Preparing a magnetic activated carbon with expired beverage as carbon source and KOH as activator

Abstract

Abstract The purpose of this study is to prepare a magnetic activated carbon by KOH activation using expired beverage of several brands as raw material. The maximum adsorption capacity of MBAC for MB (Methylene blue) at 298 K was 404.73 mg/g, could be recycled for 3 times, this study achieved a dual purpose of resource reuse and beverage wastewater treatment. The preparation of activated carbon was divided into two stages: the hydrothermal treatment and activation process. Before and after the hydrothermal treatment, the content of fructose, sucrose, glucose in expired beverages was tested by High Performance Liquid Chromatography (HPLC), it indicated that under the same reaction condition (4 h, 180 °C, 20 mL), the fructose can be converted to hydrothermal carbon much easier than that of sucrose and glucose. According to the data obtained from TOC (total organic carbon) analyzer, the removal rate of 71.6% of organic matters from the beverage can be achieved in 4 h after the hydrothermal treatment. In terms of the activation process, an activated carbon with a specific surface area of 1237 m2/g and pore size of 2.05 nm could be achieved; the XRD and magnetization analysis confirmed the Fe3O4’s crystal structure was preserved and the saturation magnetization of MBAC (magnetic beverage activated carbon) was 12.4 emu/g after the activation process. To describe the adsorption process, the pseudo-second-order and Langmuir model was more suitable.