The Future of Municipal Wastewater Reuse Concentrate Management: Drivers, Challenges, and Opportunities

UNC Libraries · 2026-04-15

Water reuse is rapidly becoming an integral feature of resilient water systems, where municipal wastewater undergoes advanced treatment, typically involving a sequence of ultrafiltration (UF), reverse osmosis (RO), and an advanced oxidation process (AOP). When RO is used, a concentrated waste stream is produced that is elevated in not only total dissolved solids but also metals, nutrients, and micropollutants that have passed through conventional wastewater treatment. Management of this RO concentrate─dubbed municipal wastewater reuse concentrate (MWRC)─will be critical to address, especially as water reuse practices become more widespread. Building on existing brine management practices, this review explores MWRC management options by identifying infrastructural needs and opportunities for multi-beneficial disposal. To safeguard environmental systems from the potential hazards of MWRC, disposal, monitoring, and regulatory techniques are discussed to promote the safety and affordability of implementing MWRC management. Furthermore, opportunities for resource recovery and valorization are differentiated, while economic techniques to revamp cost-benefit analysis for MWRC management are examined. The goal of this critical review is to create a common foundation for researchers, practitioners, and regulators by providing an interdisciplinary set of tools and frameworks to address the impending challenges and emerging opportunities of MWRC management.

Bacterial Membrane Vesicles in Wastewater Disseminate Antibiotic Resistance Genes

bioRxiv (Cold Spring Harbor Laboratory) · 2026-05-12

Abstract Bacterial membrane vesicles (BMVs) have emerged as important contributors to the dissemination of antibiotic resistance genes (ARGs) in the environment. Here, we developed a high-performance immunomagnetic isolation method that improves the purity and selectivity of BMV recovery from wastewater, minimizes contamination from eDNA and viruses, and enables differentiation of BMVs originating from Gram-positive versus Gram-negative bacteria with minimal cross-reactivity. Using this approach, we found that ARGs such as the kanamycin resistance gene ( kan R ) was highly abundant in BMVs from both raw and treated wastewater, exhibited persistence following treatment, and retained the ability to generate antibiotic-resistant bacteria via transformation. Metagenomic sequencing further revealed that tetracycline resistance genes were the most abundant ARG class across all wastewater samples, while the composition of BMV-associated ARGs differed from the bulk ARG profile. These findings highlight the critical yet underrecognized role of BMVs in the spread of antimicrobial resistance and underscore the need to address BMV-mediated pathways within a One Health framework linking environmental and human health.

Coupled chemical–microbial deterioration in stagnant fire hydrant branches threatens drinking water quality

Nature Water · 2026-01-02 · 4 citations

Spatiotemporal hotspots of potential microbial risk in shower systems

Water Research · 2025-06-14 · 3 citations

• Biomass peaked at week 4 followed by sharp decline by week 10. • Early biofilms (week 4) were loosely attached and easily detached. • L. pneumophila was detected at week 4, disappeared, and resurged after week 22. • Mycobacterium spp. emerged in large numbers after week 30. • Both L. pneumophila and Mycobacterium spp. were highly enriched in showerheads. Shower systems create conditions conducive to the growth of opportunistic pathogens, but the timing and location of associated risks are poorly understood. In this study, we constructed 48 full size shower units with six incubation periods (4, 10, 16, 22, 30, and 40 weeks) and four water heater temperature (39, 45, 51, and 58°C) to examine the dynamics of microbial growth and pathogen distribution. Results showed that during the initial stage (4 weeks), peak biomass was observed for all biofilms, ranked as shower hose (SHE) > cold-water pipe (CWP) > hot-water pipe (HWP), followed by a sharp decline by the 10 th -week. At the 4 th -week, the biofilm was loose and easily detached into the water, possibly promoted by leached organic carbon from plastic material, fostering the growth of specific microorganisms. The impacts of stagnation and temperature became more pronounced in CWP and HWP over time. Legionella pneumophila appeared in biofilms at the 4 th -week, disappeared, and reappeared in large numbers since the 22 nd -week. Differently, Mycobacterium spp. emerged in large numbers after 30 weeks. Both pathogens were notably enriched in showerheads and shower hoses. This study highlights critical periods of higher risk in shower systems, particularly in the early stages (4 weeks) and after 22 weeks, suggesting that risks can be mitigated by pre-soaking pipes or regularly cleaning (e.g., heat shock flushing) and replacing showerheads and hoses.

Examining the Persistence of Coronavirus in Septage

ACS ES&T Water · 2025-07-22

Unveiling Chemical-Microbial Cascade Risk Factors from Plastic Pipe Leaching in Drinking Water

Environmental Science & Technology · 2025-10-14 · 2 citations

Plastic pipes are increasingly used in drinking water distribution systems, yet their impact on water quality remains insufficiently understood. Here, we systematically investigate the dual outcomes posed by plastic pipes─chemical leaching and cascaded microbial exposure risks─by integrating Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and metagenomic analysis. Our results reveal that plastic pipes continuously release dissolved organic matter (DOM), including organic additives such as bisphenols (BPs) and organophosphate esters (OPEs), which profoundly reshape microbial communities. Under chlorinated conditions, leached DOM alters microbial diversity, promoting chlorine-resistant bacteria and opportunistic pathogens (OPs), while under nonchlorinated conditions, it accelerates microbial growth and enriches antibiotic resistance genes (ARGs), OPs, and virulence factors (VFs). Among plastic materials, polyethylene (PE) exhibited the highest chemical risk, releasing high concentrations of TCPP (700 ng/L) and BPF (200 ng/L) along with 207-227 unique DOM molecules. In contrast, polyvinyl chloride (PVC) supported the highest OP abundance, while polypropylene random copolymer (PPR) fostered the greatest OP diversity. These findings challenge conventional drinking water safety assessments that separate chemical contamination from microbial risk, underscoring the urgent need for an integrated risk assessment framework. Furthermore, they highlight the necessity of paying greater attention to the chemical and cascading microbial issues arising from the leaching of plastic pipes into drinking water, and of conducting a more comprehensive assessment of the associated potential health risks.

Why WE? A Scientific Odyssey for Planetary Sustainability via Water & Ecology

Water & Ecology · 2025-05-14 · 3 citations

Call for Expanding Environmental Surveillance of H5N1: The Role of Microbial Source Tracking

Environmental Science & Technology Letters · 2025-08-12 · 1 citations

Temperature-dependent microbial dynamics in touchless sensor faucets during short-term stagnation

Environmental Science and Ecotechnology · 2025-09-25 · 3 citations

Microbial contamination in building plumbing systems poses significant risks to public health at the point of use. Stagnation and warm temperatures are well-known drivers of microbial regrowth, but the effects of common short-term stagnation in touchless sensor faucets—widely used for hygiene and comfort—remain poorly understood. Here we show that microbial water quality in touchless sensor faucets changes during short-term stagnation (0.25–10 hours) at varying temperatures (10, 30, and 40 °C). We identify two pivotal time points—2 and 4 hours—where microbial diversity decreases and Legionella pneumophila concentrations increase significantly, driven by accelerated chlorine decay and biofilm contributions. Heating to 30 °C maximizes microbial biomass (measured as ATP) but minimizes L. pneumophila proliferation, whereas 40 °C reduces biomass while promoting L. pneumophila growth. These findings reveal a temperature-dependent microbial water quality guarantee period of 2–4 hours, beyond which flushing is necessary to mitigate health risks. Optimizing faucet temperatures between 30 and 40 °C could balance microbial safety, user comfort, and energy efficiency, offering practical guidance for managing water quality in modern plumbing systems. • Residual chlorine and specie richness decline while ATP rises during 0–10 h stagnation. • Microbial water quality exhibits turning points at 2 h and 4 h of stagnation. • Biofilm contributions dominate after 4 h at 10 °C, but only 2 h at 30/40 °C. • Sharp microbial shifts occur when residual chlorine falls below 0.3 mg/L. • 30 °C heating kills L. pneumophila better than 40 °C, balancing safety and energy.

Editorial Perspectives: will SARS-CoV-2 reset public health requirements in the water industry? Integrating lessons of the past and emerging research

UNC Libraries · 2025-07-03

Brian Pecson and Daniel Gerrity present an Editorial Perspective which focuses on the impact of SARS-CoV-2 on the water industry.