Evaluation of UVLED disinfection for biofouling control during distribution of wastewater effluent
Tara Randall,
Inbar Shlomo,
Emma Wells,
Breanna Real,
Ben Ma,
Yarrow Linden,
Jasmine Gamboa,
Eran Friedler,
Karl G. Linden
Affiliations
Tara Randall
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Inbar Shlomo
Department of Environmental, Water & Agricultural Engineering, Faculty of Civil and Environmental Engineering, Technion–Israel Institute of Technology, Haifa 32000, Israel
Emma Wells
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Breanna Real
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Ben Ma
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Yarrow Linden
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Jasmine Gamboa
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
Eran Friedler
Department of Environmental, Water & Agricultural Engineering, Faculty of Civil and Environmental Engineering, Technion–Israel Institute of Technology, Haifa 32000, Israel
Karl G. Linden
Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder, UCB 428, Boulder, CO 80309, USA
A commercially available UVLED flow-through device, operating at 40 mJ/cm2, was examined for biofilm control on irrigation pipe material fed by wastewater effluent. Biofouling was monitored through total coliform counts, crystal violet (CV) staining, and ATP analyses. A UV fluence of 40 mJ/cm2 at 280 nm retarded biofilm formation; however, complete biofilm prevention by UV treatment was not achieved despite a high inactivation of planktonic cells. After 5 days of the study, the total coliform and CV biofilm quantification assays between the UV-treated and control bioreactor coupons were not statistically different. The total coliform counts indicated a stable biofilm cell concentration was reached; the CV assay showed biofilm biomass accumulation with time. The ATP results revealed higher coupon ATP on the UV-treated coupons than the control coupons by day 5. The results provoke an interesting discussion surrounding the contribution of viable cells, represented by total coliforms, and extracellular polymeric substance (EPS) to total biofilm biomass. This study also highlighted a need for further investigation into the relationship between ATP responses and complex UV-stress responses of diverse microbial communities as opposed to pure bacteria cultures. HIGHLIGHTS A UV fluence of 40 mJ/cm2 at 280 nm slows biofilm formation on irrigation pipe material.; Bioreactor effluent total coliform concentrations and crystal violet coupon accumulation were not statistically different between UV-treated and control bioreactors after being fed wastewater effluent for five days.; ATP results revealed higher ATP on UV-treated coupons than control coupons after 5 days in bioreactors fed by wastewater effluent.;
