Degradation of acetonitrile residues using oxidation processes

Abstract

Neste trabalho são relatados vários processos de oxidação para a degradação de acetonitrila. Foram investigadas alternativas como fotólise, degradação com peróxido de hidrogênio, processos Fenton e foto-Fenton. A fotólise, o processo mais simples e de menor custo dentre os avaliados, promoveu 100% de degradação de soluções aquosas de acetonitrila a 20%, após 30 horas de irradiação. Este método apresenta, portanto várias vantagens dentre as opções a serem usadas em processos de decomposição de resíduos tóxicos de acetonitrila, os quais tendem a se acumular em laboratórios que utilizam equipamentos de Cromatografia Líquida de Alta Eficiência com Fase Reversa.Several oxidation processes were investigated to degrade residues of acetonitrile. Alternatives such as photolysis, degradation with hydrogen peroxide, Fenton and photo-Fenton processes were investigated. Among the options studied, photolysis proved to be the best choice. Photolysis promoted 100% degradation of 20% aqueous acetonitrile solutions in 30 hours. This method proved to be a cheap alternative to decompose toxic residues of acetonitrile, which tend to be accumulated in laboratories that use RP-HPLC equipments. Keywords: acetonitrile, oxidation process, degradation IntroductionIn the last few years, Universities and Research Institutions in Brazil have started looking for alternatives to deal properly with their growing amounts of chemical residues. Within this context, many institutions have developed Waste Management Programs aiming to reduce, reuse and recycle their chemical residues.1-3 The "Waste Management Program of the Chemistry Institute of Universidade Estadual de Campinas (UNICAMP)" includes the monitoring of the residue generated, the development of alternatives to reduce its amount and potential hazardous toxicity, as well as the evaluation of alternatives to treat residues which present incineration restrictions. 4 It is worthwhile mentioning that the organic residues generated by Chemistry Institute of UNICAMP are decomposed by incineration and the treatment of aqueous solutions containing heavy metal is carried out by precipitation of the heavy metal in loco, at their generating units. Therefore, the residues that require more attention are aqueous solutions containing organic compounds, which deserve a study of possible degradation alternatives.Acetonitrile is used in different processes in the chemical industry as a starting material for the synthesis of many chemicals, pharmaceuticals and pesticides, and also in the manufacturing of photographic films. Another common use of this substance is in research laboratories, mainly diluted in water, as mobile phase in Reversed Phase High Performance Liquid Chromatography (RP-HPLC). 5The literature presents several indications of health hazards in expositions to it.5 Aqueous residues of acetonitrile are critical at Chemistry Institute of UNICAMP and the Safety Committee has been carrying out their treatments through alkaline hydrolyses. These are also critical in all institutions that use RP-...

Acetonitrile Recovery by Distillation Techniques Combined with Salting‐Out or Sugaring‐Out in Tandem

“…To treat the aqueous residue under consideration, techniques already known and applied in teaching and research laboratories were used 26, 27, since ACN is intended to be recovered and reused in the same Faculty of Pharmaceutical Sciences of the University of São Paulo where the HPLC residue was produced. To recover ACN feasibly, the Karl‐Fischer coulometric titration was selected using a high volumetric fraction of ACN in samples (60:40 (v/v)) as suggested in the literature 24.…”

Selective photoreduction of acetonitrile to acetaldehyde in dilute aqueous solutions

“…96, No. 3, 353À361, http://dx.doi.org/10.1080/02772248.2014 sodium hydroxide, and the amount of hydrogen peroxide required (Micaroni, Bueno, and Jardim 2004) must be considered.…”

Hazardous Waste Treatment Technologies

“…Intermediates such as 1,3,5-trinitrobenzene, 1-methyl-2,4dinitrobenzene 2,5-dinitrobenzoic acid and 1,3-dinitrobenzene were identified. Micaroni et al (2004) degradation, but its formation became faster in the presence of X3B, suggesting that hole oxidation of X3B might be involved as well. Muruganandham and Swaminathan (2004) investigated the photochemical decoloration of chlorotriazine reactive azo dye, Orange 4, by Fenton and photo-Fenton processes.…”