超声预处理污泥发酵液作为反硝化聚磷补充碳源研究

剩余污泥含有丰富的有机物和氮、磷等营养物质,对其进行超声预处理及水解酸化可回收溶解性的有机物及水解产物作为生物脱氮除磷工艺的补充碳源。以增加水解酸化后污泥上清液中的挥发性脂肪酸(VFA)为目的,研究了超声声能密度及超声时间对污泥水解酸化释放SCOD和VFA的影响以及污泥水解酸化产物作为反硝化聚磷工艺补充碳源的可行性:结果表明,超声预处理可以有效促进污泥的水解酸化,在一定的范围内增加超声时间和声能密度可以提高水解酸化过程中产生的SCOD和VFA浓度;有利于水解产酸的超声预处理条件是声能密度为1.5W/mL、超声时间为10min。在实际污水中投加污泥发酵液作为补充碳源可以提高反硝化聚磷系统对PO4^3-0P的去除率,且发酵液/实际污水体积比为1/35时去除率最高;长期以污泥发酵液作为补充碳源,随着运行时间的增加,系统对PO4^3--P的去除率不断提高,运行20d以后去除率达到了100%。

Additional Carbon Source for Dentrifying Phosphorus Removal Based on Hydrolysis Acidification of Sludge Pretreated by Ultrasound

The sewage sludge contains rich organic matters and nutrients such as nitrogen, phosphorus. Ultrasonic pretreatment and hydrolysis acidification of sewage sludge can recover the dissolved organic matters and hydrolysis products which can be used as carbon sources of biological nitrogen and phosphorus removal. In order to increase the VFA in the sludge supernatant after hydrolysis acidification, the effects of energy density and duration of ultrasonic pretreatment on the hydrolysis acidification of the sewage sludge and the feasibility of anaerobic fermentation production as the carbon sources of denitrifying phosphorus removal were investigated. The experimental results showed that ultrasonic pretreatment coukl promote the hydrolysis acidification degree of sludge, the concentrations of SCOD and VFA during hydrolysis increased with the increases of energy density and duration in a certain range. The optimum energy density and duration was detennined to 1.5 W/mL and 10 min , respectively. Addition of fermentation liquid improved the removal rate of phosphate effectively and the removal rate of phosphate was the highest when the adding ratio of fermentation liquid was 1/35 of the wastewater. The system kept operating stably and the removal rate of phosphate had been increasing when using fermentation liquid as the carbon sources of denitrifying phosphoms removal for a long time, and the removal rate of phosphate reached 100% after the system operated for 20 days.