Search Results (97)

Stormwater runoff is a significant source of microplastics to surface water. This study addresses challenges in the sampling, treatment, and characterization of microplastics in existing stormwater control measures across various regions in the United States. Stormwater sediment samples were collected via traditional stormwater sampling approaches for particulate and inorganic contamination with portable automatic samplers, analyzed using visible and fluorescence microscopy with Nile red as a selective stain, and subsequently confirmed through Raman spectroscopy. The inclusion of laboratory and field blanks enabled the identification of contamination at key steps during sample handling. The results reveal that the filtration process is a significant source of laboratory contamination, while the sampling process itself could be a primary contributor to overall sample contamination. Additionally, it was found that using green fluorescence as the sole emission wavelength may underestimate MP quantities, as some particles emit fluorescence exclusively in the red spectrum. Raman analysis revealed interferences caused by pigments and additives in plastics, along with challenges evaluating particles in the low micron range (≤10 microns), which complicates a comprehensive analysis. The findings of this study emphasize the importance of implementing strong quality assurance and control measures when assessing the levels of microplastics in the environment, including sample collection, processing, and analysis. Full article

Tyre wear particles (TWPs), generated from tyre-road abrasion, are a pervasive and under-regulated environmental pollutant, accounting for a significant share of global microplastic contamination. Recent estimates indicate that 1.3 million metric tons of TWPs are released annually in Europe, dispersing via atmospheric transport, stormwater runoff, and sedimentation to contaminate air, water, and soil. TWPs are composed of synthetic rubber polymers, reinforcing fillers, and chemical additives, including heavy metals such as zinc (Zn) and copper (Cu) and organic compounds like polycyclic aromatic hydrocarbons (PAHs) and N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD). These constituents confer persistence and bioaccumulative potential. While TWP toxicity in aquatic systems is well-documented, its ecological impacts on terrestrial environments, particularly in agricultural soils, remain less understood despite global soil loading rates exceeding 6.1 million metric tons annually. This review synthesizes global research on TWP sources, environmental fate, and ecotoxicological effects, with a focus on soil–plant systems. TWPs have been shown to alter key soil properties, including a 25% reduction in porosity and a 20–35% decrease in organic matter decomposition, disrupt microbial communities (with a 40–60% reduction in nitrogen-fixing bacteria), and induce phytotoxicity through both physical blockage of roots and Zn-induced oxidative stress. Human exposure occurs through inhalation (estimated at 3200 particles per day in urban areas), ingestion, and dermal contact, with epidemiological evidence linking TWPs to increased risks of respiratory, cardiovascular, and developmental disorders. Emerging remediation strategies are critically evaluated across three tiers: (1) source reduction using advanced tyre materials (up to 40% wear reduction in laboratory tests); (2) environmental interception through bioengineered filtration systems (60–80% capture efficiency in pilot trials); and (3) contaminant degradation via novel bioremediation techniques (up to 85% removal in recent studies). Key research gaps remain, including the need for long-term field studies, standardized mitigation protocols, and integrated risk assessments. This review emphasizes the importance of interdisciplinary collaboration in addressing TWP pollution and offers guidance on sustainable solutions to protect ecosystems and public health through science-driven policy recommendations. Full article

Stormwater runoff from areas with specific industrial, agricultural or logistic land use comprises a significant source of water pollution, yet research on its specific composition remains limited compared to urban stormwater pollution. This review synthesizes findings from different studies to analyze sampling methods, types of pollution parameters and their associated concentration ranges across various non-urban land use types, including industrial and commercial zones, transportation infrastructure (ports, airports, highways, railways) and agricultural areas. Studies differed in sample strategy, investigated phase (water, sediment) and analyzed chemical parameters. The latter can be grouped into sum parameters (e.g., total suspended solids (TSS), chemical oxygen demand (COD)), metals (e.g., nickel, copper, zinc, lead), nutrients (e.g., nitrogen, phosphorus), organic micropollutants (e.g., polycyclic aromatic hydrocarbons (PAH), perfluoroalkyl acids (PFAA)) and microbial contaminants. Results indicate that pollutant loads vary widely depending on land use, with industrial and railway areas showing the highest metal contamination, while agricultural and livestock farming areas exhibit elevated nutrient and microbial concentrations. The heterogeneity of the sampling, analysis and subsequent data processing hindered the statistical condensation of data from different studies. The findings underscore the need for standardized monitoring methods and tailored stormwater treatment strategies to mitigate pollution impact effectively. Full article

We investigated the presence of the fecal indicator bacteria Escherichia coli, and other taxa associated with sewage communities in coastal sediments, near beaches with reported poor bathing water quality, focusing on the influence of effluent from a local wastewater treatment plant (WWTP) and combined sewer overflows (CSO). Using a three-year dataset, we found that treated wastewater effluent is a significant source of sewage-associated taxa and viable E. coli in the sediments and that no seasonal differences were observed between spring and summer samples. CSO events have a local and temporary effect on the microbial community of sediments, distinct from that of treated wastewater effluent. Sediments affected by CSO had higher abundances of families Lachnospiraceae, Ruminococcaceae, and Bacteroidaceae. Sewage releases may also impact the natural community of the sediments, as higher abundances of marine sulfur-cycling bacteria were noticed in locations where sewage taxa were also abundant. Microbial contamination at locations distant from known CSO and treatment plant outlets suggests additional sources, such as stormwater. This study highlights that while coastal sediments can be a reservoir of E. coli and contain sewage-associated taxa, their distribution and potential origins are complex and are likely not linked to a single source. Full article

Sequencing batch reactor Grundfos technology (SBR-GT) system efficiently treats municipal and selected industrial wastewater, designed for small and medium-scale facilities. It offers advanced solutions for biodegradable wastewater, including municipal and food industry effluents. Important features include stable sedimentation under fluctuating influent conditions, no need for sludge recirculation, and full process automation. The system uses a static decanter and constant chamber filling for optimal oxygenation efficiency and reduced costs. The system uses a static decanter and constant chamber filling for optimal oxygenation efficiency and reduced costs. It is ideal for small settlements with variable inflow, such as towns, allowing flexible operation and cost-effective maintenance. Implementations showed stable parameters for COD (chemical oxygen demand), BOD5 (biochemical oxygen demand), total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) and up to 99% pollutant reduction, demonstrating high effectiveness in regular and stormwater conditions. Using multivariate multiple linear regression, significant relationships were identified. A multiple regression analysis revealed a strong relationship between water quality parameters. Total suspended solids, Total nitrogen, and Total phosphorus collectively and significantly influenced both chemical oxygen demand and biochemical oxygen demand (p < 0.01 for all). The models explained a high proportion of variance, with R² values of 0.99 for COD and 0.93 for BOD5 (p < 0.001 for both). Specifically, TSS had a strong positive effect on COD (p < 0.001), while TN and TP also significantly affected COD (p < 0.01). Although the overall BOD5 model was highly significant, the individual effects of TSS, TN, and TP on BOD5 were not statistically significant in this model. This method demonstrated high effectiveness in both regular and stormwater conditions, enhancing overall treatment performance. Full article

The performance of urban drainage systems can be significantly compromised by siltation in pipeline networks. This study focuses on the drainage network of central Zhengzhou, analyzing operational risks under current siltation conditions. Using complex network theory, the study examines the structural characteristics and propagation mechanisms of the siltation propagation chain, quantifying node risks through indicators such as pipeline risk factors and degree centrality. Edge vulnerability is incorporated to evaluate the risk values of siltation propagation paths. The study’s findings indicate the following: (1) Despite a relatively low overall siltation risk, regular pipeline inspection and maintenance is necessary. (2) A total of 22 critical nodes, primarily located in main pipelines or confluence manholes, exhibit high risk and require priority attention. (3) Siltation propagation shows significant chain characteristics, with main pipeline and junction node failures potentially leading to systemic crises. In the central Zhengzhou stormwater network presented in this paper, high-risk factors are concentrated in a southern downstream outlet caused by an edge identified as critical that propagates siltation risks to the downstream nodes, forming a long path with elevated risk levels. This study provides crucial insights into the risk management and prevention of sedimentation and blockages in urban drainage networks, not only offering important technical references and a solid scientific basis for pipeline maintenance and network upgrades—thereby contributing to drainage system planning and the enhancement of urban flood protection capabilities—but also serving as a valuable technical reference for improving the overall resilience and operational efficiency of drainage systems. Full article

Urbanization and the expansion of impervious surfaces have increased stormwater runoff volumes, altered runoff timing, and degraded water quality and aquatic ecosystems. Runoff from urban areas carries pollutants such as nitrogen, phosphorus, sediments, and heavy metals, which can adversely impact the physical characteristics of receiving waterbodies. Stormwater management programs aim to mitigate these effects using Best Management Practices (BMPs) to retain and treat stormwater on-site. However, in densely developed areas, space constraints and high costs often make traditional BMPs impractical. This study assessed the effectiveness of expanded shale, an engineered material, as a filtration medium in bioswales, a type of linear BMP commonly used in transportation infrastructure. Thirty scenarios were tested in a 16 ft (4.9 m) long plexiglass flume using expanded shale mixed with sandy clay soil. Due to the limited scope of this study, it focused on assessing the effectiveness of expanded shale in removing suspended sediments and reducing turbidity. Results showed that expanded shale achieved removal efficiencies ranging from 20% to 82% for total suspended solids (TSS) and −4% to 61% for turbidity under different conditions. It outperformed conventional filtration materials such as sand and gravel, requiring less channel length. Remarkably, even in a small-scale laboratory setting, expanded shale met the suspended sediment removal standard of 80%, demonstrating its potential as a highly effective filtration material alternative for urban stormwater management. Full article

Growing urbanization has increased impermeable surfaces, raising and polluting stormwater runoff, and exacerbating the risk of urban flooding. Effective stormwater management is essential to curb sedimentation, minimize pollution, and mitigate urban flooding. This systematic literature review from the Web of Science and Scopus between January 2000 and June 2024 presents hydrodynamic separation (HDS) technologies. It sheds light on the significant issues that urban water management faces. HDS is classified into four categories: screening, filtration, settling, and flotation, based on the treatment mechanisms. The results show a shift from traditional standalone physical separations to multi-stage hybrid treatment processes with nature-based solutions. The great advantage of these approaches is that they combine different separation mechanisms and integrate ecological sustainability to manage urban stormwater better. The findings showed that future research will examine hybrid AI-assisted separation technologies, biochar-enhanced filtration, and green infrastructure systems. When adopting an integrated approach, the treatment system will perform like natural processes to remove pollutants effectively with better monitoring and controls. These technologies are intended to fill existing research voids, especially in removing biological contaminants and new pollutants (e.g., microplastics and pharmaceutical substances). In the long term, these technologies will help to enforce Sustainable Development Goals (SDGs) and orient urban areas in developing countries towards meeting the circular economy objective. Full article

Effective stormwater management is increasingly vital due to climate change impacts, such as intensified rainfall and flooding. Urban expansion, water scarcity, and intensified agriculture demand innovative solutions like Green Stormwater Infrastructure (GSI), including vegetated biofilters, green roofs, wetlands, bioretention systems, and high-rate filtration. These systems, enhanced by natural and engineered filter materials, improve contaminant removal across diverse contexts. Modern practices prioritize retention, infiltration, and groundwater recharge over traditional rapid drainage, reframing stormwater as a resource amid rising extreme weather events. In water-scarce regions, stormwater management offers dual-use potential for drinking and non-drinking applications, addressing freshwater scarcity exacerbated by population growth and climate change. Targeting the “first flush” of pollutants after rainfall allows for more efficient, cost-effective treatment. This paper identifies three key objectives: addressing GSI limitations and exploring new technologies, evaluating treatment train combinations for cost-effective reuse, and advancing urban stormwater treatment research. Various filter media, such as those in green roofs, bioretention systems, and swales, effectively remove pollutants like nutrients, heavy metals, PAHs, and micropollutants. Granular activated carbon (GAC) filters excel at reducing heavy metals and dissolved organic carbon (DOC), with pre-screening via anthracite filters to extend GAC lifespan by trapping sediments and pollutants. Managing emerging contaminants and microplastics remains underexplored and requires further investigation. Full article

Sustainable long-term performance of water quality swales, a common stormwater control measure (SCM), requires a futuristic view that considers the impact of socio-economic conditions. The impact of five socio-economic scenarios on a water quality swale in Knightdale, North Carolina, USA, was assessed using WinSLAMM, a stormwater quality model. Scenarios included changing annual average daily traffic (AADT) and maintenance regimes mimicking environmental protection and degradation. Statistical performance evaluation criteria (e.g., RMSE, R²) were used to assess model suitability and calibration for runoff volume and sediment. Results indicated that sediment delivery to the swale increased with AADT, and reduced maintenance negatively impacted swale performance. While the reduced AADT during the COVID-19 pandemic provided short-term water quality benefits, a lack of maintenance impacted treatment through the swale. SCM inspection and maintenance is critical for accommodating increased AADT and enhancing swale life-cycle. This exploratory impact assessment focused on the socio-economic axis of climate change scenario framework and underscored the importance of sound environmental policies for sustainable swale performance. Future studies are needed in other areas to influence local environmental policies. Full article

Permeable asphalt pavement (PAP) is an efficient solution to stormwater management, allowing water to infiltrate through its layers. This reduces surface runoff and mitigates urban flooding risks. In addition to these hydrological benefits, PAP enhances water quality by filtering pollutants such as organic and inorganic materials and microplastics. However, clogging from sediment accumulation in the pavement’s void structure often impairs its performance, reducing infiltration capacity. This review addresses several issues related to PAP, including the factors that contribute to pavement clogging and evaluates current and emerging maintenance strategies, including manual removal, pressure washing, regenerative air sweeping and vacuum truck utilization. Additionally, different methods of assessing clogging using innovative technology such as X-Ray Computed Tomography (CT), as well as a summary of the software used to process these images, are presented and discussed as tools for identifying clogging patterns, analyzing void structure and simulating permeability. This review identifies gaps in existing methodologies and suggests innovative approaches, including the creation of self-cleaning materials designed to prevent sediment buildup, biomimetic designs modeled after natural filtration systems and maintenance protocols designed for targeted clogging depths, to support the optimization of PAP systems and promote their adoption in resilient urban infrastructure designs in alignment with Sustainable Development Goals (SDGs). Full article

Construction sites rely on erosion control practices to protect bare slopes and prevent soil loss. The effectiveness of certain erosion controls is often under-evaluated if they are not a part of a product evaluation program. Furthermore, erosion controls in general are not fully understood regarding how their performance can be affected by site specific variables, such as soil variations. This study used large-scale rainfall simulators to evaluate how a commonly used erosion control on construction sites, broadcasted straw mulch, performs on three common soil types in Alabama. The study at the Auburn University, Stormwater Research Facility (AU-SRF) used the industry standard testing method and three different soil types: sand, loam, and clay in accordance with ASTM D6459-19, the standard test method for testing rolled erosion control products’ (RECPs) performance in protecting hillslopes from rainfall-induced erosion. As required by ASTM D6459-19, the rainfall simulators simulated a storm of varying 20 min increments of 2 in./h (5.08 cm/h), 4 in./h (10.16 cm/h), and 6 in./h (15.24 cm/h). A total of nine bare soil tests on the 4:1 test plots was performed with an average total soil loss of 1977 lb (897 kg), 236.2 lb (107 kg), and 114.2 lb (51.8 kg) for sand, loam, and clay, respectively. The average erodibility K-factor for each soil type is calculated to be 0.37 (sand), 0.043 (loam), and 0.013 (clay). Nine straw tests were performed on the 4:1 plots, with an average total soil loss of 44.31 lb (20.1 kg), 6.74 lb (3.1 kg), and 17.13 lb (7.8 kg) for sand, loam, and clay, respectively. Straw testing indicated substantial soil loss reduction with average cover management C-factor values under the revised universal soil loss equation (RUSLE) method of 0.021, 0.047, and 0.193 for sand, loam, and clay applications, respectively. This variation in C-factor across the three soil types indicates that the single C-factor, often reported by product manufacturers, is not adequate to imply performance. Full article

System-based approaches are critical for addressing the complex and interconnected nature of urban ecological development and restoration of ecosystem services. This study adopts a system perspective to investigate the spatiotemporal drivers of key ecosystem services, including carbon sequestration, water conservation, sediment reduction, pollution mitigation, and stormwater regulation, within the Yangtze River Delta Eco-Green Integrated Development Demonstration Area (YRDDA) from 2000 to 2020. We propose a novel framework for defining enhanced-efficiency ecosystem service management regions (EESMR) to guide targeted restoration. Our analysis revealed the complex interplay of 11, 9, 6, 6, and 10 driving factors for selected ecosystem services, highlighting the spatiotemporal heterogeneity of these drivers. By overlaying these key factors, we identified high-efficiency restoration priority areas for EESMR that ensure high returns on investment and the efficient restoration of ecosystem functions. This system-oriented approach provided critical spatial guidance for integrated ecological restoration, green development, and eco-planning. These findings offer valuable insights for policymakers and planners in the Yangtze River Delta and other rapidly urbanizing regions, supporting the formulation of effective land-use policies that balance environmental sustainability and urban growth. Full article

While the biogeochemical properties of the Israeli coastal shelf (ICS) are similar to adjacent pelagic waters, the external sources of inorganic nitrogen (N) are very different. The main source of ‘new’ N to the pelagic zone is deep winter mixing, with minor contributions from atmospheric deposition and eddy diffusion across the nutricline. For the ICS, major N sources include offshore water advection (260 × 10⁶ mol N y−¹), atmospheric input (115 × 10⁶ mol N y−¹), and riverine input (138 × 10⁶ mol N y−¹), which primarily consists of treated wastewater and stormwater runoff. Direct pollutant discharge from sewage outfalls and submarine groundwater discharge are relatively minor. Key N sinks are new production (420 × 10⁶ mol N y−¹) and sediment deposition and uptake (145 × 10⁶ mol N y−¹). Inputs of nitrate and ammonium were similar and dominant in winter. Unlike temperate shelves, where riverine input is dominant, here it was only slightly higher than atmospheric input, with net N advection onto the shelf being significant. External N inputs did not change net primary production (NPP) by more than ~30% or affect dominant pico and nanophytoplankton genera, except in localized patches. This study offers baseline values for future climate and environmental change assessments. Full article

Stormwater management ponds (SWMPs) are an important tool for sustainable urban stormwater management, controlling the quantity and quality of stormwater runoff in cities. Beyond their engineering purpose, SWMPs may hold ecological value that is often overlooked. This is especially the case for the array of geochemical, physical, and biological processes (i.e., ecosystem functions) in SWMPs. Here, we performed a scoping review of ecosystem function in SWMPs to summarize current knowledge and identify research needs. We searched peer-reviewed papers using the Web of Science database. Papers that did not report specifically on SWMPs, did not discuss ecosystem function, or were solely based on ecotoxicological tests were excluded from further assessment. For the remaining papers, information on year of publication, scope, and key findings was extracted. We found that a total of 55 papers on ecosystem function in SWMPs have been published since 1996. Our review identified important areas for advancing knowledge about nutrient dynamics, contaminants processing, sedimentation, temperature, habitat provisioning, and biodiversity in SWMPs. Overall, we identified a need to further understand how factors related to pond design and landscape and management practices influence ecosystem function. There is also a need to understand the effect of climate change on ecosystem function and to examine the interactions between ecosystem function and humans. Such information will not only provide opportunities for researchers to better understand ecological value, but also facilitate more effective sustainable management of SWMPs. Full article