污泥水解酸化液用作A^2/O系统脱氮除磷碳源的研究

Using Sludge Hydrolysis-acidification Liquor as Carbon Source for Nitrogen and Phosphorus Removal in A^2/O System

实际生活污水多属于低C/N值水质,无法同时满足脱氮除磷对碳源的需求。为此,采用批量试验考察了剩余污泥的水解酸化产物用作脱氮除磷碳源的可行性。污泥经水解酸化后SCOD的溶出率达到80%,其中VFAs占43.2%,VFAs总量是生活污水的3倍多。以污泥的水解酸化液和生活污水作为反硝化电子供体时,最大反硝化速率分别为2.7和1.6 mgNO3--N/(gMLSS.h)。将污泥酸化液用作A2/O系统的补充碳源,可提高系统的负荷,对NH4+-N、TN及PO43--P的去除率分别为92%、77.1%和89.4%。其中,对TN和PO43--P的去除率比投加甲醇分别提高了5.2%和4.8%。投加乙酸钠、甲醇和水解酸化液时,A2/O系统好氧区的吸磷速率分别为1.2、0.7和0.9 mgPO43--P/(gMLSS.h)。可见,污泥酸化液适宜用作A2/O系统的补充碳源。

Due to the low C/N ratio of domestic sewage, the demand of carbon source for nitrogen and phosphorus removal cannot be meet simultaneously. Therefore, the feasibility of using the excess sludge hydrolysis-acidification liquor as a carbon source for nitrogen and phosphorus removal was investigated by batch experiment. After the sludge hydrolysis-acidification, the maximal SCOD dissolution rate is 80%, VFAs accounts for 43.2% of total SCOD, and the total VFAs is three times of that in domestic sewage. The maximal denitrification rates are 2.7 and 1.6 mgNO^-3 - N/（gMLSS·h） respectively when sludge acidification liquor and domestic sewage are used as electron providers. Using the sludge hydrolysis-acidification liquor as an additional carbon source of A^2/O system can increase the system load, and the removal rates of NH^＋4 - N, TN and PO^3-4 - P are 92% , 77.1% and 89.4% respectively. Moreover, the removal rates of TN and PO^3-4 - P are 5.2% and 4.8% higher than those by addition of methanol. The phosphorus uptake rates in the aerobic stage of the A^2/O system are 1.2, 0.7 and 0.9 mgPO^3-4 - P/（gMLSS·h） respectively when sodium acetate, methanol and hydrolysis-acidification liquor are added. It is concluded that sludge hydrolysis-acidification liquor is suitable to be used as an additional carbon source of the A^2/O system.