复合膜生物反应器处理采油废水的挂膜及污泥驯化

On the membrane hanging and sludge reclamation in HMBR for oilfield-sewage processing

向膜生物反应器（MBR）中投加聚丙烯（PP）填料作为生物膜载体,构建复合膜生物反应器（HMBR）。为了改善HMBR对采油废水的生化处理效果,对系统内活性污泥进行驯化及挂膜培养。分别研究了驯化期系统内污泥性能、填料挂膜效果、微生物相的变化情况以及对废水的处理效果。结果表明,经过25 d的驯化培养后,评价污泥浓度与沉降性能的指标如MLSS、MLVSS、SVI等明显改善。填料挂膜成熟,填料上的生物量稳定在1 500 mg/L,生物膜厚2~3 mm,在生物膜表面以及悬浮污泥中,一些表征污泥成熟的微生物相包括菌胶团、轮虫、纤虫大量出现。系统出水的CODCr去除率为88%,含油量去除率为95.6%,表现出了对采油废水的良好处理效果与抗冲击负荷能力。相比传统MBR,HMBR中的膜孔阻力Rp和滤饼层阻力Rc分别降低了48.7%和51.8%,说明HMBR能够有效控制膜污染。

This paper is aimed at presenting our study results on the membrane hanging and sludge reclamation in HMBR for the oilfield-sewage processing of a hybrid membrane bioreactor（HMBR） by putting the polypropylene filler as the biofilm carrier into the membrane bioreactor.In order to improve the biochemical processing efficiency for the oilfield sewage,we have incubated the activated sludge from the secondary sediment tank of the oil-refinery sewage-treating station and acclimated in the HMBR.The ratio of the oilfield sewage in the mixture to the glucose-nutrient solution can be increased step by step with the sludge being acclimated in the HMBR.For this purpose,we have investigated the sludge properties,the biofilm forming property,the microbial morphology,and oilfield sewage processing efficiencies respectively.The results of our investigation indicate that the method we have worked out is effective and efficient for cultivating and enriching the activated sludge stage by stage successively.The said activated sludge can be acclimated during about 25 d at an aeration rate of 0.3 m3/h,hydraulic retention time（HRT） of 12 h and the culture temperature of 26 ℃.The results of the application of our method prove that the biofilm can be made mature with a thickness of 2-3 mm and the biomass on the filler about 1 500 mg/L in the last acclimation stage.We have found that there has occurred a change with the microbial morphology and preponderant microbe in the sludge,e.g,a certain quantity of the filamentous bacteria,rotifer,acineta tuberosa,aspidisca cicada in the sludge and the biofilm.At the same time,significant improvement has been made on the evaluation indexes of the sludge concentration and sedimentation behaviors,such as MLSS,MLVSS,SVI.The HMBR system has been made favorable for the removal of CODCr and oil content with the removal efficiency heightened to 88% and 95.6%,respectively.All of results and phenomena indicate that the HMBR system operates always in a stable and favorable way against the shock loading resistance.In so doing,we have made high-quality membrane fouling control and the film-hole resistance Rp with the cake layer resistance Rc reduced by 48.7% and 51.8% as compared with the MBR.