Investigations on Amoxicillin Removal from Aqueous Solutions by Novel Calcium-Rich Biochars: Adsorption Properties and Mechanisms Exploration

This study investigates the synthesis, characterization, and environmental application for amoxicillin (AMX) removal in batch mode of three novel calcium-rich biochars. These biochars were produced from the co-pyrolysis of poultry manure, date palm wastes, and waste marble powder at temperatures of 700 degrees C (Ca-B-700), 800 degrees C (Ca-B-800), and 900 degrees C (Ca-B-900). Characterization results show that increasing the pyrolysis temperature results in improved structural, textural, and surface chemistry properties. For instance, the BET surface area of the Ca-B-900 was assessed to be 52.3 m2 g-1, which is 14.1 and 3.1 times higher than those observed for Ca-B-700 and Ca-B-800, respectively. Moreover, the Ca-B-900 shows higher AMX removal ability (56.2 mg g-1) than Ca-B-800 (46.8 mg g-1), Ca-B-700 (14.6 mg g-1), and numerous other engineered biochars. The AMX removal process by these biochars is favorable under wide experimental conditions of initial pH and AMX concentrations. Additionally, the experimental and modeling data show that the AMX adsorption process includes both physical and chemical mechanisms. This study confirms that Ca-rich biochars can perform significant removal of AMX in batch mode.