低温条件IASBR处理养猪沼液脱氮性能研究

Nitrogen removal from digested piggery wastewater by intermittently aerated sequencing batch reactors at low temperature

以实际养猪沼液为研究对象,考察分步进水间歇曝气序批式生物反应器(IASBR)在低温条件下的脱氮性能.结果表明:IASBR反应器的硝化性能临界水温为10℃,水温低于10℃时硝化性能急剧下降,水温10℃以上时氨氮去除率达到90%以上,且水温15℃以上氨氮负荷极限可达到0.30 kg·m^(-3)·d^(-1);低碳氮比(COD/TN)1.7±0.3条件下,反硝化性能临界水温为20℃,20℃以上时TN去除率可保持在80%以上,最高达90%,20℃以下时脱氮效率明显降低,出现亚硝态氮积累现象.此外,IASBR反应器脱氮除磷效率高,温度对TOC和TP去除率的影响不敏感.不排泥条件下,进水COD/TN为3.1±0.4时,TN去除率高达90%以上,TOC和TP去除率分别高达83.6%±3.9%和58.5%±17.8%;随后COD/TN降低至1.7±0.3后,TN去除率仍高达80%以上,TOC和TP去除率仅略有降低分别为77.3%±4.6%、53.1%±10.1%.

This study was conducted to study the nitrogen removal performance of the step-feed intermittently aerated sequencing batch reactor（ IASBR）technology applied to treat digested piggery wastewater at low temperature. The results show that the critical temperature to efficient nitrification was 10℃.The ammonia nitrogen removal efficiency was higher than 90% when the temperature was above 10℃,but significantly decreased when the temperature was reduced. In addition,the ammonia nitrogen loading rate was up to 0. 30 kg-NH4^＋-N·m^-3·d^-1when the temperature was above 15℃. The critical temperature to efficient denitrification was 20 ℃ at a low carbon-nitrogen ratio（ COD/TN） of 1.7±0.3. The TN removal efficiency was more than 80%,even up to 90%,when the temperature was above 20℃,but it decreased significantly when the temperature was below 20 ° C with nitrite accumulation in the effluent. Furthermore,the IASBR achieved higher nitrogen and phosphate removal efficiencies. The temperature did not affect TOC and TP removals.At influent COD/TN of 3.1 ± 0. 4,TN was removed by above 90%,with TOC and TP removal efficiencies of 83. 6% ± 3. 9% and 58. 5% ± 17. 8%,respectively. When the influent COD/TN was decreased to 1.7±0.3,the TN removal was still above 80%,and the TOC and TP removal efficiencies were slightly reduced to 77.3% ±4.6% and 53.1% ±10.1%.