Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots

• Published in: Adsorption science & technology Vol. 2021
• Main Authors: Lu, Yie Chen, Kooh, Muhammad Raziq Rahimi, Lim, Linda Biaw Leng, Priyantha, Namal
• Format: Journal Article
• Language: English
• Published: Oxford Hindawi 01.01.2021; Sage Publications Ltd; SAGE Publications
• Subjects: Adsorbents; Adsorption; Dyes; Error functions; Regeneration; Solution heat treatment
• ISSN: 0263-6174; 2048-4038
• DOI: 10.1155/2021/5932222

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination (R2) and error functions. The Sips (R2=0.9714, χ2 =0.16) and pseudo-second-order (R2=0.9996, χ2=0.007) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.