Application of Modified Agricultural Waste in the Adsorption of Bromocresol Green Dye

Abstract

Background: The adsorptive removal of anionic dye (Bromocresol green) from aqueous solution was investigated using activated carbon prepared from rice husk.
 Place of Study: The research work took place at Nnamdi Azikiwe Univeristy Awka, Nigeria.
 Methods: The rice husk which was obtained from rice mills in Awka was activated with tetraoxophosphoric acid and carbonized in a furnace. The adsorption process was investigated by varying the contact time, temperature, dosage, pH and initial concentration in a batch process. Five isotherm models (Langmuir, Freundlich, Temkin, Halsay and Harkin-Jura) were employed in the equilibrium studies. Thermodynamics and kinetics of the adsorption were carried out.
 Results: The result indicated that increase in contact time, adsorbent dosage and temperature increased the percent uptake of the Bromocresol green dye. Maximum percentage adsorption of about 93% was obtained. Langmuir and Harkin-Jura isotherm models best described the equilibrium data of the adsorption process. Pseudo second-order kinetic model best correlates the kinetics of the experimental data. The thermodynamic study showed that the Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were –2.541 kJ/mol, -7.401 kJ/mol and –15.52 kJ/mol K respectively.
 Conclusion: This work has shown that activated carbon prepared from rice husk can be used in adsorptive removal of bromocresol green dye from solution and that the adsorption process was spontaneous and exothermic.

Preparation and Characterization of Red Mud-Based Geopolymer Composited with Rice Husk Ash for the Adsorption of Bromocresol Green in Aqueous Solution

“…The stock dye solutions of 1000 mg/L were prepared by dissolving BG in deionized water at pH 2. 24,25 The adsorbent mass of the prepared geopolymer was 0.10 g placed in 20 mL of BG solutions from 20 to 120 mg/L. The mixtures were stirred for 180 minutes at 200 rpm and 273 K. Afterwards, the sample was centrifuged at 3000 rpm for 10 min.…”

Artificial Intelligence-Based Tools for Process Optimization: Case Study—Bromocresol Green Decolorization with Active Carbon

“…Therefore, the results obtained in this case are similar to those presented in the literature. For example, in [72], for an active carbon produced from rice husks, the maximum efficiency was 93%.…”

“…The AOPs usually involve chemically assisted UV irradiation [68, 69] and/or heterogeneous photocatalysis [70, 71]. As for the active carbon-based materials, the focus is on preparing activated carbon from various low-value natural materials [72, 73] using pyrolysis and, in some cases, additional chemical activation [34]. Although this method is one of the most cost-effective, the properties of the resulting AC are highly dependent upon the conditions under which the raw material is produced (soil quality, precipitation, temperature, etc.…”