Bibliometric approach to the perspectives and challenges of membrane separation processes to remove emerging contaminants from water

Abstract

The presence of contaminants in water is concerning due to the potential impacts on human health and the environment, and ingested contaminants cause harm in various ways. The conventional water treatment systems are not efficient to remove these contaminants. Therefore, novel techniques and materials for the removal of contaminants are increasingly being developed. The separation process using modified membranes can remove these micropollutants; therefore, they have attracted significant research attention. Among the materials used for manufacturing of these membranes, composites based on graphene oxide and reduced graphene oxide are preferred owing to their promising properties, such as mechanical resistance, thermal and chemical stability, antifouling capacity, water permeability, high thermal and electrical conductivity, high optical transmittance and high surface area. Membrane separation processes can be used as secondary or tertiary treatment during the supply of wastewater. However, the efficient and accessible applications of these technologies are challenging. This study aims to demonstrate the main concepts of membrane separation processes and their application in the removal of emerging contaminants. This study reports bibliometric mapping, relevant data on studies using membranes as water treatment processes, and their viability in industrial applications. The main challenges and perspectives of these technologies are discussed in detail as well.

Removal of fluoxetine from water by nanofiltration and reverse osmosis

“…NF is an intermediate process between RO and ultrafiltration (UF), and it can retain dissolved molecules with molar mass ranging from 200 to 1,000 g mol -1 and multivalent ions (Gomes et al, 2020). Many works have shown that the membrane separation process is efficient for the tertiary treatment of effluents (Cadore et al, 2020), including NF. A similar result was reported by Azaïs et al (2014) when they used NF for the separation of carbamazepine, and the rejection was 60%.…”

“…Conventional water treatment is not efficient in removing or degrading emerging pollutants, therefore demanding studies and applications of complementary technologies (Cadore et al 2020). Thus, biological treatments, such as trickling filters or activated sludge, are mainly insufficient to remove a wide range of highly toxic contaminants, such as drugs, pesticides, and metals (Power et al, 2018).…”

“…Other treatments, such as coagulation and flocculation, are also insufficient to remove emerging pollutants that are dissolved in water. Ozonation and photocatalysis have the risks of generating undesirable by-products in treated water (Cadore et al, 2020). On the other hand, the membrane separation methods for NF and RO (Couto et al, 2020;Song et al, 2020) are promising technologies, with the advantage of removing dissolved or ionic contaminants in low concentrations at high selectivity .…”