一种新型两段式生物反应器处理生活污水的试验研究

【作者】 张栋华；

【导师】 岳钦艳；

【作者基本信息】 山东大学 ， 环境工程， 2006， 硕士

【摘要】 本论文开发研究了一种利用两段式生物反应器实现废水资源化的新型工艺，设置序批式好氧颗粒污泥生物反应器和膜生物反应器两个生物反应阶段。在第一阶段中，通过对序批式反应器内好氧颗粒污泥的培育实现了有机物的高效去除，在此过程中产生少量的剩余污泥，而随出水被洗出的分散细菌(SS)刚好成为第二个阶段即膜生物反应器内原、后生动物的养分：第二阶段则在MBR内对污水进行深一步处理，实现对第一阶段有机物的进一步降解，提高出水水质，同时微型动物大量捕食细菌，实现剩余污泥减量化。 在序批式反应器中，通过改变操作条件培养出颗粒活性污泥，较小的沉淀时间是产生颗粒污泥的主要因素。在较低的沉降速度下产生以菌胶团为主的颗粒，提高污泥的沉降速度产生以丝状菌为主要结构的颗粒污泥。反应器的容积负荷对颗粒结构有一定影响，提高容积负荷有利于形成密实且沉降速度快的颗粒污泥。容积负荷的提高对COD去除效果没有明显影响，有机物的去除主要在一个周期的前期发生。氨氮的去除约为24％左右，出水中几乎没有硝酸盐和亚硝酸盐，反应器中可能发生同步硝化反硝化。 膜生物反应器中投加粉末活性炭后形成的(PAC-MBR)组合工艺，改善了污泥混合液的性状，膜污染得到了有效缓解，同时出水水质得到提高，出水经适当处理可达到回用的目的。研究结果表明：组合工艺可以明显改善膜的过滤性能，显著提高膜的使用周期。PAC的吸附作用减少了由于胞外聚合物而引起的膜污染：膜表面PAC颗粒的存在减小了浓差极化层的厚度和水力边界层的厚度，提高了对流传质系数和过滤物质的传递速率；膜表面形成的PAC层提高了潜在污染物的反扩散，还可过滤微生物和胶体颗粒，减少它们到达膜表面的数量。 组合工艺能在不排泥的运行条件下，保证了出水水质，稳定运行后化学需氧量COD去除率可达到95％以上，出水氨氮基本维持在1mg／L以下，出水无SS检出，出水浊度小于0.3NTU，同时减缓了膜污染，大大增加了膜清洗和更换周期。两段式生物反应器工艺不仅是污泥减量技术发展的方向，也是防治膜污染的有效手段，是一项高效、节能的新型城市污水资源化技术，具有良好的经济、环境和社会效益，具有广阔的市场前景。更多还原

【Abstract】 In this paper, a novel technology using a two-stages bioreactor in order to achieve wastewater reclamation was developed. It was combined with a granular sequencing batch reactor (SBR) and a membrane bioreactor (MBR). During the first process, the organic matter could be removed effectively by the cultivated aerobic granules in the SBR. At the same time, little excess sludge was produced while the suspended solid (SS) washed out with the effluent became the nutrient of the protozoan and metazoa in the MBR. The second process could have the wastewater further treatment on the basis of the first process to improve the effluent quality, and realize the excess sludge reduction through the microfauna predation.The aerobic granules could be cultivated successfully in the SBR by changing the operating conditions, and the shorter settling time was the primary affecting factor. The zoogloea granules predominated in the lower settling velocity, then filamentous microorganisms granules could be formed with the increasing of the settling velocity. The organic loading rate (OLR) had some effects on the granular structure. With the increasing of OLR, higher settling velocity and denser granules could be shaped, but the removal efficiency of COD did not alter obviously. The removal of organic pollutants happened during the former period mainly. The removal efficiency of ammonia nitrogen was about 24%, while nitrate and nitrite were almost absent in the effluent. Simultaneous nitrification and denitrification might occur in the reactor.Adding PAC to the MBR could ameliorate the characteristics of sludge mixture and reduce the membrane fouling effectively. The effluent quality could also be advanced and reused after some other relevant treatment. Results showed that the combined technology could improve the membrane filtration performance evidently and increased the using period of membrane. The adsorption effect of PAC reduced the membrane fouling caused by EPS. The presence of PAC on the membrane surface minished the thickness of the concentration polarization and hydraulic boundary layer. The transferring velocity of the filtered matter was enhanced. At the same time, the PAC layer could also filter the microorganisms and colloids to cut down the amount landing on the membrane surface.The combined process could ensure the effluent quality without discharging sludge. The COD was reduced by 95% and the ammonium concentration in the effluent was under 1mg/L. There was no SS in the effluent, and the turbidity was less than 0.3NTU. At the same time, the membrane fouling could be alleviated and the cleaning and replacing period was prolonged.The two-stages bioreactor is not only the way of sludge reduction but also the effective measure to prevent the membrane fouling. It is a high efficiency and saving energy novel technology to realize the wastewater reclamation, which shows good economic and environmental benefit and broad market.更多还原