Reduction of Cr(VI) with Infrared Light and Chemical Adsorption of Cr(III) by a God-Crown/Bentonite Composite for Electroplating Waste Remediation

Authors

• Andre Taufik Kurniawan
• Muhammad Djoni Bustan
• Sri Haryati

Publication Date

2026

Abstract

Heavy metal pollution, particularly chromium (Cr) from electroplating industrial waste, has severely threatened environmental quality and human health. This study aims to develop a composite adsorbent material based on bentonite and god crown biomass capable of removing chromium ions from liquid waste through a combination of reduction and adsorption mechanisms. The god crown/bentonite (GC/Bt) composite was synthesized at a mass ratio of 2:1 and calcined at 900°C. FTIR characterization revealed active functional groups (–OH, C=O, Si–O, and Al–O–Si), whereas BET analysis revealed a mesoporous structure (surface area 31.12 m2 g-1, pore diameter 4.37 nm) suitable for ion diffusion. The reduction of Cr(VI) to Cr(III) was facilitated by infrared (IR) irradiation, with 950 nm identified as the optimum wavelength compared with 730 nm. This conversion was confirmed by the significant increase in removal efficiency, as Cr(III) is more readily adsorbed by the composite than Cr(VI). The integrated system achieved a maximum removal efficiency (%R) of 86% and an adsorption capacity (qe) of 703.19 mg g-1 under optimal continuous column conditions (bed height of 30 cm and flow rate of 4 L min-1). The isotherm study showed the best fit with the Freundlich model, indicating a heterogeneous adsorbent surface, whereas the adsorption kinetics followed the pseudo-second-order model (R2>0.97), indicating the dominance of the chemisorption mechanism. These results confirm that combining infrared reduction and chemical adsorption by GC/Bt composites is a practical approach for industrial chromium waste treatment.

DOI

10.35762/AER.2026007

First Page

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Last Page

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Recommended Citation

Taufik Kurniawan, Andre; Djoni Bustan, Muhammad; and Haryati, Sri (2026) "Reduction of Cr(VI) with Infrared Light and Chemical Adsorption of Cr(III) by a God-Crown/Bentonite Composite for Electroplating Waste Remediation," Applied Environmental Research: Vol. 48: No. 1, Article 7.
DOI: 10.35762/AER.2026007
Available at: https://digital.car.chula.ac.th/aer/vol48/iss1/7