scholarly journals Synthesis and performance evaluation of PES/chitosan membranes coated with polyamide for acid mine drainage treatment

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mathaba J. Machodi ◽  
Michael O. Daramola
Keyword(s):  
Performance Evaluation ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Interfacial Polymerization ◽  
Pure Water ◽  
Inversion Method ◽  
Acid Mine ◽  
Chitosan Membranes ◽  
Chitosan Content ◽  
Repulsive Forces

AbstractIn this article, performance evaluation of PES membrane infused with chitosan and coated with polyamide layer for treatment of acid mine drainage (AMD) is reported. PES/chitosan membranes were fabricated by varying chitosan concentration (0, 0.5, 0.75 and 1 wt%) using phase inversion method. PES/chitosan membranes were coated with polyamide (PA) via co-solvent assisted interfacial polymerization technique (CAIP). Scanning electron microscopy (SEM) and contact angle analysis show that chitosan and polyamide could enhance permeability without affecting rejection of the membrane. The permeability was improved with increasing chitosan content. Atomic absorption spectroscopy (AAS) was used to quantitatively determine cations in the permeate and the sulphate ions were analysed using ultraviolet and visible (UV-VIS) spectrophotometer. Pure water flux of PES/PA membrane was significantly improved from 56 to 93 l/m2.hr with 1 wt% chitosan addition. Cation rejection (90.4, 88.3, 89.3 and 75.7% for Mn2+,Fe2+, Mg2+ and Ca2+, respectively) was observed to be higher than anion rejection (56.33% for SO42−), when chitosan content was 0.75 wt%. These results indicate that the positively charged membranes under acidic condition had strong repulsive forces with the cations than attractions forces with anions. Polyethersulphone membrane modified with chitosan and coated with polyamide layer displayed potential for application in treatment of AMD.

scholarly journals Synthesis of PES and PES/chitosan membranes for synthetic acid mine drainage treatment

Water SA ◽  
2020 ◽  
Vol 46 (1 January) ◽  
Author(s):  
Mathaba J Machodi ◽  
Michael O Daramola
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Pure Water ◽  
Water Flux ◽  
Inversion Method ◽  
Separation Performance ◽  
Acid Mine ◽  
Pure Water Flux ◽  
Chitosan Membranes ◽  
Pes Membrane

In this study, chitosan was synthesised from chitin and used to modify polyethersulphone (PES) membrane prepared by the phase inversion method. PES membrane was blended with various concentrations of chitosan to produce PES/0.5 wt% chitosan, PES/0.75 wt% chitosan and PES/1 wt% chitosan membranes. The membranes were tested for metal and sulphate removal from acid mine drainage (AMD). The fabricated membranes were characterised using scanning electron microscopy (SEM), contact angle analyser, Fourier transform infrared (FTIR), porosity determination and pure water flux measurements. Separation performance was conducted on a dead-end filtration cell and metal ions were determined by atomic absorption spectroscopy (AAS), and ultraviolet and visible (UV-vis) spectrophotometry was used for sulphates. Pure water flux of the pristine PES membrane increased from 102 L∙m−2∙h−1 to 107 L∙m−2∙h−1 and 133 L∙m−2∙h−1 for PES/0.5 wt% and PES/0.75 wt%, respectively. Further addition of chitosan to 1 wt% created a dense structure on the membrane surface, thereby reducing the flux to 120 L∙m−2∙h−1. The rejection of cations and sulphate ions significantly improved for chitosan-modified membranes due to the creation of adsorptive and/or repulsive sites on the chitosan biopolymer as a result of amine group protonation. The results reveal that chitosan has potential to improve performance of PES membranes as a hydrophilic agent during AMD treatment.

scholarly journals Effect of Chitosan’s Degree of Deacetylation on the Performance of PES Membrane Infused with Chitosan during AMD Treatment

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 52 ◽  
Author(s):  
Machodi Mathaba ◽  
Michael Olawale Daramola
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Pure Water ◽  
Synergetic Effect ◽  
Synthesis Process ◽  
Process Conditions ◽  
Mining Operations ◽  
Degree Of Deacetylation ◽  
Acid Mine ◽  
Pes Membrane

Acid mine drainage is an environmental problem associated with mining operations and activities. Its treatment is essential to achieving environmental sustainability. In this study, a polyethersulphone (PES) membrane infused with chitosan is proposed as a point-of-use material for treating acid mine drainage (AMD). The composite material explored the synergetic effect between chitosan and polymer, particularly considering the effect of the degree of deacetylation (DD) of chitosan on the performance of membrane. Chitosan was produced from chitin under various synthesis process conditions and infused within polyethersulphone membrane. The results obtained show that chitosan with the highest degree of deacetylation was achieved with a temperature of 100 °C and NaOH concentration of 40 wt%. Increasing the temperature above 100 °C started degrading already formed or exposed amine groups, thus, reducing the DD of the chitosan sample. The contact angle and porosity analysis indicated that the hydrophilic nature of the membrane was enhanced with increasing DD of the chitosan. The performance of the membranes was conducted on a Dead-end filtration cell using synthetic acid mine drainage. The results showed that the flux and rejection of the membrane was enhanced with increasing degree of deacetylation. PES 5 and PES 1 were blended with chitosan having the highest (95.97%) and lowest (33.93%) degree of deacetylation, respectively. PES 5 reported pure water flux of 123 L/m2·h and PES 1 was recorded as 104 L/m2·h. Similarly, the rejection of the membrane was improved with increasing chitosan’s degree of deacetylation. PES 5 had higher rejection and PES 1 had the least rejection. Maximum rejection for the contaminants was determined as 98.05, 97.39, 96.25, 95.24 and 80.34% for Mn2+, Fe2+, Mg2+ and Ca2+ and SO42−, respectively. The results obtained show that chitosan’s degree of deacetylation has a positive effect on the performance of polyethersulphone membrane during the treatment of acid mine drainage.

scholarly journals Effect of Silica Sodalite Functionalization and PVA Coating on Performance of Sodalite Infused PSF Membrane during Treatment of Acid Mine Drainage

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 315
Author(s):  
Nobuhle C. Ntshangase ◽  
Olawumi O. Sadare ◽  
Michael O. Daramola
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mixed Matrix Membranes ◽  
Inversion Method ◽  
Force Microscopy ◽  
Acid Mine ◽  
Dead End ◽  
Removal Of Heavy Metals ◽  
Phase Inversion Method

In this study, silica sodalite (SSOD) nanoparticles were synthesized by topotactic conversion and functionalized using HNO3/H2SO4 (1:3). The SSOD and functionalized SSOD (fSSOD) nanoparticles were infused into a Polysulfone (Psf) membrane to produce mixed matrix membranes. The membranes were fabricated via the phase inversion method. The membranes and the nanoparticles were characterized using Scanning Electron Microscopy (SEM) to check the morphology of the nanoparticles and the membranes and Fourier Transform Infrared to check the surface chemistry of the nanoparticles and the membranes. Thermal stability of the nanoparticles and the membranes was evaluated using Themogravimetry analysis (TGA) and the degree of hydrophilicity of the membranes was checked via contact angle measurements. The mechanical strength of the membranes and their surface nature (roughness) were checked using a nanotensile instrument and Atomic Force Microscopy (AFM), respectively. The textural property of the nanoparticles were checked by conducting N2 physisorption experiments on the nanoparticles at 77 K. AMD-treatment performance of the fabricated membranes was evaluated in a dead-end filtration cell using a synthetic acid mine drainage (AMD) solution prepared by dissolving a known amount of MgCl2, MnCl2·4H2O, Na2SO4, Al(NO3)3, Fe(NO3)3·9H2O, and Ca2OH2 in deionized water. Results from the N2 physisorption experiments on the nanoparticles at 77 K showed a reduction in surface area and increase in pore diameter of the nanoparticles after functionalization. Performance of the membranes during AMD treatment shows that, at 4 bar, a 10% fSSOD/Psf membrane displayed improved heavy metal rejection >50% for all heavy metals considered, expect the SSOD-loaded membrane that showed a rejection <13% (except for Al3+ 89%). In addition, coating the membranes with a PVA layer improved the antifouling property of the membranes. The effects of multiple PVA coating and behaviour of the membranes during real AMD are not reported in this study, these should be investigated in a future study. Therefore, the newly developed functionalized SSOD infused Psf membranes could find applications in the treatment of AMD or for the removal of heavy metals from wastewater.

Sign in / Sign up

Export Citation Format

Share Document