Environmental Science: Water Research & Technology最新文献

Freshwater, an essential resource for survival, is becoming scarce because of overuse. A reliable and precise assessment approach is necessary to establish a sustainable water system for use in proper decision-making. This paper explores the range of approaches and methods developed over time to evaluate water consumption, considering factors related to scarcity, quality, and volume. These methods are primarily based on volumetric footprint, impact-oriented assessment, or a combination of both. The water footprinting standard defines water footprint as impact-oriented, where volumetric approach serves as an inventory in life cycle assessment (LCA), which is a widely used tool for evaluating the environmental impact of a product or a system throughout its lifetime. The work provides a thorough overview of more than forty different approaches, tools, databases, and water indices related to water use, water footprint and its environmental impact using life cycle assessment tool and compiled from more than sixty reviewed articles. Many approaches focus on availability and shortage while water quality is generally considered separately, with LCA employing specific indicators. To calculate the impact of scarce freshwater supply on the environment, methodologies are being developed to create a connection between water availability, use and impacts. This is accomplished by employing various characterization models that use environmental mechanisms to convert volumetric input flows into impacts. Some models use cause-and-effect chain relationships to evaluate the effects of water scarcity on ecosystems, human health, and natural resources. Water indices, usually focusing on scarcity or quantity, are used as characterization factors in some models. The paper also presents the most recent approaches to water use assessment that emerged from a consensus between the LCA and water scientific groups. Despite substantial progress, challenges are still present within the sector. Continuous improvement is essential for improving current methods. Enhancing environmental mechanisms, measuring uncertainty, resolving temporal and spatial disparities, undertaking regional evaluations, and improving primary or local data are some of the challenges. This study directs future research toward more efficient and comprehensive water use impact assessment techniques by outlining important areas for improvement.

In this study, nanocomposite membranes were fabricated and characterized for use in membrane bioreactors (MBRs) to treat oily wastewater. Iron oxide nanoparticles (Fe₃O₄) were first synthesized and then modified by tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTES). The membranes were prepared by adding Fe₃O₄@APTES at different concentrations of 0, 0.05, 0.1, and 0.3 wt%, which were denoted by different codes of TFC, TFN-0.05, TFN-0.1, and TFN-0.3, respectively. The highest water flux through the membrane without Fe₃O₄@APTES nanoparticles (TFC) was recorded as 58.36 L m⁻² h⁻¹, which was later reduced to 46.80 L m⁻² h⁻¹ by adding nanoparticles to the membrane (TFN-0.3). The TFN-0.1 membrane demonstrated the best membrane bioreactor performance. The final concentration of heavy metals by the MBR system with the TFN-0.1 membrane was 84.96% Pb(II) > 80.18% Zn(II) > 74.43% Cr(III) > 74.14% Ni(II). Hence, it was found that adding Fe₃O₄@APTES nanoparticles to the membranes could reduce irreversible fouling. The results showed that the TFN-0.1 membrane with a flux recovery ratio of 96.3% had the most optimal antifouling performance among the other nanocomposite membranes.

The COVID-19 pandemic provided an unprecedented opportunity to assess the value of wastewater based epidemiology (WBE) as a tool to complement clinical testing in efforts to monitor and mitigate disease outbreaks. This study presents a retrospective assessment of a WBE approach that integrated WBE from congregate living facilities with high-frequency, rapid-turnaround clinical testing within a university setting. By focusing on communal living spaces, such as dormitories, this approach made it possible to rapidly identify and counter the spread of SARS-CoV-2 as well as to monitor the efficacy of campus-focused public health measures throughout the pandemic. Beginning in 2020, the University of Denver (DU) implemented a campus-wide, dual-prong COVID-19 response that combined WBE with frequent high-sensitivity testing (FHST) of individuals by RT-qPCR. Wastewater monitoring at the building level was employed in an effort to facilitate the early detection of SARS-CoV-2 spread and thereby make it possible to more confidently and precisely allocate limited clinical testing resources to identify and isolate infected individuals. This data-driven approach to WBE-informed targeting of FHST resources contributed to markedly and consistently lower SARS-CoV-2 positivity rates on campus compared to the surrounding metropolitan area. Analyses of data from multiple dormitories, and spanning several early-stage disease outbreaks, have highlighted the potential of WBE to optimize limited clinical resources for detecting, containing, and resolving the spread of communicable diseases. The information gained from DU's COVID-19 response can help to guide the development of future public health strategies in other communities confronting similar challenges.

A novel composite membrane, comprising polystyrene, polypyrrole, and salian (PSPPY-Sa), was developed through the electro spinning technique to enhance scaling inhibition in water filtration systems. The characterization of the membrane was conducted using FTIR, XRD, and TGA measurements. An extensive study was performed to evaluate the impact of varying salian loadings, ranging from 0 to 20 weight percent, on both the morphological properties and the scaling inhibition performance. To evaluate the anti-scaling properties of the membrane, accelerated scaling tests were performed with a 2000 ppm CaSO₄ solution, filtering a synthetic scaling solution. Morphological assessments revealed a uniform distribution of salian microdomains across the fibrous surface of the PSPPY-Sa membrane. Notably, the incorporation of salian at 20% loading achieved a 95% reduction in scale formation, demonstrating superior performance compared to pristine or singly modified membranes. The PSPPY-Sa membrane also demonstrated remarkable thermal stability, underscoring its potential for effective scaling inhibition in water filtration applications.

Ribavirin (RBV) and chloroquine phosphate (CQP) are widely used antiviral drugs, and have raised considerable concern due to their ubiquitous nature, persistence, bioaccumulation, and high toxicity. In this paper, the sources and routes of RBV and CQP in the environment are documented, and the potential risks associated with these two antiviral drugs are analyzed. Besides, considering that conventional sewage treatment shows a limited removal effect on RBV and CQP, this review also provides a summary of the effectiveness of several advanced treatment processes in treating RBV and CQP, including biological treatment, photodegradation process, adsorption, membrane treatment, advanced oxidation process and advanced reduction process. The advanced oxidation process is a promising method because of its non-selectivity, short reaction time, and high treatment efficiency, and can also be combined with other treatment processes. In future research, the challenge of developing and optimizing cost-effective and efficient techniques for RBV and CQP removal should be surmounted.

Microplastics (MPs) and nanoplastics (NPs) are increasingly present in aquatic environments due to their widespread use across various sectors. These contaminants can cause adverse effects on exposed organisms, exacerbated by their potential for bioaccumulation and their ability to transport other pollutants. Conventional water treatment plants are ineffective at removing MPs and NPs, highlighting the need for alternative solutions. In this context, biochar emerges as a promising material for removing MPs and NPs from water due to its advantageous properties, such as high specific surface area, large pore volume, abundance, and versatility. Additionally, producing biochar from biomass waste ensures a low-cost and environmentally sustainable material. This review explores the application of biochar and its composites in the removal of MPs and NPs from water, exploring its applications in adsorption, filtration, and aggregation. The discussion extends to the environmental factors that influence the performance of biochar in water treatment, such as pH, temperature, and the presence of competing contaminants. Furthermore, the potential synergies between biochar and other water treatment technologies, such as coagulation–flocculation and anaerobic granular sludge, are discussed along with methods for regenerating biochar to restore its effectiveness. Notwithstanding, emphasis is also given to the possible drawbacks of negligent use of biochar, such as harmful contaminants such as polycyclic aromatic hydrocarbons (PAHs) and metal that may leach from the material. Despite these hindrances, biochar remains a valuable tool in enhancing the efficiency of water treatment systems for MPs and NPs removal, offering a sustainable and efficient approach to water treatment.

Freshwater scarcity, caused by population growth and climate change, has boosted the demand for desalination technologies. This review examines both thermal- and membrane-based desalination methods, with a particular emphasis on the environmental difficulties posed by brine, a concentrated byproduct of these processes. Novel brine management techniques, such as crystallization and resource recovery, are explored as long-term alternatives to conventional disposal methods, thereby providing opportunities to reduce environmental harm while increasing resource efficiency. Furthermore, this review explores the regulatory frameworks that control brine discharge and discusses the limitations of present technologies, such as the requirement for chemical pretreatment and high membrane replacement costs. By highlighting these aspects, this review provides insights into improving the sustainability and efficiency of desalination techniques.

Reverse osmosis (RO) systems are an essential tool for water desalination, but their effectiveness can be hampered by membrane fouling and susceptibility to chemical degradation from free chlorine. Polyamide (PA) membranes, a staple in RO systems, are particularly susceptible to such challenges. In this study, we set out to improve the resistance of PA membranes to chlorine attack and fouling by exploring surface modification with graphene oxide (GO). A variety of deposition techniques have been investigated, including dip coating, spin coating, drop casting, and vacuum filtration. Spin coating with a GO concentration of 1 g L⁻¹ in a 70% ethanol–water solvent was found to be the optimal method. This modification, while maintaining a high salt rejection rate (about 97%), resulted in a 16% increase in water permeability (from 3.1 to 3.6 L hm⁻² bar⁻¹) compared to the pristine membrane. In long-term tests using 100 ppm sodium hypochlorite for 21 days, the GO-coated membranes showed only a 69% increase in hydraulic permeability and a 13% decrease in salt rejection. In contrast, the reference membrane experienced a 245% increase in permeability and a 23% decrease in rejection. These improvements hold great promise for reducing energy consumption, minimizing maintenance downtime, and extending the membrane lifespan.

Schools are considered high-risk areas for the transmission of infectious respiratory diseases and thus could benefit from facility-level wastewater disease surveillance. This study assessed the quantitativeness, reproducibility, and feasibility of the rapid GeneXpert system for monitoring SARS-CoV-2, influenza A, influenza B, and RSV in school wastewater. We developed individual standard curves for each disease target using school wastewater spiked with known concentrations of target viruses to estimate viral concentrations in wastewater. Furthermore, we evaluated and compared the reproducibility of the GeneXpert system results against an established filtration-ddPCR workflow and compared the cost per sample of each method. Results show that the GeneXpert system can detect respiratory viruses in school wastewater. We used GeneXpert to perform daily wastewater monitoring for target respiratory viruses at four schools in Houston, TX, USA, over three months (from November 15, 2022, to February 15, 2023, n = 169). For SARS-CoV-2 and influenza A, we observed no significant differences between the positivity results (detection vs. not detected), and strong relationships between quantitative results from the two methods. The RSV detection using GeneXpert was less reproducible and sensitive, but overall consistent in terms of positive detections with the filtration-ddPCR workflow (90.5% consistent). The GeneXpert represents a cost-effective system for wastewater monitoring for respiratory viruses as compared to the filtration-ddPCR method, particularly when the number of samples is low. This study demonstrates the application of the GeneXpert system for facility-level wastewater surveillance and suggests that it represents an important technology for resource-constrained areas.

The presence of antibiotic resistant bacteria (ARB) and the horizontal gene transfer (HGT) of antibiotic resistant genes (ARGs) in water environments pose a large and increasing threat to human health. This work compares the treatment efficiency of different ultraviolet (UV) wavelengths (222 nm KrCl excimer lamp and 254 nm low pressure Hg lamp) for inactivating multidrug antibiotic resistant B. subtilis strain 1A189, damaging its intracellular and extracellular ARGs, and inhibiting HGT of ARGs into non-resistant strain 1A1. The 222 nm wavelength was more effective than 254 nm at inactivation (dose required for 1 log reduction or D₁ = 4.11 mJ cm⁻² at 222 nm and 8.99 mJ cm⁻² at 254 nm). ARG damage increased with dose and with increasing qPCR amplicon length for both UV wavelengths. Although extracellular ARG damage was similar between wavelengths, intracellular ARG damage was greater at 222 nm than 254 nm. Inhibition of HGT also increased with UV dose for both wavelengths, but was stronger at 222 nm for both extracted DNA (D₁ 8.57 mJ cm⁻² at 222 nm and 50.23 mJ cm⁻² at 254 nm) and intracellular DNA (D₁ = 20.14 mJ cm⁻² at 222 nm and 92.90 mJ cm⁻² at 254 nm). When taking into account factors such as electrical efficiency and spectral absorbance that are less favorable for 222 nm, results showed that 222 nm was still more efficient at extracellular HGT inhibition, while 254 nm was more efficient for other assay endpoints. Overall, these comparisons demonstrate the superior mechanistic efficacy of 222 nm over 254 nm UV for disinfecting ARB and for inhibiting transfer of ARG despite similar ARG damage. This information will help inform and improve tools to address the global water challenge of antibiotic resistance to minimize risks to human health.