污水中不同COD组分下A/O脱氮工艺的反硝化效率

为了研究了不同COD组分进水对A/O工艺中反硝化的影响以及COD组分中溶解性易生物降解COD(SS)、颗粒性慢速可生物降解COD (XS)比例改变后系统反硝化速率和反硝化潜力的变化。以连续流A/O反应器脱氮效率为研究对象,通过改变碳源物质投配量来配置3种SS比例分别为15%、30%和50%的城市污水,系统地考察了进水中SS比例对反硝化的影响。结果表明,进水中SS比例由15%增加到50%后,可以明显提高A/O系统TN的去除率,脱氮率由82%提高到89%。同时通过缺氧反硝化间歇实验,从反硝化动力学角度分析,进一步确定进水中SS比例对反硝化速率和反硝化潜力的影响,发现进水SS比例分别为50%、30%和15%,系统反硝化速率分别为0.027 g NO3--N/(g VSS·min )、0.022 g NO3--N/(g VSS· min )和0.020 g NO3--N/(g VSS·min ),反硝化潜力分别为16.49、13.99和13.74 mg/L。可见随着进水中SS比例的升高,系统中反硝化速率和反硝化潜力也相应增加。得出进水中COD组分不同,尤其是SS所占比例大小,是影响反硝化效果的一个关键因素。

Denitrification efficiency by changing COD fractions of wastewater in a pre-denitrification reactor

The influence of COD-fractions on denitrification was studied with a pilot-scale continuous pre-denitrification reactor (A/O process).Denitrification rate and denitrification potential were investigated by changing the fractions of soluble readily biodegaradable COD (SS) and particulate slowly biodegradable COD (XS) in the influent with bach tests.It was shown that the total nitrogen removals of A/O process increased obviously when the fraction SS in the influent was added.After SS fraction of influent increased from 15% to 50%,the total nitrogen removal was improved from 82% to 89%.The denitrification kinetic information was obtained with anoxic batch tests.When the SS fraction of influent were 50%,30%,15% respectively,the denitrification rates were 0.027 g NO3--N/(g VSS·min ),0.022 g NO3--N/(g VSS· min ),0.020 g NO3--N/(g VSS·min ),and the denitrification potential were 16.49 mg/L,13.99 mg/L,13.74 mg/L,respectively.The result showed that the denitification rate and denitrification potential were improved as the SS fraction of influent increased.As a consequence,the variation of COD-fractions in influent,especially the ratio of SS,is a key factor to influence the denitirfication.