A dual-wavelength UV-C LED unit, emitting at peaks of 260 nm, 280 nm, and the combination of 260|280 nm together was evaluated for its inactivation efficacy and energy efficiency at disinfecting Escherichia coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores, compared to conventional low-pressure and medium-pressure UV mercury vapor lamps. The dual-wavelength unit was also used to measure potential synergistic effects of multiple wavelengths on bacterial and viral inactivation and DNA and RNA damage. All five UV sources demonstrated similar inactivation of E. coli. For MS2, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was most effective. When measuring electrical energy per order of reduction, the LP UV lamp was most efficient for inactivating E. coli and MS2; the LP UV and MP UV mercury lamps were equally efficient for HAdV2 and B. pumilus spores. Among the UV-C LEDs, there was no statistical difference in electrical efficiency for inactivating MS2, HAdV2, and B. pumilus spores. The 260 nm and 260|280 nm LEDs had a statistical energy advantage for E. coli inactivation. For UV-C LEDs to match the electrical efficiency per order of log reduction of conventional LP UV sources, they must reach efficiencies of 25-39% or be improved on by smart reactor design. No dual wavelength synergies were detected for bacterial and viral inactivation nor for DNA and RNA damage.

SummarySince the beginning of environmental virology in the mid-twentieth century, a key challenge to scientists in the environmental field has been how to collect, isolate and detect pathogenic viruses from water that is used for drinking and/ or recreational purposes. Early studies investigated different types of membrane filters, with more sophisticated technologies being developed more recently. The purpose of this study was to look at the current state of the science of methods for the concentration of viruses from water. Several technologies were reviewed, and associated data were included in a meta-analysis which showed that electronegative filters, electropositive filters and ultrafilters are comparable in performance and that significant differences in recovery are due to virus type rather than filter type, water matrix or sample volume. This information is useful, as it will help to determine which method(s) should be used, particularly if there is a specific viral type being targeted for a particular study. In addition, it will be helpful when sampling different environmental water matrices and/or when budget allowance must be taken into consideration. Taken together, this will be useful in performing viral occurrence studies, which ultimately can help ensure safer water for both humans and the environment.

Urban water systems are an example of complex, dynamic human-environment coupled systems which exhibit emergent behaviors that transcend individual scientific disciplines. While previous siloed approaches to water services (i.e., water resources, drinking water, wastewater, and stormwater) have led to great improvements in public health protection, sustainable solutions for a growing global population facing increased resource constraints demand a paradigm shift based on holistic management to maximize the use and recovery of water, energy, nutrients, and materials. The objective of this review paper is to highlight the issues in traditional water systems including water demand and use, centralized configuration, sewer collection systems, characteristics of mixed wastewater, and to explore alternative solutions such as decentralized water systems, fit for purpose and water reuse, OPEN ACCESSSustainability 2015, 7 12072 natural/green infrastructure, vacuum sewer collection systems, and nutrient/energy recovery. This review also emphasizes a system thinking approach for evaluating alternatives that should include sustainability indicators and metrics such as emergy to assess global system efficiency. An example paradigm shift design for urban water system is presented, not as the recommended solution for all environments, but to emphasize the framework of system-level analysis and the need to visualize water services as an organic whole. When water systems are designed to maximize the resources and optimum efficiency, they are more prevailing and sustainable than siloed management because a system is more than the sum of its parts.

In February 2001, episodes of acute gastroenteritis were reported to the Wyoming Department of Health from persons who had recently vacationed at a snowmobile lodge in Wyoming. A retrospective cohort study found a significant association between water consumption and illness, and testing identified Norwalk-like virus (NLV) in 8 of 13 stool samples and 1 well. Nucleotide sequences from the positive well-water specimen and 6 of the positive stool samples were identical. This multistrain NLV outbreak investigation illustrates the importance of NLV as a cause of waterborne illness and should encourage monitoring for NLVs in drinking water.

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