【作者】 杨琦；

【导师】 刘振鸿；

【作者基本信息】 东华大学 ， 环境工程， 2012， 硕士

【摘要】 膜生物反应器是将膜分离技术与生物处理技术有机结合的一种污水处理新技术,具有出水水质好、工艺流程简单、剩余污泥产生量少、占地面积小、自动化程度好等优点,该项技术经过了几十年的发展,其应用领域不断的扩大,已经引起了人们广泛地关注。然而由于膜生物反应器的膜组件造价过高,限制其大范围的推广使用。因此,本课题研究采用优价廉的尼龙纺织布作为过滤组件组成新型的布生物反应器。布生物反应器除具有传统膜生物反应器流程简单、占地小、剩余污泥产量小等优点外,还具有低造价、低能耗、高强度等特点,这种新型工艺虽然处理效果不及膜生物反应器,但是完全能够替代传统工艺上的沉淀池,对于小规模的污水处理是一种很有应用前景的技术,具有重要的研究意义。本文比较了不同孔径的尼龙纺织布生物反应器处理生活污水的效果,从而分析了不同尼龙纺织布作为过滤介质的可行性。通过试验研究,考察了尼龙纺织布生物反应器对模拟生活污水的长期处理效果,获得了满意的效果。为了布生物反应器在实际工程中推广应用,本研究考察了影响布生物反应器处理效果的因素和维持其长期稳定运行的因素,通过理论分析与试验研究,得到了布生物反应器应用于处理生活污水的工艺参数,并对过滤机理及膜污染阻力进行了初步探讨。主要的研究内容和实验结果如下：(1)在本试验条件下,300目尼龙纺织布生物反应器出水中含有少量的污泥颗粒,不能作为布生物反应器的过滤材料。400目和500目尼龙纺织布组成的布生物反应器对污染物均有较好的去除效果,系统对CODcr的去除率均在90%以上,平均去除率分别为90.32%、92.89%,系统对UV254、浊度和SS的效果较好。通过比较400目和500目尼龙纺织布生物反应器可知,二者处理效果相差甚微,而400目尼龙纺织布过滤组件通量大于500目尼龙纺织布过滤组件,并且更稳定,出水效果最接近于沉淀池出水。(2)进行了400目尼龙纺织布生物反应器长期连续运行的研究。结果表明,布生物反应器工艺对污染物具有较好的处理效果。400目尼龙纺织布生物反应器连续运行41天,对有机物的平均去除率为93.68%,出水平均CODcr为104mg/L；对浊度的平均去除率为90.31%,出水平均CODcr为22.6NTU。(3)尼龙纺织布生物反应器处理效果不受污泥膨胀的影响。运行期间出现了活性污泥丝状膨胀,由于丝状菌大量生长,布生物反应器中生物处理效率得到了一定提高,尼龙纺织布能够高效截留反应器中的活性污泥,系统出水更佳清澈。布生物反应器中的尼龙纺织布对系统出水的稳定性起到了主要作用,弥补了生物反应器处理性能的不稳定,提高了系统的抗污泥膨胀的能力。(4)400目尼龙纺织布生物反应器最佳运行条件为：水力停留时间为20h,污泥浓度为7100mg/L,污泥负荷范围为0.09-0.12kg/(m3·d)。(5)尼龙纺织布生物反应器过滤机研究表明,尼龙纺织布通过机械筛分、表面吸附、架桥吸附三种方式进行固液分离。(6)尼龙纺织布过滤总阻力为0.21114 m-1,比传统膜生物反应器过滤阻力小11个数量级；尼龙纺织布固有阻力2.3005*10-5m-1,比中空纤维膜固有阻力低16个数量；尼龙纺织布过滤阻力主要由滤饼层贡献,占总过滤阻力71.93%。用水力清洗和化学清洗可有效去除尼龙纺织布污染,通量恢复90%以上。更多还原

【Abstract】 In recent years, membrane bioreactor (MBR) has been widely used in wastewater treatment to achieve higher effluent quality, which is often difficult to be effectively met by conventional activated sludge process. The advantages of MBR are high quality water, simple flow, lower excess sludge production, fewer area occupied and so on. Membrane bioreactors been developing for several decades and always broadening its application fields, and has attracted more and more attention. However, their widespread applications are hindered by their elevated energy consumption and the high costs of investment for the membrane modules. In this study, we investigated a modified an improved MBR system that utilized a cost effective woven fabric instead of nonwoven as the filter material in MBR modules for solving this problem. The fabric bioreactor. Besides simple flow, fewer area occupied et al as MBR, FBR also has the advantages of low cost, low energy consuming and high intensity. The new-style process is a promising technology for small-scale wastewater treatment, and has great significance to study.In this study, the performance of synthetic domestic wastewater treatment was evaluated in the FBR with different pore diameter nylon woven as filtration material at same operating conditions, in order to analyze whether the different pore diameter nylon as a filter medium is feasible. This study investigated the treatment performance of simulated domestic wastewater with the FBR, almost all effluent water quality can meet our hope. In order to optimize the process parameters of FBR, for its wide application of FBR in wastewater treatment, the factor that affects the effluent efficiency and the factor that affects the stable operation of FBR were analyzed in this paper. This study also discussed the filtration mechanism and resistance of the filter. The main study content and result are shown as follows:(1) The results show that effluent of FBR with mesh number of 300 is with some sludge, so the nylon woven of 300mu can not as a fabric filter material for FBR. FBR with different mesh number nylon woven of 400mu and 500mu has good removal efficiency for contamination. System CODcr removal efficiencies are all over 92%, and the average removal efficiencies are 90.32% and 92.89%respectively. FBR with different mesh number nylon woven of 400mu and 500mu have good removal efficiency for UV254, Turbidity and SS. By comparing the 400mu and 500mu nylon woven bioreactor, experimental datas show that little difference between the two nylon woven fabric. FBR with mesh number of 400 nylon fabric filter has greater flux than 500 mesh nylon fabric filter.(2) The FBR with 400mu nylon woven eliminated suction pumping by using a gravity head in the membrane filtration of the effluent over the entire operational period of 41d. The results show that FBR with t mesh number nylon woven of 400mu has good removal efficiency for contamination. System CODcr removal efficiency is 93.68%, the average CODcr of effluent is 104mg/L; turbidity removal efficiency is 90.31%, the average turbidity of effluent is 22.6NTU.(3) FBR has high resistance to sludge bulking. In conventional settling tank, sludge filamentous bulking was the most common problems that cause activated sludge settling problems and a deterioration of effluent quality. In the WFBR, since woven fabric as the solid-liquid separator could filtrate the level of suspended solids in the sludge supernatant, the effluence when sludge filamentous bulked was better than before.(4) The optimum operating condition of FBR with 400mu nylon woven is that:the optimum HRT is 20h, the optimum MLSS is about 7100mg/L, the optimum BOD loading rates is from 0.09 to 0.12 kg BOD/kg MLSS/d.(5) The results of filtration mechanism of FBR shows that the solid and liquid are separated by nylon woven fabric through mechanical sieving, superficial adsorption, bridging flocculation。(6) The total filter resistance with 400mu nylon woven is 0.21114 m-1, which is lower 11 orders of magnitude than the conventional membrane filtration resistance. The inherent resistance of 400mu nylon woven is 2.3005*10-5 m-1, which is lower 16 orders of magnitude than the conventional membrane filtration resistance. The filter cake accounts for 71.93%of the total resistance. Nylon woven fabric flux recovery after water cleaning and mechanical cleaning is above 90%.更多还原