深水水库人工介质强化脱氮作用研究

Enhanced Nitrogen Removal by Denitrification in Deep Reservoirs Using Artificial Media

为探究不同参数条件下人工介质对清洁型水体氮素的去除效果以及微生物反硝化脱氮潜力,以大型深水水库千岛湖为例,选取2种填料考察挂膜深度(0.5、5和15 m)、挂膜时间(15和30 d)、填料类型(组合填料、弹性填料)对其反硝化作用的影响.结果表明:放置于水深0.5 m处挂膜15 d和30 d的组合填料培养8 h后水体硝态氮(NO_(3)^(−)-N)浓度下降最多,分别降低35.5%和37.3%,其次为5 m深度;NO_(3)^(−)-N浓度与水体溶解性氮气净增量(ΔN2)呈显著负相关(r=−0.43,p<0.01),反映了反硝化过程对水体氮素的脱除效果.挂膜30 d的组合填料在培养前8 h内反硝化潜力最高,在0.5 m、5 m深度组合填料的反硝化潜力分别达1.52和1.71μmol/(L·h).研究显示,在千岛湖实施人工介质脱氮工程,挂膜最佳参数条件为采用组合填料,挂膜水深小于5 m,挂膜时间在30 d以上.研究结果可为深水水库深度强化反硝化脱氮作用提供科技支撑.

In order to investigate appliaction parameters of artificial media for purifying nitrogen in deep lake and the nitrogen removal potential by microbial denitrification,two types of fillers were selected to investigate the effects of film depth(0.5 m,5 m,15 m),film time(15 d and 30 d),and filler type(combination filler and elastic filler)on denitrification in Lake Qiandao,a large deep-water reservoir.The results showed that the nitrate nitrogen(NO_(3)^(−)-N)concentration of the combined filler decreased mostly in the first 8 h at the 0.5 m depth for 15 d and 30 d,with a decrease of 35.5%and 37.3%of inital concentrations,respectively,followed by fillers at the 5 m depth.The denitrification potential of the combination filler for 30 d culture was the highest in the first 8 h,and the denitrification potentials at 0.5 m and 5 m depths were 1.52μmol/(L·h)and 1.71μmol/(L·h),respectively.NO_(3)^(−)-N showed a significant negative correlation withΔN2(r=−0.43,p<0.01),reflecting the nitrogen consumption in the denitrification process in this experiment.This study indicates that the best parameter conditions for artificial media hanging film is to suspend the combined filler within 5 m of water depth for more than 30 days when implementing ecological engineering for nitrogen removal in Lake Qiandao.The present results provide a scientic support for the enhanced nitrogen removal by denitrification in deep water reservoirs.