Optimizing ozone treatment for pathogen removal and disinfection by-product control for potable reuse at pilot-scale.

Reclaimed water poses environmental and human health risks due to residual organic micropollutants and pathogens. Ozonation of reclaimed water to control pathogens and trace organics is an important step in advanced water treatment systems for potable reuse of reclaimed water. Ensuring efficient pathogen reduction while controlling disinfection byproducts remains a significant challenge to implementing ozonation in reclaimed water reuse applications.

Temporal assessment of SARS-CoV-2 detection in wastewater and its epidemiological implications in COVID-19 case dynamics.

This research evaluated the relationship between daily new Coronavirus Disease 2019 (COVID-19) cases and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) concentrations in wastewater, followed by effects of differential SARS-CoV-2 shedding loads across various COVID-19 outbreaks. Linear regression analyses were utilized to examine the lead time of the SARS-CoV-2 signal in wastewater relative to new COVID-19 clinical cases. During the Delta wave, no lead time was evident, highlighting limited predictive capability of wastewater monitoring during this phase.

Per- and poly-fluoroalkyl substances removal in multi-barrier advanced water purification system for indirect potable reuse.

The study evaluated the removal efficacy of per- and poly-fluoroalkyl substances (PFAS) across various advanced water treatment (AWT) processes in a field-scale AWT train using secondary effluent samples from a full-scale water reclamation facility (WRF). Samples collected from April to October 2020 revealed PFCAs as the dominant PFAS compounds in the WRF secondary effluent, with PFPeA having the highest average concentration and PFSAs in notably lower amounts. Temporal fluctuations in total PFAS concentrations peaked in September 2020, which may reflect the seasonality in PFAS discharges related to applications like AFFFs and pesticides.

Contaminants of emerging concern reduction and microbial community characterization across a three-barrier advanced water treatment system.

This research investigated the removal of contaminants of emerging concern (CECs) and characterized the microbial community across an advanced water treatment (AWT) train consisting of Coagulation/Flocculation/Clarification/Granular Media Filtration (CFCGMF), Ozone-Biological Activated Carbon Filtration (O3/BAC), Granular Activated Carbon filtration, Ultraviolet Disinfection, and Cartridge Filtration (GAC/UV/CF). The AWT train successfully met the goals of CECs and bulk organics removal. The microbial community at each treatment step of the AWT train was characterized using 16S rRNA sequencing on the Illumina MiSeq platform generated from DNA extracted from liquid and solid (treatment media) samples taken along the treatment train.

Significance of wastewater surveillance in detecting the prevalence of SARS-CoV-2 variants and other respiratory viruses in the community - A multi-site evaluation.

Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral genome in wastewater has proven to be useful for tracking the trends of virus prevalence within the community. The surveillance also provides precise and early detection of any new and circulating variants, which aids in response to viral outbreaks. Site-specific monitoring of SARS-CoV-2 variants provides valuable information on the prevalence of new or emerging variants in the community.

Pathogen reduction by ozone-biological activated carbon-based advanced water reclamation for reuse.

Ozone-biological activated carbon (ozone-BAC)-based technologies are emerging as an appealing option for potable reuse systems; however, uncertainty remains regarding the reduction of waterborne pathogens. Common log reduction requirements have been modeled after California Department of Drinking Water's 12-10-10 log reduction value (LRV) for enteric virus, Cryptosporidium, and Giardia, respectively. The objective of this research was to investigate appropriate LRVs of pathogens that can be achieved in ozone-BAC-based treatment systems and to assess the applicability of employing drinking water pathogen guidelines for potable reuse applications.

Longitudinal monitoring of SARS-CoV-2 in wastewater using viral genetic markers and the estimation of unconfirmed COVID-19 cases.

In this study, wastewater-based surveillance was carried out to establish the correlation between SARS-CoV-2 viral RNA concentrations in wastewater and the incidence of corona virus disease 2019 (COVID-19) from clinical testing. The influent wastewater of three major water reclamation facilities (WRFs) in Northern Nevada, serving a population of 390,750, was monitored for SARS-CoV-2 viral RNA gene markers, N1 and N2, from June 2020 through September 2021. A total of 614 samples were collected and analyzed.

Spatial and temporal variability and data bias in wastewater surveillance of SARS-CoV-2 in a sewer system.

The response to disease outbreaks, such as SARS-CoV-2, can be constrained by a limited ability to measure disease prevalence early at a localized level. Wastewater based epidemiology is a powerful tool identifying disease spread from pooled community sewer networks or at influent to wastewater treatment plants. However, this approach is often not applied at a granular level that permits detection of local hot spots.

Removal of SARS-CoV-2 viral markers through a water reclamation facility.

There have been multiple reports of COVID-19 virus, SARS-CoV-2 RNA presence in influent wastewater of water reclamation facilities (WRFs) across the world. In this study, the removal of SARS-CoV-2 RNA was investigated in a WRF by collecting samples from various stages relayed to hydraulic retention time (HRT) and analyzed for viral RNA (N1 and N2) gene markers and wastewater characteristics. SARS-CoV-2 RNA was detected in 28 out of 28 influent wastewater and primary effluent samples.

Sustainability Assessment for Indirect Potable Reuse: A Case Study from Reno, Nevada.

  A triple bottom line (TBL) approach was used to examine the trade-offs between potential reclaimed water management strategies in a closed basin. The goals of the water management strategy included minimizing water source shortages, ensuring safe and resilient future water supplies, and protecting inland ecosystems through adequate surface flows. The TBL approach consisted of quantitative and qualitative impact assessments of social, environmental, and economic criteria.

Toxicity and biogas production potential of refinery waste sludge for anaerobic digestion.

Two waste streams from an oil refinery wastewater treatment system, float from a dissolved air flotation unit (DAF sludge) and waste activated sludge (WAS), were investigated to determine toxicity and biogas production potential for anaerobic digestion through batch testing methods. Ozonation as a pretreatment was investigated to observe the impacts of waste solubilization on both toxicity and biodegradability. Anaerobic toxicity assays resulted in no detectible inhibition from WAS, neither with nor without ozonation.