水温和C/N对土地生物过滤处理系统氮去除的影响

Influence of temperature and C/N ratio on nitrogen removal in wastewater land bio-filtration process

在流量为40 L/d、回流比为200%的条件下,以碎石为填料,结合小试实验研究了温度和COD/NH4+-N(C/N)对AO型污水土地生物过滤处理系统,处理人工生活污水中氮的影响。实验结果表明,随水温和C/N的升高,首先系统对NH4+-N的去除率先增大后减小,当水温为7.3℃、C/N为5时,系统对NH4+-N的去除率最高,达到了91.1%;其次系统反硝化率逐渐升高,当水温为8.2℃、C/N为6时,反硝化率达到了95.4%;此外,系统中硝化反硝化作用受到影响,导致对TN的去除率先增大后减小,当水温为8.2℃、C/N为6时,系统对TN的去除率达到49.91%。在厌氧阶段,系统TN的去除主要靠反硝化作用将硝酸盐氮脱除,并且存在中间产物积累;进入好氧阶段,系统通过硝化作用将氨氮转化为硝酸盐氮,只是氮素形态的转化,并未从系统中脱氮。

In the flow of 40 L/d and the reflux ratio of 200%,with gravel as the media,the influence of temperature and COD/NH4＋-N ratio（C/N）on nitrogen removal of synthetic wastewater was studied,treating by wastewater land bio-filtration process.The results showed that with the temperature and C/N increasing,NH4＋-N removal of system first increased,then decreased,at the temperature of 7.3℃ and C/N ratio of 5,the removal of ammonia was best,reaching at 91.1%.And anaerobic column denitrifying rate raised gradually,at the temperature of 8.2℃ and C/N ratio of 6,denitrifying rate reached at 95.4%.Besides the nitrification and denitrification in system were affected,system for the removal of TN first increased,then decreased,at the temperature of 8.2℃ and C/N ratio of 6,the removal rate of TN was 49.91%.In anaerobic phase,the system for TN removal depended mainly on denitrifying nitrogen,and system existed intermediate product accumulation.Entering the aerobic phase,system through nitrification will take ammonia nitrogen into nitrate nitrogen,only in the form of nitrogen transformation,not from the system denitrification.