Usage of nanoparticles as adsorbents for waste water treatment: An emerging trend

Nanotechnology is the most promising and under explored branch of science of 21st century. It has the capability of generating materials with unique and unusual properties, hitherto unknown to mankind. In recent years, it has presented its potential to contribute in solving one of the greatest issues of the modern world, i.e., waste water treatment. The present review emphasizes on the potential, the nano-partides (NPs) hold in advancing the waste water treatment and augmenting the water supply by developing the unconventional resources of water. The concept of adsorption is discussed and various nano-adsorbents mostly used in waste water treatment have been discussed categorically. The review also discusses the types of pollutants that can be removed by nanoa-dsorbents with a special mention of regeneration of the nano-adsorbents. The purpose of this review is to emphasize upon the importance of adsorption and NPs in the waste water treatment industry and to showcase how the NPs have the ability to revolutionise the waste water treatment industry. This review is an attempt to compile most of the relevant knowledge of the nano-adsorbents scattered over decades of literature. It also presents the harmful effects of dyes, pesticides and most common heavy metals present in waste water, showcasing the various adsorbents researchers have used to efficiently remove them. There have been several review articles in the literature but, to the best of our knowledge, there are none that cover the nano-adsorbents and their targeted pollutants across so many categories so comprehensively. The review convincingly establishes the potential of nano-adsorbents for waste water treatment. (C) 2019 Elsevier B.V. All rights reserved.