餐厨垃圾水解酸化液作碳源的脱氮效果研究

Effect of kitchen waste hydrolysis products on domestic wastewater denitrification

针对餐厨垃圾水解酸化液作外加碳源的反硝化脱氮效果进行研究,考察了人工配水条件下水解酸化液反硝化处理的适宜 COD/NO3--N 比范围,在适宜COD/NO3--N 比条件下与甲醇、乙酸钠的反硝化效果进行对比,并验证了水解酸化液对于生活污水的反硝化效果.结果表明,人工配水条件下利用水解酸化液作碳源的适宜COD/NO3--N 比为4.9-6.0,反硝化速率最高可达25.0mg NO3--N/（gVSS·h）.反应过程存在2个不同的硝态氮去除速率阶段,并出现了亚硝氮积累.餐厨垃圾水解酸化液为含多种VFA成分的混合物,其反应过程中硝态氮的去除速率比甲醇、乙酸钠等纯物质做碳源时的硝态氮去除速率快.将餐厨垃圾水解酸化液用于生活污水脱氮处理,当COD/NO3--N 比为6时,水中的硝态氮以及亚硝氮均能够得到较为彻底的去除.

Batch experiments were carried out to determine the effect of COD/NO3--N ratio on synthetic domestic wastewater denitrification using kitchen waste hydrolysis products as carbon source, and comparision was made between kitchen waste hydrolysis products, methanol and sodium acetate for the performance of denitrification at the optimum COD/NO3--N ratio respectively. Then, the effect of kitchen waste hydrolysis products on authentic domestic wastewater denitrification was proved. For each experiment with different COD/NO3--N ratio, the concentration of nitrate（NO3--N）、nitrite （NO2--N）、ammonia nitrogen （NH4＋-N） and chemical oxygen demand （COD） were investigated. COD/NO3--N ratio ranging from 4.9 to 6.0 was suitable for domestic wastewater denitrification using the kitchen waste hydrolysis products as carbon source, and the highest denitrification rate was 25.0mg NO3--N/（gVSS？h）. In the denitrification process, there were 2stages with different nitrate removal rate as well as obvious nitrite accumulation. The self-made kitchen waste hydrolysis products consisted of various VFAs, and the denitrification rate was higher for the kitchen waste hydrolysis products compared with pure substances such as methanol and sodium acetate. The utilization of kitchen waste hydrolysis products as carbon source for authentic wastewater denitrification was proved to be at the optimal situation when the COD/NO3--N ratio of 6was achieved. At the optimal situation, the removal of nitrate and nitrite was exhaustive.