Sara Eskandarinezhad - Department of Mining and Metallurgy, Yazd University, Yazd, Iran
Reza Khosravi - Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
Mohammadamin Amarzadeh - Department of Safety Engineering, Abadan Faculty of Petroleum Engineering, Petroleum University of Technology, Abadan, Iran
Piyal Mondal - Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, ۷۸۱۰۳۹, India
Fernando Jorge Correa Magalhães Filho - Departamento de Engenharia Sanitária e Ambiental, Universidade Católica Dom Bosco, Campo Grande, Brazil

The manufacturing, application, and design of chemical processes and products that minimize or remove waste and the use of dangerous and toxic reagents are referred to as green chemistry. Green chemistry is made up of twelve principles, one of which is catalysis. The role of catalysis is to accelerate the reaction by introducing a substance called a catalyst. Because of their high efficiency, productivity, activity, and selectivity, nanocatalysts have recently received many interests. Nanocatalysts are characterized by their high surface area to volume ratio, as well as their nanoscale forms and sizes. One of the significant applications of nanocatalysts is wastewater and wastewater purification. Green and bio-synthesized nanocatalysts could be used efficiently to remove heavy metals, medicinal, organic, and inorganic pollutants from the wastewater systems. This paper reviews nanocatalysts based on noble and magnetic nanocatalysts, as well as metal catalysts supported by organic polymers, and discusses their industrial effluent treatment mechanisms.

Green chemistry, Magnetic nanocatalyst, Noble nanocatalysts, Organic polymer-supported metal catalysts