UV LED water disinfection: Validation and small system demonstration study

Abstract

What initially drew you to water research?My dedication to protect and provide water is ingrained by my Central Appalachian heritage, where my neighborhood creek was polluted by sewage and irresponsible natural resource extraction. My lifetime enjoyment of the outdoors-especially water -drove me to find solutions for these environmental problems. From my earliest undergraduate research experience studying slow sand filters for microbial water treatment in developing countries, I was captivated by the intersection of environmental microbiology and engineering. The integration of these fields unites my past experiences and informs my research plans. What is the present research focus of your group?I am building on my convergent engineering and microbiology background, and graduate certificates in both teaching and mentoring, to inspire and educate students to sustainably engineer safe water for the health and enjoyment of future generations. I lead the Water TEAM (Treatment Engineering and Microbiome) in applying emerging molecular biology tools, novel sensors, big data analyses, and optimized treatment technologies to understand and control microbiomes in natural and engineered waters. Our overarching goal 16 JOURNAL AWWA T h e o r y a n d P r a c t i c e o f S a f e , S u s t a i n a b l e W a t e r www.awwawaterscience.com Natalie enjoys the view atop Looking Glass Rock near Asheville, N.C., with her corgi, Betty.

Woven-Fiber Microfiltration (WFMF) and Ultraviolet Light Emitting Diodes (UV LEDs) for Treating Wastewater and Septic Tank Effluent

“…Ammonia nitrogen and total phosphorus were also not reduced significantly; however, nitrate nitrogen was reduced by an average of 41.4% (±40.5). Previous studies involving WFMF membrane bioreactors showed statistically significant reduction of ammonia nitrogen, nitrite nitrogen, phosphate, and other nutrients; however, those studies involved biological membrane growth in which the biomass performed a nitrification step, whereas the WFMF in this study was primarily a physical removal process [26,48]. UVT 254 improved from an average of 33.1% (±15) to an average of 52.5% (±14) after WFMF filtration.…”

“…Reduction equivalent dose (RED) and log inactivation were modeled for a single challenge microorganism based on the combined variable approach presented by Wright et al [47] and Hull et al [48] and described in Equation ( 1):…”

“…The final log inactivation and RED models included only statistically significant coefficients. Following the findings from Hull et al [48], log inactivation by UV LEDs was modeled as a function of RLE absorbance and flow rate. LP UV log inactivation was modeled as a function of UVA 254 and flow rate.…”

“…In comparison, Hull et al [48] applied the combined variable approach for a UVC LED system challenged with MS2 bacteriophage in drinking water and obtained the following statistically significant (p < 0.05) coefficients: a = −0.1952, b = −0.25607, c = 0.65497, d = −7.99858, and e = 37.65489. Differences between the calculated coefficients may be explained by the UVT ranges used for model validation as well as the reactor design.…”

Cost-effective smart microfluidic device with immobilized silver nanoparticles and embedded UV-light sources for synergistic water disinfection effects

“…Simple and economical abovementioned factors, in favour of the reported micro-device (calculated-cost ¼ 5 USD per unit, approx.) reason it to be a 5 to 10 times costeffective substitute in comparison to any UV-C based waterdisinfection unit (present in several existing commercial devices), with comparable sterilization capability [9][10]. Hence, the reported device may be considered as a compact, efficient, as well as, low-cost solution for any similar purpose.…”