生物沸石人工湿地强化硝化处理污水处理厂二级出水研究

以生物沸石人工湿地(CW)中试装置处理实际城镇污水处理厂二级出水,通过273 d的运行,探讨了生物沸石人工湿地强化硝化处理二级出水的性能及温度对其硝化率的影响。结果表明:生物沸石人工湿地能够快速高效地去除二级出水中的氨氮,正常运行阶段氨氮平均去除率达90.5%,出水氨氮平均浓度低于0.5 mg/L。系统重启恢复快、周期短,12 d后氨氮平均去除率达到70%以上。低温阶段(低于13 ℃),生物沸石人工湿地对氨氮的平均去除率依然保持在67.6%。温度对强化硝化效果有显著影响,当水温从低于15 ℃缓慢升至25 ℃以上时,生物沸石人工湿地的氨氮平均硝化率从28%升至62%;强化硝化出水无明显的亚硝态氮积累现象,除低温阶段,出水亚硝态氮平均浓度为0.16 mg/L。氨氮主要是被微生物强化硝化成硝态氮。

Nitrification performance for secondary effluent from MWTP using bio-zeolite constructed wetland

The bio-zeolite constructed wetland (CW) pilot plant receiving a real secondary effluent of the municipal wastewater treatment plant(WWTP) was set up. The performance of bio-zeolite CW enhancing the nitrification of the WWTP secondary effluent and the effect of temperature on nitrification rate were explored during 273 days. The results indicated that the N H 4 + from secondary effluent was removed rapidly and effectively. Average removal rate of N H 4 + was 90.5% and the concentration of N H 4 + in the effluent was lower than 0.5 mg/L in the normal operation phase. After a short recovery period of 12 days, the average removal rate of N H 4 + was higher than 70%. The average removal rate of N H 4 + still remained at a relative high level as 67.6% in the low temperature stage (below 13 ℃). The temperature had signi?cant impact on the nitrification, and the average nitrification rate increased from 28% to 62% as the water temperature rose slowly from below 15 ℃ to above 25 ℃ in bio-zeolite CW. No obvious accumulation of nitrite nitrogen was found in the effluent of bio-zeolite CW except the low temperature stage, and the average concentration of nitrite nitrogen in the effluent was 0.16 mg/L. N H 4 + was mainly nitrified by microorganisms and transformed into nitrate.