Adsorption Equilibrium for Heavy Metal Divalent Ions (Cu2+, Zn2+, and Cd2+) into Zirconium-Based Ferromagnetic Sorbent

Agnes Yung Weng Lee,Soh Fong Lim,Rubiyah Baini,Mohammad Omar Abdullah,Khairuddin Sanaullah,S N David Chua

doi:10.1155/2017/1210673

Agnes Yung Weng Lee, Soh Fong Lim + Show 4 more

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https://doi.org/10.1155/2017/1210673

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Abstract

Zirconium-based ferromagnetic sorbent was fabricated by coprecipitation of Fe2+/Fe3+ salts in a zirconium solution and explored as a potential sorbent for removing the Cu2+, Zn2+, and Cd2+ from aqueous solution. The sorbent could easily be separated from aqueous solution under the influence of external magnetic field due to the ferromagnetism property. A trimodal distribution was obtained for the sorbent with average particle size of 22.74 μm. The –OH functional groups played an important role for efficient removal of divalent ions. The surface of the sorbent was rough with abundant protuberance while the existence of divalent ions on the sorbent surface after the sorption process was demonstrated. Decontamination of the heavy metal ions was studied as a function of initial metal ions concentration and solution pH. Uptake of the heavy metal ions showed a pH-dependent profile with maximum sorption at around pH 5. The presence of the ferromagnetic sorbent in solution at different initial pH has shown a buffering effect. Equilibrium isotherms were analyzed using Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. Adequacy of fit for the isotherm models based on evaluation of R2 and ARE has revealed that heavy metal ions decontamination was fitted well with the Freundlich model.

Highlights

Heavy metals are natural constituents of earth’s crust, but indiscriminate human activities have drastically transformed their geochemical cycles and biochemical balance [1]
Complementary to this, the magnetic sorbent is able to be separated from dispersions with the application of a magnetic field after sorption process
The present investigation demonstrated that the zirconiumbased ferromagnetic sorbent fabricated by chemical coprecipitation method exhibited good performance to remove heavy metal ions (Cu2+, Zn2+, and Cd2+) from aqueous solution

Summary

Introduction

Heavy metals are natural constituents of earth’s crust, but indiscriminate human activities have drastically transformed their geochemical cycles and biochemical balance [1]. The toxic metal ions dissolved can reach top of food chain and developed a risk factor for human health besides causing ecological damage [3]. The risk of heavy metal pollution to public health and wildlife has led to an enlarged interest in development of effective technologies for water purification. Adsorption process has evolved into one of the prominent methods for removing organic and inorganic pollutants in waterway systems [4]. This effective and economic process has been found superior to other techniques such as ion exchange and precipitation for treating aqueous effluents in terms of initial cost, simplicity of design, ease of operation, and insensitivity to toxic substances [5]

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