Ceramic membrane for water filtration: Addressing the various concerns at once

Abstract

The scarcity of fresh water is a pressing issue due to the rapid growth of the population, industrialization, pollution, etc. Therefore, a membrane dealing with various major issues simultaneously could help for application even the pathway of commercialization and fulfil the fresh water scarcity. These issues are as following (i) One step and industrial friendly membrane fabrication technique (ii) high water flux at low transmembrane pressure (TMP) (iii) higher contamination rejection rate (iv) low fouling and (v) mechanically robust. Herein, we demonstrated an impressive approach to fabricate ceramic membranes using a large throughput atmospheric plasma spraying (APS) technique for water filtration. Plasma sprayed YSZ membranes were fabricated with three different thicknesses, viz., 100, 200, and 300 µm containing ∼ 30% porosity. Among the pores, 80% of the pores were in the range of 0.3–1.2 µm. The plasma sprayed YSZ membranes unveiled pure water flux, contamination rejection rate, and permeability for various feed water (waste, salt water) up to 370 Lm−2h−1, >95% and 380 Lm−2h−1bar−1 respectively. The membranes also showed excellent fouling resistance, a superhydrophilic nature (Contact Angle < 10°), and outstanding reusability with the added advantage of intact mechanical properties. Their mechanical properties, viz. hardness, elastic modulus, and fracture toughness, range from 5 to 7 GPa, 120–145 GPa, and 2.3–2.5 MPam−1 respectively. Our plasma sprayed YSZ membranes are cheaper and can be utilized in various sectors such as urban water filtration, industrial waste water filtration, food and pharmaceutical industries, etc.