猪场废水厌氧消化液后处理技术研究及工程应用

Study and Application of Technology for Post-Treatment of Anaerobically Digested Effluent of Piggery Wastewater

猪场废水经过厌氧消化后 ,可生化性变差 ,BOD5/ COD仅为 0 .19,并且碳、氮倒置 ,比例严重失调 ,给后续好氧处理带来很大困难。采用序批式活性污泥法 (SBR)工艺直接处理厌氧消化液 ,污染物的去除效果很差 ,COD仅去除 8.31% ,NH3- N去除 78.7%。通过改善厌氧消化液的可生化性和培养高效脱氮菌种等措施 ,COD、NH3- N去除率改善显著 ,COD、BOD5与 SS的去除分别达到 89.6 %～ 93.4 %、97.9% ,95 .6 % ,特别是对 NH3- N,达到了 99%以上去除效率。将实验室结果应用于实际工程 ,也取得了好的效果 ,工程上 SBR系统对猪场废水厌氧消化液的COD去除 90 %左右 ,出水 COD基本上在 30 0 mg/ L 以下。 NH3- N去除率大于 99% ,出水 NH3- N小于 10 mg/ L。BOD5去除率大于 98% ,出水 BOD5小于 2 0 m g/ L。 TN去除率大于 90 %。

After anaerobically digested, the biodegradability of piggery wastewater became poor. Its value of BOD 5/COD fell to 0.19, moreover carbon and nitrogen was inversive, which brought much difficulty for anaerobically digested effluent to aerobically treatment. If Sequencing Batch Reactor(SBR) was used directly to treat anaerobically digested effluent, the treatment efficiency was very poor, with only 8.31% for COD removal rate, and 78.7% for NH 3 N. A significant improvement in system performance was achieved by increasing the biodegradability of anaerobically digested effluent of piggery wastewater. The removal rate for COD, BOD 5 and SS reached 89.6%~93.4%, 97.9%, 95.6%, respectively, especially, the removal for NH 3 N was more than 99%, an extremely high rate. The result of study was applied in piggery wastewater treatment plant, the SBR system worked well. The removal rate for COD was about 90%, that for BOD 5 and NH 3 N was larger than 98% and 99% of respectively. A satisfactory effluent quality from SBR, with COD<300 mg/L, BOD 5<20 mg/L, and NH 3 N<10 m/L, was achieved. The removal of TN also reached more than 90%.