Role of Ozone and Granular Activated Carbon in the Removal of Mutagenic Compounds

Abstract

The identification of certain organic compounds in drinking water has led water treatment specialists to be increasingly concerned about the eventual risks of such pollutants to the health of consumers. Our experiments focused on the role of ozone and granular activated carbon in removing mutagenic compounds and precursors that become toxic after chlorination. We found that if a sufficient dose of ozone is applied, its use does not lead to the creation of mutagenic compounds in drinking water and can even eliminate the initial mutagenicity of the water. The formation of new mutagenic compounds seems to be induced by ozonation that is too weak, although these mutagens can be removed by GAC filtration. Ozone used with activated carbon can be one of the best means for eliminating the compounds contributing to the mutagenicity of water. A combined treatment of ozone and activated carbon also decreases the chlorine consumption of the treated water and consequently reduces the formation of chlorinated organic compounds. *Compagnie Gen6rale des Eaux, 52, rue d'Anjou

Utilisation de trois tests de génotoxicité pour l'étude de l'activité génotoxique de composés organohalogénés, d'acides fulviques chlorés et d'échantillons d'eau (non concentrés) en cours de traitement de potabilisation

“…Aucune publication ne fait état de travaux utilisant le SOS chromotest dans le cadre de l'étude de l'activité génotoxique d'eaux potables ou en cours de potabilisation sans concentration préalable des échantillons. Le SOS chromotest a toutefois été utilisé par BOURBIGOT et al (1986) pour mettre en évidence une altération primaire de l'ADN induite par des extraits d'eau potable. La méthode d'extraction utilisée par ces auteurs, le passage sur résines XAD-2 et XAD-7 suivi d'une élu-tion avec un mélange méthanol-éther, permettait de concentrer 4 000 fois les échantillons d'eau potable étudiés.…”

Water Treatment Technologies: Principles, Applications, Successes and Limitations of Bioremediation, Membrane Bioreactor and the Advanced Oxidation Processes

“…Heterogeneous catalytic ozonation is an AOP in which the oxidative property of ozone is improved by adding solid catalytic materials. The process is potentially a low cost AOP which has been operated successfully at ambient conditions by several workers and may be relatively easier to apply in a water treatment plant [118]. It has been demonstrated that GAC can enhance ozone transformation into OH radicals [87,[118][119][120].…”

“…The process is potentially a low cost AOP which has been operated successfully at ambient conditions by several workers and may be relatively easier to apply in a water treatment plant [118]. It has been demonstrated that GAC can enhance ozone transformation into OH radicals [87,[118][119][120]. Electrons in the graphenic layers and basic surface groups on GAC are the main factors responsible for the decomposition of O 3 into OH • [119,[121][122].…”

Performance of novel media in stratified filters to remove organic carbon from lake water

“…The WTP examined in this study has a source which contains NOM and has existing practices in place for mitigating THM formation. It currently uses ozonation, followed by GAC filtration to reduce the chlorine consumption of treated water, by removing biodegradable organics (Bourbigot et al, 1986), thereby reducing the likelihood of DBP formation. However, GAC exhausts quickly and requires excessive capital, which can make be costly and unsustainable to operate (Corwin and Summers 2010).…”