Manganese Biochar Composites for Adsorptive Removal of Diclofenac From Wastewater

ABSTRACT Pharmaceuticals and personal care products released into wastewater have drawn widespread attention as emerging pollutants of concern in recent years owing to their potential risks to aquatic environments and human health. Diclofenac, a commonly used drug for pain relief is environmentally hazardous due to its slow natural breakdown rate and high toxicity. Biochar composites have shown potential as a sorbent material for removal of emerging contaminants, due to their high surface area, porosity, and surface reactivity. In this work, pine needle biomass was used to derive biochar that was further treated with manganese chloride to develop manganese biochar composites. The composites were characterized by Fourier transform infrared spectroscopy, x‐ray diffraction, and scanning electron microscopy and used for adsorption studies. Batch adsorption experiments revealed that the biochar composites displayed higher affinity for diclofenac than native biochar. Sorption kinetic studies of diclofenac showed that the adsorption process followed a pseudo‐second‐order model. The adsorption isotherm was well fitted to the Langmuir model, indicating a monolayer adsorption surface and reaching an adsorption capacity of 52.63 mg/g. Thus, manganese biochar composites provided an excellent approach to eliminate diclofenac from the aqueous phase.