ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Performance of vermicompost derived hydrochars for methylene blue removal via ultrasound assisted adsorption

Eyup Yildirir

Department of Chemical Engineering, Engineering Faculty, Usak University, Usak, Turkey

E-mail: eyupyildirir@gmail.com

Received: 27 October 2023  Accepted: 28 October 2024

Abstract:

This study investigated the ultrasound-assisted adsorption of methylene blue (MB) onto vermicompost (VC) derived hydrochars prepared at different hydrothermal treatment temperatures (220, 250, and 280 °C). The effects of pH, time, and initial concentration on the adsorption process were evaluated. The kinetic and isotherm models were applied to fit the experimental data. The results showed that the VC hydrochars exhibited superior adsorption capacity for MB under alkaline conditions. The adsorption process was influenced by chemical interactions between the MB molecules and the surface of hydrochars, and the adsorption process was irreversible chemisorption. VC220 hydrochar demonstrated the highest adsorption capacity for MB, followed by VC250 and VC280 hydrochars. The Pseudo Second Order kinetic model and Langmuir isotherm model provided the best fits to the experimental data. This suggests that the adsorption of MB onto VC hydrochars follows a second-order reaction mechanism and monolayer adsorption process with high adsorption capacities.

Graphical abstract

Keywords: Environmental Chemistry; Wastewater treatment; Chemical interactions; Irreversible chemisorption; Kinetic models; Isotherm model

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-024-03777-9

Chemical Papers 79 (1) 235–245 (2025)