ABSTRACT
Background: In order to propose a destination for the bottom ash generated from biomass burning, its morphology, functional groups and mineral phases were studied. Dipyrone has been extensively used as an antipyretic, increased due to cases of COVID-19, and due to excretion by urine, incorrect disposal and industrial effluents has been destined to wastewater, being harmful to human and animal life. The present study proposes using biomass ash for the adsorption of dipyrone. Result(s): The characterization of biomass ash shows a sufficient surface area size for adsorption, and a mainly amorphous structure with some peaks of quartz, calcite and other mineral phases. The results show that the kinetic model which best describes the adsorption is the pseudo-first-order model. The Langmuir model best fits at 25 degreeC, and the Freundlich model best describes the adsorption at 35 and 45 degreeC. The thermodynamic parameters indicated that the process is endothermic with a maximum adsorptive capacity of 65.27 mg g-1. In addition, the adsorption is spontaneous, disordered and chemical. The ionic strength study reveals that the adsorbent is promising for real effluent treatment and there is evidence that electrostatic interaction is not the primary adsorptive mechanism, agreeing with the result obtained from pH testing. The proposed mechanism for dipyrone removal involves hydrogen bonds, pi bonds and electron donor-acceptor complex. Conclusion(s): The results are promising in comparison with recent literature and solve two environmental problems: biomass bottom ash disposal and pharmaceutical removal in aqueous medium. The ash may be regarded as a low-cost and environmentally friendly adsorbent. © 2023 Society of Chemical Industry (SCI).