Disinfection of roof harvested rainwater inoculated with E. coli and Enterococcus and post-treatment bacterial regrowth: Conventional vs solar driven advanced oxidation processes

2021 ◽  
pp. 149763
Author(s):  
A. Fiorentino ◽  
G. Lofrano ◽  
R. Cucciniello ◽  
M. Carotenuto ◽  
O. Motta ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Post Treatment ◽  
Bacterial Regrowth ◽  
E Coli ◽  
Oxidation Processes

scholarly journals Simultaneous Disinfection and Organic Microcontaminant Removal by UVC-LED-Driven Advanced Oxidation Processes

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1507
Author(s):  
Sara Miralles-Cuevas ◽  
Irene De la Obra ◽  
Elizabeth Gualda-Alonso ◽  
Paula Soriano-Molina ◽  
José L. Casas López ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Scaling Up ◽  
Bactericidal Effect ◽  
Secondary Effluent ◽  
Bacterial Inactivation ◽  
Bacterial Regrowth ◽  
Oxidation Processes ◽  
Bacteria Inactivation ◽  
Simulated Wastewater

This work presents the comparison of four advanced oxidation processes driven by UVC-LED radiation (278 nm—2 W/m2) for simultaneous bacteria inactivation (Escherichia coli—106 CFU/mL) and microcontaminant removal (imidacloprid—50 µg/L) in simulated wastewater secondary effluent. To this end, the activation of H2O2 and S2O82− as precursors of HO• and SO4•−, respectively, by UVC-LED and UVC-LED/Fe3+–NTA (ferric nitrilotriacetate at 0.1 mM) has been studied at different oxidant concentrations. For the purpose of comparison, conventional chlorination was used as the baseline along with bacterial regrowth 24 h after treatment. Disinfection was achieved within the first 30 min in all of the processes, mainly due to the bactericidal effect of UVC-LED radiation. UVC-LED/H2O2 did not substantially affect imidacloprid removal due to the low HO• generation by UVC irradiation at 278 nm, while more than 80% imidacloprid removal was achieved by the UVC-LED/S2O82−, UVC-LED/Fe3+–NTA/S2O82−, and UVC-LED/Fe3+–NTA/H2O2 processes. The most efficient concentration of both oxidants for the simultaneous disinfection and microcontaminant removal was 1.47 mM. Chlorination was the most effective treatment for bacterial inactivation without imidacloprid removal. These findings are relevant for scaling up UVC-LED photoreactors for tertiary wastewater treatment aimed at removing bacteria and microcontaminants.

scholarly journals Application of O3 and O3 /H2O2 for post-treatment of horizontal-flow anaerobic immobilized biomass (HAIB) effluent, treating hospital wastewater.

Inge CUC ◽  
2021 ◽  
Vol 17 (2) ◽  
Author(s):  
Tatiana Rodriguez ◽  
Juan Gabriel Rueda-Bayona
Keyword(s):  
Advanced Oxidation Processes ◽  
Flow Reactor ◽  
Advanced Oxidation ◽  
Appropriate Technology ◽  
Post Treatment ◽  
Horizontal Flow ◽  
Biological Processes ◽  
Oxidation Processes ◽  
Recalcitrant Compounds ◽  
Immobilized Biomass

Introduction: In recent years, the "emerging pollutants" in urban, industrial, and surface water bodies have called the attention worldwide.  In many cases, these substances correspond to pollutants that have not been yet regulated by the environmental authorities. Hospitals are considered the main source of these contaminants as a result of different activities.  However, there is no consensus about the appropriate treatments for removing this kind of pollutants in the wastewaters; independent conventional biological processes do not reach the desirable values of discharge limits. Advanced oxidation processes (AOP) are known as an appropriate technology, not only to improve the biodegradability of recalcitrant compounds, but also to contribute to the removal of certain substances that are difficult to treat during the biological process.   Objective: Thus, this study evaluated the application of O3z and O3 /H2O2 to the effluent of an anaerobic horizontal flow reactor and immobilized biomass (HAIB). Methodology: The oxidizers were applied in a lab-scale batch borosilicate glass reactor. The reaction time was 60 min and samples were taken at intervals of 15 min. Parameters such as absorbance at UV254, biodegradability ratio expressed as COD/BOD5, and color as VIS436 were measured. All samples were analyzed in duplicate. Results. The results showed that the application of Ozone and O3/H2O2 results in an increase in the biodegradability of 25% and 67% respectively. Concerning color, an efficiency of 85 % for Ozone and 100 % for O3 /H2O2 was observed. Besides, the AOPs applied also showed their effectiveness in removing aromatic organics, removing 40 to 50% of UV254. Conclusions: Finally, it is important to mention that the application of advanced oxidation processes as a post-treatment of anaerobic effluents increases biodegradability mainly due to the transformation suffered by recalcitrant compounds.

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