氧化沟工艺低氧同步脱氮启动研究

在常温条件下,采用小试Pasveer氧化沟处理低C/N实际污水,通过控制好氧区平均ρ(DO)为0.2～0.4 mg/L,保持好氧区与缺氧区体积比为1∶1,成功实现低氧脱氮过程。其中,模式1先接种好氧污泥并逐渐降低好氧区DO,然后接种缺氧污泥;模式2初始阶段保持低氧环境,并直接接种好氧和缺氧混合污泥。结果显示:两种方式均能成功启动低氧脱氮并保持较高的脱氮率;同时,当C/N值为1.94时,氨氮去除率较高;当C/N值为3.00时,总氮去除率较高,低氧低碳条件下脱氮效果较好。

STARTUP STUDY ON NITRIFICATION AND DENITRIFICATION AT LOW DO CONCENTRATION IN OXIDATION DITCH

At normal temperature,a lab-scale Pasveer oxidation ditch was used to treat actual wastewater with low C/N ratios.Nitrification and denitrification at low dissolved oxygen(DO) concentration could be started successfully by controlling DO concentration at 0.2~0.4mg/L in aerobic area and keeping the volume ratios between aerobic area and anoxic area at 1∶1.In the process,aerobic sludge was inoculated in mode 1 and DO concentration of the aerobic area was reduced gradually,then anoxic sludge was inoculated.During the startup of mode 2,DO was under low condition at all the time and mixed sludge from aerobic and anoxic area was inoculated directly.The results showed that both methods could start the reactor successfully and keep high efficiency of nitrogen removal.Ammonia nitrogen removal efficiency was higher while C/N was 1.94,but total nitrogen removal efficiency was higher when C/N was 3.00.On the condition of low oxygen and low C/N,the efficiency of nitrogen removal was high.