乙酸钠丙酸钠配比对A2/O-BCO反硝化除磷及菌群结构的影响

采用厌氧/缺氧/好氧和生物接触氧化反应器（A²/O-BCO）组成的反硝化除磷系统处理模拟生活污水，通过调节进水乙酸钠、丙酸钠的配比（乙酸钠：丙酸钠分别为1：0，2：1，1：1，1：2和0：1），考察了系统对有机物的去除以及同步脱氮除磷的影响，同时通过高通量测序对比了不同配比下微生物菌群结构的变化.结果表明：乙酸钠丙酸钠配比对有机物和NH₄⁺-N的去除影响较小，对厌氧段有机物的消耗和TN的去除率以及磷的释放和吸收影响较为明显；TP去除率仅为50.3%~56.8%，需进一步优化系统的运行参数.当乙酸钠：丙酸钠=1：1时，厌氧段有机物消耗量最大，占有机物流入量的61.2%，厌氧释磷量最大（23.2mg/L）且缺氧吸磷率最高（71.4%），而TN的去除效果则随丙酸钠含量的增加而增加.高通量测序结果表明：A²/O反应器中微生物多样性降低，混合碳源污泥中微生物多样性比单一碳源更丰富；驯化后的污泥中绿弯菌（Chloroflexi）和螺旋菌（Saccharibacteria）减少，变形菌（Proteobacteria）和拟杆菌（Bacteroidetes）增加.BCO反应器中Nitrospira和Nitrosomonas总占比为2.1%~31.4%，且抑制亚硝酸盐氧化菌（NOB）的活性，有利于短程硝化的实现.

Effect of the ratios of sodium acetate to sodium propionate on denitrifying phosphorus removal characteristics in the A2/O-BCO process

A denitrifying phosphorus removal system combining anaerobic/anoxic/oxic (A²/O) with biological contact oxidation process (BCO) was used to treat synthetic wastewater. By adjusting the ratio of sodium acetate to sodium propionate (sodium acetate:sodium propionate=1:0,2:1,1:1,1:2 and 0:1), the organic matter removal and denitrifying phosphorus removal characteristics of the system were investigated. The results showed that the ratio of sodium acetate to sodium propionate revealed a negligible effect on organic matter and NH₄⁺-N removals, but the influences on organic consumption in the anaerobic stage, total nitrogen removal as well as the phosphorus release and absorption were obvious. The operation parameters of the system need to be further optimized due to the low phosphorus removal of 50.3%~56.8%. When the sodium acetate/sodium propionate was 1:1, the organic matter consumption in the anaerobic section was the highest, accounting for 61.2% of the total organic matter input, with the maximum anaerobic phosphorus releaseamount(23.2mg/L) and anoxic phosphorus uptake rate (71.4%). However, the TN removal increased with the addition of sodium propionate. High-throughput sequencing results showed that the microbial diversity in the A²/O reactor was lower, while the mixed carbon source sludge was more abundant than that of the single carbon source. Particularly, the amount of Chloroflexi and Saccharibacteria reduced while the Proteobacteria and Bacteroidetes increased in the domesticated sludge. The total proportion of nitrifying bacteria in the BCO reactor was 2.1%~31.4%, and the ammonia oxidizing bacteria (AOB) was dominate which favoured the realization of short-cut nitrification.