Search Results (54)

Increasing climate change requires cities to adapt to changing weather conditions. New elements for decentralized stormwater management must be installed to protect the sewer system from overloading during heavy rainfall events and to keep water in the city for irrigation use. A pilot project was implemented in Leipzig in 2020, in which infiltration tree trench systems with three different designs were installed and equipped with measuring technology during a road renovation project. The catchment areas of these three tree trenches are between 215 and 300 m² each. In two of the systems, water retention was included to supply the tree with water during drought periods. The retention elements are sealed with clay in tree trench TT1 and bentonite in tree trench TT3. For tree trench TT2, no retention capacity was provided. This article presents the design, construction, and scientific monitoring of the three tree infiltration trenches. The conclusions after four years of operation from the perspective of two departments of the City of Leipzig are summarized. The tree trench TT1 with the clay pan for water storage shows the best performance in terms of water retention and tree fitness. For the next generation of such infiltration systems, improvements in the design of the street runoff inlets and the surface of the tree trench system’s interior are discussed. 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 containing road deicing salts has led to the increasing salinization of surface waters in northern climates, and urban municipalities are increasingly being mandated to manage stormwater runoff to improve water quality. We assessed chloride concentrations in runoff from late-winter snowmelt and rainfall events flowing into an urban Minnesota, USA, lake during two different years, predicting that specific stormwater drainages with greater concentrations of roadways and parking lots would produce higher chloride loads during runoff than other drainages with fewer impervious surfaces. Chloride levels were measured in runoff draining into Lake Winona via 11 stormwater outfalls, a single channelized creek inlet, and two in-lake locations during each snowmelt or rainfall event from mid-February through early April in 2021 and 2023. In total, 33% of outfall runoff samples entering the lake collected over two years had chloride concentrations exceeding the 230 ppm chronic standard for aquatic life in USA surface waters, but no sample exceeded the 860 ppm acute standard. Chloride concentrations in outfall runoff (mean ± SD; 190 ± 191 ppm, n = 143) were significantly higher than in-lake concentrations (43 ± 14 ppm, n = 25), but chloride levels did not differ significantly between snowmelt and rainfall runoff events. Runoff from highway locations had higher chloride concentrations than runoff from residential areas. Site-specific chloride levels were highly variable both within and between years, with only a single monitored outfall displaying high chloride levels in both years. There are several possible avenues available within the city to reduce deicer use, capture and treat salt-laden runoff, and prevent or reduce the delivery of chlorides to the lake. Full article

Stormwater runoff from large roads is a major source of pollutants to receiving waters, and reduction of these pollutants is important for sustainable water resources and transportation networks. Porous pavements have been shown to substantially reduce many of these pollutants, but studies are lacking on arterial roads. We sampled typical stormwater pollutants in runoff from sections of an arterial road 9–16 years after installation of three pavement types: control with conventional asphalt, porous asphalt overly, and full-depth porous asphalt. Both types of porous pavements substantially reduced most of the stormwater pollutants measured. Total suspended solids, turbidity, total lead, total copper, and 6PPD-quinone were all reduced by >75%. Total nitrogen, ammonia, total phosphorus, biochemical oxygen demand, total and dissolved copper, total mercury, total zinc, total polycyclic aromatic hydrocarbons, and di-2-ethylhexyl phthalate were all reduced by >50%. Reductions were lower or absent for nitrate, orthophosphate, E. coli, dissolved lead, and dissolved zinc. Most reductions were statistically significant. Many pollutants exceeded applicable water quality standards in the control samples but met them with both types of porous pavement. This study demonstrates that porous overlays and full-depth porous asphalt can provide substantial reductions of several priority stormwater pollutants on arterial roads for many years after installation. Porous pavements have the potential to substantially enhance water quality of urban waterways and provide ecological benefits on urban thoroughfares. Full article

The drainage capacity of stormwater inlets, which serve as the connection between the surface and the underground drainage system, directly affects surface runoff and the drainage capacity of underground drainage systems. However, in reality, stormwater inlets are often blocked due to the accumulation of leaves, human waste disposal and other factors, resulting in a greatly reduced drainage capacity of the drainage network and, in turn, urban waterlogging disasters. In view of the problem of stormwater inlet blockage, employing a typical waterlogging point in the Lianjiang Middle Road area of Fuzhou city as the research object, the stormwater inlet equivalent drainage method was adopted in this paper to characterize the drainage capacity of the pipe network and enable the control of the stormwater inlet blockage state. Coupled with the stormwater inlet drainage equation, an improved ITF-FLOOD two-dimensional hydrodynamic model was constructed, and the influence of stormwater inlet blockage on urban waterlogging under different rainfall return periods was simulated and analyzed. With increasing rainfall return period, the influences of stormwater inlet blockage on both the maximum area and the depth of accumulated water in the study area gradually decreased compared with those of a nonblocked stormwater inlet, and the growth proportions decreased from 43.35% and 34.58% under the 1-year rainfall scenario to 3.34% and 9.76% under the 50-year rainfall scenario, respectively. However, in terms of the change in the accumulated water level, stormwater inlet blockage will cause an increase, and the influence will always be significant. Overall, stormwater inlet blockage aggravated the waterlogging risk and the extent of waterlogging. Therefore, the results provided a reference for the construction of an urban waterlogging model and have certain guiding significance for waterlogging prevention and control in the study area prone to stormwater inlet blockage. Full article

The expansion of impervious areas in the context of climate change leads to an increase in stormwater runoff. Runoff from roads, petrol stations, and service stations is the most common form of unintentional release of petroleum hydrocarbons (PHs). Rain gardens are an important practice for removing PHs from stormwater runoff, but little data exist on the removal efficiency and behaviour of these substances within the system. The main objective of the study is to investigate the effectiveness of rain gardens in removing pollutants such as diesel fuel (DF) and used engine oil (UEO) in a laboratory setting, as well as to study the behaviours of these pollutants within the system. Eight experimental columns (7.164 dm³) were packed with soil (bulk density 1.48 kg/dm³), river sand (1.6 kg/dm³), and gravel. Plants of the Physocarpus opulifolia Diabolo species were planted in the topsoil to study their resistance to PHs. For 6 months, the columns were watered with model PHs followed by simulated rain events. The concentrations of PHs in the leachate and soil media of the columns were determined by reverse-phase high-performance liquid chromatography (RP-HPLC). The results of HPLC indicated the absence of UEO and DF components in the leachates of all experimental columns, which suggested 100% removal of these substances from stormwater. The chromatography results showed that 95% of the modelled PHs were retained in the surface layer of the soil medium due to the sorption process, which led to a change in hydraulic conductivity over time. Recommendations are proposed to increase the service life of rain gardens designed to filter PHs from stormwater. Full article

Precipitation is an important factor that influences the quality of surface water in many regions of the world. The pollution of stormwater runoff from roads and parking lots is an understudied area in water quality research. Therefore, a comprehensive analysis of the physicochemical properties of rainwater flowing from parking lots was carried out, considering heavy metals and organic micropollutants. High concentrations of zinc were observed in rainwater, in addition to alkanes, e.g., tetradecane, hexadecane, octadecane, 2,6,10-trimethyldodecane, 2-methyldodecane; phenolic derivatives, such as 2,6-dimethoxyphenol and 2,4-di-tertbutylphenol; and compounds such as benzothiazole. To remove the contaminants present in rainwater, adsorption using silica carriers of the MCF (Mesostructured Cellular Foams) type was performed. Three groups of modified carriers were prepared, i.e., (1) SH (thiol), (2) NH₂ (amino), and (3) NH₂/SH (amine and thiol functional groups). The research problem, which is addressed in the presented article, is concerned with the silica carrier influence of the functional group on the adsorption efficiency of micropollutants. The study included an evaluation of the effects of adsorption dose and time on the efficiency of the contaminant removal process, as well as an analysis of adsorption isotherms and reaction kinetics. The colour adsorption from rainwater was 94–95% for MCF-NH₂ and MCF-NH₂/SH. Zinc adsorbance was at a level of 90% for MCF-NH₂, and for MCF-NH₂/SH, 52%. Studies have shown the high efficacy (100%) of MCF-NH₂ in removing organic micropollutants, especially phenolic compounds and benzothiazole. On the other hand, octadecane was the least susceptible to adsorption in each case. It was found that the highest efficiency of removal of organic micropollutants and zinc ions was obtained through the use of functionalized silica NH₂. Full article

With the rapid advancement of ecological civilization construction, prioritizing green stormwater infrastructure to address urban stormwater management issues has become an important strategy for ecological priority and green development in sustainable urban development. Green stormwater infrastructure, as a major facility in the construction of sponge cities, can reduce the generation and external discharge of runoff and play a purification role. However, there are various types of green stormwater infrastructure, each with different control effects and applicable conditions. Therefore, to facilitate the planning, design, acceptance, assessment, and monitoring evaluation of sponge city green stormwater infrastructure, this study proposes the “sponge equivalent” method. By comparing the control effects of different facilities with bioretention facilities, the method standardizes the effects, making them easier to understand and apply. Taking a typical area of Beijing and its urban roads as examples, the study analyzed and applied planning and design control strategies. The results show that for a residential area of 1 km², to achieve the annual runoff total control rate target of 85%, the method of converting runoff volume control equivalents, using bioretention pools as a benchmark, allows for the calculation of various combinations of areas of different types of green stormwater infrastructure, such as sunken green spaces, permeable paving bricks, green roofs, and water storage tanks. This optimizes the planning index of Beijing, which mandates stormwater detention facilities for new projects with a hardened surface area of 2000 m² or more. The sponge equivalent method can optimize the planning and design control strategy of green stormwater infrastructure, allowing for rapid assessment and application of the design scale of green stormwater infrastructure in areas during the planning and design stage, providing theoretical and technical support for ecological and green urban stormwater management. The application of this research method helps promote green development and ecological priority in urban sustainable development strategies, and the conclusions provide valuable references for decision-makers and practitioners in related fields. Full article

The creation of the greenIZOLA Experimental Center results from a long-term collaboration between the Faculty of Civil Engineering, Technical University of Košice, and the construction company, IZOLA Košice, s.r.o. The project focuses on a four-story administrative building with four terraces and services, asphalt roads, and warehouses located in the industrial part known as Nad Jazerom, in Košice, Slovakia. This study examines the benefits of green roofs as a case study in green transformation processes. Green roofs have multiple benefits. In addition to reducing energy demands for heating and cooling through better insulation properties, green roofs can improve stormwater management and local water balances by mitigating water runoff and increasing local evaporation. They can reduce energy demands, improve stormwater management, and enhance biodiversity. The research involved comparing pre- and post-establishment data with simulations. The roof was divided into three test segments for temperature measurements throughout the year. External climatic parameters were monitored using a weather station and a pyranometer. Long-term temperature monitoring in the individual roof layers was also conducted. This data was crucial for validating the building energy demand simulation models, assessed using the SimStadt platform. The results showed a 15–40% reduction in U-values with different types of greening. The findings could encourage more widespread implementation of green roofs in Slovakia and Eastern Europe. Full article

Road dust is one of the environment’s most important microplastic and plastic additive sources. Traffic vehicles and the wear of tires can release these emerging contaminants, which can be resuspended in the air and washed off by stormwater runoff. In this study, a concurrent quantification and chemical characterization of additives, plasticizers, natural and non-plastic synthetic fibers (APFs), and small microplastics (SMPs, <100 µm) in samples of highway road dust (HWRD) was performed. The sampling procedure was optimized, as well as pretreatment (extraction, purification, and filtration) and analysis via micro-FTIR. The average length of the SMPs was 88 µm, while the average width was 50 µm. The highest abundance of SMPs was detected in HWRD 7 (802 ± 39 SMPs/g). Among the polymers characterized and quantified, vinyl ester and polytetrafluoroethylene were predominant. APFs’ average particle length was 80 µm and their width was 45 µm, confirming that both of these emerging pollutants are less than 100 µm in size. Their maximum concentration was in RD7, with 1044 ± 45 APFs/g. Lubricants and plasticizers are the two most abundant categories, followed by vulcanizing agents, accelerators, and pre-vulcanizing retarders derived mainly from tires. A potential relationship between APFs and SMPs in the different seasons was observed, as their concentration was lower in summer for both and higher in winter 2022. These results will be significant in investigating the load of these pollutants from highways, which is urgently necessary for more accurate inclusion in emission inventories, receptor modeling, and health protection programs by policymakers, especially in air and water pollution policies, to prevent risks to human health. Full article

Stormwater quality in an urban watershed can be influenced by several factors, including land use patterns, atmospheric deposition, and human activities. The objective of this study was to investigate spatial and temporal changes in stormwater quality and heavy metal content during the rainfall–runoff in an urban sub-catchment (30 ha) in the town of Olsztyn (NE Poland). Samples were collected from six locations along the rainfall–runoff pathway, including the following direct rainfall and runoff locations: roof runoff, surface runoff, storm collector, and the river. Parameters such as pH, specific conductivity, fluorescent dissolved organic matter (fDOM), total dissolved solids (TDS), and turbidity were measured in situ, while samples were analyzed for heavy metal content (Cu, Cr, Fe, Ni, Zn, and Pb) in the lab (ICP-OES). The results showed significant changes in water quality along the runoff. The highest concentrations of heavy metals were found in samples from a stormwater collector and surface runoff, particularly in winter and spring, due to the increased deposition of air pollutants and salt washout from roads. This study highlights the importance of monitoring stormwater quality and heavy metals in urban watersheds in terms of impacts on the river ecosystem as a recipient of stormwater. Solutions such as green infrastructure and stormwater management are proposed to mitigate the impacts of urbanization on water quality and protect the aquatic environment. Full article

One alternative measure to minimise the stormwater runoff volume and its pollutants and reduce impervious areas is to use permeable pavement. However, due to weak mechanical performance under heavy-load traffic related to fatigue resistance, porous mixtures and permeable pavements have restricted applications, i.e., parking lots and low-traffic roads. This work aims to evaluate the fatigue resistance of a porous asphalt mixture produced with highly modified asphalt (HiMA) and its potential contribution to reducing stormwater runoff and pollutants. In order to estimate the capability of runoff pollutants and stormwater flood reduction, a case study was performed on an urban road. A permeable pavement was designed using the porous mixture as a surface layer. The mixture volumetric parameters and asphalt content were established using the Marshall method, considering the void content, interconnected voids, permeability, Cantabro test, and moisture damage test evaluation. The resilient modulus and fatigue resistance tests were performed on a diametral compression device. The mixture design resulted in an asphalt content of 5.1% and a void content of 21.5%. The resilient modulus was 2764 MPa, and the porous mixture obtained excellent fatigue performance, allowing its application in diverse traffic conditions. The porous mixture efficiency infiltration capacity was 90%, and some runoff pollutants could be reduced after being filtered by the pavement surface, contributing to minimizing environmental contamination. This work filled part of a gap in predicting porous mixtures’ fatigue performance, collaborating to popularise and expand its use for various purposes. Full article

Pervious concrete has been reported as a viable solution to reduce stormwater run-off, the heat-island effect, road noise, and pavement flooding. Previous researchers have focused on analysing the structural properties and functionality of pervious concrete. However, relatively few studies have been conducted into the addition of supplementary cementitious materials (SCMs), such as calcined clay, in pervious concrete and its effect on long-term durability. This paper has studied the effect of calcined clay pozzolan as a partial substitute for Portland cement in pervious concrete, together with the influence of coarse aggregate size. A water–binder ratio of 0.4 and aggregate–binder ratio of 4.0, as well as a superplasticiser content of 0.95%, were maintained for all mixes. Two sizes of coarse aggregates were used for this study: 9.5 mm and 20 mm. CEM-I cement was partly substituted with calcined clay in dosages of 0 to 30% in replacement intervals of 5%. The mechanical tests conducted included the split tensile test, compressive strength test, and flexural strength test. Durability measurements such as the rapid chloride permeability test (RCPT), thermal conductivity and sulphate resistance tests were also carried out. The mechanical properties of the pervious concrete followed a similar trend. The results showed that at 20% replacement with calcined clay, the compressive strength increased by 12.7% and 16% for 9.5 mm and 20 mm aggregates, respectively. The flexural strength improved by 13.5% and 11.5%, whereas the splitting tensile strength increased by 35.4% and 35.7%, respectively, as compared to the reference concrete. Beyond 20% replacement, the tested strengths declined. The optimum calcined clay replacement was found to be 20% by weight. Generally, pervious concrete prepared with 9.5 mm obtained improved mechanical and durability properties, as compared to those of 20 mm aggregates. Full article

Nature-based solutions and similar natural water retention measures to manage urban runoff are often implemented by cities in order to reduce runoff peaks, catch pollutants, and improve sustainability. However, the performance of these stormwater management solutions is relatively rarely assessed in detail prior to their construction, or monitored and evaluated following implementation. The objective of this study was to investigate the field-scale performance of road runoff filters with respect to the management of stormwater quantity and quality. This study synthesizes data from two intensive measurement surveys after the construction of sand and biochar-amended road runoff filters. The filters were able to strongly control the runoff volume and shape of the hydrograph. The long-term retention was about half that of the water inflow, and a hydrographic analysis showed the significant but strong event-size-dependent detention of runoff in both the sand and the sand–biochar filters. The biochar amendment in the filter showed no clear hydrological impact. The pollutant attenuation of the implemented road runoff filters was modest in comparison with that observed under controlled conditions. The impact of the biochar layer on the effluent water quality was observed as the levels of phosphorous, organic carbon, K, Ca and Mg in the sand–biochar filter effluent increased in comparison with the sand filter. Full article

Declining wetland areas cause many amphibian species to breed inside stormwater ponds (SWPs), which have been constructed alongside major roads to collect and retain polluted road runoff water. However, the suitability of such artificial ponds as a breeding habitat for amphibians remains unclear. Recently, a study found a very low survival rate of European green toad tadpoles (Bufotes viridis) inside SWPs, presumably because of high sediment pollution and/or the presence of a leech Helobdella stagnalis. To establish the effects of sediment pollution and leech presence on tadpole growth and survival, we exposed 480 green toad tadpoles to a number of controlled conditions inside holding tanks. We tested the following conditions: (1) ‘control’ (clean sediment + clean water); (2) ‘leech’ (clean sediment + clean water + leeches); (3) ‘SWP sediment’ (clean water + polluted sediment); and (4) ‘SWP sediment + leech’ (clean water + polluted sediment + leeches). Tadpole size and survival was monitored until metamorphosis and, individuals participated in swim tests and respirometry trials to the test potential effects of pollution on their escape capacity and metabolic rate. We found that the growth rate of tadpoles exposed to the SWP sediment (condition 3) was increased, while pollution had no effect on survival. By contrast, leeches heavily preyed upon tadpoles, leaving no survivors in conditions 2 and 4. Tadpoles swim speed and metabolic rate of toadlets did not differ between the ‘control’ and ‘SWP sediment’ group, the only conditions with surviving individuals. Our study found that leeches had the strongest effect on tadpole survival and were likely responsible for the low survival rates in SWPs observed recently. Hence, we suggest that adequate management measures are needed to limit leech penetration inside SWPs (frequent dredging/draining) to prevent these artificial structures from becoming an ecological trap for locally endangered amphibians but rather a base to help in their recovery. Full article