Tailor-made high-performance reverse osmosis membranes by surface fixation of hydrophilic macromolecules for wastewater treatment

Abstract

Polyamide aromatic (PA) reverse osmosis (RO) membranes are currently the most important materials in the seawater desalination and wastewater treatment industry. This study used hydrophilic macromolecular polyvinylpyrrolidone (PVP) in a PA selective layer to develop a new polyamide thin-film composite (TFC), namely PA-g-PVP RO, which will be used for water treatment. The TFC is prepared via an interfacial polymerisation process, and TFC-based PVP can be transplanted on a PA surface by radiation. PA-g-PVP RO was characterised by ATR-FTIR, SEM, XPS, AFM and contact angle test and then evaluated by determining its permeability, salt retention and antifouling performance, among other properties. Resultsshow that the chemical composition and surface morphology of the polyamide film significantly changed. A PVP brush grafted on an RO membrane surface significantly enhanced the hydrophilicity and antifouling performance of the membrane. When the PVP concentration was increased in an aqueous solution to 2%, the water contact angle of the sacrificial layer of the modified membrane decreased to 24.3 , the fouling recovery ratio to 93.4% and the salt retention increased to 99.5% at a small flux change. This combined technology can also be used for other macromolecules to modify the membrane and study the preparation and modification of ultra-filtration and nano-filtration membranes. Fig. 9 (a) Filtration performance (water fluxs and salt rejections) and (b) separation layer structure (surface roughness and thickness) of the composite membranes by varying the PVP concentration while keeping the irradiation dose (20 kGy) constant.This journal is

Interpenetrating network nanoarchitectonics of antifouling poly(vinylidene fluoride) membranes for oil–water separation

“…For the PEG-modified membrane, the hydrophilic modified layer has a certain promoting effect on the water flux of the membrane. 35 After the introduction of PEG, the surface roughness and porosity of the membrane are increased. Enlarged pores and filtration area can help more water molecules pass through the membrane surface to further enhance water flux.…”

Advancing Strategies of Biofouling Control in Water-Treated Polymeric Membranes

“…Membranes with an anti-adhesive surface have been reported, including surface coating/grafting of hydrophilic monomers, zwitterionic/amphiphilic polymers, and incorporation of nanomaterials [ 64 , 65 ]. The polymer with hydrophilic groups facilitates the formation of a compact hydration layer through electrostatic interactions and hydrogen bonds, which can sufficiently prevent macromolecules and microbes from adsorption onto the membrane surface, reducing the irreversible membrane fouling [ 66 , 67 ]. The low surface energy structure can minimize the intermolecular forces between foulants and the membrane, thereby mitigating the extent of the reversible membrane fouling.…”

Hydrothermal Synthesis of K2Ti6O13 Nanotubes/Nanoparticles: A Photodegradation Study on Methylene Blue and Rhodamine B Dyes

“…13−15 The new insight toward restraining the plight is degradation of these synthetic dyes in a much efficient way, considering the factors such as low cost, more reliability, and biodegradability, with high stability and reusability. 16,17 Many researchers have emerged with their interests and have successfully reported a few techniques in this regard such as conventional coagulation, 18 chemical precipitation, 19 reduction, 20 adsorption, 21 ion exchange, 22 electrolysis, 23 impregnation, 24 reverse osmosis, 25 and photocatalytic degradation. 26−29 Considerably, adsorption and photocatalytic degradation are the most commonly used techniques by the researchers as rejoinders for the plight of water contamination, treating them as efficient, economic, and ecofriendly approaches.…”

“…Synthetic dyes, − paints, leather, paper pulp, printing, fabric materials––textiles, cosmetics, and so on , are considered as the major sources of water pollution. The use of synthetic dyes is inexorable due to their wide range of applications owing to the fact that synthetic dyes are toxic, poorly biodegradable, and have hazardous characteristics causing the groundwater to pollute indelibly, further leading to health complications in humans and contamination of other water bodies. − The new insight toward restraining the plight is degradation of these synthetic dyes in a much efficient way, considering the factors such as low cost, more reliability, and biodegradability, with high stability and reusability. , Many researchers have emerged with their interests and have successfully reported a few techniques in this regard such as conventional coagulation, chemical precipitation, reduction, adsorption, ion exchange, electrolysis, impregnation, reverse osmosis, and photocatalytic degradation. − Considerably, adsorption and photocatalytic degradation are the most commonly used techniques by the researchers as rejoinders for the plight of water contamination, treating them as efficient, economic, and ecofriendly approaches. Methylene blue (MB) and rhodamine B (Rh B) dyes are commonly considered to mimic the wastewater, and many metal-oxide nanoparticles such as ZnO, TiO 2 , SnO 2 , Fe 2 O 3, MgO, V 2 O 5 , and so on are generally employed as efficient sources in photocatalyst applications. − …”