Comparative assessment of the degradation of 2-methylisoborneol and geosmin in freshwater using advanced oxidation processes

ABSTRACT

Traditional methodologies of conventional drinking water treatment are unable to remove some chemical compounds, such as those that cause odor and taste in drinking water. The present work aims to evaluate the efficiency of advanced oxidations processes, using UV radiation, O₃ and O₃ + UV in the degradation of geosmin (GSM) and 2-methylisoborneol (2-MIB) in synthetic samples. The efficiency of the processes was monitored by Gas Chromatography coupled with Mass Spectrometry using solid phase microextration technique. Experiments were carried out for 45 min with samplings every 15 min. The degradation results showed that UV radiation alone was not efficient for the degradation of both compounds. The fasted decay was observed by the combined use of O₃ and UV with an ozone concentration of 15.84 mg L⁻¹. Under these conditions, the final concentration of GSM was below the limit of quantification, so that approximately 99% of the initial concentration was degraded, while 2-MIB was degraded by 95%. With the same O₃ concentration without the use of UV radiation, 63% and 65.7% of MIB and GSM, respectively, were removed. Higher efficiency of the treatment was observed with a higher O₃ concentration which allows a shorter reaction time.

GRAPHICAL ABSTRACT

KEYWORDS:

• Eutrophication
• GSM
• 2-MIB
• ozone
• UV radiation

Acknowledgments

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001; by Conselho Nacional de Pesquisa – Brasil (CNPq) -Protocol Numbers 309652/2016-2 and 307599/2018-3; and by Ministério de Ciência, Tecnologia e Inovação (MCTI) – Agreement Number 01.0144.00/2010.

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Mariana Maria Gassen Berlt http://orcid.org/0000-0001-5911-0085

Rosana de Cassia de Souza Schneider http://orcid.org/0000-0003-1400-8401

Ênio Leandro Machado http://orcid.org/0000-0003-0140-4966

Lourdes Teresinha Kist http://orcid.org/0000-0003-3278-8966

Additional information

Funding

This work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico: [grant number 307599/2018-3,309652/2016-2]; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior: [finance code 001]; Ministério da Ciência, Tecnologia e Inovação: [grant number 01.0144.00/2010].