Removal of cadmium from aqueous solutions by adsorption on granular red mud (GRM)

Abstract

This study puts forward a novel method to prepare granular red mud (GRM) and evaluates its potential use to remove cadmium ions from aqueous solutions as a low-cost adsorbent. The properties of the novel adsorbent were examined and then used for cadmium adsorption experiments. Batch experiments were conducted and equilibrium isotherms at different temperatures (20• C) have been determined and analyzed with a Freundlich model. Kinetics data at initial pH 6.0 and 3.0 were fitted with Pseudo-second-order model and external mass transfer coefficients, effective particle diffusion coefficients were subsequently calculated for cadmium-GRM system at initial pH 6.0. Column breakthrough curves were depicted and the data were analyzed with a Thomas model. The column adsorption was reversal and the regeneration operation was accomplished by pumping 0.1 mol/L hydrochloric acid through the adsorbed column.

Removal of Toxic Chemicals and Biological Pollutants from Groundwater Wells Using Modified Downflow Hanging Sponge Reactor

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Biosorption of Cd+2 by green plant biomass, Araucaria heterophylla: characterization, kinetic, isotherm and thermodynamic studies

“…These heavy metals are toxic, non-biodegradable and become a source from which they are accumulated by absorption into living organisms (Victor et al 2007). Metal plating, metallurgic alloying, ceramics, textile printing industry, photograph development, electroplating, alkaline battery manufacturing are the major industrial fields responsible for cadmium pollution (Kadirvelu et al 2001;Zhu et al 2007). In plants, absorption of Cd ?2 is more when compared to other heavy metals.…”

Raw and calcination-modified coal waste as adsorbents to remove cadmium from simulated mining wastewater

“…Among heavy metals, cadmium is an extremely toxic metal, which is usually found in wastewater from mining, metal plating, smelting, batteries, phosphate fertilizers, pigments, stabilizers, plastics and other industrial process. Excessive exposure to cadmium can cause harmful effects on human health, including itai-itai disease, emphysema, kidney damage and renal damage (Zhu et al 2007;Munagapati et al 2010). Therefore, many methods have been developed to remove cadmium from aqueous solution such as chemical precipitation, membrane separation, ion exchange and electrochemistry removal.…”