Synthesis and optimization of a selective treatment network of wastewater streams contaminated with paracetamol

Abstract

The synthesis and optimization of a selective treatment system for contaminated wastewater using Fenton and sono-Fenton oxidation processes is addressed in this work. The problem investigated can be useful for the selective treatment of hospital effluents contaminated with traces of some drug, and the removal of paracetamol is used as a study case. A nonlinear programming model (NLP) that uses a single treatment unit with a defined volume is proposed for the removal of paracetamol by using reported degradation kinetics for each advanced oxidation process evaluated. The cost of the treatment system is considered to be directly proportional to the treated flow. The use of the proposed model is illustrated with the solution of a case study that shows its versatility to achieve optimal treatment systems. Results show that, for the same set of effluents to be treated, the sono-Fenton process exhibits a better paracetamol remotion efficiency, i.e., requires less flow through the treatment unit. As higher concentrations of paracetamol are demanded in the discharge, the lesser is the flow of contaminant effluent that is sent to the treatment unit as well. Whilst, as lower concentrations of paracetamol are demanded in the discharge, an opposing effect is observed. Finally, a discussion of the removal ratio of paracetamol in the overall process and in the treatment unit as a function of the discharged limit of paracetamol in the effluent is addressed.