Fundamentals and Sources of Magnetic Nanocomposites and Their Sorption Properties

Abstract

Over the years, adsorption has been the most widely applied technique for pollutants remediation in conventional water and wastewater treatment regimes with commendable results. Consequently, multiple adsorbents have been synthesized, characterized and tested for various pollutants sequestration such as; heavy metals, dyes, pharmaceutically active ingredients, among others, in aqueous media. Unfortunately, most of the sorbents face many inherent limitations such as high production cost, difficult separation of adsorbent from solution, and complex synthesis processes. Therefore, an efficient adsorbent that would be sustainably adopted for industrial application in wastewater treatment requires, among other properties, a simple and efficient recovery step from a continuous flowing system. The regenerated adsorbent must also possess near original properties after several cycles of reuse thereby resulting to low capital investment. To address this challenge, studies conducted in the past few years incorporating magnetism in both natural and synthetic sorbents to improve their removal from water via magnetic separation have yielded stupendous results compared to conventional technologies. This chapter concisely discusses synthesis methods and adsorption capacities and mechanisms of selected magnetic nanocomposite adsorbents under diverse physicochemical conditions for removal of cations, dyes and organic pollutants from wastewater. Magnetic nanocomposites present eco-friendly properties and are potential alternatives for application in water purification processes subject to commercial viability evaluation before practical use.