scholarly journals Optimization of In Situ Backwashing Frequency for Stable Operation of Anaerobic Ceramic Membrane Bioreactor

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 545 ◽  
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Tuo Wang ◽  
Hongyan Wang ◽  
Dawei Yu ◽  
Junya Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Pure Water ◽  
Ex Situ ◽  
Stable Operation ◽  
Chemical Cleaning ◽  
Cake Layer

The cost-effective and stable operation of an anaerobic ceramic membrane bioreactor (AnCMBR) depends on operational strategies to minimize membrane fouling. A novel strategy for backwashing, filtration and relaxation was optimized for stable operation of a side stream tubular AnCMBR treating domestic wastewater at the ambient temperature. Two in situ backwashing schemes (once a day at 60 s/day, and twice a day at 60 s × 2/day) maintaining 55 min filtration and 5 min relaxation as a constant were compared. A flux level over 70% of the initial membrane flux was stabilized by in situ permeate backwashing irrespective of its frequency. The in situ backwashing by permeate once a day was better for energy saving, stable membrane filtration and less permeate consumption. Ex situ chemical cleaning after 60 days’ operation was carried out using pure water, sodium hypochlorite (NaOCl), and citric acid as the order. The dominant cake layer was effectively reduced by in situ backwashing, and the major organic foulants were fulvic acid-like substances and humic acid-like substances. Proteobacteria, Firmucutes, Epsilonbacteria and Bacteroides were the major microbes attached to the ceramic membrane fouling layer which were effectively removed by NaOCl.

scholarly journals The Effect of Ca and Mg Ions on the Filtration Profile of Sodium Alginate Solution in a Polyethersulfone-2-(methacryloyloxy) Ethyl Phosphorylchloline Membrane

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1207 ◽  
Author(s):  
Nasrul Arahman ◽  
Suffriandy Satria ◽  
Fachrul Razi ◽  
M. Bilad
Keyword(s):  
Sodium Alginate ◽  
Relative Permeability ◽  
Hollow Fiber ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Hollow Fiber Membrane ◽  
Pure Water ◽  
Fiber Membrane ◽  
Cake Layer ◽  
The Stability

The efforts to improve the stability of membrane filtration in applications for wastewater treatment or the purification of drinking water still dominate the research in the field of membrane technology. Various factors that cause membrane fouling have been explored to find the solution for improving the stability of the filtration and prolong membrane lifetime. The present work explains the filtration performance of a hollow fiber membrane that is fabricated from polyethersulfone-2-(methacryloyloxy) ethyl phosphorylchloline while using a sodium alginate (SA) feed solution. The filtration process is designed in a pressure driven cross-flow module using a single piece hollow fiber membrane in a flow of outside-inside We investigate the effect of Ca and Mg ions in SA solution on the relative permeability, membrane resistance, cake resistance, and cake formation on the membrane surface. Furthermore, the performance of membrane filtration is predicted while using mathematical models that were developed based on Darcy’s law. Results show that the presence of Ca ions in SA solution has the most prominent effect on the formation of a cake layer. The formed cake layer has a significant effect in lowering relative permeability. The developed models have a good fit with the experimental data for pure water filtration with R2 values between 0.9200 and 0.9999. When treating SA solutions, the developed models fit well with experimental with the best model (Model I) shows R2 of 0.9998, 0.9999, and 0.9994 for SA, SA + Ca, and SA + Mg feeds, respectively.

scholarly journals UV and bacteriophages as a chemical-free approach for cleaning membranes from anaerobic bioreactors

2020 ◽  
Author(s):  
Giantommaso Scarascia ◽  
Luca Fortunato ◽  
Yevhen Myshkevych ◽  
Hong Cheng ◽  
TorOve Leiknes ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Combined Treatment ◽  
Chemical Cleaning ◽  
High Quality ◽  
Anaerobic Membrane Bioreactor ◽  
Membrane Biofouling ◽  
Uv C

ABSTRACTAnaerobic membrane bioreactor (AnMBR) for wastewater treatment has attracted much interest due to its efficacy in providing high quality effluent with minimal energy costs. However, membrane biofouling represents the main bottleneck for AnMBR because it diminishes flux and necessitates frequent replacement of membranes. In this study, we assessed the feasibility of combining bacteriophages and UV-C irradiation to provide a chemical-free approach to remove biofoulants on the membrane. The combination of bacteriophage and UV-C resulted in better log cells removal and twice higher extracellular polymeric substance (EPS) concentration reduction in mature biofoulants compared to UV-C. A reduction in the relative abundance of Acinetobacter spp. and selected gram-positive bacteria associated with the membrane biofilm was also achieved by the new cleaning approach. Microscopic analysis further revealed the formation of cavities in the biofilm due to bacteriophages and UV-C irradiation, which would be beneficial to maintain water flux through the membrane. When the combined treatment was further compared with the common chemical cleaning procedure, a similar reduction on the cell numbers was observed (1.4 log). However, combined treatment was less effective in removing EPS compared with chemical cleaning. These results suggest that the combination of UV-C and bacteriophage have an additive effect in biofouling reduction, representing a potential chemical-free method to remove reversible biofoulants on membrane fitted in an anaerobic membrane bioreactor.SIGNIFICANCEAnaerobic membrane bioreactors can achieve high quality effluent with a reduced energy consumption. However, biofouling represents the main bottleneck for membrane filtration efficiency. Biofouling is commonly reduced through chemical treatment. These agents are often detrimental for the environment and health safety due to the formation of toxic byproducts. Therefore, we present a new approach, based on the additive antifouling action of bacteriophages infection and UV-C irradiation, to reduce anaerobic membrane biofouling. This new strategy could potentially delay the occurrence of membrane fouling by removing the reversible fouling layers on membranes, in turn reducing the frequencies and amount of chemicals needed throughout the course of wastewater treatment.

Ultrafiltration of activated sludge with ceramic membranes in a cross-flow membrane bioreactor process

2000 ◽  
Vol 41 (10-11) ◽  
pp. 243-250 ◽  
Author(s):  
X-j. Fan ◽  
V. Urbain ◽  
Y. Qian ◽  
J. Manem
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Ceramic Membrane ◽  
Treatment Plant ◽  
Cross Flow ◽  
Ceramic Membranes ◽  
Permeate Flux ◽  
Chemical Cleaning

A cross-flow membrane bioreactor (MBR) for raw municipal wastewater treatment, consisting of a suspended growth bioreactor and a ceramic membrane ultrafiltration unit, was run over a period of more than 300 days in a wastewater treatment plant (WWTP). Sludge Retention Times (SRT) of 20, 10 and 5 days, respectively, and Hydraulic Retention Times (HRT) of 15 and 7.5 hours were tested. Membrane fouling was found to be a function of SRT and permeate flux. Under an SRT of 20 days and flux of 71 l/m2\ · h at 30°C, the MBR was successfully run over 70 days without the need for chemical cleaning. However chemical cleaning had to be undertaken every 3–5 days at shorter sludge retention times (typically an SRT of five days and a flux of 143 l/m2\ · h at 30°C). In this study, fouling materials were removed efficiently through chemical cleaning, with an average permeablity recovery of 87±11%.

scholarly journals Proof of Concept for Light Conducting Membrane Substrate for UV-Activated Photocatalysis as an Alternative to Chemical Cleaning

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 122 ◽  
Author(s):  
Lavern Nyamutswa ◽  
Bo Zhu ◽  
Dimuth Navaratna ◽  
Stephen Collins ◽  
Mikel Duke
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Current Method ◽  
Dip Coating ◽  
Polluted Water ◽  
Chemical Cleaning ◽  
Cake Layer

Adopting an effective strategy to control fouling is a necessary requirement for all membrane processes used in the water/wastewater treatment industry to operate sustainably. The use of ultraviolet (UV) activated photocatalysis has been shown to be effective in mitigating ceramic membrane fouling by natural organic matter. The widely used configuration in which light is directed through the polluted water to the membrane’s active layer suffers from inefficiencies brought about by light absorption by the pollutants and light shielding by the cake layer. To address these limitations, directing light through the substrate, instead of through polluted water, was studied. A UV conducting membrane was prepared by dip coating TiO2 onto a sintered glass substrate. The substrate could successfully conduct UV from a lamp source, unlike a typical alumina substrate. The prepared membrane was applied in the filtration of a humic acid solution as a model compound to study natural organic matter membrane fouling. Directing UV through the substrate showed only a 1 percentage point decline in the effectiveness of the cleaning method over two cleaning events from 72% to 71%, while directing UV over the photocatalytic layer had a 9 percentage point decline from 84% to 75%. Adapting the UV-through-substrate configuration could be more useful in maintaining membrane functionality during humic acid filtration than the current method being used.

scholarly journals Membrane fouling control and cleaning technology of ceramic membrane treating wastewater

2019 ◽  
Vol 118 ◽  
pp. 04023
Author(s):  
Guoqiang Ma ◽  
Shoubin Zhang ◽  
Yanming Yang ◽  
Liping Qiu ◽  
Guicai Liu ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Effective Means ◽  
Stable Operation ◽  
Efficient Technology ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Membrane Technique ◽  
Cleaning Methods ◽  
Cleaning Technology

Ceramic membrane technique was a new and efficient technology for wastewater treatment and used more and more widely in recent years. Controlling membrane fouling was the key method to ensure the efficient and stable operation of ceramic membrane. In this paper, the causes, influencing factors and control methods of ceramic membrane fouling were summarized. As one of the most effective means to control membrane fouling, several common membrane cleaning methods, such as physical cleaning, chemical cleaning, ultrasonic cleaning and combined cleaning, were introduced. And the application of ceramic membrane cleaning was presented too. Then the future directions for ceramic membrane techniquresearching was prospected.

scholarly journals Effects of Solids Retention Time on the Anaerobic Membrane Bioreactor with Yttria-Based Ceramic Membrane Treating Domestic Wastewater at Ambient Temperature

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 196
Author(s):  
Rathmalgodage Thejani Nilusha ◽  
Dawei Yu ◽  
Junya Zhang ◽  
Yuansong Wei
Keyword(s):  
Microbial Community ◽  
Ambient Temperature ◽  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Archaeal Community ◽  
Stable Operation

The effects of solid retention times (SRTs) (100 days, 50 days, 25 days) on the performance, microbial community, and membrane fouling of a lab-scale anaerobic yttria-based ceramic membrane bioreactor (AnCMBR) treating synthetic domestic wastewater at ambient temperature (31.2 ± 2.7 °C) were examined. The soluble chemical oxygen demand (SCOD) removal was higher (89.6%) at 25 days SRT compared with 50 days (39.61%) and 100 days (34.3%) SRT. At 100 days SRT, more Bacteroidetes, Firmicutes, and Proteobacteria were present in the microbial community. At 25 days SRT, more Chloroflexi, Synergistetes, and Pastescibacteria emerged, contributing to the stable performance. The SRT of 25 days has resulted in a more stable microbial community compared with 50 days and 100 days SRT. Both bacterial and archaeal community diversities were higher at 25 days SRT, and the specific production of soluble microbial by-products (SMPs) and extracellular polymeric substances (EPSs) were higher at 25 days SRT as well. Consequently, the membrane flux was lower at 25 days SRT with the increased particle size and the enhanced SMPs and EPSs production. Fourier transform infrared spectroscopy analysis (FTIR) and three-dimensional excitation and emission matrix (3D-EEM) analysis showed that protein and SMPs were the major membrane foulants at all SRT stages. In this study, SRT at 25 days was favorable for the stable operation of an AnCMBR treating domestic wastewater at ambient temperature.

Treatment of domestic wastewater with an anaerobic ceramic membrane bioreactor (AnCMBR)

2015 ◽  
Vol 72 (12) ◽  
pp. 2301-2307 ◽  
Author(s):  
Xiaodi Yue ◽  
Yoong Keat Kelvin Koh ◽  
How Yong Ng
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Ceramic Membrane ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ceramic Membranes ◽  
Transmembrane Pressure ◽  
Mixed Liquor ◽  
Cake Layer ◽  
Excellent Stability

In this study, a ceramic membrane with a pore size of 80 nm was incorporated into an anaerobic membrane bioreactor for excellent stability and integrity. Chemical oxygen demand (COD) removal efficiencies by biodegradation reached 78.6 ± 6.0% with mixed liquor suspended solids (MLSS) of 12.8 ± 1.2 g/L. Even though the total methane generated was 0.3 ± 0.03 L/g CODutilized, around 67.4% of it dissolved in permeate and was lost beyond collection. As a result, dissolved methane was 2.7 times of the theoretical saturating concentration calculated from Henry's law. When transmembrane pressure (TMP) of the ceramic membrane reached 30 kPa after 25.3 d, 95.2% of the total resistance was attributed to the cake layer, which made it the major contributor to membrane fouling. Compared to the mixed liquor, cake layer was rich in colloids and soluble products that could bind the solids to form a dense cake layer. The Methanosarcinaceae family preferred to attach to the ceramic membranes.

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