by Aerobic Coupled SNAD-MBBR Process

The treatment efficiency of SNAD-MBBR for nitrogen removal from coal gasification wastewater was studied.The results showed that,the inhibition of nitrifying bacteria accumulation in the aerobic reactor was accomplished by controlling the low DO content and SRT,which provided a suitable influent for the SNAD process.The coal gasification wastewater flowed into SNAD reactor for nitrogen removal after COD removal by aerobic reactor,in the SNAD reactor,the temperature,mass concentration of DO,pH and HRT was maintained at 31~33℃,0.5~0.8 mg/L,7.5~7.7 and 24 h respectively.The total nitrogen and COD removal rate could reach 90.7%and 89.6%,respetively.In the effluent,the mass concentration of total nitrogen,ammonia nitrogen and COD was lower than 20 mg/L,5 mg/L and 60 mg/L,respectively.After operation of 25 d,the genus of anammox bacteria changed from Candidatus Brocadia to Candidatus Kuenenia in the SNAD reactor.