UASB-A/O耦合工艺处理高含氮印染废水中试

通过现场中试考察了UASB-A/O耦合工艺分类处理印染废水的效果. 在前处理废水UASB进水流量为0.065 m3/h,染色废水UASB进水流量为0.260 m3/h,同时A/O工艺混合液回流比为200%的情况下,该耦合工艺对印染废水中污染物去除效果最好:最终出水ρ(COD_Cr)<200 mg/L,ρ(NH₃-N)<10 mg/L,ρ(TN)<15 mg/L；染色废水和前处理废水在耦合工艺的UASB段都实现了高效厌氧氨化,染色废水厌氧出水ρ(NH₃-N)占ρ(TN)的比例稳定在80%以上,前处理废水稳定在85%以上,并且在常温厌氧条件下也可以实现较好的氨化效果；通过调整前段UASB的运行参数可有效实现对VFAs(挥发性脂肪酸)的调控,使之为缺氧反硝化提供充足的高品质碳源,以达到高效脱氮的目的；耦合工艺对印染废水中的PVA(聚乙烯醇)有较好的处理效果,UASB段对PVA的去除率在10%~40%之间,A/O段对PVA的去除率稳定在60%以上. 

Pilot Study on Treatment of Printing and Dyeing Wastewater by UASB-A/O Process

In a pilot experiment, the treatment of printing and dyeing wastewater by the UASB(up-flow anaerobic sludge bed)-A/O coupling process was studied. Optimal pollutant removal performance was obtained under the conditions of inflow rates 0.065 m3/h and 0.260 m3/h for pretreatment and dyeing wastewater, respectively, and reflux ratio fixed at 200% for the A/O process. In the effluent, COD_Cr was <200 mg/L, ammonia nitrogen was <10 mg/L, and total nitrogen was <20 mg/L. In the UASB process section, the dyeing and pretreatment wastewater showed high efficiency anaerobic ammoniation. Ammonia nitrogen occupied more than 80% and 85% of the total nitrogen in the anaerobic effluent of the dyeing and pretreatment wastewater, respectively. Even at normal temperature, anaerobic digestion could also achieve good ammoniation. In order to enhance the denitrification, VFAs(volatile fatty acid) could be controlled by adjusting the operation parameters of the UASB section, which produced a sufficient and high-quality carbon source for anoxic denitrification. The coupling process had a good removal efficiency of PVA(polyviny alcohol) in printing and dyeing wastewater. The removal rate of PVA was 10%-40% in the UASB section, while in the A/O section the removal rate was more than 60%.