EXPERIMENTAL INVESTIGATION ON CHROMIUM(VI) REMOVAL FROM AQUEOUS SOLUTION USING ACTIVATED CARBON RESORCINOL FORMALDEHYDE XEROGELS

Eghe A Oyedoh,Michael C Ekwonu

doi:10.14311/ap.2016.56.0373

Abstract

The adsorption of chromium(VI) metal ion in aqueous solutions by activated carbon resorcinol formaldehyde xerogels (ACRF) was investigated. The results showed that pore structure, surface area and the adsorbent surface chemistry are important factors in the control of the adsorption of chromium(VI) metal ions. The isotherm parameters were obtained from plots of the isotherms and from the application of Langmuir and Freundlich Isotherms. Based on regression analysis, the Langmuir isotherm model was the best fit. The maximum adsorption capacity of ACRF for chromium (VI) was 241.9 mg/g. The pseudo-second-order kinetic model was the best fit to the experimental data for the adsorption of chromium metal ions by activated carbon resorcinol formaldehyde xerogels. The thermodynamics of Cr(VI) ions adsorption onto ACRF was a spontaneous and endothermic process.

Highlights

IntroductionChromium is used in various industries such as the metallurgical industry (steel, ferro- and nonferrous alloys), refractories (chrome and chrome-magnesite), and in the chemical industry (pigments, electroplating and tanning) [1]
Chromium is used in various industries such as the metallurgical industry, refractories, and in the chemical industry [1]
This study investigates the adsorption of chromium(VI) onto activated carbon resorcinol formaldehyde xerogels using the Langmuir and Freundlich isotherms

Summary

Introduction

Chromium is used in various industries such as the metallurgical industry (steel, ferro- and nonferrous alloys), refractories (chrome and chrome-magnesite), and in the chemical industry (pigments, electroplating and tanning) [1]. As a result of these industrial processes, large amounts of chromium compounds are discharged into the environment. These compounds are toxic and have negative effects on humans and the environment. The maximum level for chromium in drinking water permitted by the World Health Organization (WHO) is 0.05 mg/L [4]. Cr(III) and Cr(VI) species are the two stable forms of chromium present in the environment. They have different chemical, biological and environmental characteristics. Cr(III) is less mobile, less toxic and is mainly found bound to organic matter in soil and aquatic environments [5]

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