Salicylic Acid and 4-Nitroaniline Removal from Water Using Magnetic Biochar: An Environmental and Analytical Experiment for the Undergraduate Laboratory

Adsorption studies of salicylic acid (SA) and 4-nitroaniline (4NA) from aqueous solutions were performed with magnetic biochar (MBC) in order to train students in analytical techniques such as standard calibration curves, UV–vis spectrophotometry, and chemical separations within the context of wastewater purification. Analysis of samples purified by MBC enhances student understanding of water quality and the importance of potable water production, a growing worldwide concern. MBC was prepared by iron oxide precipitation onto the biochar surface using an aqueous Fe3+/Fe2+ solution followed by NaOH treatment. MBC effectiveness in removing organic contaminants from water was evaluated using UV–vis spectroscopy, Beer’s law, and a comparison to standard calibration curves while determining the concentrations of two contaminant compounds. The use of MBC to remove organic contaminants in water highlights the effectiveness of this technique for wastewater remediation and prompt discussion of water quality concern...