Addition of hydrogen peroxide enhances abiotic sunlight-induced processes to simultaneous emerging pollutants and bacteria abatement in simulated groundwater using CPC solar reactors

GUTIÉRREZ-ZAPATA, HECTOR MARIO; SANABRIA, JANETH; RENGIFO-HERRERA, JULIÁN ANDRÉS

SOLAR ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2017 vol. 148 p. 110 - 116

0038-092X

Results revealedthat almost 90% of 2,4-D (70 μg L-1), present in simulated groundwater containing 0.3 mg L-1of iron at pH 7.0, was degraded after 320 minutes (60 min t30w) ofnatural sunlight irradiation while the viability of Escherichia coli cells(followed by DVC-FISH) was completely reduced after 220 minutes (40 min t30w)by simple addition of 10 mg L-1 of hydrogen peroxide. Klebsiellapneumoniae exhibited an especial behavior since its viability was onlyreduced in 3.5 logs after 320 minutes of sunlight irradiation (60 min t30w).Dark experiment (in presence 10 mg L-1 of H2O2)showed that Fenton processes may also play an important role reducing the 40%of 2,4-D after 320 minutes (60 min t30w) while viability of E.coli and K. pneumoniae underwent a reduction of 2.5 and 2 logsrespectively. Photolysis experiments were not able to degrade 2,4-D and E.coli and K. pneumoniae viability was partially reduced (2 logs).Results showedthat high 2,4-D abatement could be due to photo-induced and/or dark processessuch as photo-Fenton and Fenton (dissolved and colloidal iron), photocatalysis(colloidal iron) and UV-B photolysis of H2O2. Viabilityreduction of microorganisms should be related to combined effects of UV-A+Birradiation, rising of temperature (44 ºC), photo-Fenton, Fenton andphotocatalytic processes.