A review of advances in engineered composite materials popular for wastewater treatment

Abstract

Abstract Water is the need of every individual and plays a vital role in the world’s economy. Almost 70% of freshwater is used by humans for agriculture. Agriculture and industries introduce many pollutants and contaminants into water bodies. This not only affects the quality of water but also pose serious threats to the number of aquatic species. Several techniques are known to remove the contaminants from wastewater. Composites have gained significant attention of researchers to remove the contaminants through adsorption, flocculation, coagulation, ion exchange, electrostatic interactions, and membrane filtration methods. Composites are blend of two or more different constituents that impart unique characteristics to the final product. Composites can be fabricated through grafting, functionalization, and crosslinking to improve the properties of composite materials. This review comparatively highlights several composites that shows amazing power of removing contaminants from wastewater and could change the future of wastewater treatment processes. The present review critically describes the recent advancements in manufacturing/fabrication, introduction of functional groups and functioning of constructing tailored layered double hydroxide (LDH)-based nanocomposites and 3-dimensional (3D) hierarchical nanostructure with many functional groups. Among several discussed composites, those that showed maximum efficiency includes graphene composite (CdSe-G) that gave 100 % removal efficiency for Methylene Blue (MB) from wastewater through photo-catalytic degradation. ZnFe2O4/G composite could remove Methyl Orange (MO) and Methylene Blue (MB) with 100 % efficiency.