Loofah sponge: a sustainable material for wastewater desalination

Abstract

Treatment of wastewater has become a necessity to address the shortage of drinking water in this era due to population explosion as well as shortage of water resources. It is necessary to develop wastewater treatment approaches that are facile, eco-friendly, scalable, and low cost. Among the various choices available to date, desalination is a versatile and suitable method which involves an interfacial evaporation of salt ions from seawater to produce freshwater. The desalination method involves a membrane-based process in which the development of suitable and cost-effective ways is a prerequisite. There have been many membranes developed in the recent past including carbon-based membranes (such as graphene membranes, graphene oxide membranes, etc.), MXene-based membranes, etc. Among the various available choices, biomass-based materials have become attractive to develop membranes which are economically feasible and environmentally friendly materials that can be produced on a large scale. By considering the advantageous features of biomass-based materials, water desalination becomes a cost-effective approach for the present and future. Herein, we review the recent developments of a biomass material, loofah sponge, for water desalination applications by serving it as a sustainable membrane. Loofah sponge-based materials are highly promising candidates for saltwater desalination. Initially we discuss the salient features of loofah sponge that make it suitable for water desalination applications including chemical properties and further we discuss the synthesis of various natural carbon derivatives from it including mesoporous carbons and biochar. Furthermore, the preparations of composites with other materials systems such as transition metal oxides and MXenes are outlined by emphasizing the microstructural and morphological influence on the performance of membranes for water desalination applications. The present review provides an in-depth understanding of natural loofah sponge-based membranes for desalination application.