Review of catalytic activities of biosynthesized metallic nanoparticles in wastewater treatment

ABSTRACT Biologically synthesized metallic nanoparticles for catalytic activities in wastewater treatment applications is regarded as a safer alternative to usual physical and chemical methods due to their cost-effectiveness, environmental friendliness and easy handling. Recently, research into nanotechnological applications of catalytic and wastewater treatment processes has increased exponentially because of its numerous benefits. This work reviews and summarizes several articles published from 2014 till now concerning biosynthesized nanoparticles and their applications in treating pollutants from wastewater. This review shows that biosynthesized nanoparticles using plant, algae and fungi, microorganisms, enzymes and other biomaterials and polymers have been efficient in removing heavy metals, pathogenic bacteria and organic pollutants, such as dyes, from synthetic wastewaters. This review looks in further detail at significant contributions of biosynthesized nanoparticles in treating pollutants from real wastewater samples, establishing their potency in large-scale real wastewater treatment plants. Comparatively, it is demonstrated that biosynthesized nanoparticles are very promising candidates to treat various contaminants found in wastewater than chemically synthesized nanoparticles, due to smaller sizes in general, good stability, high surface area charge and better photoluminescence emission properties of biosynthesized nanoparticles. Further discussed are the future opportunities of these biosynthesized nanoparticles in contaminant removal. Overall, this review aims to project a rapid developmental path showing a broad overview of recent nanobiotechnologies, applications, and prospects for researchers in nanotechnological fields in wastewater treatment. GRAPHICAL ABSTRACT