CONICET | Buscador de Institutos y Recursos Humanos

This work studied environmental evaluations of wastewater treatments of a residual stream contaminated with phenol. A process simulator was used in order to design four alternative treatments: liquid-liquid extraction, supercritical extraction, catalytic oxidation and supercritical oxidation. On the other hand, the Waste Reduction Algorithm (WAR GUI 1.0, USEPA) was chosen to determine potential environmental impacts for each treatment process design. The information obtained in this work is used to determine which alternative is more environmentally friendly to remove phenol, and to find an environmental metric to carry out preliminary designs of environmentally friendly processes. To evaluate environmental behavior a tree steps process was used. First, a limited number of alternatives were generated from a basic scheme. Subsequently, simulations of each process were worked out by a chemical process simulator and optimal operational conditions were chosen. As last step, influence of different environmental index of each analyzed process was weighted qualitatively and quantitatively. Once collected all necessary information, a critical evaluation of data was carried out and diverse observations were extracted. First, total generation rate of PEI (Potential Environmental Impact) presents negative values in all cases, which shows that processes are environmental friendly. In addition, in liquid-liquid extraction and supercritical extraction, recovered phenol may be recycled as product and any waste is generated. Second, the impact generated by energy production is lower than the benignity of the whole process even when the worst energy source (coal) is chosen. Finally, as complex calculations were done process simulation has been essential to determine thermodynamic behavior of all analyzed processes and to select their best operational conditions.