煤气废水好氧—缺氧—好氧生物处理研究

Coal gasification wastewater treatment by aerobic-anoxic-aerobic biological process

煤气废水生物处理目前遇到的主要问题是系统运行不稳定及氨氮去除率低,针对这些问题开发出好氧—缺氧—好氧生物处理工艺。实验表明,新工艺在入水COD较高的条件下可以稳定运行,系统中一级好氧白土-活性污泥单元作用较大。系统在平均入水COD为2204 mg/L、氨氮为244mg/L的条件下,COD和氨氮去除率分别可达87.6%和80%,HRT的降低对系统COD去除率影响不大,但使氨氮去除率降低到67%,主要是由于一级好氧单元硝化作用减弱所致。该工艺提高了煤气废水生物处理的功效,特别是在去除氨氮方面具有很大的优势,为后续深度处理奠定了基础。

Aerobic （O）- anoxic （A）- aerobic （O）biological process is put forward for gasification wastewater treatment. The experiment data shows that the new system is operated stably during a period of five months when the COD concentrations of the influent water are higher than 2 200 mg/L. The diatomite-activated sludge unit of the system is important for this stability. The total COD and NH4^4- N removals are more than 87% and 80% respectively and are superiority to the process operated in the Harbin Coal Gasification Plant. When the HRT decreases and the concentrations of influent increases, the COD removal rate remaines at 86%, but the NH4^4- N removal rate is decreased to 67%.