| Autor: |
Garkusheva N; a Laboratory of Engineering Ecology , Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences , Ulan-Ude , Russia., Matafonova G; a Laboratory of Engineering Ecology , Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences , Ulan-Ude , Russia., Tsenter I; a Laboratory of Engineering Ecology , Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences , Ulan-Ude , Russia., Beck S; b Department of Civil, Environmental and Architectural Engineering , University of Colorado at Boulder , Boulder , Colorado , USA., Batoev V; a Laboratory of Engineering Ecology , Baikal Institute of Nature Management, Siberian Branch of Russian Academy of Sciences , Ulan-Ude , Russia., Linden K; b Department of Civil, Environmental and Architectural Engineering , University of Colorado at Boulder , Boulder , Colorado , USA. |
| Abstrakt: |
This work evaluated the feasibility of a photo-Fenton-like process using persulfate (PS) and ferrous iron (Fe 2+ ) under simulated solar radiation for degrading the herbicide atrazine (ATZ, 6-Chloro-N-ethyl-N'-isopropyl-1,3,5-triazine-2,4-diamine) and inactivating E. coli. Milli Q water, lake water, and diluted wastewater effluents were spiked both simultaneously and separately with ATZ (4 mg/L) and E. coli (10 5 CFU/mL), and exposed to treatment. A method for determining the average irradiance throughout the water media in the UV(A+B) range of the Xe lamp emission was developed for bench-scale experiments. These values were used to calculate the UV(A+B) fluences and the solar UV(A+B) energy doses per unit of volume (Q UV(A+B) , kJ/L). The obtained kinetic data were presented versus energy dose. Treatment of lake water at near-neutral pH was ineffective via the photo-Fenton-like process, attaining only 20% ATZ removal and 1-log reduction of E. coli. In Milli Q water and wastewater, the complete degradation of ATZ in the absence of bacteria was observed at an average energy dose of 1.5 kJ/L (60 min), while in the presence of cells the degradation efficiency was ∼60%. When ATZ was present, E. coli inactivation was also affected in Milli Q water, with 1.4-log reduction (93%) at a dose of 1.6 kJ/L (60 min), whereas in wastewater complete inactivation was achieved at a lower dose of 1.3 kJ/L (45 min). The energy requirements on a Q UV(A+B) basis for simultaneous 90% ATZ removal and 99.99% E. coli inactivation in Milli Q water and wastewater were shown to be less than 10 kJ/L. This suggests the solar/PS/Fe 2+ system is promising for simultaneous treatment and disinfection of wastewater effluents. |
