膜生物反应器中污泥膨胀对脱氮除磷的影响

膜生物反应器以其膜取代了常规活性污泥法中的二沉池的突出优点迅速成为污水处理的新的发展方向.试验研究了污泥膨胀时,膜生物反应器对脱氮除磷的影响.分别对比了在正常情况下和污泥膨胀时,膜生物反应器对CODCr、氨氮、TN、TP的去除率.试验结果表明:发生污泥膨胀后,对CODCr的去除率达到96.51%有所提高,对氨氮、TN、TP的去除率分别为75.9%、39.8%、19.7%均有不同程度的下降.     

膜生物反应器脱氮除磷技术的研究进展

膜生物反应器(MBR)脱氮除磷技术是一种新型的脱氮除磷技术,在单一好氧膜生物反应器基础上,向与A/O、A2/O和SBR等工艺形式相结合的方向发展。介绍了近年来膜生物反应器在脱氮除磷方面的基本特点、研究现状、存在问题,分析了运行方式、技术参数对处理效果的影响,并指出了膜生物反应器脱氮除磷技术的发展方向。     

膜生物反应器同步脱氮除磷研究进展

综述了膜生物反应器的同步脱氮除磷工艺,介绍了影响膜生物反应器同步脱氮除磷效率的几个因素,探讨了同步脱氮除磷工艺中同时脱氮除磷的机理,并在此基础上提出了研究方向和应用前景.     

膜生物反应器强化脱氮除磷的研究进展

综述了膜生物反应器强化脱氮除磷的多种工艺,介绍了复合式膜生物反应器强化脱氮除磷以及反硝化聚磷菌脱氮除磷的研究成果,并在此基础上提出了研究方向和应用前景。     

一体化脱氮除磷反应器研究进展

叙述了一体化脱氮除磷反应器现状及新进展,对目前一体化脱氮除磷反应器存在的问题进行了分析。认为基于MBR反应器构型、高效脱氮除磷菌种应用及计算流体力学(CFD)优化设计的一体化脱氮除磷反应器是未来研究与开发应用的一个热点方向。一体化高效脱氮除磷反应器的创新发展与应用将为点源水污染控制、水源水质保护和污水资源化提供一种具有广阔应用前景关键实用技术,产生出良好环境效益及可观经济效益。     

膜生物反应器强化脱氮除磷工艺优化与控制

随着城镇污水排放标准对氮、磷等营养元素的进一步提高,对于传统污水处理工艺来讲是一种挑战.膜生物反应器工艺技术以其独特的优势备受关注,在强化脱氮除磷方面亦表现出优于传统工艺的特点.非传统脱氮除磷的观念的后置反硝化工艺(无外加碳源)在膜生物反应器中得到了应用,并取得良好的去除营养物的效果.从现有的MBR脱氮除磷工艺着手,分析探讨了MBR脱氮除磷工艺研究进展及其应用前景.     

一体化复合式膜生物反应器除磷研究

本文通过对比实验，研究了不同工艺组合条件下一体化复合式膜生物反应器（HCMBR）的除磷效果，研究表明，在无厌氧段的情况下，反应器内保持好氧状态的同时，填料内部存在厌氧环境，TP的去除率为22％，在有厌氧段（A／O）的情况下，TP的去除率可达70％，采用化学方法时，TP去除率可达82．1％，但过高的n(Al^3 )/n(TP)值将会影响污泥的活性，并且HCMBR对NH3－N，CODCr,TN等污染物有十分良好的去除效果。     

不同C/N对气升式内循环膜反应器的脱氮除磷的影响

提出了一种新型的气升式内循环膜反应器的设计构想,利用曝气来实现混合液在厌氧区和好氧区的循环,采用变液位间歇交换模式在厌氧区创造厌氧、缺氧交替环境,通过加强反硝化除磷过程实现污水同步脱氮除磷。对气升式内循环膜反应器进行了初步的研究,考察了不同m(C)/m(N)对脱氮除磷的影响。结果表明,在高的m(C)/m(N)(有机碳源和无机氨氮的质量比)条件下,TN、COD和PO43--P的去除率可以分别达到85%、95%和95%,该反应器需要高含量的碳源;在周期试验表明该反应器中具有反硝化聚磷菌,并且了解到了TN、COD和PO43--P等污染物的去除过程。     

复合式膜生物反应器强化脱氮除磷的实验研究

在传统好氧膜生物反应器(MBR)的基础上,结合厌氧/缺氧/好氧(A2/O)工艺开发了复合式A2/O膜生物反应器,并对其处理小区生活污水中的氮、磷等污染物的特性进行了研究。实验表明:在各自合适的条件下复合式A2/O膜生物反应器可保证化学需氧量(COD)的平均去除率达到90.17%,NH4+-N的去除率可达到92.32%,总氮(TN)平均去除率可达到72%,而总磷(TP)的平均去除率达到71.23%。     

MBR在脱氮除磷方面的最新研究与进展

介绍了近年来膜生物反应器(MBR)在脱氮除磷等方面的研究成果，论述了环境微生物学的进展在MBR脱氮除磷领域的发展和运用，指出了MBR工艺的发展方向，提出将来只有和微生物工程技术等结合，MBR脱氮除磷工艺才能取得更大的突破。     

Filterability of activated sludge in membrane bioreactors

The filterability of activated sludge is an important factor for the economical operation of membrane bioreactors (MBR). In the literature mainly investigations on sludge dewaterability in respect to further disposal are published. In this study, a procedure for determining filterability in a crossflow test cell is introduced. Its features are: no increase in sludge concentration during batch trials, crossflow conditions, and little impact on the sludge structure. The activated sludge filterability is given as the ratio of permeate flux after 40 min of operation to clear water flux. Sludge samples of eight different MBR and one conventional wastewater treatment plant (wwtp) have been examined and compared. Contrary to the literature, no impact of suspended solids (SS) concentration, sludge viscosity, or extractable extracellular polymer substances (EPS) concentration on the filterability was found. Instead, the composition of the liquid phase was found to effect most the filterability of activated sludge, a major influence being the concentration of suspended EPS: the higher the suspended EPS concentration, the lower the filtration index. Suspended EPS concentration increases with high mechanical stress in the MBR and high F/M ratios, if the treated wastewater contains considerable amounts of proteins or polysaccharides.     

Impact of chemical oxidation on sludge properties and membrane flux in membrane separation bioreactors

The effects of sodium hypochlorite (NaOCl) on sludge properties and membrane permeate flux were studied using a pressurized stirred ultrafiltration cell. Oxidation with NaOCl resulted in sludge solubilization and decreased sludge floc sizes. The sludge dissolution constant was estimated at 0.3 ± 0.1 mg sludge mg^?1 free chlorine under testing conditions. The increases in soluble chemical oxygen demand and total carbohydrate concentration in centrifuged supernatant were less than proportional to chemical dosage. Membrane permeate fluxes were much lower as a result of oxidation. Soluble biopolymers accounted for more than 76% of the total hydraulic resistance during ultrafiltration of oxidized sludge. By contrast, both the settleable sludge flocs and the soluble biopolymers were important contributors to the hydraulic resistance of sludge before oxidation. Given the benefits of NaOCl solution for membrane cleaning and its negative impact on sludge properties, the quantity of NaOCl solution used for maintenance cleaning of membranes should be optimized. Copyright © 2004 Society of Chemical Industry     

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。     

NOx——N对初沉污泥厌氧发酵及反硝化性能的影响

为了解决低C/N比污水的脱氮问题,本研究将NO_x^--N引入到初沉污泥厌氧发酵系统,利用初沉污泥厌氧发酵过程释放的有机碳源完成反硝化,以达到利用初沉污泥作为碳源强化污水脱氮的目的。通过对系统中VFAs积累、NO_x^--N去除及VSS变化情况的考察,对比研究了4种不同电子受体类型初沉污泥厌氧系统发酵性能、反硝化能力。得出:在34 d的发酵期里,NO₃^--N型系统以及NO₂^--N、NO₃^--N混合型系统中没有出现明显VFAs积累,而在NO₂^--N型系统和纯厌氧系统中出现了不同程度的VFAs积累,说明在试验条件下,NO₃^--N型和混合型系统发酵过程所释放的碳源能得到较好的利用;各系统中NO_x^--N还原总量分别为1692 mg·L^-1(NO₃^--N型)、1330 mg·L^-1(混合型)、1223 mg·L^-1(NO₂^--N型),表明NO₃^--N型系统反硝化能力最强;此外,虽然各NO_x^--N系统中的VSS减量程度相对于厌氧系统稍有降低,但各系统均达到了60%以上的高VSS减量水平,其中NO₃^--N型系统VSS减量67.9%,在各NO_x^--N系统中最高。综上,NO₃^--N型初沉污泥厌氧发酵系统能同时取得相对最好的反硝化脱氮及污泥减量性能。     

Fouling control in activated sludge submerged hollow fiber membrane bioreactors

The goal of this study is to determine the impact of various operating factors on membrane fouling in activated sludge membrane bioreactor (MBR) process, typically used for water reclamation. In this process, ultrafiltration (UF) and microfiltration (MF) hollow fiber membranes, submerged in the bioreactor, provided a solid—liquid separation by replacing gravity settling. Activated sludge from a food wastewater treatment plant was inoculated to purify synthetic wastewater consisting of glucose and (NH₄)₂SO₄ as a source of carbon and nitrogen, respectively. The results clearly showed that membrane fouling, defined as permeate flux decline due to accumulation of substances within membrane pores and/or onto membrane surface, was greatly influenced by membrane type and module configuration. It was also found that the rate and extent of permeate flux decline increased with increasing suction pressure (or initial operating flux) and with decreasing air-scouring rate. The mixed liquor suspended solids (MLSS) concentrations, however, exhibited very little influence on permeate flux for the range of 3600-8400 mg/L. Another important finding of this investigation was that non-continuous membrane operation significantly improved membrane productivity. This observation can be explained by the enhanced back transport of foulants under pressure relaxation. During non-suction periods, the foulants not irreversibly attached to the membrane surface, diffused away from the membrane surface because of concentration gradient. Furthermore, the effectiveness of air scouring was greatly enhanced in the absence of transmembrane suction pressure, resulting in higher removal of foulants accumulated on the membrane surface. The use of intermittent suction operation may not be economically feasible at large-scale, but it may offer an effective fouling control means for small-scale MBR processes treating wastewaters with high fouling potential.     

Comparison of the filtration characteristics between biological powdered activated carbon sludge and activated sludge in submerged membrane bioreactors

The filtration performances of submerged membrane bioreactors (SMBR) with and without the addition of powdered activated carbon (PAC) were investigated respectively under the same feed and operation conditions. A series of experiments were conducted to analyze near-critical flux, effect of air-scouring rate and time of stable filtration operation of both systems. The experimental results demonstrated that pronounced flux enhancement was achieved by adding 1.2 g/L PAC. The near-critical flux for the biological powdered activated carbon (BPAC) system was about 32% higher than that for the activated sludge (AS) system. Increasing the air-scouring rate led to a more significant flux improvement for the BPAC system compared to the AS system. Long-term operation indicated that, at constant flux, the TMP increasing rate of the BPAC system could be lagged and thus cause the extension of operating intervals about 1.8 times compared to the AS system. Quantitative calculations showed the total hydraulic resistance of the BPAC system was about 44% lower than that of the AS system, and this decrease was mainly caused by the reduction in cake resistance. Analyses were then made from various aspects such as floc size distribution and apparent viscosity of the mixed liquor to elucidate the major factors giving rise to different filtration characteristics.     

Effect of swelling on mass transfer performance in membrane extraction

The membrane extraction experiments were performed with tributyl phosphate/acetic acid (HAc)/water, n-butanol/HAc/water and 20% Alamine (in kerosene); HAc; and water as working systems. HAc was transferred from the aqueous phase to the organic phase. The effect of flat membranes swelling on mass transfer was studied. The membranes were microporous polysulfone and microporous polytetrafluoroethylene. The overall mass transfer coefficients based on the water phase were calculated and compared between nonswollen and swollen membranes. The experimental results show that the physical structure of the flat membranes used in our experiments was changed if soaked by organic solvents; however, change in thickness was not found. The overall mass transfer coefficients clearly were decreased after the flat membranes were swollen. The most likely reason is that the mass transfer resistance was increased because of the change of the membrane structure. The results also show that it is better to choose a hydrophilic membrane to reach high mass transfer performance when the equilibrium constant is very low. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1555–1561, 1999     

新型膜生物反应器及膜污染的研究进展

膜生物反应器技术是近年新发展起来的污水处理技术.作者介绍了几种新型膜生物反应器(生物膜-膜生物反应器、动态膜-生物反应器、气升循环膜生物反应器、PAC-膜生物反应器)的发展状况,并对膜生物反应器的膜污染机理及其控制方法进行了探讨,对今后膜生物反应器的研究和发展进行了展望.     

剩余污泥发酵同步反硝化系统污泥减量及反硝化性能

引言城市污水生物处理系统反硝化的顺利进行通常需要足够的碳源保证[1],而我国大部分污水厂存在碳源不足的问题,许多工艺中外加碳源的投加[2-3]大大增加了运行成本及控制系统的复杂性。剩余污泥的处理处置是城市污水处理厂的另一重点和难点[4]。为了实现剩余污泥的减量化和资源化[5-6],