生物膜厚度对膜曝气生物膜反应器硝化性能的影响

在设定的膜内压力下(2 k Pa)启动并运行膜曝气生物膜反应器(MABR),对生物膜生长过程中的硝化性能及生物膜组成变化进行了分析。实验结果表明,在生物膜厚度增长到(293.3±5.8)μm的过程中,生物膜内的总氧通量先增加后减少,最高可达21.3 g O2?m?2?d?1,证实了生物膜的存在可增强MABR的氧传质能力。在生物膜厚度增长的过程中,氨氮表面去除负荷也是先增加后减少,最高可达4.91 g N?m?2?d?1,表明在MABR硝化过程中存在最佳的生物膜厚度,根据所研究最佳生物膜厚度为(119.0±3.0)μm,此时MABR具有最高的氧通量和氨氮表面去除负荷,硝化性能最好。生物膜内胞外聚合物(EPS)成分分析结果表明,随着生物膜厚度的增加,生物膜内层紧密型EPS的含量增加,导致氧传质阻力增加,这是生物膜内氧通量及氨氮去除负荷随生物膜厚度先增加后下降的内在原因。     

膜曝气生物膜反应器内流场的CFD模拟及组件优化

基于数值模拟的方法研究了不同填充方式、填充密度、循环流量下膜曝气生物膜反应器(MABR)内流场特性。研究结果表明, 随机填充时, 反应器内存在偏流沟流现象, 且进口处动能损失大;规则填充时, 截面流速稳定区域较长, 更适于MABR生物膜的生长。填充密度对MABR壳程速度场的影响显著, 并且存在一最佳值;当填充密度为30%时, 反应器整体速度场比较均匀稳定。实验采用三维电磁测速仪对实体模型进行流场测量, 得到反应器内流场速度与模拟值接近, 误差小于10%;当循环流量为7.62 L·min^-1时, 反应器截面平均流速可以维持在0.026 m·s^-1, 并且进口最大流速低于0.20 m·s^-1, 不会导致生物膜的脱落, 该稳定的流场分布符合MABR内部的速度场分布需求。     

膜曝气生物膜反应器处理餐饮废水的研究

采用自然挂膜法进行培养微生物,研究了以疏水性中空纤维膜作为膜组件膜曝气生物膜反应器(MABR)好氧、厌氧、先好氧后厌氧以及先厌氧后好氧等不同曝气方式、不同膜丝种类和曝气压力对系统序批式去除餐饮废水COD、NH3-N的影响。结果表明,好氧方式不仅对餐饮废水处理效果较好,而且还可以降低经济成本;当进水COD和NH3-N的质量浓度分别为1.8~6.0 g/L、30~60 mg/L,曝气压力为60 kPa,膜丝为聚四氟乙烯中空纤维,好氧曝气处理12 h时,MABR能够较容易的使餐饮废水出水的COD保持在0.4 g/L以下,NH3-N的质量浓度保持在4 mg/L以下,达到CJ 343-2010排放标准。     

生物膜法新工艺--无泡曝气膜生物反应器

无泡曝气膜生物反应器是一种可同时去除COD和氮的新型膜生物反应器,其主要特征是利用蔬水性微孔膜作为生物膜载体并进行无泡供氧。介绍了该反应器的工艺原理及无泡曝气的特点,讨论了其运行影响因素和未来研究方向。     

膜曝气生物膜反应器处理合流制溢流污水的实验研究

以聚丙烯复合材料经熔融拉伸制成的帘式超薄微孔中空纤维膜为载体,构建膜曝气生物膜反应器装置处理合流制溢流污水,研究在不同水力停留时间、曝气压力、水流流速条件下,膜曝气生物膜反应器对水体中污染物COD、NH₄⁺-N、TN的去除率。结果表明：膜曝气生物膜反应器对水体中各项污染物均有较好去除效果。水力停留时间为12 h时,COD、NH₄⁺-N、TN去除效果较好,去除率分别为80.8%、82.4%、65.4%;水力停留时间为8 h时,TP去除效果达到34.2%,后期逐渐趋于平缓。溶解氧浓度随曝气压力增加而增加,曝气压力达到25 kPa之后COD、NH₄⁺-N达到较佳的去除率,平均去除率分别为82.2%、84.1%;而TN去除的最佳曝气压力为15 kPa,去除率为70.0%。水流流速为0.03 m/s和0.05 m/s时,反应器整体运行效果较好,对COD、NH₄⁺-N、TN的平均去除率分别为81.8%、83.5%、67.8%...     

碳管膜曝气膜生物反应器处理高浓度氨氮污水的研究

对以煤基微孔碳管为组件的碳膜曝气膜生物反应器(MABR)处理高浓度氨氮污水进行了实验研究。碳膜同时起到生物膜载体和无泡曝气的双重作用。氧气和营养物分别从生物膜的两侧进入膜内。本实验进行150d,分阶段对不同溶解氧(DO)条件,不同进水浓度和不同水力停留时间(HRT)下,MABR的硝化、反硝化同时去除COD的性能进行研究。研究表明,在溶解氧为0.8 mg/L的条件下,TN有最佳去除效果,NH3-N、TN和COD去除率分别为87.88%、86.5%和87.64%。NH3-N的去除率随DO的升高而增大,去除率可达99.7%,但更高的溶解氧(>1.6 mg/L)对去除率影响甚微。高进水负荷实验于16d内,进水NH3-N浓度增大4倍,至214.25 mg/L,去除率仍保持92%以上。HRT由20h逐渐降低至8h时,去除率略有降低,但去除负荷增长2倍以上。说明该MABR装置有良好的脱氮能力和较高负荷下的污水处理能力。     

膜生物反应器污水处理过程中膜生物污染的研究进展

本文论述了用于污水处理的膜生物反应器的膜污染及其影响因素，同时，重点分析了膜生物污染的形成机理、微生物粘附和繁殖生长，并讨论了膜的生物污染现象、形成过程、危害以及防治措施。     

膜生物膜反应器的研究与应用

为提高反应器中氧的利用率,高效去除水中的有机碳和氨氮,介绍了一种新型的水处理反应器-膜生物膜反应器,该反应器通过膜分离技术与生物膜技术相接合,可获得100%氧利用率.并且能够起到快速降解挥发性有机物和高效去除有机碳和氨氮的作用,是一种很有发展潜力的污水处理工艺.     

膜生物反应器中曝气方式的比较及改进思路

膜生物反应器虽然已成功地应用于废水处理系统,但是膜污染限制了其进一步的推广和应用,因此,有效控制膜污染已成为影响该技术运用的首要因素。通过分析比较现有曝气方式均存在能耗高、氧传递速率低、以及容易导致膜污染等问题,提出了改进一体式膜生物反应器所采用的曝气方式,即采用射流曝气来解决这些问题的思路。     

硅胶膜曝气生物反应器同步短程硝化反硝化研究

以疏水性无孔硅橡胶管为膜曝气组件,通过长期的运行试验,对硅胶膜曝气生物反应器中实现同步短程硝化反硝化的可行性进行了研究。结果显示:在温度为32℃,p H为7.5~8.0,溶解氧为0.5 mg/L,HRT为12 h,进水COD为300 mg/L,NH4+-N为60 mg/L时,SMABR具有最佳去除效果,此时出水NO2--N为7.3 mg/L,NO3--N未检测到,NH4+-N、TN、COD去除率分别为82.9%、71.0%、90.0%。研究结果表明:SMABR通过改变反应条件能稳定实现同步短程硝化反硝化。     

Effect of perchloroethylene (PCE) and hydraulic shock loads on a membrane‐aerated biofilm reactor (MABR) biodegrading PCE

BACKGROUND: A membrane‐aerated biofilm reactor (MABR) has previously been used to provide both anaerobic and aerobic conditions for mineralisation of perchloroethylene (PCE). However, very little is known about the stability of this reactor under hydraulic and PCE shock loads. An MABR was therefore subjected to sudden hydraulic and PCE shock loads in order to investigate its stability under such conditions. RESULTS: After each shock, the reactor responded with an increase of chemical oxygen demand (COD) and volatile fatty acids (VFA)s, a breakthrough of PCE and its biodegradation intermediates in the effluent, and a decrease in methane production. Although some PCE biodegradation intermediates were found in the effluent during each shock loading, the MABR performance recovered without the accumulation of any particular PCE biodegradation intermediates during PCE shock loads. During the hydraulic shock loads, the MABR was unstable at hydraulic retention times (HRTs) of 6 h with PCE and its biodegradation intermediates detected in the effluent. However, these intermediates were degraded when the HRT was reset to 48 h. CONCLUSIONS: This study suggests that MABRs can withstand fluctuations in influent strength and flows which occur in wastewater treatment works. Copyright © 2009 Society of Chemical Industry     

Development of a membrane‐aerated biofilm reactor to completely mineralise perchloroethylene in wastewaters

The feasibility of perchloroethylene (PCE) biodegradation using hybrid aerobic/anaerobic microcosms was investigated. Four main factors were evaluated in batch studies; the type of the electron donor, the nature of the inoculum, the effect of different concentrations of electron donor, and the effect of addition of different concentrations of oxygen. Results from these studies showed that; glucose was the best electron donor for PCE degradation, serum bottles seeded with acclimated biomass performed better than those seeded with the unacclimated biomass, glucose in excess did not improve PCE degradation, and the addition of pure oxygen significantly enhanced degradation. It was observed that serum bottles with acclimated sludge receiving oxygen achieved complete mineralisation of PCE to ethylene with mineralisation rates of 0.27 mg L^?1 mg cells^?1 h^?1. Following these results a membrane‐aerated biofilm reactor (MABR) was constructed, and the batch degradation of 5.5 mg L^?1 of PCE was followed for 44 days and PCE was completely removed from the system. The appearance of intermediate compounds proved that PCE was degraded, but not completely stripped out from the system. Degradation was not complete as some bio‐products were still found in the effluent, but there was no accumulation of a particular intermediate compound. The PCE removal rate observed in this MABR was 0.24 mg L^?1 h^?1. During the study on the effect of adding different concentrations of oxygen, a mass balance based on chloride in the bottles revealed that, 92–95% of the PCE could be accounted for, while only 60–65% of the PCE fed in the reactor could be accounted for as chloride. The MABR developed here may prove to have considerable potential in treating wastewater containing a variety of refractory organics such as PCE. Copyright © 2006 Society of Chemical Industry     

Double‐deck aerated biofilm membrane bioreactor with sludge control for municipal wastewater treatment

Alternative designs of an aerated moving‐bed biofilm reactor and a flat‐sheet membrane module for a biofilm membrane bioreactor process have been investigated to overcome a membrane clogging problem and to determine the performance of a new membrane module. Double‐deck aerated biofilm reactor with integrated designs of sludge hopper, thickener, and velocity‐zone concept for particle settlement was evaluated for the suspended solid control and removal. Hydrodynamics of bubbling, liquid, and solid particles were arranged in the bioreactor to obtain a particle settlement. New membrane modules used under low suspended solid environment having smaller membrane gaps were evaluated for filtration performance and clogging problems for long‐term operation. The average suspended solids concentration in the bioreactor effluent was 44.6 mg/L. Relaxation applied with the membrane module provided the most optimum result for fouling control, and no clogging problems in the modules were observed in the system after continuous operation of 3 weeks. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

去除饮用水中氧化态污染物的氢基质膜生物反应器

环境污染的加剧导致饮用水中不断出现新的污染物,由于饮用水的贫营养性及传统工艺自身的缺点使传统工艺在实际应用中受到限制.而氢基质膜生物反应器(MBfR)能够有效地利用中空纤维膜外自养微生物以氢气作为电子供体去除饮用水中的氧化态污染物.成本较其他深度处理工艺低,且无后续污染物.作者介绍了MBfR的构造和工作原理,分析了MBfR处理饮用水中各种氧化态污染物的原理.并探讨了该领域的研究重点与方向.     

氢基质膜生物膜反应器去除饮用水中氧化性物质研究进展

介绍了氢基质中空纤维膜生物膜反应器去除饮用水中氧化性物质的机理及国内外研究现状。膜生物膜反应器采用中空纤维膜,利用氢气作为电子供体来还原水中氧化性物质(如硝酸盐、砷酸盐、高氯酸盐、溴酸盐和硒酸盐等)。氢基质膜生物膜反应器具有氢气利用率高、操作方便、占地面积小、剩余污泥量少、膜污染小等优点,相对传统污水生物处理是一种新型的水处理技术,因此具有良好的应用前景。     

PVDF/PES-C共混膜的结构与性能

以邻苯二甲酸二丁酯(DBP)和N,N-二甲基乙酰胺(DMAc)为混合稀释剂,采用热致相分离法(TIPS)制备了聚偏氟乙烯(PVDF)和酚酞型聚醚砜(PES-C)共混膜,采用扫描电镜观察了膜的截面结构,测试了膜的纯水通量。通过膜生物反应器处理生活污水,检验了膜的污水处理性能。与PVDF膜相比,共混膜具有一个较薄的致密的皮层和较为疏松的支撑层,共混膜的纯水通量约为纯聚偏氟乙烯膜的两倍。同时共混膜的污水通量较高,COD和NH4+-N的去除率与PVDF膜相比约增加10%,共混膜的通量衰减系数较小,具有更好的抗污染性能。     

LDV技术优化膜反应器结构

通过采用激光多普勒测速仪（LDV）测定膜反应器内气水混合液的流速分布,研究了膜反应器中设置导流板、膜出水流速以及曝气强度对膜面的剪切流速的影响。研究结果表明,导流板可以增大混合液在中下部膜面附近的切向上升时均流速,混合液的紊动性增强,进而增强了对膜面的剪切作用,有助于延缓膜面滤饼层的形成,缓解浓差极化现象。增大膜出水流速,混合液上升流速和指向膜面的流速均有所增大。曝气强度也会影响流速。时均上升流速和脉动上升流速与曝气强度符合正对数关系。增大气量后,混合液的紊动性增大,气水混合液对膜面的剪切强度也增大。