Assessing the feasibility of a vertical double submerged membrane modules system for wastewater reclamation under different conditions

Nowadays, water is deteriorating for several reasons, such as an increase in wastewater that flows into rivers and the limitation of water resources. Therefore, we have concentrated our plans on securing water resources by reusing wastewater treatment effluent. In this study the reuse system was organized using a submerged membrane bioreactor (SMBR) consisting of an anoxic, select, and aerobic tank. Our plan to solve the problems mentioned above involved optimizing the operating hydraulic retention time (HRT), which was done by comparing the characteristics of water treatment for several HRTs. Also, the simple and vertical double membrane modules were analyzed to find more effective operating condition in SMBR. The Specific characteristics of the SMBR system were represented as follows. We could know below 10 mg/L of BOD, below 5 mg/L of COD, 0 mg/L of SS without changes of HRT, which was satisfied with the standard of reuse water. Optimized HRT was 2.3 h and by composing the vertical double membrane modules, air flow rate could be reduced by 28.5%, lower than that of the simple membrane module.     

Nitrification and sludge characteristics in a submerged membrane bioreactor on synthetic inorganic wastewater

A submerged membrane bioreactor (SMBR) treating ammonia-bearing synthetic inorganic wastewater withoutsludge purge was studied in respect to nitrification and microbial parameters over a period of 210 days. The reactor was operated at a hydraulic retention time (HRT) of 24 h, and the NH_4-N volumetric loading rate increased from 0.18 to 1.30 kg NH₄⁺-N m⁻³d⁻¹ by increasing influent NH₄⁺-N from 180 mg/l⁻¹ to 1300 mg/l⁻¹. With the exception of a short period after the failure of pH control, the NH₄⁺-N⁺ removal rate, was constantly above 99%. Due to the influent characteristics and the interception of the membrane module, the mixed liquor suspended solids (MLSS) varied from 3000 to 5000 mg/l⁻¹ and the nitrifying bacteria were dominant in the SMBR. The numbers of ammonia oxidizers and nitrite oxidizers in the mixed liquor increased from 0.9×10⁸ ml⁻¹ and 1.0×10⁸ ml to 1.6×10⁸ ml⁻¹ and 9×10⁸ ml⁻¹ respectively, and the specific nitrification rate from 0.27 to 0.56 g NH₄⁺-N g⁻¹ SS⁻¹ d⁻¹. An increasing occurrence of extracellular polymeric substances (EPS) around microbial clusters with operation time was clearly observed on scanning electron micrographs (SEM). The pressure difference of the membrane module was not over 0.01 mPa over the whole operation period. Present results show that SMBR can be operated efficiently and stably as a high-rate nitrifying technology.     

一体化膜生物反应器处理印刷线路板综合废水

采用自制一体化膜生物反应器(SMBR)处理印刷线路板(PCB)综合废水,对系统驯化过程的污泥生物相变化,SV30(污泥沉降比)、SVI(污泥沉降指数),MLSS(混合液悬浮固体浓度)、MLVSS(混合液挥发性悬浮固体浓度)等污泥特性,以及系统pH,铜离子浓度、化学耗氧量(COD)等水质指标进行了监测.试验结果表明:污泥培养驯化过程中,游泳型纤毛虫、固着型纤毛虫(累枝虫、钟虫)、轮虫、红斑顠体虫、表壳虫、固着型纤毛虫交替成为优势种群.进水铜离子质量浓度为12 mg/L左右驯化完成,此时污泥MLSS为6 100 mg/L,SV30为29%～38.5%,SVI为75～90 mL/g.系统出水COD、铜离子浓度和pH均达广东省水污染物排放限值一级标准,COD和铜离子的去除率分别超过85%和95%.     

Filterability in a submerged anaerobic membrane bioreactor

Studies on anaerobic membrane bioreactor (AMBR) show high variability about filterability. Therefore, in this study, a laboratory-scale submerged AMBR (SAMBR) was operated with the aim of identifying operational conditions and sludge characteristics that influence the membrane flux. Short-term experiments applying the flux-step method resulted in values of the critical flux (Jc) variable depending on the operational condition applied in the SAMBR. The application of different parameters for the identification of Jc gave comparable results. Although the plant was operated applying different operational conditions, a rapid membrane fouling was usually observed. The applicable fluxes were between 2 and 5 L/(m² h) depending on operational conditions. Therefore, the results confirm the much lower sludge filterability in anaerobic than aerobic MBRs. Multiple regression analysis showed that the supernatant composition plays the most important role in membrane fouling.     

Sustainable reclamation and reuse of industrial wastewater including membrane bioreactor technologies: case studies

One of the most crucial and difficult elements of the bioprocess is its ability to separate between the biosolids and the liquid effluent phase. The objectives of this study were to evaluate practical possibilities to upgrade existing wastewater treatment facilities by operating aerobic treatment based on MBR technology, in order to obtain high quality effluent for sustainable reclamation and reuse of industrial wastewater. Three different types of industrial wastewaters have been biologically treated by MBR working on hollow fiber technology: (a) paper mill; (b) food production; (c) fuel port facilities. The MBR received preliminarily treated effluent by anaerobic, chemical and physical processes, respectively. The experimental work in this study indicated that biological treatment of industrial wastewater containing contaminants characterized by hydrophobicity and/or by low biodegradability would require the adaptation of the MBR operation conditions, by lowering cell residence time and MLVSS in the bioreactor and by increasing the amounts of excess biosolids accordingly. The effluent was of high quality and could be considered for reuse in paper mill and food production.     

膜生物反应器废水处理组合工艺的研究进展

膜生物反应器（MBR）是近年来发展起来的一种新型的废水处理工艺,作者阐述了膜生物反应器的应用类型、机理以及应用现状,并对膜生物反应器组合工艺的特点、存在的问题和应用前景进行了分析评价。     

一体式膜生物反应器膜污染研究

膜生物反应器(MBR)是一种新型污水处理器,对生活污水处理效果显著,在使用过程中不可避免地会产生污染。为此,对膜生物反应器处理模拟生活污水的膜污染和清洗方法进行了研究,通过红外光谱分析了活性污泥性质的变化,利用扫描电镜分析了中空纤维膜表观结构的变化,探讨了膜污染的机理。结果表明,细菌滋生和污泥沉积造成了膜污染,泥饼层阻力占膜总阻力的89.86%,是膜污染的主要组成部分,水力清洗结合化学清洗可以很好地恢复膜的比通量。     

浸没式膜生物反应器膜污染研究现状

简要分析了浸没式膜生物反应器(SMBR)中膜污染的机理.在文献和现场考察的基础上,对膜材料、混合液特性、操作参数与条件、膜的清洗与再生等几个主要方面的研究现状进行了分析和综述,指出目前研究的不足在于缺乏反应器结构优化及反应器内流场优化方面的研究.     

Microbial community structure in an intermittently aerated submerged membrane bioreactor treating domestic wastewater

The microbial community structure in an intermittently aerated submerged membrane bioreactor treating domestic wastewater was investigated using the respiratory quinone profiling method. The operating cycle consisted of feeding the domestic wastewater into a 90-min oxic condition and a 60-min anoxic condition. A slight difference was observed in the microbial community structure of the suspended microorganisms in anoxic and oxic conditions. The dominant quinone type of anoxic and oxic conditions was ubiquinone (UQ)-8 followed by UQ-10 and menaquinone (MK)-6. The quinone profiles of the suspended microorganisms in the intermittently aerated SMBR with anoxic and oxic cycling showed that Nitrosomonas species, Alcaligenes species, and Thiobacillus, the dominant quinone of there are UQ-8 actively contributed to the biological nitrification/denitrification. The microbial diversities of suspended microorganisms in the anoxic and oxic conditions calculated on the molar fraction basis of all quinone compositions were 8.79-10.38 and 10.03-11.82, respectively.     

Viability of microbial mass in a submerged membrane bioreactor

In this study the viability of biomass in a submerged membrane activated sludge system (sMBR) which treats domestic wastewater was investigated by dealing with non-biodegradable COD, specific oxygen uptake rate and MLVSS during operation for 100 days. It was shown that the viability of biomass in the bioreactor was reduced at the 50% level because of the accumulation of inert compounds and the reduction in the activities of poor biomass. After inoculating the bioreactor again, the specific OUR increased because of young biomass entering into the bioreactor. It was shown that there was an exponential relationship between OUR and MLVSS and there was a logarithmic relationship between specific OUR and MLVSS.     

一体式膜生物反应器中料液粘度的研究

探讨了一体式膜生物反应器中料液粘度变化的原因,以及料液粘度对膜过滤阻力的影响。试验结果表明:料液粘度的增加主要因反应器中累积的高浓度胞外聚合物(EPS)所致;污泥粘度随着EPS浓度的变化而变化,二者之间存在很好的相关性(r=0.9958);污泥粘度与膜过滤阻力有较好的相关性(r=0.9006)。     

无机膜-生物反应器处理啤酒废水及其膜清洗的试验研究

无机膜－生物反应器（ＩＭＢＲ）是９０年代兴起的一种废水生化处理的新技术。笔者介绍了无机膜－生物反应器用于啤酒废水的处理研究。采用好氧分置式膜生物反应器,膜组件是无机陶瓷膜,生物反应是活性污泥曝气池。     

浸没式厌氧双轴旋转膜生物反应器的膜污染特性研究

试验研究了浸没式厌氧双轴旋转膜生物反应器处理啤酒废水时膜的污染特性.试验分析了膜阻力分布和膜污染速率及稳定运行时膜过滤阻力随运行时间变化的阻力模型.结果表明,膜表面滤饼层很薄,膜污染很轻,膜污染速率很小.结果表明系统由膜组件双轴旋转而形成的良好水力学条件,能有效地减小浓差极化和避免污泥颗粒在膜表面的沉积.可有效控制膜污染.     

Coupling of nanofiltration with microfiltration and membrane bioreactor for textile effluent reclamation

This work investigates the application of a microfiltration–membrane bioreactor–nanofiltration hybrid process for textile effluent reclamation. The indigo blue dye was efficiently retained by the microfiltration membrane (100%), which allows its recovery from the concentrate stream. The membrane bioreactor resulted in chemical oxygen demand (COD) and ammonia removal of 73% and 100%, respectively. Nanofiltration technology was successfully applied to polish textile effluent. The principal cause of flux decline was determined to be concentration polarization. The nanofiltration permeate meets the quality requirements for all processes within the textile industry, while the nanofiltration concentrate can be used for less demanding purposes.     

Removal of nitrogen from wastewater for reusing to boiler feed-water by an anaerobic/aerobic/membrane bioreactor

The innovative process anaerobic/aerobic/membrane bioreactor (A/O/MBR) was developed to enhance pre-denitrification without the energy consumption of the recirculation pump for reusing wastewater to boiler feed-water. The performance of this bioreactor was investigated. Firstly, the septic tank wastewater with low ratio of COD/TN was disposed by a dynamic membrane bioreactor (DMBR). It was found that, although the high concentration of NO₂⁻–N in the effluent implied the potential ability of DMBR to realize shortcut nitrification and denitrification, the effluent of single DMBR was difficult to reach the criteria of reusing to boiler feed-water. Then, the process A/O/DMBR in disposing the septic tank wastewater was studied. The results indicated that this process not only accomplished the removal of 91.5% COD, 90.3% NH₄⁺–N and 60.2% TN, but also successfully realized pre-denitrification without additional recirculation pump. At last, based on the A/O/DMBR, a pilot plant A/O/MBR was built to dispose the municipal raw sewage. In the stable operation period, the average removal efficiencies for COD, NH₄⁺–N, TP and turbidity reached 90%, 95%, 70% and 99%, respectively. During the tested HRT run of 9.0 h, the effluent of COD, NH₄⁺–N, TP and turbidity was about 10 mg/L, 3 mg/L, below 1 mg/L and 1.2 NTU, respectively, which reached the criteria of the boiler feed-water in China.     

Dyeing and printing wastewater treatment using a membrane bioreactor with a gravity drain

A laboratory-scale membrane bioreactor (MBR) with a gravity drain was tested for dyeing and printing wastewater treatment from a wool mill. The MBR was operated with continuous permeate by gravity and without chemical cleaning for 135 days. Results showed that excellent effluent quality could meet the reuse water standard in China. The average concentrations of COD, BOD₅, turbidity and color in the effluent were 36.9 mg l⁻¹, 3.7 mg l⁻¹, 0.2 NTU and 21 dilution times (DT), respectively. The average removal rates of COD, BOD₅, turbidity and color were 80.3%, 95.0%, 99.3% and 58.7%, respectively. The membrane flux increased with increasing of aeration intensity, and its increasing rate was related to pressure-heads. The higher the pressure-head, the greater the impact of aeration intensity on membrane flux. Statistical analysis also showed that both the pressure-head and aeration intensity significantly affected membrane flux. Due to its compact design, simple operation and easy maintenance, MBR with a gravitational filtration system hs low energy consumption and is cost-effective to build and operate. If the life expectancy of the membrane is set for 3–4 years and the membrane flux is set at 15 l/m²·h, such a MBR would be very competitive.     

Treatment performance of metal membrane microfiltration and electrodialysis integrated system for wastewater reclamation

The integrated system with microfiltration/electrodialysis was proposed for wastewater reclamation. The filterability of metal membrane, membrane fouling reduction by ozonated water and the effect of operational parameters were experimentally investigated. Backwashing by ozonated water showed stable and effective membrane fouling reduction. The removal ratio of nutrients such as NH₄⁺-N and PO₄³⁻-P concentration was about 96 and 94%, respectively, within 30 min of operation in the system. Proposed system showed good rejections on bacteria, suspended solids as well as ionic nutrients. Suggested wastewater reclamation system showed stable water quality during operational period over 6 months. Therefore, it is expected to be an effective and useful system for the reclamation of wastewater.     

Flat-plate submerged membrane bioreactor for the treatment of higher-load graywater

Graywater treatment has been the focus when topics of decentralized treatment systems are discussed. In this paper, the treatment of higher-load graywater, a mixture of washing machine and kitchen sink wastewater, was investigated. A 10 L lab-scale submerged membrane bioreactor (subMBR) was operated with a flat-plate membrane for 87 days. Permeate was intermittently withdrawn at constant transmembrane pressure (TMP) induced by water level difference and without pump requirement. The pollutants' removal and membrane behavior were monitored. The COD removal was around 96% and a permeate COD of about 26 mg L^− 1 was obtained. The total linear alkylbenzene sulfonate (LAS) removal achieved was > 99%, indicative of its non-inhibited degradation even at influent concentration of 30.8 mg L^− 1. The subMBR was operated at almost stable and constant flux of 0.22 m³ m^− 2 d^− 1 at a mean HRT of 13.6 h.     

两种膜生物反应器工艺在养殖废水处理中的运行效果

采用动态膜生物反应器（dynamic membrane bioreactor,DMBR）和膜生物反应器（membrane bioreactor,MBR）两种处理工艺,研究在相同条件下对养殖废水的处理效果和运行条件。结果表明,不同溶解氧（dissolve oxygen,DO）条件下,DMBR和MBR对CODMn的去除率可达95%以上。DO为0～1 mg/L条件下,DMBR和MBR的总氮平均去除率分别达到71.4%、75.8%;在DO为2～3 mg/L条件下,DMBR和MBR的总氮平均去除率分别为46.3%、44.1%。DMBR和MBR两种工艺均能达到较好的污染物去除效果。MBR的过滤压差明显高于DMBR,低DO条件下（0～1 mg/L）的运行周期约为5天,DMBR采用重力流出水,运行周期约为10天,过滤压差最高时仅为3.97 kPa,在一定程度上克服MBR成本高、易污染等缺点。     

Comparison of a sMBR with a CASP system for wastewater reclamation and re-use

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