Storm runoff pollutants are among the major sources of surface water impairments, globally. Despite several monitoring programs and guidance on stormwater management practices, there are many streams still impaired by urban runoff. This study evaluates an industry sector’s pollutant discharge characteristics using the self-reported data collected under Tennessee Multi Sector Permit program. The stormwater pollutant discharge characteristics were analyzed from 2014 to 2018 for an industry sector involving twelve facilities in West Tennessee, USA. The data analysis revealed the presence of both organic and inorganic contaminants in stormwater samples collected at all twelve industrial facilities, with the most common metals being magnesium, copper, and aluminum. The principal component analysis (PCA) was applied to better understand the correlation between water quality parameters, their origins, and seasonal variations. Furthermore, the water quality indexes (WQIs) were calculated to evaluate the stormwater quality variations among studied facilities and seasons. The results demonstrated slight variations in stormwater WQIs among the studied facilities ranging from “Bad” to “Medium” quality. The lowest seasonal average WQI was found for spring compared to the other seasons. Certain limitations associated with the self-reported nature of data were identified to inform the decision makers regarding the required future changes.

Extensive building closures due to the unprecedented COVID-19 pandemic resulted in long-term water stagnation within the plumbing of large buildings. This study examined water chemical quality deterioration in ten large buildings after prolonged stagnation caused by the closure of a university campus in response to the COVID-19 pandemic. Volume-based and constant-duration flushing protocols were implemented to replace stagnant water with fresh drinking water. The effectiveness of the developed water flushing protocols was examined by monitoring the disinfectant residuals, heavy metal concentrations and temperature for water samples collected from the buildings' point of entry (POE) and select water fixtures. More than 14 m³ of water were flushed in all ten large buildings. The results demonstrated a significantly greater average total chlorine residual concentration in POE water samples collected after flushing (1.1 mg L⁻¹) compared to the stagnant condition (0.6 mg L⁻¹). For water samples collected from fixtures during the extended stagnation, chlorine was absent in 71% of samples from academic buildings and 69% of samples from athletic buildings. The effectiveness of flushing practices is underscored by increasing the median total chlorine concentration from <0.1 to 1.0 mg L⁻¹ in academic buildings and from <0.1 to 0.75 mg L⁻¹ in athletic buildings. Furthermore, the concentrations of Pb, Zn, and Cu had decreased following the water flushing, but the concentration of Fe had increased in some buildings. This study could be beneficial to prepare for prolonged water stagnation events including but not limited to pandemics.

Phosphorous (P) removal in wastewater treatment is essential to prevent eutrophication in water bodies. Side‐stream enhanced biological phosphorous removal (S2EBPR) is utilized to improve biological P removal by recirculating internal streams within a side‐stream reactor to generate biodegradable carbon (C) for polyphosphate accumulating organisms (PAOs). In this study, a full‐scale S2EBPR system in a water resource recovery facility (WRRF) was evaluated for 5 months. Batch experiments revealed a strong positive correlation (r = 0.91) between temperature and C consumption rate (3.56–8.18 mg‐COD/g‐VSS/h) in the system, with temperature ranging from 14°C to 18°C. The anaerobic P‐release to COD‐uptake ratio decreased from 0.93 to 0.25 mg‐P/mg‐COD as the temperature increased, suggesting competition between PAOs and other C‐consumers, such as heterotrophic microorganisms, to uptake bioavailable C. Microbial community analysis did not show a strong relationship between abundance and activity of PAO in the tested WRRF. An assessment of the economic feasibility was performed to compare the costs and benefits of a full scale WRRF with and without implementation of the S2EBPR technology. The results showed the higher capital costs required for S2EBPR were estimated to be compensated after 5 and 11 years of operation, respectively, compared to chemical precipitation and conventional EBPR. The results from this study can assist in the decision‐making process for upgrading a conventional EBPR or chemical P removal process to S2EBPR.Practitioner Points: Implementation of S2EBPR presents adaptable configurations, exhibiting advantages over conventional setups in addressing prevalent challenges associated with phosphorous removal. A full‐scale S2EBPR WRRF was monitored over 5 months, and activity tests were used to measure the kinetic parameters. The seasonal changes impact the kinetic parameters of PAOs in the S2EBPR process, with elevated temperatures raising the carbon demand. PAOs abundance showed no strong correlation with their activity in the full‐scale S2EBPR process in the tested WRRF. Feasibility assessment shows that the benefits from S2EBPR operation can offset upgrading costs from conventional BPR or chemical precipitation.

This study assesses waste-derived crude glycerol (CG) as a supplemental carbon (C) source to enhance polyphosphate accumulating organisms (PAOs) activity through direct addition and fermentation preprocessing. Batch experiments measured PAO kinetic parameters (phosphorus (P) release, C uptake, and P uptake rates) with direct CG addition, showing CG as a sustainable alternative for PAO activity. While P release and uptake rates with CG were lower than those with volatile fatty acids (VFAs) like acetate and propionate, CG performed comparably to other waste-derived C sources (MicroC® 2000 and 3000). Additionally, CG-supplemented waste-activated sludge (WAS) fermentation increased soluble chemical oxygen demand (sCOD) by 64.6 ± 5.7% after 5 days, enhancing PAO activity with 61.0 ± 11.8% higher P release and 22.2 ± 3.3% higher P uptake than WAS-alone fermentation. Lastly, an economic analysis comparing direct and indirect CG use in biological P removal focused on 15-year operational costs. Results indicated a 69% reduction in operational costs with indirect CG use. This study highlights CG's potential to enhance PAO activity in water resource recovery facilities (WRRFs), particularly those with easy access to CG. Findings from this study also promoted sustainability by repurposing biodiesel waste, creating a circular economy in WRRFs.