摘要
采用UCT-MBR工艺处理合成市政污水，考查不同曝气强度与回流比的运行条件对该工艺在营养物去除效能及膜污染方面的影响。研究结果表明：曝气强度与回流比的变化对该工艺在COD （chemical oxygen demand, COD）及NH4＋-N去除效能影响不大，平均去除率分别保持在89.4%和99.7%，出水质量浓度维持在31.8和0.2 mg/L左右；在进水ρ（COD）/ρ（N）/ρ（P）为49.1/8.3/1.0的条件下，回流比的增加（r1由200%提高到400%）强化了反硝化除磷的效果，其中在低曝气强度条件（100-125 L/h，ρ（DO）=1-2 mg/L），回流比为400%的条件下, 反硝化除磷菌（denitrifying poly-phosphate accumulating organisms, DPAOs）占聚磷菌（poly-phosphate accumulating organisms, PAOs）的数量比例达到最大值，稳定在50.7%左右；曝气强度的增加 （250-300 L/h，ρ（DO）=2-3 mg/L），对缺氧除磷率（Rano-p）, 总磷（total phosphorus，TP）及总氮（total nitrogen, TN） 的去除效能均具有一定的抑制作用，分别由93.0%，92.6%和79.6%降至78.0%，77.0%及70.0%，且发现出水中TN与TP的含量及TN与TP的去除率具有一定的正相关性（ =0.636 0； =0.678 6）。此外，曝气强度的增加虽然使得结合型胞外聚合物（bound extracellular polymeric substances，Bound-EPSs）的含量增加，但气水两相流的刮刷作用明显地降低了滤饼层的污染阻力；增大回流比（r1由200%提高到400%）可增加对污泥的剪切作用，导致污泥粒径的减小及溶解性微生物代谢产物（soluble microbial productions, SMPs）的增加，是导致膜孔内部阻力增加的主要原因；红外光谱对膜表面污染物质的分析表明曝气强度与回流比的变化并没有造成其组成成分的变化。
A bench-scale UCT-type submerged membrane bioreactor was operated to treat synthetic municipal wastewater regarding the influences of aeration and recirculation ratios on process performance and membrane fouling. The results show that variations of aeration intensity and recirculation rations in UCT-MBR process have no effects on the COD and NH4＋-N removals, with removal efficiencies of COD （chemical oxygen demand） and NH4＋-N stabilizing at 89.4% and 99.7% on an average and with effluent concentrations of 31.8 and 0.2 mg/L respectively. In the feed condition of ρ（COD）/ρ（N）/ρ（P） at 49.1/8.31/1.0, the increase of recirculation ratio （r1 from 200% to 400%） strengthens the denitrifying phosphorus removal, during which in the condition of lower aeration intensity （100-125 L/h, ρ（DO）=1-2 mg/L） and the recirculation ratio of 400%, the ratio of DPAOs to PAOs reaches the maximum value, and stabilizes at about 50.7%. The increase of the aeration intensity （250-300 L/h, ρ（DO）=2-3 mg/L） inhibits anoxic phosphorus removal efficiency （Rano-p） and removal efficiencies of TP and TN, decreasing to 78.0%, 77.0% and 70,0% from 93.0%, 92.6% and 79.6% respectively. Furthermore certain positive correlations between effluent concentrations of TN and TP, removal efficiencies of TN and TP are observed （ =0.636 0; =0.678 6）. In addition, the increase of the aeration intensity induces the increase amount of Bound-EPSs （bound extracellular polymeric substances, Bound-EPSs）, whereas the scouring effect of the gas-water two-phase flow significantly reduces the resistance of the cake layer; the increase of recirculation ratio （r1 from 200% to 400%） also increases shear stress for activated sludge resulting in the decrease in particle size and the increase of SMPs （soluble microbial productions, SMPs）, which become the main reason for the increased resistance of deep pore clogging. FT-IR （Fourier translation infrared spectroscopy, FT-IR） analysis of the membrane foulants shows
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第7期2509-2516,共8页
Journal of Central South University:Science and Technology
基金
国家水体污染控制与治理科技重大专项(2008ZX07314-008)
关键词
膜生物反应器
回流比
反硝化除磷
曝气冲刷
膜污染
membrane bioreactor
recirculation ratio
denitrifying phosphorus removal
aeration scouring
membrane fouling
