The effect of wastewater pretreatment on nanofiltration membrane performance

Membrane fouling is considered a serious obstacle for operation and cost efficiency in wastewater treatment using nanofiltration (NF). However, pretreatment is the most practical way to reduce this prior to NF. In this research, two types of wastewaters were pretreated with different methods prior to NF to examine the effect of pretreatment on membrane fouling in terms of turbidity, chemical oxygen demand (COD) and permeate flux. Turbidity and COD were measured to assess solid foulants and organic species in the wastewater, respectively. The first sample was secondary treated sewage, which was pretreated using coagulation-flocculation-sedimentation (CFS) only. Steady flux was increased from 24 L/m2h for wastewater without pretreatment to 32.1 L/m2h with pretreatment. COD was also eliminated after CFS/NF, and turbidity was reduced to 0.6 NTU. The second sample was diluted biodiesel wastewater, which was pretreated using a combination of powdered-activated carbon (PAC) adsorption and CFS (PAC/CFS). Steady flux was increased from 22.3 L/m2h for wastewater without pretreatment to 28.7 L/m2h with pretreatment; biodiesel wastewater quality also improved. Turbidity was reduced from 12 to 0.6 NTU, and COD was reduced from 526 to 4 mg/L after NF with PAC/CFS pretreatment, while COD was reduced from 526 to 95 mg/L using NF without pretreatment.

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Hybrid System Coupling Moving Bed Bioreactor with UV/O3 Oxidation and Membrane Separation Units for Treatment of Industrial Laundry Wastewater

Materials ◽

10.3390/ma13112648 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2648

Author(s):

Sylwia Mozia ◽

Magdalena Janus ◽

Sławomira Bering ◽

Krzysztof Tarnowski ◽

Jacek Mazur ◽

...

Keyword(s):

Membrane Fouling ◽

Membrane Separation ◽

Oxygen Demand ◽

Membrane System ◽

Permeate Flux ◽

Moving Bed ◽

System A ◽

Water Recycle ◽

Recycle And Reuse ◽

System Coupling

This paper describes the investigations on the possibilities of treatment of wastewater generated in an industrial laundry with application of a combined biological-photooxidation- membrane system aimed at water recycle and reuse. The two treatment schemes were compared: 1) scheme A consisting of a treatment in a moving bed biological reactor (MBBR) followed by microfiltration (MF) and nanofiltration (NF), and 2) scheme B comprising MBBR followed by oxidation by photolysis enhanced with in situ generated O3 (UV/O3) after which MF and NF were applied. The removal efficiency in MBBR reached 95–97% for the biochemical oxygen demand; 90–93% for the chemical oxygen demand and 89–99% for an anionic and a nonionic surfactants. The application of UV/O3 system allowed to decrease the content of the total organic carbon by 68% after 36 h of operation with a mineralization rate of 0.36 mg/L·h. Due to UV/O3 pretreatment, a significant mitigation of membrane fouling in the case of both MF and NF processes was achieved. The MF permeate flux in the system B was over two times higher compared to that in the system A. Based on the obtained results it was concluded that the laundry wastewater pretreated in the MBBR-UV/O3-MF-NF system could be recycled to any stage of the laundry process.

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Assessing Enzyme Immobilization on Reverse Asymmetric Membranes and Biocatalytic Reactor Performance

10.21203/rs.3.rs-931423/v1 ◽

2021 ◽

Author(s):

Amirah Syakirah Zahirulain ◽

Fauziah Marpani ◽

Syazana Mohamad Pauzi ◽

'Azzah Nazihah Che Abd Rahim ◽

Hang Thi Thuy Cao ◽

...

Keyword(s):

Enzyme Immobilization ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Separation ◽

Permeate Flux ◽

Reactor Performance ◽

Membrane Performance ◽

Reverse Mode ◽

Substrate Conversion ◽

Product Separation

Abstract Integration of membrane filtration and biocatalysis has appealing benefits in terms of simultaneous substrate conversion and product separation in one reactor. Nevertheless, the interaction between enzymes and membrane is complex and the mechanism of enzyme docking on membrane is similar to membrane fouling. In this study, focus is given on the assessment of enzyme immobilization mechanism on reverse asymmetric polymer membrane based on the permeate flux data during the procedure. Evaluation of membrane performance in terms of its permeability, fouling mechanisms, enzyme loading, enzyme reusability and biocatalytic productivity were also conducted. Alcohol Dehydrogenase (EC 1.1.1.1), able to catalyze formaldehyde to methanol with subsequent oxidation of NADH to NAD was selected as the model enzyme. Two commercial, asymmetric, flat sheet polymer membranes (PES and PVDF) were immobilized with the enzyme in the reverse mode. Combination of concentration polarization phenomenon and pressure driven filtration successfully immobilized almost 100% of the enzymes in the feed solutions. The biocatalytic membrane reactor recorded more than 90% conversion, stable permeate flux with no enzyme leaching even after 5 cycles. The technique showing promising results to be expanded to continuous membrane separation setup for repeated use of enzymes.

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Effect of Photooxidation on Nanofiltration Membrane Fouling During Wastewater Treatment from the Confectionery Industry

Water ◽

10.3390/w12030793 ◽

2020 ◽

Vol 12 (3) ◽

pp. 793

Author(s):

Anna Marszałek ◽

Ewa Puszczało

Keyword(s):

Wastewater Treatment ◽

Membrane Fouling ◽

Cross Flow ◽

Oxygen Demand ◽

Industrial Applications ◽

Treated Wastewater ◽

Toc Removal ◽

Before And After ◽

Wastewater Quality ◽

Uv Lamp

The research in this article aimed to present the possibilities of wastewater treatment coming from the confectionery plant in the nanofiltration (NF) process and the use of photooxidation to mitigate membrane fouling. The process was carried out initially in a dead-end flow system, where the most favorable membrane was selected. Next, the purification efficiency and blocking intensity of this membrane in the system were compared with cross flow. The next research involved the use of a photolytic oxidation process to pretreat sugar wastewater. UV radiation was emitted by a medium pressure mercury UV lamp model TQ 150 V. The effectiveness of the process was also evaluated based on the degree of pollutant load removal. The evaluation of the efficiency of a treatment process was based on the change of wastewater quality indicators before and after the membrane process. The following parameters were controlled: color, COD (chemical oxygen demand), TOC (total organic carbon), absorbance of UV254, nitrate, phosphate, ammonium, conductivity, and pH. During the course of pressure filtration, the following properties of the membrane were determined: the dependence of the volumetric flux of the permeate on the process duration, the permeability of the membrane, as well as the contact angle of the membranes. It was found that the use of UV reduced the phenomenon of fouling of nanofiltration membranes. The value of the permeate volumetric flow after the hour of running the process increased by 17%. However, no impact of UV on the efficiency of wastewater treatment was found. However, the NF process provided the required quality of treated wastewater that can be reused in industrial applications. The NF process resulted in a total decrease in absorbance, 99% TOC removal, and 98% color removal.

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Partial dealcoholization of red wine by nanofiltration and its effect on anthocyanin and resveratrol levels

Food Science and Technology International ◽

10.1177/1082013216642331 ◽

2016 ◽

Vol 22 (8) ◽

pp. 677-687 ◽

Cited By ~ 7

Author(s):

Szilvia Banvolgyi ◽

K Savaş Bahçeci ◽

Gyula Vatai ◽

Sandor Bekassy ◽

Erika Bekassy-Molnar

Keyword(s):

Low Temperature ◽

Factorial Design ◽

Red Wine ◽

Sensory Attributes ◽

Transmembrane Pressure ◽

Nanofiltration Membrane ◽

Permeate Flux ◽

Alcohol Content ◽

Membrane Performance ◽

Low Alcohol

The present work studies the use of nanofiltration for the production of red wine concentrate with low alcohol content. Factorial design was applied to measure the influences of transmembrane pressure (10–20 bar) and temperature (20–40 ℃) on the retention of valuable components such as anthocyanins and resveratrol, and on the nanofiltration membrane performance. The highest retention of anthocyanin and resveratrol was achieved at low temperature (20 ℃), while the high transmembrane pressure (20 bar) was found to increase the permeate flux considerably. The experiments demonstrated that nanofiltration appears as a valid technique for the production of low alcohol content red wine concentrate. Reduction of volume by a factor of 4, leads to 2.5–3 times more anthocyanins and resveratrol in the wine concentrates. The final new wine products – obtained by using various forms of reconstitution of the concentrated wine – had low alcohol content (4–6 % by volume) and their sensory attributes were similar to those of the original wine.

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Pilot trial study of a compact macro-filtration membrane bioreactor process for saline wastewater treatment

Water Science & Technology ◽

10.2166/wst.2014.180 ◽

2014 ◽

Vol 70 (1) ◽

pp. 120-126 ◽

Cited By ~ 8

Author(s):

Dao Guan ◽

W. C. Fung ◽

Frankie Lau ◽

Chao Deng ◽

Anthony Leung ◽

...

Keyword(s):

Wastewater Treatment ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Treatment Process ◽

Pilot Trial ◽

Operating Cost ◽

Oxygen Demand ◽

Laser Scanning Microscopy ◽

Permeate Flux ◽

Saline Wastewater

Conventional membrane bioreactor (MBR) systems have increasingly been studied in recent decades. However, their applications have been limited due to their drawbacks such as low flux, membrane fouling, and high operating cost. In this study, a compact macro-filtration MBR (MfMBR) process was developed by using a large pore size membrane to mitigate the membrane fouling problem. A pilot trial of MfMBR process was set up and operated to treat 10 m3/day of saline wastewater within 4 h. The system was operated under an average permeate flux of 13.1 m3/(m2·day) for 74 days. The average total suspended solids, total chemical oxygen demand, biological oxygen demand, total Kjeldahl nitrogen, and total nitrogen removal efficiencies achieved were 94.3, 83.1, 98.0, 93.1, and 63.3%, respectively, during steady-state operation. The confocal laser scanning microscopy image indicated that the backwash could effectively remove the bio-cake and dead bacteria. Thus, the results showed that the MfMBR process, which is essentially a primary wastewater treatment process, had the potential to yield the same high quality effluent standards as the secondary treatment process; thereby suggesting that it could be used as an option when the economic budget and/or land space is limited.

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Numerical Simulation of Hollow Fiber Ultrafiltration Membrane

Volume 12: Micro and Nano Systems, Parts A and B ◽

10.1115/imece2009-11705 ◽

2009 ◽

Author(s):

Nina Zhou ◽

A. G. Agwu Nnanna

Keyword(s):

Numerical Model ◽

Hollow Fiber ◽

Membrane Fouling ◽

Hollow Fiber Membrane ◽

Membrane Surface ◽

Operating Conditions ◽

Permeate Flux ◽

High Productivity ◽

Design And Optimization ◽

Membrane Performance

Low pressure driven ultrafiltraion (UF) processes has been applied in various industries due to its economical and easy operated benefits. Hollow fiber membrane is one of the most used membrane configuration in industry, membrane fouling is the major challenge for widely usage. Most of the investigation of UF was carried out by experiments to determine the effect of different operating conditions on permeate flux. However, experiments provide limited insight information on the membrane performance. In addition, the prediction of permeate flux under different operating conditions is necessary for experimental design and optimization. The purpose of the present study is to develop a numerical model to simulate the UF process and investigate the UF mechanism. A numerical model was developed using commercial CFD package (FLUENT). The effects of various operating conditions on permeate flux were determined by experiments and simulations, the comparison of the experimental and CFD results shows good agreements. Controlling membrane fouling will maintain a high productivity. The simulations were carried out to investigate the efficiency of removing accumulated particles on membrane surface by installing spacer filaments in membrane channels. The results suggested that the zigzag type spacer has d/h = 0.5 and l/h = 5 is more economical and efficient in reducing fouling.

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Removal of Naturally Occurring Strontium by Nanofiltration/Reverse Osmosis from Groundwater

Membranes ◽

10.3390/membranes10110321 ◽

2020 ◽

Vol 10 (11) ◽

pp. 321

Author(s):

Yang-Hui Cai ◽

Xiao Jin Yang ◽

Andrea Iris Schäfer

Keyword(s):

Reverse Osmosis ◽

Membrane Fouling ◽

Bone Growth ◽

Water Flux ◽

Applied Pressure ◽

Permeate Flux ◽

Membrane Performance ◽

Toc Removal ◽

Naturally Occurring ◽

The Impact

Removal of naturally occurring strontium (Sr) from groundwater is vital as excessive exposure may lead to bone growth problems in children. Nanofiltration/reverse osmosis (NF/RO) is commonly used in groundwater treatment due to the high effectiveness and simple maintenance of these pressure driven membrane processes. In this research, a pilot-scale NF/RO system was used to desalinate a natural groundwater sample containing high Sr concentration (10.3 mg/L) and “old” groundwater organic matter (70.9 mg/L) from Esilalei in northern Tanzania to understand the removal of strontium by NF/RO. The impact of applied pressure (10–15 bar) and groundwater pH (3–12) on the membrane performance including permeate flux, strontium and total organic carbon (TOC) flux and removal was investigated. Increasing applied pressure was found to enhance the flux by increasing the driving force and enhance Sr and TOC removal by dilution effect (water flux higher than Sr passage). The alkaline pH caused severe flux decline likely due to membrane fouling and scaling, while it slightly enhanced Sr removal of RO membranes, but weakened the TOC removal. In contrast, acidic and neutral pH of groundwater enhanced TOC removal. These findings suggest that appropriately high applied pressure and acidic pH condition of groundwater are recommended to apply to the NF/RO membrane system in groundwater desalination to achieve better membrane performance.

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REMOVAL OF REFRACTORY COMPOUNDS FROM LANDFILL LEACHATE BY USING NANOFILTRATION

Jurnal Teknologi ◽

10.11113/jt.v80.12728 ◽

2018 ◽

Vol 80 (3-2) ◽

Author(s):

Titik Istirokhatun ◽

Desinta Aswin Amalia ◽

Wiharyanto Oktiawan ◽

Arya Rezagama ◽

M. Arief Budihardjo ◽

...

Keyword(s):

Landfill Leachate ◽

Nanofiltration Membrane ◽

Permeate Flux ◽

Leachate Treatment ◽

Membrane Pore ◽

Effluent Quality ◽

Membrane Performance ◽

Refractory Compounds ◽

Membrane Pore Size ◽

Synthetic Leachate

Landfill leachate is a serious problem during treatment of municipal solid waste using landfill method. Less attention has been paid for the treatment of this leachate while this leachate is usually highly polluted. This study investigated the performances of nanofiltration membrane for treatment of landfill leachate (from Semarang, Indonesia). Landfill leachate was treated using NF99 nanofiltration membrane (pore size 200 Da). Synthetic leachate was used in this research which follows the characteristics of real leachate. Microfiltration (MF) membrane was used as a pretreatment before Nanofiltration (NF). The effect of pressure on membrane performance was observed. The membrane performance was examined for permeate flux and membrane rejection for TSS, TDS, and COD then compared to the effluent quality of existing leachate treatment. The rejection of COD, TSS and TDS were 96, 100 and 62%, respectively. The results suggest that the effluent had much better quality than the existing installation leachate treatment.

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Pilot scale nanofiltration membrane separation for waste management in textile industry

Water Science & Technology ◽

10.2166/wst.2001.0629 ◽

2001 ◽

Vol 43 (10) ◽

pp. 233-240 ◽

Cited By ~ 18

Author(s):

I. Koyuncu ◽

E. Kural ◽

D. Topacik

Keyword(s):

Membrane Fouling ◽

Textile Industry ◽

Membrane Separation ◽

Transport Model ◽

Pilot Scale ◽

Operating Pressure ◽

Nanofiltration Membrane ◽

Permeate Flux ◽

Feed Concentration ◽

Mass Transport Model

This paper presents the pilot scale membrane separation studies on dyehouse effluents of textile industry. Nanofiltration (NF) membranes which have 2 m2 of surface area were evaluated for membrane fouling on permeate flux and their suitability in separating COD, color and conductivity in relation to operating pressure and feed concentration from textile industry dyehouse effluents. Successive batch runs demonstrated that any serious membrane fouling was not experienced for NF membrane tested in treating this type of wastewater. The permeate flux was found to increase significantly with operating pressure. Flux decreased with increasing recovery rate. The overall removal efficiencies of COD, color and conductivity were found as greater than 97%. COD was lower than 10 mg/l at 12 bar pressures. Permeate COD was also increased with increasing recovery and COD was 30 mg/l with recovery of 80%. Almost complete color removal was achieved with nanofiltration membrane. Color value was also decreased from 500 Pt-Co to 10 Pt-Co unit. This significant reduction in color and COD makes possible the recycle of the permeate in the dyehouse. Permeate conductivity was decreasing with increasing pressure and retention of conductivity increases with increasing pressures. This phenomenon is expected from the analysis of conductivity mass transport model. Economical analysis have been done and the total estimated cost will be 0.81 $/m3 based on 1000 m3/day of and this value is very economical for Istanbul City due to increasing industrial water supply tariffs.

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Pilot Tests and Fouling Identification in the Ultrafiltration of Model Oily and Saline Wastewaters

Ecological Chemistry and Engineering S ◽

10.1515/eces-2019-0037 ◽

2019 ◽

Vol 26 (3) ◽

pp. 493-507

Author(s):

Konrad Ćwirko ◽

Elwira Tomczak ◽

Daniela Szaniawska ◽

Ryszard Buczkowski

Keyword(s):

Experimental Design ◽

Membrane Fouling ◽

Ceramic Membrane ◽

Main Process ◽

Permeate Flux ◽

Membrane Performance ◽

Pore Blocking ◽

Oil In Water ◽

Model Oil ◽

Ultrafiltration Process

Abstract This paper evaluates ceramic membrane performance and fouling mechanisms in the ultrafiltration of model oil-in-water solutions with addition of NaCl. First, the work estimated the effect of main process parameters, i.e. transmembrane pressure, cross-flow velocity and NaCl content in the feed on oil rejection and permeate flux using 23 experimental design. The ultrafiltration experiments were carried out using pilot installation with commercial tubular ceramic 300 kDa membrane. Ultrafiltration data obtained using experimental design technique was used to determine the regression coefficients of polynomial equations. These equations give information on non-conjugated as well as conjugated effects of two operating parameters and one feed parameter on ceramic membrane performance in ultrafiltration process of model oil-in-water-NaCl solutions. Moreover, these equations can help to determine optimal conditions for ultrafiltration process from the point of view of membrane permeability and selectivity. Next, ultrafiltration results were analyzed using resistance-in-series model. It was found that the process is membrane resistance limited. It was also stated that, resistance caused by reversible fouling is greater than irreversible fouling resistance. Finally, pore blocking models based on modified Hermia’s equation were used to determine membrane fouling mechanism responsible for permeate flux decline with ultrafiltration time. In investigated system ceramic membrane fouling was caused by complete and intermediate pore blocking mechanisms.

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