Search Results (167)

Microplastics (MPs) are becoming an increasingly common pollutant in the aquatic environment, including stormwater. This is a serious problem, as stormwater is becoming an essential transport route for MPs from urban areas to surface waters. Rainwater flowing from roofs, roads, and other impermeable surfaces contains a variety of plastic particles originating from tire abrasion or waste disposal. This article presents an overview of current research on the occurrence of MPs in stormwater. The potential of selected green infrastructure solutions—particularly bioretention systems, constructed wetlands, and permeable pavements—for their reduction is assessed. Individual solutions present how the change in filter material, selection of vegetation, or the method of conducting the process (e.g., direction of stormwater flow in constructed wetlands) affects their effectiveness. The potential of green infrastructure is also compared with the traditional gray solution of sewage management in cities. This article emphasizes the importance of integrating such solutions in spatial planning as an effective tool to combat climate change and limit the spread of microplastics in the environment. Full article

Freshwater resources are scarce in tropical island areas. Treating rainwater to produce drinking water through biological slow filtration (BSF) technology can significantly alleviate the problem of freshwater shortages. The characteristics of the filter material are the key factors determining the decontamination performance of BSF technology. However, most existing studies focus on a single filter material. This study was conducted using volcanic rock and coconut shell activated carbon to compare their pollutant removal characteristics in slightly polluted rainwater during the early stage of BSF operation (from the start of operation to day 6, with the first sampling time being 48 h after operation) and during the stable stage (26 days later) and further explore the influence of their mixing ratio. The results show that in the early stages of operation, the pollutant removal performance of volcanic rock and coconut shell activated carbon is better than that of quartz sand. Among them, coconut shell activated carbon showed average removal rates for NH₃-N, TOC, and Cr(VI) that were 6.72, 8.46, and 19.01 percentage points higher than those of volcanic rock, respectively, but its average turbidity removal rate decreased by 5.00%. The removal effect of the mixed filter material was enhanced through the synergistic adsorption mechanism, but most of the improvements were within the standard deviation range and did not exceed the removal range of the single filter material. When the mixing ratio was 1:3, the average total organic carbon removal rate of the filter material was 71.51 ± 0.64%, approximately 0.96 percentage points higher than that of coconut shell activated carbon (70.55 ± 0.42%). While coconut shell activated carbon showed the best removal effect among all single filter materials, this improvement was still within the standard deviation range. Full article

The efficient use of energy is a sign of conscious environmental responsibility. Sustainable management also refers to water resources, where emphasis is placed on the possibility of retaining rainwater at the point of the precipitation occurrence. This article focused on the reuse of runoff from a rest area (RA) along the expressway, wherever drinking water quality is not required. The runoff from RAs can be significantly contaminated due to the traffic-related issues. The objective of this article was to evaluate the energy efficiency of preliminary treatment of raw meltwater from a selected rest area using electrodialysis for Cl⁻ and Na⁺ removal. The treatment was carried out under various conditions, including different solution temperatures (20 °C and 30 °C) and electric voltages (10 V, 20 V, 30 V). The energy efficiency assessment was preceded by a characterization of runoff quality and the analysis of pollutant removal efficiency in the electrodialysis process. The most energy-efficient variant was characterized with the 0.097 Wh/(mg/L) energy expenditure ratio and 93% efficiency removal for Cl⁻ and 0.147 Wh/(mg/L) and 90% for Na⁺. In this variant, the permissible Cl⁻ and Na⁺ concentrations limits were achieved after 27 min with an energy consumption of 57 Wh. In general, the observed highest energy efficiency occurred at the beginning of the electrodialysis process and decreased over time. Full article

Urban water management faces growing pressure from population growth, pollution, and climate variability, demanding innovative strategies to ensure long-term sustainability. This study applies the Life Cycle Sustainability Assessment (LCSA) across four case studies in Brazil and Germany, evaluating integrated systems that combine constructed wetlands for greywater treatment with rainwater harvesting for non-potable use. The scenarios include a single-family household, a high-rise residential building, a rural residence, and worker housing. A multi-criteria analysis was conducted to derive consolidated sustainability indicators, and sensitivity analysis explored the influence of dimension weighting. Results showed that water reuse scenarios consistently outperformed conventional counterparts across environmental, economic, and social dimensions. Life Cycle Assessment (LCA) revealed notable reductions in global warming potential, terrestrial acidification, and eutrophication. Life Cycle Costing (LCC) confirmed financial feasibility when externalities were considered, especially in large-scale systems. Social Life Cycle Assessment (S-LCA) highlighted the perceived benefits in terms of health, safety, and sustainability engagement. Integrated water reuse systems achieved overall sustainability scores up to 4.8 times higher than their baseline equivalents. These findings underscore the effectiveness of decentralized water reuse as a complementary and robust alternative to conventional supply and treatment models, supporting climate resilience and sustainable development goals. Full article

Green roofs (GRs) are increasingly implemented for stormwater management, and retrofitting conventional roofs is emerging as a key strategy for climate change resilience. However, their impact on diffuse pollution, particularly regarding total organic carbon (TOC) and pollutant mass transport, remains insufficiently understood, especially in aged substrates. This study evaluated and compared the runoff quality from aged GRs and ceramic roofs (CRs) by analyzing TOC, pH, electrical conductivity (EC), first-flush occurrence and intensity, and pollutant release patterns. Results showed that GR retrofitting could help mitigate acid-rain effects due to its elevated pH. Despite higher TOC and EC concentrations in runoff, GRs remained within acceptable water quality limits and exhibited a more gradual release of organic matter over time compared with CRs. Statistical analysis revealed that pollutant concentrations in CR runoff followed Lognormal and Weibull distributions, while GR runoff was best described by Normal, Lognormal, and Weibull distributions. These findings reinforce GRs as a viable stormwater management strategy but highlight the need for full runoff treatment when used for rainwater harvesting. The results also emphasize the importance of tailored statistical models to enhance runoff predictions and optimize GR performance in urban water management. The results provide valuable insights for urban planners and policymakers by reinforcing the potential of GRs in stormwater quality management and supporting the development of incentives for green infrastructure. Future research should expand to different GR configurations, climates, and maintenance practices to enhance the understanding of long-term hydrological and water quality performance. Full article

The Urban Drainage Network (UDN) is a type of underground municipal infrastructure responsible for transporting sewage and rainwater. To keep abreast of the hydraulic and water quality conditions of the pipes and to detect problems such as pipe clogging, pollution and leakage, real-time monitoring sensors have been widely adopted, accomplished with the development of IoT technologies. However, the intricate topology and numerous nodes of drainage pipes complicate IoT sensor placement strategies, especially in the selection of sensors and the location of monitoring points. This review examines application cases of IoT sensors in UDNs and some other hydraulic networks, evaluating the characteristics and applicability of various optimal placement methods and theories. A general framework was proposed applicable to the optimal placement of IoT sensors in the UDN, including object classification–method selection–quantitative evaluation. Currently, the quantitative evaluation of monitoring schemes lacks a systematic process, and existing layout methods may not be optimal. Future research can explore dynamic optimization strategies through phased deployment and feedback iteration, which can enhance the accuracy and objectivity of sensor layout design and evaluation. Full article

This study evaluates the impact of phosphogypsum stacks on the chemical composition of rainwater in the Huelva metropolitan area, a metal-polluted area with high cancer and heart disease mortality rates. A total of 612 rainwater samples were collected using 17 rain gauges located around the study area between January 2021 and December 2022. The pH, conductivity, major ions, and trace metals were detected in the soluble fraction of rainwater. The results revealed spatial variability in the rainwater quality. The highest values of As, Ca²⁺, Cr, F⁻, NH₄⁺, Ni, PO₄³⁻, SO₄²⁻, Sr, and V were detected in rain-gauges near phosphogypsum stacks, exceeding the levels of pH, F⁻, and Ni according to the guideline values for drinking water quality from the WHO. Additionally, other pollution sources also contributed: a regional source (marine factors: Ca²⁺, Cl⁻, K⁺, Mg²⁺, and Na⁺) and a local source (chemical complexes emissions: Co, Cu, Pb, and Zn). A downward trend of most toxic metal(loid) concentrations in wet depositions was detected as the distance to the affected area increased. The findings revealed that phosphogypsum stacks are a relevant source of metal(loid)s with potentially adverse environmental and public health effects that, if replicated, could be relevant for environmental monitoring and policy making. Full article

With the advancement of sponge city construction, rain gardens, as key facilities for concentrating and infiltrating rainwater runoff, have been widely established. However, the accumulation of heavy metals (HMs) in the fillers and the associated pollution risks cannot be ignored, which have a significant impact on the operational lifespan of these facilities. This study took the observation point (P) within a rain garden that has been in operation since 2012 and the control point (CK), which is the soil sample collection point in the natural infiltration area, as samples. Based on the monitoring data of HM content from 2017 to 2022, the pollution characteristics of Cu, Zn, and Cd were analyzed using enrichment factors and the geo-accumulation index, and the potential ecological risks were evaluated to reveal the impact of concentrated infiltration of runoff. The results showed that Cu and Cd accumulated in the 0–10 cm depth, while Cu and Zn exhibited seasonal annual variations, and the variation of Cd was not obvious. The study found that Cu and Zn were in a non-enriched state, while Cd was slightly enriched. Among the single ecological risk factor indices, the pollution levels of Cu and Zn were low, while that of Cd was relatively high. Comparison of the data from the observation point and the control point reveals that 88.9% of the data points of single ecological risk factor indices at each soil depth at the observation point are higher than those at the control point, revealing the impact of concentrated infiltration of rainwater runoff on the soil. However, the comprehensive assessment indicated that the overall ecological risk of the soil in the rain garden and the natural filtration area was at a low level. Nevertheless, given that the long-term operation of rain gardens may still pose pollution risks to the soil and groundwater, it is imperative to take timely measures to control HM pollution to ensure the long-term stable operation of sponge city facilities and the safety of the ecological environment. Full article

Urbanization leads to increased stormwater runoff, placing enormous pressure on the drainage system, including that of port cities in Hunan Province. This increases the risk of urban flooding and threatens the sustainability of the urban ecosystem. In this study, we employed the Storm Water Management Model (SWMM) to assess surface runoff and pollutant accumulation (TSS, COD, TN, and TP) under varying storm conditions and evaluate the efficacy of low-impact development (LID) measures in mitigating these impacts. The results included a peak ratio of 0.45, indicating complex concentration dynamics and good agreement with the observed rainfall patterns. The installation of permeable paving, rainwater infiltration ditches, and rainwater storage tanks reduced the peak flows by 33.3%, 30%, and 50%, respectively, with the rainwater storage tanks also reducing the total phosphorus (TP) load by 29.17%. In addition, it was found that rainwater collected in cisterns could be used not only for resource recycling but also to replenish groundwater resources. This demonstrates that low-impact development (LID) measures significantly reduce peak flows and pollutant loads and effectively promote the sustainable use of urban stormwater resources. The cost–benefit analyses show that the long-term benefits of LID systems are superior to those of traditional stormwater management systems. Therefore, LID measures can not only effectively reduce the pressure on urban drainage systems and improve flood prevention and mitigation capabilities but also promote sustainable development and the green transformation of cities. Full article

Currently, solid waste storage systems generate secondary pollutants such as leachates, derived from rainwater infiltration or produced during their storage, which affect water quality, human health, and the environment. This study evaluated a bioremediation system for leachates from the “Rancho Triste” landfill using Spirulina sp. as a microalgal strain. Its rapid adaptation to the leachate was identified through respirometry based on CO₂ measurement, allowing the modeling of microalgal adaptation using a Log-Normal Peak Shifted with Offset function. Tests conducted in a 0.5 L reactor determined an optimal treatment time of 10 days, achieving removals of 87.17% for iron, 28.96% for magnesium, and 90.74% for manganese. Subsequently, a 2³ factorial design was implemented to optimize the reduction of chemical oxygen demand (COD), evaluating agitation, lighting, and nitrogen supplementation, achieving a COD removal efficiency exceeding 50% under optimal conditions. The fed-batch technique enabled an enrichment of microbiological populations, which, together with bio-stimulation, bioventilation, and photoperiods, demonstrated the scalability of the bioprocess and the significant reduction of metallic and recalcitrant contaminants present in the leachate. This approach proposes an ecological alternative with potential application in water treatment industries aiming for carbon neutrality and optimal transformation of high-effluent volumes. Full article

Water is a crucial resource in agriculture, but climate change has led to more frequent droughts, particularly at the start of the growing season, adversely affecting crop yields. This paper evaluates soil water retention capacity (SWRC) in the Protected Water Management Area Žitný ostrov, which is home to Slovakia’s most fertile soils and significant groundwater reserves. In our study, we adopted a new methodological approach and developed an algorithm for weighting selected physical parameters from the valued soil-ecological units (VSEUs) database, applicable to larger territorial units. To estimate SWRC, we used an algorithm based on the physical parameters of VSEUs, reclassifying them into 10 categories of cumulative water retention capacity (CWRC) and mapping SWRC in the model area. Most of the area demonstrates high water retention due to groundwater, but these sources are being increasingly depleted. Agriculture, as a significant contributor to groundwater pollution, must adapt to climate change by implementing crop management practices that reduce agrochemical seepage and preserve water supply. Regenerative agriculture and agroforestry, which enhance soil properties, are proposed as viable solutions. Additionally, infrastructure such as dams, ponds, and rainwater harvesting systems, along with the expansion of wetlands, can help capture and store water in areas with lower retention capacity. This study aims to identify critical zones with varying retention capacities and recommends crop rotation adjustments to prevent agrochemical seepage and enhance water retention. These practices are essential for sustaining agriculture while protecting water resources amidst global climate challenges. Full article

Urbanization necessitates Low Impact Development (LID) practices for sustainable development, but existing studies lack analysis about the comprehensive effect and optimal allocation of LID combination practices. To address this gap, this study conducted an in-depth analysis of the runoff control effects of individual and combined LID practices and pollutants under varying retrofit proportions, utilizing the Storm Water Management Model (SWMM). Four evaluation metrics were employed for parameter calibration and validation assessment to ensure the accuracy of the SWMM. The Response Surface Methodology (RSM) was then employed to optimize the retrofit proportions of LID practices due to its high efficiency and statistical rigor. The results showed that, under the same retrofit ratio, bio-retention (BC) has a better runoff reduction rate and pollutant removal rate. For example, when the retrofit proportion is 100%, the runoff pollutant removal rates of BC in Parcel 1 and Parcel 2 are 29.6% and 32.9%, respectively. To achieve a 70% runoff control rate, the optimal retrofit proportions for Parcel 1 were 67.5% for green roofs (GR), 92.2% for permeable pavements (PP), 88.9% for bio-retention cells (BC), and 50% for low-elevation greenbelts (LEG); these correspond to the proportions for Parcel 2 that were 65.1%, 68.1%, 82.0%, and 50%, respectively. In conclusion, this study provides scientific and technical support for urban planners and policymakers in urban rainwater management, especially in similar regions. Full article

Climate change and its effects, for instance drought, drive the search for alternative water sources. One of these sources is rainwater, especially the runoff from various roof surfaces in cities. In turn, its use in the city for the production of food as part of hydroponic and aquaponic systems requires knowledge of possible pollutants and their varied concentrations. In this article, the concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) in rainwater collected in cities from various surfaces and stored in various types of tanks (open and closed) are analysed. Tests were carried out on extracted specimens using gas chromatography with a flame ionisation detector (FID). BTEX compounds were determined using a chromatograph with a FID sensor and a capillary column. Organic substances were extracted from the water with dichloromethane. The possibility of occurrence of BTEX compounds in rainwater flowing down from various roof surfaces in the city was confirmed. The obtained results suggest future research directions for mitigating BTEX rainwater pollution in order to expand the scope of its subsequent use. Preliminary guidelines for its treatment based on the literature were proposed. The possibility of using urban rainwater for hydroponic and aquaponic systems was assessed in terms of BTEX content. Full article

Domestic sewage pollution poses significant risks to human health and the ecological environment but sewage water is gradually recognized as a renewable water resource worldwide. To enhance water resource utilization and facilitate reclamation from domestic sewage, substantial global efforts have focused on developing systematic management strategies and advanced technologies for treatment and resource recovery. This study examines and presents the case of domestic sewage reclamation and water reuse in the rural Hangjiahu region, situated on the southern bank of Taihu Lake in Northern Zhejiang Province, Eastern China. It provides a comprehensive overview of state-of-the-art technologies implemented in the region. In rural areas, sewage treatment is decentralized and involves two primary streams: one where urine is separately disinfected and sterilized, with feces processed into agricultural fertilizer; and another where greywater undergoes bio-composting and wetland treatment to produce recycled water. Additionally, natural rainwater is collected and stored in ponds, enhancing the region’s water resources. The results demonstrate that the integration of domestic sewage reclamation and rainwater storage has effectively mitigated the risks of flooding during rainy seasons and water shortages during droughts. Remarkably, no severe floods or droughts have occurred in the region since 1991, contrasting with historical records from 1909 to 1954, when such events were frequent. This study underscores the potential for replicating these approaches in other regions facing similar challenges. Full article

Acid mine drainage (AMD) generated during the exploitation and utilization of mineral resources poses a severe environmental problem globally within the mining industry. The Xiaomixi Stream in Ziyang County, Shaanxi Province, is a primary tributary of the Han River, which is surrounded by historically concentrated mining areas for stone coal and vanadium ores. Rainwater erosion of abandoned mine tunnels and waste rock piles has led to the leaching of acidic substances and heavy metals, which then enter the Haoping River and its tributaries through surface runoff. This results in acidic water, posing a significant threat to the water quality of the South-to-North Water Diversion Middle Route within the Han River basin. According to this study’s investigation, Xiaomixi’s acidic water exhibits yellow and white precipitates upstream and downstream of the river, respectively. These precipitates stem from the oxidation of iron-bearing minerals and aluminum-bearing minerals. The precipitation process is controlled by factors such as the pH and temperature, exhibiting seasonal variations. Taking the Xiaomixi Stream in Ziyang County, Shaanxi Province, as the study area, this paper conducts field investigations, systematic sampling of water bodies and river sediments, testing for iron and aluminum pollutants in water, and micro-area observations using field emission scanning electron microscopy (FESEM) on sediments, along with analyzing the iron and aluminum content. The deposition is analyzed using handheld X-ray fluorescence (XRF) analyzers, X-ray diffraction (XRD), and visible–near-infrared spectroscopy data, and a geochemical model is established using PHREEQC software. This paper summarizes the migration and transformation mechanisms of iron and aluminum pollutants in acidic water and proposes appropriate prevention and control measures. Full article