低氨氮原水生物活性炭工艺启动判定指标中试

Pilot-Scale Test of Judgment Indices for BAC Process Start-Up in WTPs with Raw Water of Low Ammonia Nitrogen

生物活性炭(BAC)工艺在我国水厂中已经得到了广泛应用,新安装炭池或活性炭更换后,炭池启动期活性炭上微生物挂膜情况对于判断炭池启动成功至关重要。对原水中氨氮水平较低的Y水厂沉淀池出水进行中试试验研究,跟踪检测上向流生物活性炭(UBAC)启动期的进出水水质指标以及炭上ATP含量。结果发现,生物活性炭启动期COD_(Mn)和DOC指标去除率均呈先下降后上升的趋势,去除率转折点出现的时间接近,均在45~50 d,但DOC去除率转折点出现的时间不够清晰。DO消耗量呈先上升后平稳的趋势,转折点出现的时间在45 d左右,转折点较为清晰且易于判断。同时,DO消耗量与ATP含量变化的相关性最强。在原水氨氮水平较低时,建议将DO作为活性炭启动期挂膜成功的判定指标,同时将COD_(Mn)去除率用作补充参考指标。

Biological activated carbon(BAC) process has been widely used in WTPs at home. After a new carbon filter is installed or the activated carbon is replaced, the biofilm formation on the activated carbon during the start-up period of the carbon filter is critical to judge the successful start-up of the carbon filter. The pilot test was carried out with treated water of sedimentation tank in WTP Y with low ammonia nitrogen level in raw water to track and detect the inlet and treated water quality indices, and the ATP content on the carbon during the start-up period of the upflow BAC(UBAC) column. The results showed that the removal rates of COD_(Mn),DOC in the biological activity start-up period showed a trend of first decreasing and then increasing, and the turning points of the removal rates were close to each other, both in 45~50 d, but the turning points of the DOC removal rates were not clear enough. The dissolved oxygen(DO) consumption showed a trend of first rising and then stabilizing. The turning point occurs was about 45 d, and the turning point was clear and easy to judge. At the same time, the correlation between DO consumption and ATP content was the strongest. When the level of ammonia nitrogen in raw water was low, it was recommended to use DO as a judgment index for the success of membrane formation during the startup period of activated carbon, and use the COD_(Mn) removal rate as a supplementary reference index.