Two Phase Anaerobic Digestion in Membrane Separated Bio-Reactor

膜分离生物反应器是一种适合于单相厌氧消化而不是两相厌氧消化的技术。在该计划的第一年，在实验室规模的实验中研究了膜分离厌氧消化。制备3L玻璃瓶作为反应器，用磁力搅拌器和热板加热混合。带超滤膜的膜组件（直径75mm）连接到反应器上，通过吸力将渗透液从混合液中分离出来。以某实际污水处理厂的污水污泥为基材，每天向反应器投料。在该计划的第二年，反应器的体积增加到5L，目的是测量反应器中的质量平衡。膜组件的直径也增加到150mm。在该计划的最后一年，使用塑料反应器代替，并引入机械混合。采用中空纤维膜…More模块进行分离。手术在很长一段时间内都很好，很稳定。在最后一年的研究中得到的结果和结论如下。(1)甲烷气产率较高时，渗透液中CODcr浓度小于200mg/l。(2)随着底物加载速率的增加，反应器中MLSS浓度可达40000 mg/l。(3)运行过程中反应器内约60%的MLSS为有机物，反应器内未见无机物积累。(4) MLSS的自降解率很低。(5)挥发性脂肪酸浓度在污泥投料后4-5h达到最高，之后逐渐降低。(6)反应器中固体水解率很低。(7)微滤膜和超滤膜都能产生几乎相同质量水平的处理水。高分子量有机物在两种体系中均被去除。(8)在甲烷产量受到破坏的情况下，即使降低了装载率，也需要数周时间才能恢复作业。通过防止膜分离对细菌的完全冲刷，使反应器内达到平衡细菌生长和自降解的平衡条件。除渗透液中的有机物外，输入的有机物几乎全部进入气相（小于总输入的1%）。占据污泥30%以上的无机物将被完全溶解。通过引入膜分离厌氧消化技术，可以使灰渣处理成为不必要的过程。少

Membrane separated bio-reactor was found to be an appropriate technology for single-phase anaerobic digestion rather than for two-phase anaerobic digestion. In the first year of the program, membrane separated anaerobic digestion was studied in laboratory scale experiments. Glass bottles (3L) were prepared as reactors, which were heated and mixed with magnetic stirrers and hot plates. Membrane modules (75mm diameter) with ultrua-filtration membrane were connected to the reactors therefore separating permeate from the mixed liquor by suction. Sewage sludge from an actual wastewatter treatment plant was used as a substrate and was fed to the reactors everyday. In the second year of the program the volume of the reactors was increased to 5L with the purpose of measuring mass balance in the reactors. The diameter of the membrane module was also increased to 150mm. In the last year of the program, plastic reactors were used instead and mechanical mixing was introduced. Hollow-fiber membrane … More module was used for the separation. The operation had been very good and stable during a long period. The results and conclusions obtained in the last year of the research were as follows.(1) CODcr concentration of the permeate was less than 200mg/l when the production rate of methane gas was reasonably high.(2) MLSS concentration in the reactor was increased up to 40,000mg/l with the increase of the substrate loading rate.(3) About 60% MLSS in the reactor had been organic matter during the operation and no accumulation of inorganics in the rector was observed.(4) The self-degradation rate of MLSS was very low.(5) Volatile fatty acid concentration becomes the highest level in 4-5h after the feeding of sludge and then gradually decrease.(6) Hydrolysis rate of solids in the reactor was very low.(7) Both microfiltration membrane and ultrafiltration membrane can produce treated water at almost similar quality level. High molecular weight organics were removed in the both system.(8) It took several weeks for the recovery of the operation even by the reduction of the loading rate when methane production was damaged.An equilibrium condition can be obtained in the reactor balancing the growth of bacteria and the selfdegradation by preventing the wash-out of bacteria completely with the membrane separation. Input organics can almost completely go to gas phase besides organics in the permeate (less than 1% of total input). Inorganics, which occupies more than 30% of sludge will be dissolved completely. Ash treatment could be non-necessary process by introducing membrane-separated anaerobic digestion. Less