Study on adsorption of methylene blue by modified peanut shell: adsorption kinetics, thermodynamics, isotherm properties

AbstractIn order to study the adsorption effect of peanut shell as adsorbent on dye wastewater in industry, the optimum adsorption conditions of peanut shell for methylene blue were explored in this article. The decolorized peanut shell was activated by zinc chloride and the adsorption rate of methylene blue dye was improved. Through the research of different conditions such as pH value, contact time, adsorption temperature, initial dye concentration and adsorbent dosage, the optimal adsorption conditions of methylene blue dye were obtained. The adsorption effect achieved was the best at pH 10. Kinetics, thermodynamics, adsorption isotherm properties of the adsorption of methylene blue onto the peanut shell activated by zinc chloride were studied. The adsorption satisfied the Freundlich isothermal adsorption equation and the adsorption process was exothermic. The present adsorption system is a heterogeneous adsorption. The adsorption of methylene blue onto peanut shell accorded with a quasi-second-order adsorption kinetics. This adsorption was a physicochemical adsorption. Finally, the involved adsorption materials prepared were characterized by scanning electron microscopy, X-ray diffraction and infrared spectroscopy. This method can effectively adsorb the methylene blue pollutants in water and solves the problem of the environmental pollution caused by the direct discharge of dye wastewater, which has certain economic and social benefits.Keywords: Adsorptionisothermkinetic propertymethylene bluepeanutshellthermodynamic propertyzinc chloride modification Availability of data and materialsThe datasets used or analyzed during the current study are available from the corresponding author on reasonable request.Authors’ contributionQ.-Z. Zhai conceived and designed the experiments. The experiments were performed by Q.-Z. Zhai. Data was analyzed by Q.-Z. Zhai. The manuscript was written by Q.-Z. Zhai. The manuscript was reviewed and corrected by Q.-Z. Zhai.Consent for publicationAll authors have read this manuscript and consent for publication.Disclosure statementThe authors declare no competing interests.Additional informationFundingThe authors thank the financial support “Research on the Adsorption of Water and Soil Pollutants Heavy Metals and Harmful Dyes by Waste Tea and Peanut Shell” by the Natural Science Foundation of Jilin Provincial Science and Technology Department from the Science and Technology Development Program of Jilin Province, China (20220101096JC/611220683029/KYC-JC-XM-2022−111).