A study presented at the 15th Brazilian Meeting about Adsorption, conducted by Jorge Vinícius Fernandes Lima Cavalcanti, Júlia Maciel Calazans, Maurício Alves da Motta Sobrinho, Antônio Demóstenes de Sobral, Valmir Felix de Lima, and Ramon Borges Cordeiro, explored the potential of gasified biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More (C2) as an adsorbent for benzene and toluene in mono-compound systems. This research, stemming from the Department of Chemical Engineering (DEQ) at the Federal University of Pernambuco (UFPE), compared the performance of biochar with commercial activated charcoalCharcoal is a black, brittle, and porous material produced by heating wood or other organic substances in a low-oxygen environment. It is primarily used as a fuel source for cooking and heating.   More (C1), highlighting the significant capabilities of this residual material in addressing water contamination.

The petroleum industry, a major consumer of water, generates vast amounts of effluents contaminated with harmful compounds, including aromatic hydrocarbons like benzene and toluene. These compounds, often found in gasoline, engine exhaust, and the burning of wood and tobacco, are toxic, mobile in water, and can be persistent pollutants. Conventional effluent treatment methods frequently fall short in removing these BTEX (benzene, toluene, ethylbenzene, xylene) mixtures, creating an urgent need for effective, low-cost remediation technologies. Adsorption presents a viable solution, and the use of industrial waste products like biochar offers a sustainable and robust alternative.

The study rigorously evaluated the adsorption potential of both commercial activated charcoal (C1) and gasified biochar (C2). C1 was a commercial product from the brand Synth, while C2 was sourced from wood industry waste, produced in a natural gas gasifier under oxygen-deficient conditions. Both materials underwent preparation, including pulverization, sieving, washing, filtering, and drying. Characterization techniques such as X-Ray Diffraction Analysis (XRD) and Brunauer-Emmett-Teller (BET) isotherm were used to assess their crystalline structure, specific surface area, pore volume, and pore diameter. The findings indicated that C1 had a larger surface area and pore volume compared to C2 ).

Adsorption results demonstrated impressive maximum adsorptive capacities. The experimental data satisfactorily fit both the Freundlich and Langmuir adsorption isotherms. Thermodynamic studies revealed that all adsorption processes were exothermic and spontaneous. The proximity of the results obtained between the gasified biochar (a residual material) and the commercial activated charcoal underscores the significant potential of biochar as a cost-effective and environmentally friendly adsorbent for organic pollutants. The findings encourage further research into new systems utilizing this promising material for a variety of wastewater treatment applications.

Source: Cavalcanti, J. V. F. L., Calazans, J. M., Sobrinho, M. A. M., de Sobral, A. D., de Lima, V. F., & Cordeiro, R. B. (n.d.). Adsorption of Benzene and Toluene on Activated Charcoal and Gasified Biochar in Mono-compound Systems. 15th Brazilian Meeting about Adsorption