Environmental Impact of Ionic Liquids: Automated Evaluation of the Chemical Oxygen Demand of Photochemically Degraded Compounds

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Costa, SPF (Author) Other; Pereira, SAP (Author) Other; Pinto, PCAG (Author) Other; Araujo, ARTS (Author) Other; Passos, MLC (Author) Other; Lucia L M F S Saraiva (Author) FFUP

Journal

Title: ChemPhysChem

Vol. 18

Pages: 1351-1357

ISSN: 1439-4235

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 5 Citations

Other information

Authenticus ID: P-00N-JTR

DOI: 10.1002/cphc.201601416

Abstract (EN): A novel automated fluorimetric technique was developed for the assessment of the chemical oxygen demand (COD) of ionic liquids (ILs) and combined with a photodegradation step to promote IL degradation. The method was implemented on a sequential injection analysis (SIA) system and is based on the reduction of cerium(IV) in the presence of irradiated ILs. Compounds incorporating the chloride anion were found to exhibit higher COD values and 1-butyl-3-methylimidazolium chloride ([bmim](+)[Cl](-)), 1-butyl-1-methylpyrrolidinium chloride ([bmpyr](+)[Cl](-)), and1-hexyl-3-methylimidazolium chloride ([hmim](+)[Cl](-)) also exhibited considerable photodegradability, whereas the cholinium cation and methanesulfonate and tetrafluoroborate anions showed resistance to photolysis. The developed methodology proved to be a simple, affordable, and robust method, showing good repeatability under the tested conditions (rsd < 3.5%, n=10). Therefore, it is expected that the developed approach can be used as a screening method for the preliminary evaluation of compounds' potential impact in the aquatic field. Additionally, the photolysis step presents an attractive option to promote degradation of ILs prior to their release into wastewater.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7