Magnetic sugarcane bagasse composite for atrazine and fluoride removal

Abstract

BACKGROUND: The present investigation focuses on the synthesis and application of a magnetic adsorbent material formed by the agro-industrial waste sugarcane bagasse (SCB). Its application in the removal of fluoride and atrazine demonstrates its properties as a potential adsorbentmaterial for the treatment of contaminated wastewater. RESULTS: The synthesis method proved to be simple and reproducible. The presence and distribution ofmagnetite and fluoride on the surface of the material were studied by characterization techniques (SEM, EDX, FTIR-ATR). Several specific functional groups were identified which may interact with atrazine and fluoride molecules in the adsorption process. Kinetic results indicated that second- and pseudo-second-ordermodel fitted better for the fluoride and atrazine adsorption processes, respectively. The adsorption processes took place by chemisorption onto heterogeneous surfaces. Isotherm data fitted better to the Langmuir–Freundlichmodel in both systems; therefore, the process took place by a combination of mechanisms. Cellulose and lignin fromsugarcane bagasse contribute in the adsorption process, while magnetite not only improve performance of composite for the removal of the chemical species tested, but also achieve a simple separation process via magnetic interactions’ with a commonmagnet. The adsorption capacities of the composites were 0.5036mgg−1 for fluoride and 40.11mgg−1 for atrazine. CONCLUSION: The synthesis of the magnetic composite is simple and generates a material that is easy tomanipulate and isolate after the process. The affinity of the composite with atrazine is greater than with fluoride; however, the composite can be used in systems with low concentration.