UASB反应器对印染废水中碳、氮、硫的协同去除研究

采用"UASB-缺氧好氧-混凝沉淀"组合工艺对印染废水进行中试处理研究.结果发现,UASB反应器不仅可以解决印染废水可生化性低、色度高的问题,还对废水中的碳、氮、硫具有协同去除作用,优化条件下UASB可将废水B/C从0.18~0.26提高至0.4以上,对色度、COD、TN、SO_4~(2-)、S~(2-)平均去除率分别为77.0%、36.4%、38.5%、77.5%、60.1%.同时,为了探究碳、氮、硫协同去除机理,对优化条件下的运行数据进行了分析并采用454高通量测序技术进行菌种鉴定.结果表明,UASB反应器内存在硫酸盐还原、厌氧氨化、同步脱硫反硝化和硝化反硝化4种作用,从而造成了碳、氮、硫的同步去除.菌种鉴定未发现产甲烷菌,说明产甲烷菌受到了抑制,UASB反应器很好地停留在了水解酸化阶段.进一步结合小试研究得出,硫酸盐还原是促使硝化反硝化、脱硫反硝化产生的原因,同时也促进了有机物去除.总体而言,硫酸盐还原促进了碳、氮、硫的协同去除.

Study on the synergistic removal of carbon, nitrogen and sulfur in dyeing wastewater by UASB reactor

It has been observed that UASB reactor not only could improve biodegradability and remove color effectively, but also had a synergistic removal of carbon, nitrogen and sulfur when a pilot process combining UASB, anoxic-aerobic and coagulation-sedimentation to treat dyeing wastewater.The indice of B/C in wastewater could be increased from 0.18~0.26 to above 0.4 and average removal rates of color, COD, TN, SO₄^2- and S^2- could reach to 77.0%, 36.4%, 38.5%, 77.5% and 60.1% respectively, by UASB reactor under optimal conditions. In order to explore the mechanism of synergistic removal of carbon, nitrogen and sulfur in the reactor, the performance were analyzed under the optimized conditions and bacteria were identified by using 454 high-throughput sequencing technology. The results show that there were four reactions in UASB, including sulfate reduction, anaerobic ammoniation, simultaneous desulfurization & denitrification and traditional nitrification & denitrification, which led to the simultaneous removal of carbon, nitrogen and sulfur. Methanogens were not found by species identification, which meant that methanogens was inhibited and UASB reactor stayed in the hydrolysis acidification stage. Results also show that the nitrification & denitrification and simultaneous desulfurization & denitrification was due to sulfate reduction, which also acceletated the removal of organic compounds. Briefly, sulfate reduction stimulated the synergic removal of carbon, nitrogen and sulfur.