多级生物强化反应器处理煤制气废水试验研究

Experimental study on multistage bio-augmented reactor for treating coal gasification wastewater

为了优化煤制气废水关键污染物去除方式,采用四级生物强化反应器进行中试研究,分析了工艺启动过程与反应器沿程水质变化特征,探讨了水力停留时间、外加碳源对同步硝化反硝化(SND)效率和处理效果的影响。结果表明:在ρ(NH_(4)^(+)-N)=126~165 mg/L、ρ(TN)=139~178 mg/L、ρ(总酚)=286~352 mg/L、ρ(COD)=1340~2296 mg/L的进水条件下,反应器历时27 d完成了微生物的驯化与固定化;在水力停留时间HRT=62 h并且实施限氧曝气的条件下,C1~C4反应室均可实现SND,反应器出水NH_(4)^(+)-N(氨氮)、TN(总氮)、总酚和COD(化学需氧量)浓度分别为0.12~1.25、79.1~109、17.8~26.7、128~196 mg/L;在HRT为38.8~62 h内,缩短HRT可显著提高反应器TN去除效果;HRT=62 h条件下的TN去除率与SND率分别为38.9%和37.3%,HRT=38.8 h条件下的TN去除率与SND率分别达到53.0%和51.2%;300 mg/L浓度下的5种甲醇外加方式均可进一步提升TN去除效果,方式Ⅱ运行条件下的TN去除效果最佳,TN去除率与SND率分别达到92.8%和94.4%;方式Ⅰ、Ⅱ、Ⅲ、Ⅳ均可通过共代谢作用提升COD去除效果,方式Ⅰ运行条件下的COD去除率最高,达到91.8%。

In order to optimize the key pollutant removal mode of coal gasification wastewater,a bio-augmentated reactor composed of 4 tandem units was used to conduct pilot scale tests.The start-up procedure and water quality variation characteristics along the reactor were analyzed.In addition,the influences of hydraulic retention time and additional carbon source on the simultaneous nitrification&denitrification(SND)efficiency and removal effect were also discussed.The results indicate that under the influent quality of ρ(NH_(4)^(+)-N)126 to 165 mg/L,ρ(TN)139 to 178 mg/L,ρ(total phenol)286 to 352 mg/L andρ(COD)1340 to 2296 mg/L,the microbial acclimation and immobilization of the reactor were completed in 27 days.Under the oxygen-limiting aeration condition and HRT 62 h,SND was achieved in all the reaction chambers from C1 to C4,and the mass concentrations of NH_(4)^(+)-N,TN,total phenol,COD in the last effluent were respectively 0.12-1.25,79.1-109,17.8-26.7,128-196 mg/L.The TN removal effect of the reactor was enhanced by HRT reduction in the HRT range from 38.8 h to 62 h.The TN removal rate and SND efficiency were 38.9% and 37.3% when the HRT=62 h.For comparison,the TN removal rate and SND efficiency were 53.0% and 51.2% when the HRT=38.8 h.The TN removal effect could be all further enhanced by the 5 modes of carbon source dosing with 300 mg/L.The reactor achieved highest TN removal rate under the dosing mode of Ⅱ.The coresponding TN removal rate and SND efficiency were 92.8% and 94.4%.The COD removal effect could be enhanced by the modes of Ⅰ,Ⅱ,Ⅲ and Ⅳ,and the COD removal rate achieved the maximum value of 91.8%under the condition of modeⅠ.