A/O-MBBR工艺处理低浓度城镇污水研究

A/O-MBBR Process for Treatment of Low-concentration Municipal Sewage

采用A/O-MBBR工艺处理低浓度、低C/N值城镇污水,着重考察了载体投加位置及温度对硝化及反硝化的影响。当生化系统的水力停留时间为12 h、回流比为300%、好氧池DO为2.7～7.0 mg/L、K3型生物悬浮载体投加量为好氧池总池容的11%时,在正常水温下,投加在好氧池前端和后端的装置对氨氮的平均去除率分别为95.7%和92.6%,对总氮的平均去除率分别为22.4%和9.1%,且投加在好氧池前端比投加在后端的抗氨氮冲击负荷能力强;在6.3～10.5℃低温下,系统仍保持了较高的氨氮去除率,载体投加在好氧池前端时对氨氮的平均去除率为82.9%,比投加在后端高8%左右。

A/O -MBBR process was used to treat low-concentration and low C/N municipal sew- age. The influence of carrier dosing point and temperature on nitrification and denitrification was investi- gated. Under normal water temperatures, the average removal rates of ammonia nitrogen by dosing carri- ers at the front-end and back-end of the aerobic tank were 95.7% and 92.6%, respectively. The corre- sponding average removal rates of TN were 22.4% and 9.1% , respectively. These results were obtained when the hydraulic retention time in the biochemical system was 12 h, reflux ratio was 300%, DO in aer- obic tank was 2.7 to 7.0 mg/L, and dosage of K3 suspended biological carrier was 11% of aerobic tank volume. The resistance to ammonia nitrogen shock loading by dosing carriers at the front-end was higher than at the back-end of the aerobic tank. Under low temperatures of 6.3 to 10.5 ℃, the system still maintained a high ammonia nitrogen removal rate. The average removal rate of ammonia nitrogen by do- sing carriers at the front-end of the aerobic tank was 82.9%, which was 8% higher than at the back-end.