Investigation of polar mobile organic compounds (PMOC) removal by reverse osmosis and nanofiltration: rejection mechanism modelling using decision tree

Abstract Polar mobile organic compounds (PMOC) are highly polar chemicals and tend to accumulate in short water cycles. Due to their properties, PMOC might be partially eliminated by advanced water treatment technologies. The goal of this study is to investigate the rejection of 22 PMOC (highly mobile and persistent) by reverse osmosis (RO) and nanofiltration (NF) membranes. The impact of transmembrane pressure was evaluated through laboratory-scale cross-flow constant pressure filtration tests. Among the investigated experimental conditions, PMOC rejection with NF at eight bars is comparable to values obtained on RO at 15 bars. Negatively charged PMOC are highly rejected by both RO and NF membranes while guanidine-like compounds exhibit higher passage values and are strongly impacted by transmembrane pressure. In order to model the rejection mechanism, decision tree methodology was employed to link PMOC physicochemical properties to rejection values. Based on laboratory-scale results, decision trees were computed and emphasized that the NF rejection mechanism is governed by electrostatic interaction and sieving effects. In contrast, PMOC rejection on the RO membrane strongly depends on the topological polar surface area (TPSA) of the PMOC. This study suggests that micropollutant TPSA should be more investigated in order to describe RO removal efficiency. Moreover, it is shown that the decision tree is a powerful numerical tool in order to reveal the specific sequence leading to micropollutant removal by RO and NF membranes.

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Data-driven Modelling of Microfiltration Process with Embedded Static Mixer for Steepwater from Corn Starch Industry

Periodica Polytechnica Chemical Engineering ◽

10.3311/ppch.10400 ◽

2017 ◽

Author(s):

Laslo Šereš ◽

Ljubica Dokić ◽

Bojana Ikonić ◽

Dragana Šoronja-Simović ◽

Miljana Djordjević ◽

...

Keyword(s):

Corn Starch ◽

Desirability Function ◽

Specific Energy Consumption ◽

Cross Flow ◽

Operating Conditions ◽

Transmembrane Pressure ◽

Static Mixer ◽

Permeate Flux ◽

Experimental Conditions ◽

Starch Industry

Cross-flow microfiltration using ceramic tubular membrane was applied for treatment of steepwater from corn starch industry. Experiments are conducted according to the faced centered central composite design at three different transmembrane pressures (1, 2 and 3 bar) and cross-flow velocities (100, 150 and 200 L/h) with and without the usage of Kenics static mixer. For examination of the influence of the selected operating conditions at which usage of the static mixer is justified, a response surface methodology and desirability function approach were used. Obtained results showed improvement in the average permeate flux by using Kenics static mixer for 211 % to 269 % depending on experimental conditions when compared to the system without the static mixer. As a result of optimization, the best results considering flux improvement as well as reduction of specific energy consumption were obtained at low transmembrane pressure and lower feed cross-flow rates.

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The Fracture and Aerosol Release of Impacted HLW Glasses and HLW Canisters

MRS Proceedings ◽

10.1557/proc-127-181 ◽

1988 ◽

Vol 127 ◽

Cited By ~ 1

Author(s):

Hans G. Scheibel ◽

V. Friehmelt ◽

H. Froehlich

Keyword(s):

Impact Velocity ◽

Thermal Stresses ◽

Full Scale ◽

Laboratory Scale ◽

Small Scale ◽

Release Mechanism ◽

Experimental Conditions ◽

Drop Tests ◽

Ground Plate ◽

The Impact

ABSTRACTThe fracture and release mechanism of radioactive aerosols of HLW glass and HLW canisters are studied experimentally by laboratory scale and full scale drop tests. The experimental conditions model the conditions of accidental drops in a deep salt repository. The laboratory scale drop tests have a scaling factor of 1:10. Accelerated probes of simulated HLW glass impact on a ground plate and the size distributions of broken fines and released aerosols are measured by sieving and scanning electron microscopy (SEM) of aerosol samples.The impact velocity is determined as the dominating impact parameter. Further parameters tested, such as waste glass composition, cooling time (residual thermal stresses), probe temperature at impact, and ground characteristics, show no measurable influence. Source terms of released respirable aerosols are evaluated for two reference cases, borehole drop (impact velocity v = 80 m/s) and reloading hall drop (v = 14 m/s), the values being 0.1 % and to 2.10-4 % respectively of the glass probe mass. The full scale drop tests are performed with European Standard HLW canisters. The canisters keep their integrity in all tests up to drop heights of 14 m. On opening the canisters, the broken fines are analyzed by sieving. The results are in good agreement with the small scale tests and confirm their acceptability for use in a safety analysis.

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The impact of diatoms on the biofouling of seawater reverse osmosis membranes in a model cross-flow system

Desalination ◽

10.1016/j.desal.2016.04.019 ◽

2016 ◽

Vol 392 ◽

pp. 8-13 ◽

Cited By ~ 4

Author(s):

Sophie C. Leterme ◽

Charlotte Le Lan ◽

Deevesh A. Hemraj ◽

Amanda V. Ellis

Keyword(s):

Reverse Osmosis ◽

Flow System ◽

Cross Flow ◽

Seawater Reverse Osmosis ◽

The Impact ◽

Reverse Osmosis Membranes

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Cross-Flow Microfiltration of Glycerol Fermentation Broths with Citrobacter freundii

Membranes ◽

10.3390/membranes10040067 ◽

2020 ◽

Vol 10 (4) ◽

pp. 67 ◽

Cited By ~ 4

Author(s):

Wirginia Tomczak ◽

Marek Gryta

Keyword(s):

Colloidal Particles ◽

Ceramic Membrane ◽

Fermentation Broth ◽

Cross Flow ◽

Transmembrane Pressure ◽

Citrobacter Freundii ◽

Permeate Flux ◽

Glycerol Fermentation ◽

Fermentation Broths ◽

The Impact

This paper reports the study of the cross-flow microfiltration (MF) of glycerol fermentation broths with Citrobacter freundii bacteria. A single channel tubular ceramic membrane with a nominal pore size of 0.14 µm was used. It has been demonstrated that the MF ceramic membrane has been successfully applied to bacteria cell removal and to effectively eliminate colloidal particles from glycerol fermentation broths. However, due to fouling, the significant reduction of the MF performance has been demonstrated. In order to investigate the impact of transmembrane pressure (TMP) and feed flow rate (Q) on MF performance, 24 experiments have been performed. The highest steady state permeate flux (138.97 dm3/m2h) was achieved for 0.12 MPa and 1000 dm3/h. Fouling analysis has been studied based on the resistance-in series model. It has been found that the percentage of irreversible fouling resistance during the MF increases with increasing TMP and Q. The permeate flux regeneration has been achieved by membrane cleaning with 3 wt % NaOH and 3 wt % H3PO4 at 45 °C. The results of this study are expected to be useful in industrially employing the MF process as the first step of glycerol fermentation broth purification.

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The concentrating of alizarin using a reverse osmosis process

Journal of the Serbian Chemical Society ◽

10.2298/jsc0501107m ◽

2005 ◽

Vol 70 (1) ◽

pp. 107-114 ◽

Cited By ~ 1

Author(s):

S.S. Madaeni ◽

H. Daneshvar

Keyword(s):

Flow Velocity ◽

Reverse Osmosis ◽

Cross Flow ◽

Operating Conditions ◽

Optimum Operating ◽

Transmembrane Pressure ◽

Reverse Osmosis Membrane ◽

Cross Flow Velocity ◽

Membrane Technologies ◽

Madder Root

Membrane technologies in general and reverse osmosis in particular have been employed for the concentrating of solutions. In this study, the concentrating of a heat sensitive alizarin extracted from madder root was realized using an FT30 reverse osmosis membrane. The effects of cross flow velocity, transmembrane pressure and pH on the flux and rejection were studied. Increasing the transmembrane pressure increased the flux while the rejection was constant. At pH 7-8, the highest flux was achieved. This study showed that reverse osmosis is the process of choice for the concentrating of alizarin solutions. The optimum operating conditions were 1.0 m/s cross flow velocity, 16 bars transmembrane pressure and pH 7. The system was tested for 12 h without severe fouling problems.

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Box Behken design for optimization of COD removal from Palm oil mill effluent (POME) using Reverse osmosis (RO) membrane

Indonesian Journal of Environmental Management and Sustainability ◽

10.26554/ijems.2019.3.4.39-46 ◽

2019 ◽

Vol 3 (1) ◽

Author(s):

Muhammad Said ◽

Muneer ba Abbad ◽

Siti Rozaimah Sheik Abdullah ◽

Abdul Wahab Mohammad

Keyword(s):

Reverse Osmosis ◽

Palm Oil ◽

Polynomial Regression ◽

Cod Removal ◽

Palm Oil Mill Effluent ◽

Transmembrane Pressure ◽

Affecting Factors ◽

Experimental Conditions ◽

Ro Membrane ◽

Palm Oil Mill

The optimization of COD removal from palm oil mill effluent (POME) using the Reverse Osmosis (RO) membrane was investigated. Experimental conditions for reduce the COD value of POME were achieved successfully using the Box Behken design. The values of affecting factors (POME concentration, pH and Transmembrane pressure were optimized according to the polynomial regression model. The predicted conditions to produce lower COD values were found to be POME concentration (vol. %) =28.30, pH =10.75 and Transmembrane pressure= 0.69 kPa. The predicted of COD value was 24.137 mg/l which in good agreed with experiment value as 25.763 mg/l was obtained.

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The role of interaction between low molecular weight neutral organic compounds and a polyamide RO membrane in the rejection mechanism

RSC Advances ◽

10.1039/d0ra01966f ◽

2020 ◽

Vol 10 (26) ◽

pp. 15642-15649

Author(s):

Muxue Zhang ◽

Lauren Breitner ◽

Kerry J. Howe ◽

Daisuke Minakata

Keyword(s):

Molecular Weight ◽

Reverse Osmosis ◽

Organic Compounds ◽

Membrane Technology ◽

Low Molecular Weight ◽

Dissolved Species ◽

Rejection Mechanism ◽

Ro Membrane ◽

Neutral Organic Compounds

Reverse osmosis (RO) is a membrane technology that separates dissolved species from water.

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Characterization of seawater reverse osmosis fouled membranes from large scale commercial desalination plant

10.31221/osf.io/96zj5 ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Reverse Osmosis ◽

Large Scale ◽

Retention Rate ◽

Local Level ◽

Microscopic Analysis ◽

Transmembrane Pressure ◽

Hydraulic Permeability ◽

Seawater Reverse Osmosis ◽

A Chain

The objective of this work is to study the ageing state of a used reverse osmosis (RO) membrane taken in Algeria from the Benisaf Water Company seawater desalination unit. The study consists of an autopsy procedure used to perform a chain of analyses on a membrane sheet. Wear of the membrane is characterized by a degradation of its performance due to a significant increase in hydraulic permeability (25%) and pressure drop as well as a decrease in salt retention (10% to 30%). In most cases the effects of ageing are little or poorly known at the local level and global measurements such as (flux, transmembrane pressure, permeate flow, retention rate, etc.) do not allow characterization. Therefore, a used RO (reverse osmosis) membrane was selected at the site to perform the membrane autopsy tests. These tests make it possible to analyze and identify the cause as well as to understand the links between performance degradation observed at the macroscopic scale and at the scale at which ageing takes place. External and internal visual observations allow seeing the state of degradation. Microscopic analysis of the used membranes surface shows the importance of fouling. In addition, quantification and identification analyses determine a high fouling rate in the used membrane whose foulants is of inorganic and organic nature. Moreover, the analyses proved the presence of a biofilm composed of protein.

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Tanning Wastewater Treatment by Ultrafiltration: Process Efficiency and Fouling Behavior

Membranes ◽

10.3390/membranes11070461 ◽

2021 ◽

Vol 11 (7) ◽

pp. 461

Author(s):

Fu Yang ◽

Zhengkun Huang ◽

Jun Huang ◽

Chongde Wu ◽

Rongqing Zhou ◽

...

Keyword(s):

Wastewater Treatment ◽

Shear Rate ◽

Membrane Surface ◽

Filtration Efficiency ◽

Operating Conditions ◽

Process Efficiency ◽

Transmembrane Pressure ◽

Leather Industry ◽

Pore Blocking ◽

The Impact

Ultrafiltration is a promising, environment-friendly alternative to the current physicochemical-based tannery wastewater treatment. In this work, ultrafiltration was employed to treat the tanning wastewater as an upstream process of the Zero Liquid Discharge (ZLD) system in the leather industry. The filtration efficiency and fouling behaviors were analyzed to assess the impact of membrane material and operating conditions (shear rate on the membrane surface and transmembrane pressure). The models of resistance-in-series, fouling propensity, and pore blocking were used to provide a comprehensive analysis of such a process. The results show that the process efficiency is strongly dependent on the operating conditions, while the membranes of either PES or PVDF showed similar filtration performance and fouling behavior. Reversible resistance was the main obstacle for such process. Cake formation was the main pore blocking mechanism during such process, which was independent on the operating conditions and membrane materials. The increase in shear rate significantly increased the steady-state permeation flux, thus, the filtration efficiency was improved, which resulted from both the reduction in reversible resistance and the slow-down of fouling layer accumulate rate. This is the first time that the fouling behaviors of tanning wastewater ultrafiltration were comprehensively evaluated, thus providing crucial guidance for further scientific investigation and industrial application.

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Glucuronides Hydrolysis by Intestinal Microbial β-Glucuronidases (GUS) Is Affected by Sampling, Enzyme Preparation, Buffer pH, and Species

Pharmaceutics ◽

10.3390/pharmaceutics13071043 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1043

Author(s):

Christabel Ebuzoeme ◽

Imoh Etim ◽

Autumn Ikimi ◽

Jamie Song ◽

Ting Du ◽

...

Keyword(s):

Enzyme Preparation ◽

Reaction System ◽

Reaction Rates ◽

Experimental Conditions ◽

Model Animal ◽

Fresh Feces ◽

Time Buffer ◽

Exogenous Compounds ◽

Activity Loss ◽

The Impact

Glucuronides hydrolysis by intestinal microbial β-Glucuronidases (GUS) is an important procedure for many endogenous and exogenous compounds. The purpose of this study is to determine the impact of experimental conditions on glucuronide hydrolysis by intestinal microbial GUS. Standard probe 4-Nitrophenyl β-D-glucopyranoside (pNPG) and a natural glucuronide wogonoside were used as the model compounds. Feces collection time, buffer conditions, interindividual, and species variations were evaluated by incubating the substrates with enzymes. The relative reaction activity of pNPG, reaction rates, and reaction kinetics for wogonoside were calculated. Fresh feces showed the highest hydrolysis activities. Sonication increased total protein yield during enzyme preparation. The pH of the reaction system increased the activity in 0.69–1.32-fold, 2.9–12.9-fold, and 0.28–1.56-fold for mouse, rat, and human at three different concentrations of wogonoside, respectively. The Vmax for wogonoside hydrolysis was 2.37 ± 0.06, 4.48 ± 0.11, and 5.17 ± 0.16 μmol/min/mg and Km was 6.51 ± 0.71, 3.04 ± 0.34, and 0.34 ± 0.047 μM for mouse, rat, and human, respectively. The inter-individual difference was significant (4–6-fold) using inbred rats as the model animal. Fresh feces should be used to avoid activity loss and sonication should be utilized in enzyme preparation to increase hydrolysis activity. The buffer pH should be appropriate according to the species. Inter-individual and species variations were significant.

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