Controlling Bacterial Pathogens in Water for Reuse: Treatment Technologies for Water Recirculation in the Blue Diversion Autarky Toilet.

The Blue Diversion AUTARKY Toilet is a urine-diverting toilet with on-site treatment. The toilet is being developed to provide a safe and affordable sanitation technology for people who lack access to sewer-based sanitation. Water used for personal hygiene, hand washing, and flushing to rinse urine- and feces-collection bowls is treated, stored, and recycled for reuse to reduce reliance on external water supplies.

Life-Cycle Energy Use and Greenhouse Gas Emissions of a Building-Scale Wastewater Treatment and Nonpotable Reuse System.

Treatment and water reuse in decentralized systems is envisioned to play a greater role in our future urban water infrastructure due to growing populations and uncertainty in quality and quantity of traditional water resources. In this study, we utilized life-cycle assessment (LCA) to analyze the energy consumption and greenhouse gas (GHG) emissions of an operating Living Machine (LM) wetland treatment system that recycles wastewater in an office building. The study also assessed the performance of the local utility's centralized wastewater treatment plant, which was found to be significantly more efficient than the LM (79% less energy, 98% less GHG emissions per volume treated).

Sunlight inactivation of fecal indicator bacteria in open-water unit process treatment wetlands: Modeling endogenous and exogenous inactivation rates.

A pilot-scale open-water unit process wetland was monitored for one year and found to be effective in enhancing sunlight inactivation of fecal indicator bacteria (FIB). The removal of Escherichia coli and enterococci in the open-water wetland receiving non-disinfected secondary municipal wastewater reached 3 logs and 2 logs in summer time, respectively. Pigmented enterococci were shown to be significantly more resistant to sunlight inactivation than non-pigmented enterococci.

Sunlight inactivation of viruses in open-water unit process treatment wetlands: modeling endogenous and exogenous inactivation rates.

Sunlight inactivation is an important mode of disinfection for viruses in surface waters. In constructed wetlands, for example, open-water cells can be used to promote sunlight disinfection and remove pathogenic viruses from wastewater. To aid in the design of these systems, we developed predictive models of virus attenuation that account for endogenous and exogenous sunlight-mediated inactivation mechanisms.

Sunlight inactivation of MS2 coliphage in the absence of photosensitizers: modeling the endogenous inactivation rate using a photoaction spectrum.

The endogenous sunlight inactivation rates of MS2 coliphage in photosensitizer-free water were measured (kobs) under different light conditions and compared to modeled inactivation rates (kmod) computed using a previously published action spectrum. Experiments were conducted under simulated and natural sunlight. There was generally good agreement between modeled and observed MS2 sunlight inactivation rates in the summer and winter, suggesting that the action spectrum can be used to predict changes in the inactivation rate caused by diurnal and seasonal changes in natural sunlight irradiance.

Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents.

Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants.