不同生物载体模拟河道反应器的微污染水源水修复研究

分别以弹性填料和AquaMats生态基为载体,比较了2组模拟河道生物反应器启动过程及其修复微污染水源水性能.结果表明,在间歇曝气与逐步增强曝气强度的挂膜启动方式下,悬挂弹性填料的模拟河道反应器运行50d即启动完成,其高锰酸盐指数、氨氮去除率分别高达78.2%、93.5%;AquaMats生态基反应器的高锰酸盐指数、氨氮去除率则在2周后分别达到70%、80%以上.不同曝气方式的影响研究发现,曝气/停曝时间比3h:3h、曝气量250L·h-1工况下,弹性填料生物膜反应器的高锰酸盐指数、氨氮、TN、TP的去除率均优于AquaMats反应器;随着曝气强度减至120L·h-1及曝气/停曝时间比缩短,AquaMats反应器的污染物去除性能逐步提高,表明其在确保一定的污染物去除率的前提下具有低气水比潜力与节能降耗的应用优势.镜检分析发现,弹性填料表面以颗粒物质截留、丝状菌包裹为主,而AquaMats生态基上附着的生物膜微生物群落相对较丰富.研究认为,呈辐射状结构的弹性填料对颗粒态污染物具有较强的截留能力,可实现微污染源水修复系统快速挂膜与稳定运行;而AquaMats生态基内部微孔结构有利于不同功能的微生物富集,可在低气水比条件下强化多种低浓度污染物的协同去除.

Bioremediation of Micro-polluted Source Water by Simulated River Bioreactor with Different Carriers

Two simulated river bioreactors with elastic filler and AquaMats were applied to remediate micro-polluted source water. Under intermittent aeration and gradual increase of aeration intensity, the biofilm reactor with elastic filler was successful start-up within 50 days, and average removal efficiencies of permanganate index, NH4(+) -N were 78.2% and 93.5%, respectively, but the removal efficiencies of the reactor with AquaMats were more than 70% and 80% after two weeks. On the condition of aerobic to anoxic ratio of 3 h: 3 h and aeration intensity of 250 L x h(-1), elastic filler was more efficient for the removal of permanganate index, NH4(+) -N, TN and TP. The pollutant removal of AquaMats was strongly enhanced when the aerobic to anoxic ratio and aeration intensity changed to 2 h :4 h and 120 L x h(-1), which suggested its potential of energy saving. Microscopic observation revealed that the surface of elastic filler was fully surrounded with filamentous bacteria and more inorganic particulate matter after successful start-up of the reactor, and the biofilm attaching to AquaMats was of higher microbial population diversity. The results indicated that elastic filler with homogeneous biofilm had a strong retention capacity for its radial structure, and the AquaMats with microporous structure was more suitable for the enrichment of different functional microorganisms and enhanced the collaborative removal of multiple pollutants.