Heavy Metals Removal from Water by Efficient Adsorbents

Abstract

Natural occurrence and anthropogenic practices contribute to the release of pollutants, specifically heavy metals, in water over the years. Therefore, this leads to a demand of proper water treatment to minimize the harmful effects of the toxic heavy metals in water, so that a supply of clean water can be distributed into the environment or household. This review highlights several water treatment methods that can be used in removing heavy metal from water. Among various treatment methods, the adsorption process is considered as one of the highly effective treatments of heavy metals and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four classes of adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal from water by emphasizing the adsorption capability, effect of pH, isotherm and kinetic model, removal efficiency and the contact of time of every adsorbent.

Preparation of Magnetic MIL-68(Ga) Metal–Organic Framework and Heavy Metal Ion Removal Application

“…Among them, adsorption is a promising and effective method for practical use due to its high efficiency, simple design and easy operation [ 14 , 15 , 16 , 17 ]. Various adsorbents, such as carbon materials (activated carbon, nanotubes), polymers, metallic and metal compounds (nanoparticles, metal–organic frameworks, and magnetic materials), and minerals (silica, zeolites, and clays) have been developed to remove heavy metal ions in water [ 18 , 19 , 20 , 21 ]. As a kind of organic–inorganic hybrid nanomaterial, metal–organic frameworks (MOFs) possess the advantages of high surface area, adjustable porosity, better functionality, and easy design and synthesis, making them highly desirable in various research fields, such as adsorption [ 22 , 23 , 24 , 25 , 26 ].…”

Biosorption of Cr(VI) Using Cellulose Nanocrystals Isolated from the Waterless Pulping of Waste Cotton Cloths with Supercritical CO2: Isothermal, Kinetics, and Thermodynamics Studies

“…The Freundlich and Langmuir isothermal models were employed to illustrate the Cr(VI) removal behavior using CNCs isolated from WCCs, as shown in Supplementary Figure S1 . The Langmuir isotherm model illustrates that the adsorption of heavy metals ion occurred on the adsorbent in monolayer formation and in homogeneous distribution [ 51 , 52 , 53 , 54 ]. The Langmuir isotherm model for Cr(VI) removal using CNCs isolated from the WCCs as an adsorbent is displayed in Figure S1a .…”

Application of Biochar as Functional Material for Remediation of Organic Pollutants in Water: An Overview

“…Physisorption by electrostatic attraction is highly influenced by the surface change of biochar and pollutants. Chemisorption, on the contrary, occurs when stronger chemical bonds such as H-bonds and coordination bond, and covalent bonds are formed between the pollutant and the active sites of biochar [119,120]. In addition, the enthalpy of physisorption (20-40 kJ/mol) is less than that of chemisorption (200-400 kJ/mol) [120,121].…”