Hydrologie : recherche actuelle

Wastewater Containing 1,2-Dihydro-2,2,4-Trimethylquinoleyn Treated by Electrolysis and Respirometric Method

Abstract

Thelma Helena Inazaki, Peterson Bueno de Moraes, Gisela Regis, Paulo Renato Matos Lopes, Renato Nallin Montagnolli, Antonio Carlos Simões Piao3 and Ederio Dino Bidoia

The electrolytic treatment of a real industrial effluent and simulated wastewater containing the 1,2-dihydro- 2,2,4-trimethylquinoleyn compound (Naugard Q®) had been investigated in order to improve the wastewater biodegradability. The electrolysis was carried out in a batch electrolytic cell using 70TiO2/30RuO2 electrodes (DSA® anode). After electrochemical treatment, wastewaters were evaluated in terms of Naugard Q® concentration, UV-visible spectrophotometry and biodegradation. Further analyses were conducted in simulated wastewater by gas chromatography and the biodegradation process was monitored using respirometric flasks. Both real effluent and simulated wastewater presented a decrease in Naugard Q® concentration. The simulated wastewater electrolytic treatment provided concentration reduction of Naugard Q® about 52.04% after 60 min, whereas real effluent concentration was reduced by 62.60% after 40 minutes. Furthermore, UV-visible spectra and gas chromatograms presented significant alterations in molecular structure of the compound. After 30 min electrolysis, an increase in simulated wastewater biodegradation was observed. In real effluent, the biodegradation response was faster, as more CO2 was produced in assays that underwent 10 and 25 minutes of electrolytic treatment. This result is probably related to modifications in Naugard Q® molecular structure. It was concluded that the electrolytic treatment followed by bioremediation could be an alternate treatment to degrade this compound.