The Adsorption Equilibrium and Kinetic Studies for The Removal of Crystal Violet Dye (Methyl Violet 6b) from Aqueous Solution Using Avocado Pear Seed Activated Carbon

The Adsorption Equilibrium and Kinetic Studies for The Removal of Crystal Violet Dye (Methyl Violet 6b) from Aqueous Solution Using Avocado Pear Seed Activated Carbon

Anwana Abel UKPONG*, Etim Okon ASUQUO, and Godwin Ime EDEKHE
Department of Chemical/ Petrochemical Engineering, Akwa Ibom State University, Ikot Akpaden, Mkpat Enin L.G.A, P.M.B 1167, Uyo, Akwa Ibom State, Nigeria.
*Corresponding author

DOI: https://doi.org/10.51244/IJRSI.2023.10419

Received: 22 April 2023; Accepted: 26 April 2023; Published: 25 May 2023

Abstract: In this study, adsorption equilibrium and kinetic studies for the removal of crystal violet (CV) from an aqueous solution were investigated using a batch adsorption process. The activated carbon was prepared by carbonizing the avocado pear seed at a carbonization temperature of 500OC for 1hr and was impregnated with a 30% concentration of aqueous HCl solution which was further activated in a muffle furnace at a temperature of 500OC for 1hr. The avocado pear seed activated Carbon obtained was characterized using proximate analysis, Fourier Transform Infra-Red Spectrophotometer (FT-IR) analysis and Scanning Electron Microscope (SEM) analysis. The effect of various adsorption parameters such as contact time (15-150 min), initial dye concentration (25-150 mg/L), adsorbent dosage (1-9 g), particle size and pH of dye solution were investigated. The adsorption equilibrium data were fitted into different isotherm models and the Langmuir model exhibited the best fit which implied that the adsorption of CV dyes onto avocado pear seed activated carbon was monolayer and the adsorbent surface was homogeneous and also; adsorption energy was uniform for all sites and there was no transmigration of adsorbate in the plane of the surface. The kinetic studies revealed that the adsorption data fitted well to the pseudo-second-order model with a high correlation coefficient of 0.977 when compared to other models, thus; signifying that the adsorption’s mechanism was chemisorption. APSAC shows a much better adsorption capacity for CV dye removal having a maximum adsorption capacity of 3.3254 mg/g and percentage removal of 99.995 %. Hence, APSAC can be used as an effective and low-cost adsorbent for the removal of CV dye from an aqueous solution.

Key Words: Adsorption studies, Isotherm models, Kinetic models, Activated carbon, Wastewater treatment, Chemical activation, Crystal violet dye.

I. Introduction

Globally, textile and dye intermediate industries are considered to be major sources of industrial waste water, resulting in critical environmental pollution problems (Rosenwinkel and Haun, 2008). Water pollution is one of the most undesirable environmental problems in the world; thus, requires urgent solutions. Textile industries produce a lot of waste water which contains several contaminants including acidic or caustic dissolved solids, toxic compounds and different dyes; many of these dyes are carcinogenic, mutagenic, and teratogenic and also toxic to human beings, fish species, and microorganisms (Konicki et al., 2013). Hence, their removal from aquatic waste water becomes environmentally important. Large quantities of dangerous dyes, pigments and metals originating from dye manufacturing; textile as well as pulp and paper industries are emitted into these waste waters. This makes the treatment of contaminated water difficult, because the colour tends to persist even after the conventional removal processes (Visa et al., 2010). The dye contaminations in water tend to prevent light penetration and therefore, affect photosynthesis considerably (Banerjee and Chattopadhyaya, 2017; Hajati et al., 2014; Hameed et al., 2017).

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