A performance evaluation of three membrane bioreactor systems: aerobic, anaerobic, and attached-growth

2011 ◽  
Vol 63 (12) ◽  
pp. 2999-3005 ◽  
Author(s):  
A. Achilli ◽  
E. A. Marchand ◽  
A. E. Childress
Keyword(s):  
Membrane Fouling ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Developed Countries ◽  
Operating Conditions ◽  
Growth Media ◽  
Positive Role ◽  
Critical Flux ◽  
Attached Growth ◽  
Human Needs

Water sustainability is essential for meeting human needs for drinking water and sanitation in both developing and developed countries. Reuse, decentralization, and low energy consumption are key objectives to achieve sustainability in wastewater treatment. Consideration of these objectives has led to the development of new and tailored technologies in order to balance societal needs with the protection of natural systems. Membrane bioreactors (MBRs) are one such technology. In this investigation, a comparison of MBR performance is presented. Laboratory-scale submerged aerobic MBR (AMBR), anaerobic MBR (AnMBR), and attached-growth aerobic MBR (AtMBR) systems were evaluated for treating domestic wastewater under the same operating conditions. Long-term chemical oxygen demand (COD) and total organic carbon (TOC) monitoring showed greater than 80% removal in the three systems. The AnMBR system required three months of acclimation prior to steady operation, compared to one month for the aerobic systems. The AnMBR system exhibited a constant mixed liquor suspended solids concentration at an infinite solids retention time (i.e. no solids wasting), while the aerobic MBR systems produced ∼0.25 g of biomass per gram of COD removed. This suggests a more economical solids management associated with the AnMBR system. Critical flux experiments were performed to evaluate fouling potential of the MBR systems. Results showed similar critical flux values between the AMBR and the AnMBR systems, while the AtMBR system showed relatively higher critical flux value. This result suggests a positive role of the attached-growth media in controlling membrane fouling in MBR systems.

scholarly journals Performance evaluation of novel attached-growth high rate algal pond system with additional artificial illumination for wastewater treatment and nutrient recovery

2020 ◽  
Author(s):  
Kesirine Jinda ◽  
Thammarat Koottatep ◽  
Chawalit Chaiwong ◽  
Chongrak Polprasert
Keyword(s):  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Cost Effective ◽  
High Rate ◽  
Nutrient Recovery ◽  
Growth Media ◽  
Light Sources ◽  
Attached Growth ◽  
Artificial Illumination ◽  
Conventional Systems

Abstract Domestic wastewater containing a high proportion of organic matter and nutrients is a serious pollution problem in developing countries. This study aimed to evaluate the performance of a novel attached-growth high rate algal pond (AG-HRAP) employing attached-growth media and artificial light sources for treating domestic wastewater and enhancing nutrient recovery. Light intensities in the range of 40–180 μmol/m2/s were used in the AG-HRAPs. The experimental results showed that the highest chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal efficiencies of 88, 62 and 69%, respectively, were found at the hydraulic retention time (HRT) of 15 days and the average light intensity of 180 μmol/m2/s. Moreover, the effluent COD concentrations could meet Thailand's national discharge standard. The highest biomass and protein productivities of 54 ± 4 and 37 ± 8 g/m2/d, respectively, were found in the AG-HRAPs, which were higher than in previous studies of HRAPs. The Stover-Kincannon kinetic values for COD, TN and TP removals of the AG-HRAPs (R2 = 0.9) were higher than those of the conventional systems. Additionally, the novel AG-HRAP system could provide a highly cost-effective operation when compared to other microalgal systems.

scholarly journals Multivariate Chemometric Analysis of Membrane Fouling Patterns in Biofilm Ceramic Membrane Bioreactor

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 982 ◽  
Author(s):  
Olga Kulesha ◽  
Zakhar Maletskyi ◽  
Harsha Ratnaweera
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Operating Conditions ◽  
Volume Index ◽  
Least Squares Regression ◽  
Effective Lifetime ◽  
Term Operation

Membrane fouling highly limits the development of Membrane bioreactor technology (MBR), which is among the key solutions to water scarcity. The current study deals with the determination of the fouling propensity of filtered biomass in a pilot-scale biofilm membrane bioreactor to enable the prediction of fouling intensity. The system was designed to treat domestic wastewater with the application of ceramic microfiltration membranes. Partial least squares regression analysis of the data obtained during the long-term operation of the biofilm-MBR (BF-MBR) system demonstrated that Mixed liquor suspended solids (MLSS), diluted sludge volume index (DSVI), chemical oxygen demand (COD), and their slopes are the most significant for the estimation and prediction of fouling intensity, while normalized permeability and its slope were found to be the most reliable fouling indicators. Three models were derived depending on the applied operating conditions, which enabled an accurate prediction of the fouling intensities in the system. The results will help to prevent severe membrane fouling via the change of operating conditions to prolong the effective lifetime of the membrane modules and to save energy and resources for the maintenance of the system.

Membrane fouling and performance evaluation of conventional membrane bioreactor (MBR), moving biofilm MBR and oxic/anoxic MBR

2014 ◽  
Vol 69 (7) ◽  
pp. 1403-1409 ◽  
Author(s):  
Sher Jamal Khan ◽  
Aman Ahmad ◽  
Muhammad Saqib Nawaz ◽  
Nicholas P. Hankins
Keyword(s):  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Water Flux ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Membrane Bioreactors ◽  
Nitrogen And Phosphorus ◽  
Biofilm Carrier ◽  
Cake Layer ◽  
And Performance

In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes® plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.

Treatment of Wastewater Using an Integrated Submerged Attached Growth System

2014 ◽  
Vol 567 ◽  
pp. 167-171 ◽  
Author(s):  
Ezerie Henry Ezechi ◽  
Shamsul Rahman Mohamed Kutty ◽  
Mohamed Hasnain Isa ◽  
Ahmad Fitri Abd Rahim
Keyword(s):  
Nitrate Removal ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ammonia Removal ◽  
Integrated System ◽  
Synthetic Wastewater ◽  
Biological Nutrient Removal ◽  
Attached Growth ◽  
Growth System ◽  
Solids Removal

The performance of a single sludge integrated attached growth system comprising of an aerobic and anoxic tanks in biological nutrient removal was evaluated in treating synthetic wastewater simulating medium strength domestic wastewater. An aero-packer and bio-balls were installed in the aeration and anoxic tank occupying about 40% and 25% of both tanks respectively. The efficiency of the integrated attached growth system was evaluated on the removal of chemical oxygen demand (COD), ammonia removal (NH3), nitrate removal (NO3), total suspended solids removal (TSS) and biochemical oxygen demand removal (BOD5). Effluent results show that the integrated attached growth system had a removal efficiency of 97.8% (COD), 97.5% (NH3), 87.5% (NO3), 97% (TSS) and 97.1% (BOD). These results support the viability of an integrated system in mitigating the enormous challenges of a conventional wastewater treatment.

Performance of a modified RBC system in simulated municipal wastewater treatment

2012 ◽  
Vol 66 (9) ◽  
pp. 2014-2019
Author(s):  
Tang Yun-lu ◽  
Liu Dong-fang ◽  
Meng Xian-rong ◽  
Yu Jie ◽  
Wang Jin ◽  
...  
Keyword(s):  
Rotational Speed ◽  
System Performance ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Engineering Application ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Municipal Wastewater Treatment ◽  
Positive Role ◽  
Cod Removal Rate

A new method based on rotating biological contactor (RBC) was employed for solving the problems of long hydraulic retention times (HRT) low specific surface area and organic loading rates (OLR) in conventional RBCs. The system showed its particular adsorption ability of microorganisms in the biofilm-attaching period. Microbes on the first cage were observed in comparison with the second one. Packing biodisc also had a good shock load tolerance. It was observed that the system performance improved at higher HRTs, while at the increased level of input OLR, the removal performance worsened slightly. The positive role of rotational speed in the treatment of municipal wastewater was more pronounced in the range of 10–12 rpm. Chemical oxygen demand (COD) removal rate achieved 94% under the optimal operating conditions, which were HRT of 1.5 h, rotational speed of 9.9 rpm. The modified RBC system is highly beneficial to engineering application for better system performance and lower energy consumption.

Removal of Suspended Solids, Chemical Oxygen Demand and Color from Domestic Wastewater Using Sago Starch as Coagulant

2015 ◽  
Vol 802 ◽  
pp. 519-524
Author(s):  
Wan Izatul Saadiah Wan Kamar ◽  
Hamidi Abdul Aziz ◽  
Siti Fatihah Ramli
Keyword(s):  
Chemical Oxygen Demand ◽  
Suspended Solids ◽  
Sewage Treatment Plant ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Operating Conditions ◽  
Wastewater Sample ◽  
Sago Starch ◽  
Rapid Mixing ◽  
Slow Mixing

Sago starch has been widely used in industrial fields, especially in food, non-food, and animal feed biotechnology. Malaysia is one of the highest local sources of sago starch. The alternative use of sago starch as a coagulant for domestic wastewater treatment was investigated in this study. The wastewater sample was collected from the Juru Regional Sewage Treatment Plant in Juru, Penang. The studied parameters include the chemical oxygen demand (COD), suspended solids, and color. Standard jar test procedures were conducted. The initial operating conditions were 200 rpm for 3 min of rapid mixing, 40 rpm for 30 min of slow mixing, and 30 min of settling. The optimum conditions included a pH of 7 and dosage of 2000 mg/L, with rapid mixing at 100 rpm for 1 min, slow mixing at 20 rpm for 30 min, and 18 min of settling. The removal rate of COD and color at these conditions was 70%. Simultaneously, 82% of SS was also removed. The results indicated that sago starch has good potential to treat domestic wastewater; the coagulant may also efficiently treat other types of wastewater.

scholarly journals Synthesis of Atmospherically Stable Zero-Valent Iron Nanoparticles (nZVI) for the Efficient Catalytic Treatment of High-Strength Domestic Wastewater

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Afzal Ansari ◽  
Vasi Uddin Siddiqui ◽  
Md. Khursheed Akram ◽  
Weqar Ahmad Siddiqi ◽  
Anish Khan ◽  
...  
Keyword(s):  
Positive Impact ◽  
Oxygen Demand ◽  
Visible Spectrum ◽  
Aerobic Condition ◽  
Domestic Wastewater ◽  
Operating Conditions ◽  
Bandgap Energy ◽  
Ambient Conditions ◽  
High Concentration ◽  
Catalytic Treatment

Here, we report the fabrication of nZVI by the wet chemical technique in the presence of ethanol using ferric iron and sodium borohydride as the reducing agents under ambient conditions. The obtained nZVI particles are mainly in a zero-valent oxidation state and do not undergo significant oxidation for several weeks. The structural and morphological parameters of nZVI were investigated by using UV, XRD, SEM, EDX, TEM, and DLS analysis. The optical nature, bandgap energy, and absorption edge were all revealed by the UV–visible spectrum. The phase development and crystallinity of nZVI particles were shown by the XRD pattern. The morphological investigation revealed that the nanoparticles were spherical with an average size of 34–110 nm by using ImageJ software, and the elemental analysis was analyzed using EDX. Furthermore, the catalytic treatment performance of domestic wastewater was evaluated in terms of pH, COD (chemical oxygen demand) solubilization, total solids (TS), volatile solids (VS), phosphorous, and total nitrogen (TN) reduction under aerobic and anaerobic operating conditions. The effluent was subjected to a process evaluation with a different range (100–500 mg/L) of nZVI dosages. The COD solubilization and suspended solids reduction were significantly improved in the anaerobic condition in comparison to the aerobic condition. Furthermore, the effect of nZVI on phosphorous (PO43−) reduction was enhanced by the electrons of iron ions. The high concentration of nZVI dosing has a positive impact on COD solubilization and phosphorous removal regardless of the aeration condition with 400 mg/L of nZVI dosage.

Optimal performance of an immersed membrane bioreactor equipped with a draft tube for domestic wastewater reclamation

2006 ◽  
Vol 54 (10) ◽  
pp. 155-162 ◽  
Author(s):  
F. Yang ◽  
A. Bick ◽  
S. Shandalov ◽  
G. Oron
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Hollow Fiber Membrane ◽  
Membrane Surface ◽  
Domestic Wastewater ◽  
Operating Conditions ◽  
Hydrodynamic Conditions ◽  
Wastewater Reclamation ◽  
Ambient Conditions ◽  
Optimal Operating

One of the options to prevent membrane fouling is to implement air lifting that can improve the cake removal from the membrane surface. This study presents the results of tests that were carried out at the Institutes for Desert Research, Kiryat Sde-Boker, Israel, and focused on the influence of hydrodynamic conditions on fouling in a pilot-scale immersed membrane bioreactor (IMBR) using a hollow fiber membrane module of ZW-10 (Zenon Environmental, Canada) under ambient conditions. In this system, the cross-flow velocities across the membrane surface were induced by one conical and four cylindrical draft-tubes. The relationship between the crossflow velocity and the aeration intensity, the influence of the crossflow on fouling rate under various hydrodynamic conditions were investigated and optimal operating conditions were obtained. Optimal operating conditions were reached during the long-term experiment period (70 days) for the treatment of domestic wastewater. The system was stable without external chemical cleaning. The results showed that the permeate was of high quality, and the removal of COD and BOD was 94.0% and 98.8%, respectively.The crossflow near the membrane surface reveals a major contribution for minimizing membrane fouling, and could offer guidelines for future design of similar systems.

scholarly journals SMP Production in an Anaerobic Submerged Membrane Bioreactor (AnMBR) at Different Organic Loading Rates

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 317
Author(s):  
Sandra C. Medina ◽  
Nataly Zamora-Vacca ◽  
Hector J. Luna ◽  
Nicolas Ratkovich ◽  
Manuel Rodríguez Susa
Keyword(s):  
Membrane Fouling ◽  
Energy Demand ◽  
Membrane Surface ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Term Operation ◽  
Submerged Membrane Bioreactor ◽  
Anaerobic Membrane Bioreactors ◽  
Microbial Products

Anaerobic membrane bioreactors (AnMBRs) have demonstrated an excellent capability to treat domestic wastewater. However, biofouling reduces membrane permeability, increasing operational costs and overall energy demand. Soluble microbial products (SMPs) that build up on the membrane surface play a significant role in the biofouling. In this study, the production of SMPs in a 32 L submerged AnMBR operated at three different organic loads (3.0, 4.1 and 1.2 kg chemical oxygen demand (COD)/m3d for phases 1, 2 and 3, respectively) during long-term operation of the reactor (144, 83 and 94 days) were evaluated. The samples were taken from both the permeate and the sludge at three different heights (0.14, 0.44 and 0.75 m). Higher production of SMPs was obtained in phase 2, which was proportional to the membrane fouling. There were no statistically significant differences (p > 0.05) in the SMPs extracted from sludge at different heights among the three phases. In the permeate of phases 1, 2 and 3, the membrane allowed the removal of 56%, 70% and 64% of the SMP concentration in the sludge. SMPs were characterized by molecular weight (MW). A bimodal behavior was obtained, where fractions prevailed with an MW < 1 kDa, associated with SMPs as utilization-associated products (UAPs) caused fouling by the pore-blocking mechanism. The chemical analysis found that, in the SMPs, the unknown COD predominated over the known COD, such as carbohydrates and proteins. These results suggest that further studies in SMP characterization should focus on the unknown COD fraction to understand the membrane fouling in AnMBR systems better.

Physico-chemical characterisation versus in situ micro-structural characterisation of membrane fouling in membrane bioreactors

2011 ◽  
Vol 63 (8) ◽  
pp. 1781-1787 ◽  
Author(s):  
T. C. A Ng ◽  
H. Y. Ng
Keyword(s):  
Membrane Fouling ◽  
Laser Scanning ◽  
Extracellular Polymeric Substances ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Critical Flux ◽  
Membrane Materials ◽  
Physico Chemical

Fouling characteristics of aerobic submerged membrane bioreactors were analysed under two different membrane materials. Polyethersulfone (PES) membranes were found to foul faster at sub-critical flux than polyolefin (PO) membranes. Physico-chemical characterisation, by means of comparison of extracellular polymeric substances (EPS) and soluble microbial products (SMP) concentrations, as well as the mixed liquor suspended solids (MLSS) concentration were unable to explain the differences in membrane fouling of the contrasting membrane materials. The use of confocal laser scanning microscopy (CLSM) to image organic foulants directly on the membrane surface, coupled with image analyses showed that membrane fouling mechanism shifted from a biofilm initiated process on PO membranes to a bio-organic dominated process on PES membranes under sub-critical flux conditions. These results show that physico-chemical characterisation of an MBR process may not effectively distinguish the effectiveness of different membrane materials, so long as operating conditions are identical, and that characterisation of foulants on the membrane surfaces was necessary to elucidate the differences in membrane fouling.

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