固液碳源对反硝化脱氮及污泥产量影响研究

Study on the Effect of Solid and Liquid Carbon Sources on Nitrogen Removal by Denitrification and Sludge Production

分别用乙酸钠和聚己内酯作为外加碳源,对反硝化滤池中固液碳源对污水厂出水脱氮的反硝化效果和污泥产量进行了对比研究。结果表明,液体碳源的反硝化速率更快,可达到2.19 g/(L·d),氮去除率最高可达到95%以上,固体碳源的反硝化速率低于液体碳源,受HRT的影响更大。固体碳源中NO2^--N几乎不积累,液体碳源更容易积累且积累量与HRT有关,2种碳源中均存在异化性硝酸盐还原成铵反应,但出水NO2^--N和NH4^+-N含量均未超标。固体碳源的出水COD稳定低于50 mg/L,当HRT缩短时,液体碳源出水COD存在超标的风险。液体碳源的浓缩污泥产量和单位污泥产量分别为固体碳源的3倍和1.6倍。使用固体碳源可以有效减少污泥的产生。

The denitrification performance and sludge yield of liquid or solid carbon sources in denitrifying filter for effluent of sewage plant were compared,using sodium acetate and polycaprolactone as additional carbon sources.The results showed that,the denitrification rate of liquid carbon source was faster,reaching to 2.19 g/(L·d),the nitrogen removal rate could reach more than 95%.The denitrification rate of solid carbon source was lower than that of liquid carbon source,which was affected by residence time(HRT).Nitrite was easier to accumulate in liquid carbon source,and it had related to HRT.There was a dissimilatory nitrate reduction to ammonium in both systems,but the effluent NO2^--N and NH4^+-N content did not exceed the standard.The effluent COD of solid carbon source was below 50 mg/L.When HRT was shortened,the effluent COD of liquid carbon source was at risk of exceeding the standard.The sludge production and unit sludge production of liquid carbon source were 3 times and 1.6 times than that of solid carbon source.Solid carbon source could effectively reduce the production of sludge.