Ultrafiltration (UF) Pilot Plant for Municipal Wastewater Reuse in Agriculture: Impact of the Operation Mode on Process Performance (original) (raw)
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Desalination, 2009
The quality of effluent from urban wastewater destined for reuse was compared after treatment by a submerged membrane bioreactor (MBR) and a conventional activated sludge system followed by ultrafiltration (CAS-U). The study was carried out at pilot scale, using an MBR module equipped with hollow-fibre ultrafiltration membranes fed with pre-treated raw urban wastewater, and a flat-membrane ultrafiltration module fed with effluent from a conventional activated sludge plant. A comparative analysis was carried out for physicochemical quality parameters (turbidity, suspended solids, colour and COD) and microbiological quality parameters (E. coli, faecal coliforms, total aerobic bacteria and coliphages). A particle distribution analysis (2-125 µm) was also undertaken. The two systems produced water with similar phsyicochemical characteristics, although the MBR proved more efficient at reducing COD. However, the colour of the MBR effluent was more marked. With regard to microbiological quality, the differences observed between the two systems were due to variations in the periods of chemical cleaning applied to the membranes in order to prevent progressive fouling of the permeate zone. Independently of the frequency of chemical cleaning, the MBR system proved more efficient at retaining coliphages.
Water Supply, 2011
Fouling remains one of the major constraints on the use of low pressure membranes in drinking water treatment. Work over the last few years has shown the importance of biopolymers (carbohydrates and protein-like material) as foulants for ultrafiltration (UF) membranes. The purpose of this study was to investigate at pilot scale the use of rapid biofiltration (without prior coagulation or ozone addition) as an innovative pretreatment to reduce fouling of UF membranes. The investigation was carried out on a water with a higher than average DOC and significant temperature variation. The biofilters, each operated at a hydraulic loading of 5 m/h, had empty bed contact times of 5, 10 and 15 minutes. The membrane unit was operated at a flux equivalent to 60 LMH at 20°C. The investigation confirmed the encouraging results obtained in an earlier smaller scale study with essentially the same water. Increased biofiltration contact time (i.e. increased bed depth) led to lower rates of hydraulic...
Performance of an ultrafiltration membrane bioreactor (UF-MBR) in wastewater treatment
DESALINATION AND WATER TREATMENT, 2019
This work presents the performance of an ultrafiltration membrane bioreactor (UF-MBR) system used as a means of removing pollution from domestic wastewater. Considering the technical performances of the process under different operational conditions, influence of hydraulic retention time (HRT), aeration rate and transmembrane pressure were observed. The evaluation of permeate quality, calculated by the removal efficiencies for various water quality indicators: chemical oxygen demand, biological oxygen demand, total suspended solids, total nitrogen (TN) and total phosphorous (TP). The best results obtained on the system (pressure p = 1.27 bar), HRT (15 h) showed removal efficiencies up to 90% in terms of organic compounds removal, 100% in terms of suspended solids presence and up to 80% reduction of TN and TP. The overall results suggest that the performance of the UF-MBR are likely to impact on the operation and maintenance of the system. However, the MBR process might be successfully applied as a treatment for the removal of pollution from domestic wastewater.
Desalination, 2011
This study investigates and compares the performance of two different types of ultrafiltration (UF) membranes in the recovery of water from secondary treated wastewater. Filtration experiments were carried out on a pilot scale cross-flow unit using synthetic wastewater similar to the quality of secondary treated wastewater by varying the operating parameters such as transmembrane pressure (TMP), feed composition and membrane configuration. The filtration experiments demonstrated that the flux recovery through spiral polymeric UF membrane was more sensitive to the variation in TMP compared to the tubular ceramic UF membrane over the range of TMP studied. The resistance in series model was used for the evaluation of the resistance to the permeate flux. The fouling resistance, particularly irreversible resistance compared to reversible resistance plays a major role in the total resistance for the tubular ceramic membrane. In contrast clean membrane resistance is the major contributor for the total resistance of the spiral polymeric membrane. Finally, the effectiveness of the filtration treatment was determined by evaluating the rejection coefficients for various pollution indices of the wastewater. Significant differences in the performance of the membrane types were observed which are likely to impact on the selection, operation and maintenance of the membrane system. Desalination j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / d e s a l Wastewater Filtration Water Rinsing Chemical Cleaning J m J f J fw J fc Fig. 2. A schematic diagram showing different stages of the filtration cycle.
Ultrafiltration Process in Disinfection and Advanced Treatment of Tertiary Treated Wastewater
Membranes, 2021
The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fec...
Clarification: Impact on Ultrafiltration Membrane Fouling in Drinking Water Treatment
Journal AWWA, 2015
The impact of different pretreatment conditions (powdered activated carbon [PAC] addition, iron chloride coagulation, and anionic polymer addition) on ultrafiltration membrane fouling was studied. Experiments were carried out at laboratory scale with new membranes and at pilot scale with used membranes. Results show that PAC has a positive effect—or at least, no negative effect—as long as backwashing allows effective removal of the filtration cake. On the other hand, excess PAC can generate irreversible fouling. Iron chloride has no negative impact for either native or used fibers as long as acid backwashes are effective. Inversely, an anionic polymer has a negative impact in every case—causing irreversible membrane fouling—despite its effectiveness in the clarification process. Test results also confirm that aged membranes are more sensitive to fouling than are pristine membranes. Their more hydrophobic structure is caused by the consumption of the hydrophilic agent under the effec...
Journal of Water Process Engineering, 2020
The primary intention of this review is to showcase and quantify the level of research interest and current research trends, concerning UF membrane applications and processes within the past decade (2009-2018). Detected statistics manifested a resurgent interest in the UF technology on a yearly basis. "Journal of Membrane Science" and "Desalination and Water Treatment" were the primary journals dominating the size of the annual publication among more than 120 ones, with 854 and 683 papers, respectively. Based on ScienceDirect research platform, fouling (27%), modelling (17%) and wastewater (12%), were the dominating research topics and counting for more than half of total scientific articles published (4547 articles) within the specified period of the research. Unsurprisingly, topics like UF membrane fabrication and modification, food processing, hybrid membrane process have disclosed a distinguished growing up trends in terms of annual publications. The current review unrevealed the present-day significance of the UF membranes along with their prospective opportunities for attaining sustainable water industries and materializing the efforts of future researchers into the right orientation. Highlights: • Fouling, modelling and wastewater are dominating research areas of UF membrane which counted for 27%, 17%, and 12% of the total publication's size, respectively. • Journal of Membrane Science was the primary journal dominating the size of the annual publication about UF. • Fouling of the UF membrane is the largest single area of research interest. • Potential research trends in UF membrane applications are critically reviewed • Topics of Optimization and Hybrid UF membrane processes are getting a consistent research interest.
Ultrafiltration of wastewater: effects of particles, mode of operation, and backwash effectiveness
Water Research, 2001
AbstractÐThe eects that wastewater quality and mode of operation have on the performance of an asymmetric, hollow ®ber, polysulfone, ultra®ltration (UF) membrane with a molecular weight cuto of 100,000 Daltons were investigated. Performance was assessed through monitoring membrane¯ux, transmembrane pressure, euent biochemical oxygen demand, and operational cost of the experimental system while treating ®ltered secondary, secondary, and ®ltered primary euents. Fluxes achieved for ®ltered secondary (129±173 l/m 2 h), secondary (101±158 l/m 2 h), and ®ltered primary (20±41 l/m 2 h) euents were compared to those obtained at three other locations where similar UF systems were operated. A conceptual model of the impact of an insucient backwash and of operating the UF system at constant¯ux on membrane performance is presented to explain the dierences in¯uxes. Employing pre-membrane granular ®ltration to remove a portion of the problematic particles in secondary euent prior to UF led to optimal operational conditions. The costs associated with the operation of pre-membrane granular ®ltration were oset by the increase in production achieved. Although the use of recirculation could increase maintainable¯ux when treating a concentrated feed (e.g., ®ltered primary euent), the associated costs were high. Improved UF performance was found to result from allowing¯ux to decline naturally, rather than using a constant¯ux mode of operation. The euents produced when ®ltered secondary and secondary euents were the feeds would be equivalent to an oxidized, coagulated, clari®ed, and ®ltered wastewater as per Title 22 California Wastewater Reclamation Criteria. 7
Journal of Membrane Science, 2006
Experimental results are presented for a two-fiber, bench-scale test that was designed to evaluate the effect of setpoint flux, backwash frequency, and backwash time on long-term fouling rate of low-pressure membrane systems. An ultrafiltration (UF) membrane was used to treat granular-media filtered, secondary wastewater effluent. The fouling rate was measured by the decline in specific flux over many backwash cycles. The long-term fouling rate was decreased substantially by a modest lowering of setpoint flux from 65 to 50 L/(m 2 h) and by an increase in backwash frequency from 15 to 10 min. Increasing the backwash time from 30 s to 1 min did not decrease the fouling rate substantially. Microscopic observation and chemical analysis suggest that the extracellular polymeric substances (EPS) play an important role in fouling resistance for UF membranes treating secondary wastewater effluent. Both adsorption inside membrane pores and deposition on the membrane surface may occur. The comparison of bench-scale and pilot-scale test also shows that the two-fiber, bench-scale test is a very useful, first-cut approach for acquiring process design information for pilot-scale and full-scale operation.