Effect of solvents on performance of polyethersulfone ultrafiltration membranes: investigation of metal ion separations

The new polyethersulfone (PES) based ultrafiltration membranes were formed using a two stage process of dry and wet phase inversion in non solvent coagulation bath. The effects of three different solvents such as, N, N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP) and Dimethyl sulphoxide (DMSO) of 82.5% and 85% concentrations on the performance of final membranes were extensively investigated. Scanning electron microscopy (SEM) image results proved that PES membranes with an asymmetric structure were successfully formed. The number of pores formed on the top layer of PES membranes using above-mentioned three solvents was the result of the combined effect of the thermodynamic properties of the system (composition, concentrations, and phase behaviour) and membrane formation kinetics, whereas, the formation of the macroporous sub layer of those membranes was controlled by the diffusion rate of solvent– nonsolvent. The flux of pure water, membrane resistance, mechanical stability, molecular weight cut-off (MWCO) and separation performance of the PES membranes were studied. Separation of metal ions from aqueous solutions was studied for Ni(II), Cu(II) and Cr(III) using two complexing polymer ligands: polyvinyl alcohol (PVA) and poly(diallyldimethylammonium chloride) (PDDA).The separation and permeate rate (flux) efficiencies of the new membranes are compared using different solvents and different PES/solvent compositions

Removal of hazardous material from wastewater by using metal organic framework (MOF) embedded polymeric membranes

© 2018, © 2018 Taylor & Francis. Heavy metals in wastewater can cause acute and chronic toxicity which leads to learning disabilities, cancer, and even death. In the present work, Zn-based MOF (MOF-5) was prepared, and it is characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscope (SEM) analyses. MOF-5-incorporated polymeric membranes (polyethersulfone [PES], cellulose acetate [CA], and polyvinylidene fluoride [PVDF]) prepared by phase inversion method. The morphology, hydrophilicity, porosity, permeation performance, antifouling properties, and the rejection of Cu (II) and Co (II) metal ions of the membranes were significantly improved with the addition of MOF-5. Higher rejection efficiency for Co (II) in PES/MOF-5 and CA/MOF-5 was found to be 74.40% and 77%, respectively

Influences of nano zero valent ion of kaolin and Fe2+ supported kaolin nanoparticles for metal ion separation thorough ultrafiltration

In this work, clay based nanocomposite material was synthesized by wet chemical route and nano zero valent ion of kaolin (nZVI:Kaolin) were prepared using sodium borohydride reduction method. The nZVI:Kaolin and Fe:Kaolin nanoparticles were characterized using XRD, FTIR and SEM and antimicrobial activity. The nZVI:Kaolin and Fe:Kaolin were incorporated into polyethersulfone (PES) membranes for metal ion separation through ultrafiltration. The influences of nZVI:Kaolin and Fe supported clay nanoparticles on PES membranes were characterized their modification in functional properties, hydrophilicity and morphological structure. The clean water flux was enhanced to PES membrane by addition of nZVI:Kaolin and Fe:Kaolin nanoparticles. The Cu (ii), Ni (ii) and Cd (ii) metal ions flux was increased for 0.15 wt% of nZVI and Fe:Kaolin nanoparticles in PES which is due to increase in hydrophilicity and change in morphological structure

Zero-valent iron impregnated cellulose acetate mixed matrix membranes for the treatment of textile industry effluent

Novel green synthesized zero valent iron (ZVI) nanoparticles of distinct mass fractions of 0.5, 1.5 and 2.5 wt% are blended with cellulose acetate (CA) to prepare CA/ZVI mixed matrix membranes (MMMs). The thermal stability and roughness were improved by increasing the mass fraction of ZVI in CA. The morphology of the prepared CA/ZVI membranes has been studied using transmission electron microscopy (TEM). Pure water permeability (PWP) is increased when adding 0.5 wt% of ZVI nanoparticles. When 2.5 wt% is added, PWP decreased due to the aggregation of ZVI nanoparticles in the CA polymer matrix. The adsorption capacity of ZVI nanoparticles on the CA/ZVI membrane during polymer enhanced ultrafiltration of textile effluent is also investigated. The equilibrium adsorption isotherms are well fitted with the Freundlich model, implying the influence of active adsorptive sites of the ZVI nanoparticles

Efficient rejection of organic compounds using functionalized ZSM-5 incorporated PPSU mixed matrix membrane

Zeolite (ZSM-5) and functionalised zeolite blended polyphenylsulfone (PPSU) mixed matrix membranes (MMMs) were fabricated for comparing their performance with virgin PPSU. Similar to zeolite-MMMs, functionalised zeolites such as Fe-ZSM-5 (Fe-Z) and Cu-ZSM-5 (Cu-Z) were mixed with PPSU in the presence of N-methyl pyrrolidone (NMP) solvent. The synthesized zeolite nanoparticles were ultra-sonicated before incorporation to ensure uniform dispersion in PPSU. The PPSU MMMs with incorporated nanomaterials were fabricated as flat sheet modules by means of the phase inversion method. The developed MMMs were examined for homogeneity and characterized for their properties, such as surface hydrophilicity, membrane morphology, thermal stability and surface roughness. An enhanced pure water flux of 62 L m−2 h−1 and a highest lignin retention of 85.2% were observed for a PPSU membrane with 0.5 wt% of zeolite nanomaterials incorporated. The 3D porous structure of the zeolite favoured the enhancement of flux during water and lignin separation. However, the incorporation of functionalised zeolite nanomaterials influenced the increase in maximum lignin rejection to 88.5%. The performance and anti-fouling ability of synthesized MMMs has been evaluated based on the rejection of organic components. Higher preferential permeation with great rejection of lignin were simultaneously observed for zeolite and Cu-zeolite incorporated MMMs

In Vitro Photo-Catalytic Degradation of Chloramphenicol Using Pharmaceutical Wastewater

Abstract: In this work, the performance of composite membranes for the treatment of Chloramphenicol (CAP) pollutants was investigated from pharmaceutical industrial wastewater. The composite membrane was under operated with different concentrations of CAP with Titanium dioxide (TiO2) in 10mg/L, 20mg/L and 30 mg/L. The composite membranes were cross-linked with glutaraldehyde for the elimination of H2SO4. Characterizations of synthesized composite membranes were carried out to analyze functionality, morphology, and hydrophilic behaviours. In continuous operation, the different time intervals of TiO2 were removed in centrifuging. The performance of the composite membrane is the removal of pollutant CAP by UV analysis, and kinetics model at different concentrations. The degree of swelling and contact angle were measured in different concentrations of CAP at TiO2. Liquid Chromatography (LC) is used to CAP with Titanium dioxide mixtures. Mass Spectrometry (MS) can be used for structural identity with high specificity. The MS is also used to analyze CAP from pharmaceutical industrial wastewater. The membranes were subjected to filtration of pharmaceutical wastewater which gave a maximum rejection of 95% of Chloramphenicol

Perspective of renewable desalination by using membrane distillation

As the water demand increases continuously, large capacities of desalination plant are added every year to meet freshwater demand. The higher carbon footprint of desalination raises concern on global climate change. The integration of desalination and renewable energy source could mitigate this water-energy nexus. Membrane distillation (MD) is a non-isothermal desalination process in which the low-grade heat is used as the driving force. Many researchers have tried to integrate solar energy and MD for sustainable water desalination. This article presents a comprehensive review of solar MD desalination to understand its current state of development. Solar powered MD systems have been investigated for last few decades. However, its commercialization is very limited due to low flux, high specific energy consumption and large collector area requirement. Further, this review presents the recent developments in MD membrane, innovative MD modules and the importance of optimization, which was able to improve the performance of solar MD