Biosorption of Hexavalent Chromium Metal Ions by Lentinula Edodes Biomass: Kinetic, Isothermal, and Thermodynamic Parameters

Aslı Göçenoğlu Sarıkaya

doi:10.17344/acsi.2020.6408

Abstract

Lentinula edodes was investigated as a biosorbent for hexavalent chromium biosorption in this study. To examine the optimum conditions of biosorption, the pH of the hexavalent chromium solution, biosorbent dosage, temperature, contact time, and initial hexavalent chromium concentration were identified. Further, to clarify the biosorption mechanism process, the isothermal, kinetic, and thermodynamic parameters were determined. The functional groups and surface morphology of the biosorbent were identified using Fourier transform infrared spectrometry and scanning electron microscopy in the absence and presence of hexavalent chromium, respectively. Based on the results, the maximum biosorption capacity was determined as 194.57 mg g-1 under acidic conditions at 45 °C. From the kinetics studies, the biosorption process was observed to follow the Freundlich isotherm and pseudo-second-order kinetic models well. Thus, L. edodes as a biosorbent has potential usage for wastewater treatment owing to its effective biosorption capacity.

Highlights

Pollution by heavy metal impurities is one of the major problems of increasing industrial development.[1,2] Chromium is one of the common pollutants in nature and exists in different oxidation states (–2 to +6) in the environment; trivalent chromium (Cr3+) and hexavalent chromium (Cr6+) forms tend to be the most available and stable oxidation states in water.[3]
The maximum biosorption capacity of hexavalent chromium on the L. edodes biosorbent was determined as 6.12 mg g–1 at a pH of 2.0 (Figure 1)
The main aim of this study was to examine the viability of L. edodes as a biosorbent for hexavalent chromium biosorption

Summary

Introduction

Pollution by heavy metal impurities is one of the major problems of increasing industrial development.[1,2] Chromium is one of the common pollutants in nature and exists in different oxidation states (–2 to +6) in the environment; trivalent chromium (Cr3+) and hexavalent chromium (Cr6+) forms tend to be the most available and stable oxidation states in water.[3]. The traditional processes used to remove hexavalent chromium are electrochemical reduction, solvent extraction, electro dialysis, ion exchange, reverse osmosis, and chemical precipitation. Owing to disadvantages such as high cost and increased time consumption of these methods, new procedures have been developed. Biosorption is one of the alternative methods for wastewater treatment and is widely used in batch and continuous studies because of its advantages such as low cost, reusability, and easy operation, which are attractive benefits.[9,10] Shells,[11] leaves,[12] fungi,[9] bacteria,[13] and yeast[14] have been previously reported as biosorbents for hexavalent chromium biosorption

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Conclusion