燃煤厂烟气脱硫废水处理新策略及其作用机制

New Strategy and Mechanism of Flue Gas Desulfurization Wastewater Treatment in Coal-fired Plant

为了探究颗粒污泥对燃煤厂烟气脱硫废水营养型污染物的去除及微生物种群结构的变化特征,建立序批式厌氧/好氧反应器,以预处理后的燃煤厂烟气脱硫废水为研究对象,分析了污泥颗粒化进程中污泥特征,营养型污染物去除及微生物群落结构的演变规律。结果表明污泥颗粒化进程中污泥沉降指数(SVI)显著下降,污泥中生物量显著升高,在120 d时,SVI下降至62 mL/g,混合液总悬浮固体(MLTSS)升高至7.1 g/L。此外颗粒污泥胞外聚合物中蛋白质(PN)显著提高,PN/多糖(PS)升高至2.71~2.74。在稳定运行期,颗粒污泥对化学需氧量(COD)、铵氮(NH+4-N)及总磷(TP)去除效率分别高达89.25%~89.56%、93.4%和73.2%。微生物群落结构演变揭示污泥颗粒化进程提高Comamonadaceae及Pseudomonadaceae的相对丰度,从而提高脱氮除磷效率。

In order to investigate the removal of nutrient pollutants from flue gas desulfurization wastewater from coal-fired plants and the characteristics of microbial population structure changes in granular sludge, a sequential batch anaerobic/oxic reactor was established to pre-process coal fired plant smoke. The gas desulfurization wastewater was taken as the research object, and the sludge characteristics, nutrient pollution removal, and microbial community structure evolution during sludge granulation were analyzed. The results show that the sludge volume index(SVI) decreases significantly during sludge granulation, and the biomass in the sludge increases significantly. At 120 d, the SVI decreases to 62 mL/g, and the mixed liquid total suspended solids(MLTSS) increases to 7.1 g/L. In addition, the protein(PN) in the extracellular polymers of granular sludge increases significantly, and PN/PS increases to 2.71 to 2.74.During the stable operation, the removal efficiencies of COD, NH+4-N and total phosphorus(TP) by granular sludge is 89.25 to 89.56%, 93.4% and 73.2%, respectively. The evolution of microbial community structure reveales that the sludge granulation process increases the relative abundance of Comamonadaceae and Pseudomonadaceae, thereby improving the efficiency of nitrogen and phosphorus removal.