Polymer-Based Membranes for Oily Wastewater Remediation

Abstract

The compounds found in industrial wastewater typically show high toxicity, and in this way, they have become a primary environmental concern. Several techniques have been applied in industrial effluent remediation. In spite of the efforts, these techniques are yet to be ineffective to treat oily wastewater before it can be discharged safely to the environment. Membrane technology is an attractive approach to treat oily wastewater. This is dedicated to the immobilisation of TiO2 nanoparticles on poly(vinylidene fluoride–trifluoro ethylene) (PVDF-TrFE) porous matrix by solvent casting. Membranes with interconnected pores with an average diameter of 60 µm and a contact angle of 97°, decorated with TiO2 nanoparticles, are obtained. The degradation of oily wastewater demonstrated the high photocatalytic efficiency of the nanocomposite membranes: Under sunlight irradiation for seven hours, colourless water was obtained.

Reusable Ag@TiO2-Based Photocatalytic Nanocomposite Membranes for Solar Degradation of Contaminants of Emerging Concern

“…Additionally, as water remediation applications require an interaction between water and the membrane, it is essential to assess its wettability. The water contact angle measurements (Figure 5c) show that PVDF-HFP and Ag@TiO2/PVDF-HFP possess a higher water contact angle than 120⁰ and, therefore, both behave as hydrophobic materials, in agreement with previous works [17,48]. Despite its hydrophobicity, this membrane presents a highly porous structure, confirmed by SEM pictures (Figure 4) and previous works [54], that aids in mitigating its hydrophobic effect by favouring water perculation throughout the pores.…”

“…In the photocatalytic process, pollutants are oxidised by reactions with free radicals generated by photocatalysts. Titanium dioxide (TiO 2 ) is the utmost used photocatalyst, as it presents a high photocatalytic activity, large surface area, reduced toxicity, low cost, and excellent thermal as well as chemical stability [16,17]. Despite the efficient degradation rates, pristine TiO 2 nanoparticles present limitations, such as reduced photocatalytic activity under visible radiation and a high recombination of electron/hole pairs [18].…”

“…Among several substrates, poly (vinylidene fluoride) (PVDF) and co-polymers arise as engaging materials for membrane applications based on their exceptional chemical, UV, mechanical, and thermal stability [17,30,31]. Poly (vinylidene fluoride-hexafluoropropylene), PVDF-HFP, is a co-polymer of PVDF, widely used in different applications, including energy harvesting [32] and water remediation [33].…”

Bio-Based Polyurethane Foams for the Removal of Petroleum-Derived Pollutants: Sorption in Batch and in Continuous-Flow

“…Still, for several years there will be the need to develop new methods for the removal of these dangerous pollutants from water sources. Oil contaminants are commonly detected in the form of fats, lubricants and light and heavy hydrocarbons such as gasoline, kerosene and diesel [ 9 , 10 ]. There are different methodologies that have been introduced to decontaminate water sources, and they can be divided into three macro-areas: chemical, physical and biological [ 11 , 12 , 13 ].…”

Functional Hydrophilic Membrane for Oil–Water Separation Based on Modified Bio-Based Chitosan–Gelatin

“…However, synthetic polymer membranes are easily fouled, causing a decreased flux and separation efficiency [ 1 ]. The hydrophobic membrane polymer resulted in their contamination especially during the oil–water separation filtration process, leading to the decrease of water flow efficiency [ 5 ]. The fabrication of membranes with high performance that are eco-friendly and created using sustainable, bio-based material has attracted significant interest.…”