Effect of pH on membrane fouling during alcohol dehydrogenase immobilization in PES membrane

Fouling-induced enzyme immobilization is a technique to immobilize enzyme by positively manipulating the knowledge of membrane fouling. In this study, Alcohol dehydrogenase (ADH) (EC 1.1.1.1) was immobilized in the support layer of ultrafiltration PES membrane at different solution pH (acid, neutral and alkaline). ADH catalyses formaldehyde (CHOH) to methanol (CH3OH) and simultaneously oxidised nicotinamide adenine dinucleotide (NADH) to NAD+. The initial feed amount of enzyme is 3.0 mg. The objective of the study aims at the effect of different pH of feed solution during enzyme immobilization, in terms of permeate flux, observed rejection, enzyme loading and fouling mechanism. The results showed that, pH 5 holds the highest enzyme loading which is 65% while pH 7 holds the lowest at 52% out of 3.0 mg as the initial enzyme feed. The permeate flux for each pH decreased with increasing cumulative permeate volume. The observed rejection is inversely correlated with the pH where increase in pH will cause a lower observed rejection. The fouling model predicted that irreversible fouling occurs during enzyme immobilization at pH 7 with standard blocking mechanism while reversible fouling occurs at pH 5 and 9 with intermediate and complete blocking, respectively.

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Biocatalytic Reduction of Formaldehyde to Methanol: Effect of pH on Enzyme Immobilization and Reactive Membrane Performance

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.16.3.10568.472-480 ◽

2021 ◽

Vol 16 (3) ◽

pp. 472-480

Author(s):

Norhayati Abdul Rahman ◽

Fauziah Marpani ◽

Nur Hidayati Othman ◽

Nur Hashimah Alias ◽

Junaidah Jai ◽

...

Keyword(s):

Enzyme Immobilization ◽

Enzymatic Reaction ◽

Feed Solution ◽

Permeate Flux ◽

High Concentration ◽

Enzyme Loading ◽

Reaction Conversion ◽

Observed Rejection ◽

Pes Membrane ◽

Reactive Membrane

Thermodynamic stabled CO2 molecules can be biocatalytically reduced to methanol via three cascade dehydrogenases (formate, formaldehyde and alcohol) with the aid of cofactor as the electron donor. In this study, Alcohol dehydrogenase (EC 1.1.1.1), the third step of the cascade enzymatic reaction which catalyzed formaldehyde (CHOH) to methanol (CH3OH) will be immobilized in an ultrafiltration membrane. The enzyme will be immobilized in the support layer of a poly(ether)sulfone (PES) membrane via a technique called fouling induced enzyme immobilization. The objective of this study is to evaluate the effect of varying pH (acid (pH 5), neutral (pH 7) and alkaline (pH 9)) of the feed solution during immobilization process of ADH in the membrane in terms of permeate flux, observed rejection, enzyme loading and fouling mechanism. The experiment was conducted in a pressure driven, dead-end stirred filtration cell. Reaction conversion and biocatalytic productivity will be also evaluated. The results showed that permeate flux for acid solution were the lowest during immobilization. High concentration polarization and fouling resistance cause lower observed rejection for pH 7 and 9. Enzyme loading for pH 5 give 73.8% loading rate which is the highest compared to 62.4% at pH 7 and 70.1% at pH 9. Meanwhile, the conversion rate during the reaction shows that reaction on fouled membrane showed more than 90% conversion for pH 5 and 7. The fouling model predicted that irreversible fouling occurs during enzyme immobilization at pH 7 with standard blocking mechanism while reversible fouling occurs at pH 5 and 9 with intermediate and complete blocking, respectively. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

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Organic Fouling Impact in a Direct Contact Membrane Distillation System Treating Wastewater: Experimental Observations and Modeling Approach

Membranes ◽

10.3390/membranes11070493 ◽

2021 ◽

Vol 11 (7) ◽

pp. 493

Author(s):

Amine Charfi ◽

Fida Tibi ◽

Jeonghwan Kim ◽

Jin Hur ◽

Jinwoo Cho

Keyword(s):

Particle Size ◽

Membrane Fouling ◽

Direct Contact ◽

Feed Solution ◽

Membrane Distillation ◽

Mixed Solution ◽

Permeate Flux ◽

Direct Contact Membrane Distillation ◽

Organic Fouling ◽

Specific Cake Resistance

This study aims to investigate the effect of operational conditions on organic fouling occurring in a direct contact membrane distillation (DCMD) system used to treat wastewater. A mixed solution of sodium alginate (SA) and bovine serum albumin (BSA) was used as a feed solution to simulate polysaccharides and proteins, respectively, assumed as the main organic foulants. The permeate flux was observed at two feed temperatures 35 and 50 °C, as well as three feed solution pH 4, 6, and 8. Higher permeate flux was observed for higher feed temperature, which allows higher vapor pressure. At higher pH, a smaller particle size was detected with lower permeate flux. A mathematical model based on mass balance was developed to simulate permeate flux with time by assuming (i) the cake formation controlled by attachment and detachment of foulant materials and (ii) the increase in specific cake resistance, the function of the cake porosity, as the main mechanisms controlling membrane fouling to investigate the fouling mechanism responsible of permeate flux decline. The model fitted well with the experimental data with R2 superior to 0.9. High specific cake resistance fostered by small particle size would be responsible for the low permeate flux observed at pH 8.

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In-Situ Ultrasound-Assisted Control of Polymeric Membrane Fouling

10.32920/ryerson.14662725.v1 ◽

2021 ◽

Author(s):

Westphalen Dornelas Camara Heloisa

Keyword(s):

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Separation ◽

Feed Solution ◽

Solution Concentration ◽

Polymeric Membrane ◽

Permeate Flux ◽

Latex Paint ◽

Water And Wastewater Treatment ◽

Maximum Increase

Membrane separation processes have been more widely applied to industrial activities, especially in water and wastewater treatment. However, there are still challenges associated to the use of membranes. Concentration polarization and fouling can cause significant permeate flux decay during the filtration process, hindering its efficiency and increasing cost. Among many strategies, the combination of membrane filtration with ultrasound (US) application has shown promising results in reducing membrane fouling. The main goal of this research was to identify the effect of US frequency, US power intensity and feed solution concentration on permeate flux during ultrafiltration of simulated latex paint effluent. Maximum increase in permeate flux of 19.7% was obtained by applying 20 kHz and 0.29 W.cm-2 to feed solution with 0.075 wt.% of solid concentration. The effect of feed flow rate was analyzed showing that an increase in feed flowrate is not beneficial to the fouling minimization process. Overall, the application of US improves permeate flux by reducing fouling of ultrafiltration polymeric membrane.

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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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In-Situ Ultrasound-Assisted Control of Polymeric Membrane Fouling

10.32920/ryerson.14662725 ◽

2021 ◽

Author(s):

Westphalen Dornelas Camara Heloisa

Keyword(s):

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Separation ◽

Feed Solution ◽

Solution Concentration ◽

Polymeric Membrane ◽

Permeate Flux ◽

Latex Paint ◽

Water And Wastewater Treatment ◽

Maximum Increase

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Assessment of membrane fouling indices during removal of reactive dye from batik wastewater

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2016.072 ◽

2016 ◽

Vol 6 (4) ◽

pp. 505-514 ◽

Cited By ~ 1

Author(s):

Indok Nurul Hasyimah Mohd Amin ◽

Muhamad Hafiz Muhammad Nizam

Keyword(s):

Membrane Fouling ◽

Polyvinylidene Fluoride ◽

Reactive Dye ◽

Permeate Flux ◽

Solution Ph ◽

Membrane Materials ◽

A Value ◽

Uf Membranes ◽

Dye Rejection ◽

Modified Fouling Index

‘Batik’ is known as one of the most popular textile industries in Malaysia, and it produces wastewater in its processing. The wastewater contains reactive dye and is released into drains as well as rivers. It could cause harm to the environment and interrupt the food chain due to the chemicals contained in it. The aim of the present study is to determine the flux performance and modified fouling index using ultrafiltration (MFI-UF) by using different membrane materials, feed concentrations and feed chemistry. The sample was obtained from Romi Batik located at Chendering Terengganu. Two UF membranes were used, with the membrane materials made from cellulose acetate and polyvinylidene fluoride (PVDF). The permeate flux and fouling indices were investigated at the solution pH values of 3 and 7 for different concentrations. It was clearly observed that the highest percentage dye rejection and MFI-UF obtained at pH 7 using a PVDF membrane was a value of 85.3792% and 72,088 s/L2, respectively. Overall results revealed that an ultrafiltration process can be used to treat reactive dye from textiles before it is channelled into the sea or rivers, and has great potential to be commercialized as a new alternative in dye wastewater treatment.

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Effect of heat treatment on fouling resistance and the rejection of small and neutral solutes by reverse osmosis membranes

Water Science & Technology Water Supply ◽

10.2166/ws.2014.135 ◽

2014 ◽

Vol 15 (3) ◽

pp. 510-516 ◽

Cited By ~ 12

Author(s):

Takahiro Fujioka ◽

Nagayasu Oshima ◽

Ryoichi Suzuki ◽

Michael Higgins ◽

William E. Price ◽

...

Keyword(s):

Heat Treatment ◽

Reverse Osmosis ◽

Free Volume ◽

Membrane Fouling ◽

Volume Fraction ◽

Membrane Surface ◽

Feed Solution ◽

Membrane Properties ◽

Permeate Flux ◽

Fouling Resistance

The effects of heat treatment on membrane fouling resistance and the rejection of small and neutral solutes by reverse osmosis (RO) membranes were elucidated. RO membrane modification by heat treatment reduced fouling and improved boron rejection. However, heat treatment also caused a decrease in the water permeability of RO membranes. Significant improvement on fouling resistance by heat treatment was observed when RO concentrate was used to simulate a feed solution with high fouling propensity. The improved fouling resistance is likely to be due to changes in the hydrophobic interaction between the membrane surface and foulants. Boron rejection by the ESPA2 membrane was enhanced by heat treatment from 26 to 68% (when evaluated at the permeate flux of 20 L/m2 h). Positron annihilation lifetime spectroscopy revealed that heat treatment did not significantly influence the free-volume hole-radius of the membrane active skin layer. The results reported in this study suggested that changes in the other membrane properties such as free-volume fraction and thickness may be the main cause improving boron rejection.

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Isolation and Purification of a Hyperthermostable Superoxide Dismutase from Thermus thermophilus HB27 Using Two-Stage Ultrafiltration

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.1601 ◽

2011 ◽

Vol 396-398 ◽

pp. 1601-1604

Author(s):

Jian Guo Liu ◽

Meng Meng Yin ◽

Meng Wang ◽

Chang Zhen Chen ◽

Hu Zhu

Keyword(s):

Superoxide Dismutase ◽

Thermus Thermophilus ◽

Regenerated Cellulose ◽

Permeate Flux ◽

Solution Ph ◽

Two Stage ◽

Isolation And Purification ◽

E Coli ◽

Pes Membrane ◽

Optimized Conditions

In the present work, a hyperthermostable superoxide dismutase (SOD) was isolated from Thermus thermophilus HB27 using a membrane-based process after being expressed in E. coli. It was found that a two-stage ultrafiltration process using a 100 kDa MWCO regenerated cellulose (RC) membrane and a 50 kDa MWCO polyethersulfone (PES) membrane could successfully employed to isolate SOD from the crude feedstock. The effects of solution pH, ionic strength and permeate flux on the transmission of proteins were quantified using parameter scanning ultrafiltration. Under optimized conditions, the purity of SOD obtained was 96% with a sepcific activity of 1412 U/mg protein and the recovery of SOD from the feedback was close to 87%. The enzyme was highly stable at 90°C and retained 63% activity after heat treatment at 100°C for 1 h.

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Optimization of MCM-41 Mesoporous Material Mixed Matrix Polyethersulfone Membrane for Dye Removal

Membranes ◽

10.3390/membranes11060414 ◽

2021 ◽

Vol 11 (6) ◽

pp. 414

Author(s):

Rana J. Kadhim ◽

Faris H. Al-Ani ◽

Qusay F. Alsalhy ◽

Alberto Figoli

Keyword(s):

Membrane Fouling ◽

Mesoporous Material ◽

Optimization Technique ◽

Operating Conditions ◽

Mixed Matrix ◽

Pareto Chart ◽

Significance Level ◽

Pes Membrane ◽

Wasted Energy ◽

Mcm 41

The aim of this work is the optimization of the operating conditions under which MCM-41-mesoporous material can be incorporated into polyethersulfone (PES)/MCM-41 membranes for nanofiltration (NF) applications. MCM-41 mesoporous material mixed matrix PES membranes have the potential to reduce membrane fouling by organic dye molecules. Process optimization and modeling aim to reduce wasted energy while maintaining high flow during the operation to handle the energy efficiency problems membranes often have. An optimization technique was applied to obtain optimum values for some key parameters in the process to produce a certain amount of flux above the desired values. Response surface methodology (RSM) and analysis of variance (ANOVA) were used as mathematical and statistical analyses to improve the performance of the process on a larger scale. This work investigated the influence of the operating parameters, such as the feed pH values (3–11), MCM-41 content (0–1 wt.%), and the feed dye concentration (10–100 ppm) for each of the two studied dyes, acid black 210 (AB-210) and rose bengal (RB), and their interactions on the PES membrane permeability. The results showed that the PES membrane had the best performance at 64.25 (L·m−2·h−1·bar-1) and 63.16 (L·m−2·h−1·bar-1) for the AB-210 and RB dyes, respectively. An MCM-41 content of nearly 0.8 wt.% in the casting solution, feed dye concentration of 10 ppm for the studied dyes, and feed pH of 3 for the RB dye was found to be the optimal parameters for eliciting the response. The pH had no significant influence on the response for the AB-210 dye, while the pH shows some minor effects on response with the RB dye, and the Pareto chart of the standardized effects on the permeation flux of both dyes using statistically significant at the 5% significance level support these results.

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