UV LED wastewater disinfection: The future is upon us.

The world's first full-scale, 280 nm UV LED reactor for wastewater disinfection was tested at flows of 545 and 817 m day. The system achieved > 3 average log reduction of total coliform at 545 m day and the 817 m day flow rate achieved over > 2.5 average log reduction for all operational conditions.

A critical review of ultra-violet light emitting diodes as a one water disinfection technology.

UV light emitting diode (LED) disinfection technologies have advanced over the last decade and expanded the design space for applications in point of use, industrial, and now full-scale water treatment. This literature review examines the progression of UV LED technologies from 2007 to 2023 using key features such as total optical power, price, and wall-plug efficiency. The review found that optical power is increasing while the price per Watt is decreasing; however, the wall plug energy (WPE) is slowly improving over the last decade.

UV LED disinfection as a novel treatment for common salmonid pathogens.

Aeromonas salmonicida and Yersinia ruckeri are common pathogenic bacteria that impact salmonid aquaculture. Although vaccinations are available against both organisms, large-scale vaccination efforts can be expensive, cumbersome, and are not always reliable. Alternatively, these pathogens have been effectively inactivated using UV radiation from mercury-based systems.

Comparison of and Quantification Methods for Assessing UV LED Disinfection.

This study assesses the efficacy of ultraviolet light-emitting diodes (UV LEDs) for deactivating (pure culture) and (pure culture and biofilms) on relevant drinking water distribution system surfaces (cast iron and stainless steel). UV LED treatment at 280 nm demonstrated superior performance compared to that at 365 nm, achieving a 4.8 log reduction value (LRV) for pure cultures and, for biofilms, 4.

Raw water biofiltration for surface water manganese control.

Manganese (Mn) control in surface water systems is a challenge for the drinking water industry, especially through a sustainability framework. Current methods for removing manganese from surface water use strong oxidants that embed carbon and can be expensive and harmful to human health and the environment. In this study, we used a simple biofilter design to remove manganese from lake water, without conventional surface water pre-treatments.

Improved disinfection performance for 280 nm LEDs over 254 nm low-pressure UV lamps in community wastewater.

Ultraviolet (UV) disinfection has been incorporated into both drinking water and wastewater treatment processes for several decades; however, it comes with negative environmental consequences such as high energy demands and the use of mercury. Understanding how to scale and build climate responsive technologies is key in fulfilling the intersection of UN Sustainable Development Goals 6 and 13. One technology that addresses the drawbacks of conventional wastewater UV disinfection systems, while providing a climate responsive solution, is UV light emitting diodes (LEDs).

Adsorption of SARS-CoV-2 onto granular activated carbon (GAC) in wastewater: Implications for improvements in passive sampling.

Based on recent studies, passive sampling is a promising method for detecting SARS-CoV-2 in wastewater surveillance (WWS) applications. Passive sampling has many advantages over conventional sampling approaches. However, the potential benefits of passive sampling are also coupled with apparent limitations.

Operational Constraints of Detecting SARS-CoV-2 on Passive Samplers using Electronegative Filters: A Kinetic and Equilibrium Analysis.

In developing an effective monitoring program for the wastewater surveillance of SARS-CoV-2 ribonucleic acid (RNA), the importance of sampling methodology is paramount. Passive sampling has been shown to be an effective tool to detect SARS-CoV-2 RNA in wastewater. However, the adsorption characteristics of SARS-CoV-2 RNA on passive sampling material are not well-understood, which further obscures the relationship between wastewater surveillance and community infection.

Specificity of UV-C LED disinfection efficacy for three N95 respirators.

The recent surge in the use of UV technology for personal protective equipment (PPE) has created a unique learning opportunity for the UV industry to deepen surface disinfection knowledge, especially on surfaces with complex geometries, such as the N95 filter facepiece respirators (FFR). The work outlined in this study addresses the interconnectedness of independent variables (e.g.

Assessing the impact of multiple ultraviolet disinfection cycles on N95 filtering facepiece respirator integrity.

During the COVID-19 pandemic, N95 filtering facepiece respirators (FFRs) were recommended to protect healthcare workers when providing care to infected patients. Despite their single-use disposable nature, the need to disinfect and repurpose FFRs is paramount during this global emergency. The objectives of this study were to (1) determine if UV treatment has an observable impact on respirator integrity; (2) test the impact of UV treatment on N95 FFR user fit; and (3) test the impact of UV treatment on FFR integrity.

Pandemic danger to the deep: The risk of marine mammals contracting SARS-CoV-2 from wastewater.

We are in unprecedented times with the ongoing COVID-19 pandemic. The pandemic has impacted public health, the economy and our society on a global scale. In addition, the impacts of COVID-19 permeate into our environment and wildlife as well.

Source Water Characteristics and Building-specific Factors Influence Corrosion and Point of Use Water Quality in a Decentralized Arctic Drinking Water System.

Access to clean and safe drinking water is a perpetual concern in Arctic communities because of challenging climatic conditions, limited options for the transportation of equipment and process chemicals, and the ongoing effects of colonialism. Water samples were gathered from multiple locations in a decentralized trucked drinking water system in Nunavut, Canada, over the course of one year. The results indicate that point of use drinking water quality was impacted by conditions in the source water and in individual buildings and strongly suggest that lead and copper measured at the tap were related to corrosion of onsite premise plumbing components.

Inactivation of biofilm-bound Pseudomonas aeruginosa bacteria using UVC light emitting diodes (UVC LEDs).

Ultraviolet light emitting diodes (UV LEDs) are a promising technology for the disinfection of water and wetted surfaces, but research into these applications remains limited. In the drinking water field, UV LEDs emitting at wavelengths ranging from 254 nm to 285 nm (UVC LEDs) have been shown to be effective for the inactivation of numerous pathogens and pathogen surrogate organisms at UV doses comparable to conventional germicidal UV lamps. Surface disinfection with UV light, from UVC LEDs or from conventional UV lamps, is not as well understood.

Understanding the Impact of Extracellular Polymeric Substances on Lead Release in Drinking Water Systems.

Lead release in a lead (Pb, anode)-iron oxide (α-FeO, cathode) galvanic system was studied under the influence of synthetic extracellular polymeric substances (sEPS). Sodium alginate, bovine serum albumin (BSA), and cytochrome c represented extracellular polysaccharides, proteins, and electrochemically active components, respectively. Microbiologically influenced corrosion was investigated using sEPS and pelleted and resuspended cells.

Water safety plans as a tool for drinking water regulatory frameworks in Arctic communities.

Arctic communities often face drinking water supply challenges that are unique to their location. Consequently, conventional drinking water regulatory strategies often do not meet the needs of these communities. A literature review of Arctic jurisdictions was conducted to evaluate the current water management approaches and how these techniques could be applied to the territory of Nunavut in Canada.

Lake Recovery Through Reduced Sulfate Deposition: A New Paradigm for Drinking Water Treatment.

This study examined sulfate deposition in Nova Scotia from 1999 to 2015, and its association with increased pH and organic matter in two protected surface water supplies (Pockwock Lake and Lake Major) located in Halifax, Nova Scotia. The study also examined the effect of lake water chemistry on drinking water treatment processes. Sulfate deposition in the region decreased by 68%, whereas pH increased by 0.

Combined use of resin fractionation and high performance size exclusion chromatography for characterization of natural organic matter.

The number and complexity of natural organic matter (NOM) species limits identification of individual NOM compounds. The objective of this study was to employ several characterization techniques (resin fractionation, high performance size exclusion chromatography (HPSEC), and strategic UV254 absorbance) to samples from seven surface water sites in North America, and overcome the shortfalls of each tool. Resin fractionation indicated the samples were all high in hydrophobic acids (HOA), hydrophilic neutrals (HIN) and hydrophilic acids (HIA).