Gestión de residuos químicos en el Instituto de Química de la universidad de São Paulo

Abstract

This work describes the actions taken since the beginning of our Chemical Waste Management Program: i) identification of the main types of residues; ii) quantification of the residues already existing; iii) inventory of the reagents and solvents stored and iv) outfit of a laboratory for chemical residues treatment (CTRQD). In CTRQD both heavy metal solutions and organic solvents were treated. Since 2003, we processed almost 5.000 Kg of about 10 types of solvents using batch distillation. Some of these solvents were recovered from mixtures: HPLC was recovered from acetonitrile/water mixtures, n-hexane and dichloromethane were recovered from dichloromethane/n-hexane mixtures and hexanes were recovered from hexanes/ethyl acetate mixtures after ester hydrolysis with KOH using phase transfer catalysis. Organic solvents were also recovered from liquid scintillation wastes. It was also established the feasibility of reusing solid KOH, dryers and phase transfer catalysts. Other solvents could be recovered by washing with aqueous HCl.