75 / 2021-06-30 15:09:46

Preparation of grape leaf biochar and removal of methylene blue in aqueous environment

Grape leaf; Agricultural solid waste; Resource utilization; Biochar; Adsorption properties

Abstract：With the development of science and technology, the discharge of wastes in the process of industrial production has caused serious environmental pollution. Meanwhile it also causes a shortage of resources and energy. Nowadays, green development has increasingly become the theme of the Times. Hence, the Resource utilization of agricultural solid waste is one of the ways to solve the environmental pollution and resource shortage problems. Because of its large specific surface area, porosity and ion exchange capacity, activated carbon can adsorb heavy metal ions and organic pollutants in water, and is usually used to clean the environment. In this paper, grape leaves were used as raw materials to prepare biochar by pyrolysis. The pyrolysis temperature and time were investigated. The obtained grape leaf biochar (GLB) was characterized by FT-IR, SEM and XRD methods. SEM images showed that GLB has a porous structure. FT-IR spectra indicated that obtained GLB has —C=O and —OH functional groups. The results of XRD show that the GLB contains cellulose graphite microcrystals and CaCO₃.  Methylene blue aqueous solution was employed to study the adsorption properties of GLB. The results showed that the adsorption kinetics of GLB to MB solution belonged to the pseudo second order kinetics. Adsorption thermodynamics fit both Freundlich and Langmuir models. Therefore, the development and application of GLB can not only repair the environment, but also realize the resource utilization of agricultural wastes. act：With the development of science and technology, the discharge of wastes in the process of industrial production has caused serious environmental pollution. Meanwhile it also causes a shortage of resources and energy. Nowadays, green development has increasingly become the theme of the Times. Hence, the Resource utilization of agricultural solid waste is one of the ways to solve the environmental pollution and resource shortage problems. Because of its large specific surface area, porosity and ion exchange capacity, activated carbon can adsorb heavy metal ions and organic pollutants in water, and is usually used to clean the environment. In this paper, grape leaves were used as raw materials to prepare biochar by pyrolysis. The pyrolysis temperature and time were investigated. The obtained grape leaf biochar (GLB) was characterized by FT-IR, SEM and XRD methods. SEM images showed that GLB has a porous structure. FT-IR spectra indicated that obtained GLB has —C=O and —OH functional groups. The results of XRD show that the GLB contains cellulose graphite microcrystals and CaCO₃.  Methylene blue aqueous solution was employed to study the adsorption properties of GLB. The results showed that the adsorption kinetics of GLB to MB solution belonged to the pseudo second order kinetics. Adsorption thermodynamics fit both Freundlich and Langmuir models. Therefore, the development and application of GLB can not only repair the environment, but also realize the resource utilization of agricultural wastes.