Search Results (48)

Urbanization and climate change have disrupted natural water circulation by increasing impervious surfaces and altering rainfall patterns, leading to reduced groundwater infiltration, deteriorating water quality, and heightened flood risks. This study investigates the application of Low Impact Development (LID) and flood control facilities as structural measures to address these challenges in the upper watershed of the Fucha River in Bogotá, Colombia. The methodology involved analyzing watershed characteristics, defining circulation problems, setting hydrological targets, selecting facility types and locations, evaluating performance, and conducting an economic analysis. To manage the target rainfall of $26.5$$\mathrm{m}$$\mathrm{m}$ under normal conditions, LID facilities such as vegetated swales, rain gardens, infiltration channels, and porous pavements were applied, managing approximately 2362 ${\mathrm{m}}^3$ of runoff. For flood control, five detention tanks were proposed, resulting in a 31.8% reduction in peak flow and a 7.3% decrease in total runoff volume. The flooded area downstream was reduced by $46.8$$\mathrm{h}\mathrm{a}$, and the benefit–cost ratio was calculated at 1.02. These findings confirm that strategic application of LID and detention facilities can contribute to effective urban water cycle management and disaster risk reduction. While the current disaster management approach in Bogotá primarily focuses on post-event response, this study highlights the necessity of transitioning toward proactive disaster preparedness. In particular, the introduction and expansion of flood forecasting and warning systems are recommended as non-structural measures, especially in urban areas with complex infrastructure and climate-sensitive hydrology. Full article

Morocco’s Témara Plain relies heavily on its aquifer system as a critical resource for drinking water, irrigation, and industrial activities. However, this essential groundwater reserve is increasingly threatened by over-extraction, seawater intrusion, and complex hydrogeochemical processes driven by the region’s geological characteristics and anthropogenic pressures. This study aims to assess groundwater quality and its vulnerability to pollution risks and map the spatial distribution of key hydrochemical processes through an integrated approach combining Geographic Information System (GIS) techniques and multivariate statistical analysis, as well as applying the DRASTIC model to evaluate water vulnerability. A total of fifty-eight groundwater samples were collected across the plain and analyzed for major ions to identify dominant hydrochemical facies. Spatial interpolation using Inverse Distance Weighting (IDW) within GIS revealed distinct patterns of sodium chloride (Na-Cl) facies near the coastal areas with chloride concentrations exceeding the World Health Organization (WHO) drinking water guideline of 250 mg/L—indicative of seawater intrusion. In addition to marine intrusion, agricultural pollution constitutes a major diffuse pressure across the aquifer. Shallow groundwater zones in agricultural areas show heightened vulnerability to salinization and nitrate contamination, with nitrate concentrations reaching up to 152.3 mg/L, far surpassing the WHO limit of 45 mg/L. Furthermore, other anthropogenic pollution sources—such as wastewater discharges from septic tanks in peri-urban zones lacking proper sanitation infrastructure and potential leachate infiltration from informal waste disposal sites—intensify stress on the aquifer. Principal Component Analysis (PCA) identified three key factors influencing groundwater quality: natural mineralization due to carbonate rock dissolution, agricultural inputs, and salinization driven by seawater intrusion. Additionally, The DRASTIC model was used within the GIS environment to create a vulnerability map based on seven key parameters. The map revealed that low-lying coastal areas are most vulnerable to contamination. Full article

Rapid population growth and urbanization are transforming natural landscapes into built environments, resulting in increased stormwater runoff, which poses significant challenges for local governments to manage. Water-Sensitive Urban Design (WSUD) techniques have been implemented to enhance urban stormwater quality, but their effectiveness in managing stormwater quantity and quality across different scales remains uncertain. This study examines the capacity of various WSUD approaches to reduce stormwater runoff volume and peak flow rates in a residential allotment transitioning from a single dwelling to a redeveloped condition with two dwellings. The tested techniques included a rainwater tank, infiltration trench, rain garden, vegetated swale, and permeable pavement. For storm events with a 1-in-5-year Annual Recurrence Interval (ARI)—aligning with typical piped drainage design standards—peak flow rates were reduced by 90% in the redeveloped scenario. Smaller storm events, up to a 1-in-1-year ARI, were frequently eliminated, thereby minimizing disturbances to waterways caused by frequent runoff discharges. Among the tested techniques, the combination of a rainwater tank, rain garden, and infiltration trench demonstrated the greatest effectiveness in reducing stormwater runoff volume and peak flow rates despite considerations of life cycle costs. These findings highlight the potential of integrated WSUD techniques in addressing urban stormwater management challenges. 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

An innovative way to combat water scarcity brought on by population increase and climate change is rainwater harvesting (RWH), particularly in arid and semiarid areas. Currently, Pakistan is facing major water issues due to underprivileged water resource management, climate change, land use changes, and the sustainability of local water resources. This research aims to find out the suitable sites and options for RWH structures in the Quetta district of Pakistan by integrating the depression depth technique, Boolean analysis, and weighted linear combination (WLC) with hydrological modeling (HM), multicriteria analysis (MCA), a geographic information system (GIS), and remote sensing (RS). To find suitable sites for RWH, a collection of twelve (12) thematic layers were used, including the slope (SL), land use land cover (LULC), subarea (SA), runoff depth (RD), drainage density (DD), lineament density (LD), infiltration number (IFN), distance from built-up area (DB), distance from roads (DR), distance from lakes (DL), maximum flow distance (MFD), and topographic wetness index (TWI). The Boolean analysis and WLC approach were integrated in the GIS environment. The consistency ratio (CR) was calculated to make sure the assigned weights to thematic layers were consistent. Overall, results show that 6.36% (167.418 km²), 14.34% (377.284 km²), 16.36% (430.444 km²), 18.92% (497.663 km²), and 18.64% (490.224 km²) of the area are in the categories of very high, high, moderate, low, and very low suitability, respectively, for RWH. RWH potential is restricted to 25.35% (666.86 km²) of the area. This research also identifies the five (5) best locations for checking dams and the ten (10) best locations for percolation tanks on the streams. The conducted suitability analysis will assist stakeholders in selecting the optimal locations for RWH structures, facilitating the storage of water, and addressing the severe water scarcity prevalent in the area. This study proposes a novel approach to handle the problems of water shortage in conjunction with environmental and socioeconomic pressures in order to achieve the sustainable development goals (SDGs). Full article

In the central region of Chile, the Mega-Drought together with the demographic increase near the coast threatens groundwater availability and the hydrogeological functioning of coastal wetlands. To understand the hydric relationship between an aquifer and a wetland in a semi-arid coastal region of Central Chile (Valparaíso, Chile), as well as its geoenvironmental effects, four data collection campaigns were conducted in the wetland–estuary hydric system and surroundings, between 2021 and 2022, including physical, hydrochemical, and isotopic analyses in groundwater (n = 16 sites) and surface water (n = 8 sites). The results generated a conceptual model that indicates a hydraulic connection between the wetland and the aquifer, where the water use in one affects the availability in the other. With an average precipitation of 400 mm per year, the main recharge for both systems is rainwater. Three specific sources of pollution were identified from anthropic discharges that affect the water quality of the wetland and the estuary (flow from sanitary landfill, agricultural and livestock industry, and septic tank discharges in populated areas), exacerbated by the infiltration of seawater laterally and superficially through sandy sediments and the estuary, increasing salinity and electrical conductivity in the coastal zone (i.e., 3694 µS/cm). The Del Sauce subbasin faces strong hydric stress triggered by the poor conservation state of the riparian–coastal wetland and groundwater in the same area. This study provides a detailed understanding of hydrological interactions and serves as a model for understanding the possible effects on similar ecosystems, highlighting the need for integrated and appropriate environmental management. Full article

A wastewater treatment plant (WWTP) prototype coupled with Moringa oleifera seeds (MOSs) was developed to evaluate its effectiveness to reduce metallic trace elements (MTEs) in domestic wastewater. The WWTP is composed of a septic tank (F0) where wastewater is treated by biological processes under anaerobic conditions, followed by a bacterial filter (F1) where wastewater is filtered under aerobic conditions, followed by an infiltration well (F2), which provides additional filtration of wastewater before discharge into the soil. MTEs present in waters can bind with humic substances contained in colloid particles and then be eliminated by coagulation–flocculation with a cationic polyelectrolyte. MOSs contain positively charged cationic polymers that can neutralize the colloids contained in waters, which are negatively charged. Based on this observation, 300 mg·L⁻¹ of MOS was added into F0, 50 mg·L⁻¹ into F1, and 50 mg·L⁻¹ into F2 mg·L⁻¹. MOS activation in samples was performed by stirring rapidly for 1.5 min, followed by 5 min of gentle stirring and 3 h of settling. The data analysis shows that wastewater samples had significant concentrations of MTEs, particularly for Cu, Ni, Sr, and Ti, and sediment samples had high amounts of Cr, Cu, Ni, Sr, Ti, and V. The addition of MOS to F0, F1, and F2 samples resulted in reductions in MTE concentration of up to 36%, 71%, 71%, 29%, 93%, 81%, 13%, 52%, and 67% for Co, Cr, Cu, Ni, Pb, Se, Sr, Ti, and V, respectively. The quantified MTEs (As, Co, Cr, Cu, Ni, Pb, Se and V) in treated samples were reported to be lower than UN-EP standards for a safe reuse for irrigation and MOS proved to be as effective as chemical coagulants such as lime and ferric iron for the removal of MTEs contained in wastewater. These results highlight the potential of MOSs as natural coagulants for reducing MTE content in domestic wastewater. This study could be the first to evaluate the effectiveness of MOS in reducing 10 MTEs, including As, Co, Se, Sr, Ti, and V, which are currently understudied. It could also provide a better understanding of the origin of MTEs found in domestic wastewaters and how an effective treatment process can result in high-quality treated wastewaters that can be reused for irrigation without posing health or environmental risks. However, more research on MOSs is needed to determine the type and composition of the coagulant substance found in the seeds, as well as the many mechanisms involved in the decrease in MTEs by MOSs, which is currently understudied. A better understanding of MOS structure is required to determine the optimum alternative for ensuring the optimal effect of MOS paired with WWTP in removing MTEs from domestic wastewaters. Full article

Chile has numerous areas that lack sewage collection, including in the capital city. Sanitation in these cases is managed through individual solutions like septic tanks or small wastewater treatment plants (WWTPs) that use biological treatment, usually activated sludge with extended aeration. In general, the design of these systems adheres to the quality standards mandated by regulations for discharge, infiltration, or irrigation. In this scenario, traditional methods like increasing dissolved oxygen (DO) or hydraulic retention time (HRT) were unable to effectively reduce excessive nutrients. Therefore, literature related to nutrient excess and denitrification systems is consulted and reviewed to compile different solutions suitable for the presented issue. Potential solutions were modeled and verified using the free simulation software WRc STOAT. The software accurately predicted the unsatisfactory results of the current setup and provided parameters for the proposed modifications. Experience, precise user definition, influential characteristics, and modeling are essential in the design of WWTPs. Full article

The spill pressure of the contaminant source is an important factor affecting the amount, location, form, and behavior of the dense non-aqueous phase liquids (DNAPLs) that plume in a contaminated subsurface environment. In this study, perchloroethylene (PCE) infiltration, distribution and, remediation via a surfactant-enhanced aquifer remediation (SEAR) technique for a PCE spill event are simulated to evaluate the effects of the spill pressure of the contaminant source on the DNAPLs’ behavior in two-dimensional homogeneous and heterogeneous aquifers. Five scenarios with different spill pressures of contamination sources are considered to perform the simulations. The results indicate that the spill pressure of the contaminant source has an obvious influence on the distribution of DNAPLs and the associated efficiency of remediation in homogeneous and heterogeneous aquifers. As the spill pressure increases, more and more contaminants come into the aquifer and the spread range of contamination becomes wider and wider. Simultaneously, the remediation efficiency of contamination also decreases from 93.49% to 65.90% as the spill pressure increases from 33.0 kPa to 41.0 kPa for a heterogeneous aquifer with 200 realizations. The simulation results in both homogeneous and heterogeneous aquifers show the same influence of the spill pressure of the contaminant source on PCE behaviors in the two-dimensional model. This study indicates that the consideration of the spill pressure of the contaminant sources (such as underground petrol tanks, underground oil storage, underground pipeline, and landfill leakage) is essential for the disposal of contaminant leakage in the subsurface environment. Otherwise, it is impossible to accurately predict the migration and distribution of DNAPLs and determine the efficient scheme for the removal of contaminant spills in groundwater systems. Full article

A field trial was conducted in Tianjin to assess the impact of “three-compartment septic tank (SPT) + soil wastewater infiltration system (SWIS)” on vegetable crop soil, determine the SPT effluent quality, and establish the consumer safety of vegetables grown above the SWIS. The effluent total nitrogen (TN), total phosphorus (TP), ammonium-N (NH₄⁺-N), chemical oxygen demand (COD), and 5-d biochemical oxygen demand (BOD₅) levels all varied largely every month. The average COD failed to meet the criteria of the Standard for Irrigation Water Quality (No. GB5084-2021) but significantly influenced bacterial community distribution. Hierarchical clustering disclosed seasonal variation in SPT effluent. SWIS treatment of rural black-grey water significantly affected both the vegetable soil TN and TP content, and it promoted microbial community diversity and richness in deep soil. The treatment also increased the relative abundances of the beneficial bacterial genera Thiobacillus and Arthrobacter by more than 320% and decreased the relative abundance of the pathogenic bacterial genus Streptomyces in vegetable soil by more than 20.33%. The faecal coliform levels and ascaris egg mortality rates in the vegetable crop soils lay within published human health and safety thresholds both before and after SWIS treatment. All vegetable crops grown above the SWIS were fit for human consumption. The VC level in the vegetables planted in experimental households were higher than those for the vegetables planted in ordinary households. The present work provides reasonable theoretical and empirical bases for optimising the “SPT + SWIS” process and SPT discharge standards in rural areas. Full article

The application of infiltration basins and tanks is one of the primary means of sustainable stormwater management. However, the methods currently used to size these facilities do not take into account a number of parameters that have a significant impact on their required capacity. In light of this, the aim of this research was to develop a new method for selecting the geometry of the infiltration basins and tanks. Its application in the initial phase of designing stormwater management systems will allow assessing the validity of using such facilities in a given catchment area. This paper also presents the results of local and global sensitivity analyses examining how changes in individual design parameters influence stormwater infiltration facilities. The effectiveness of the developed model was evaluated through the example of a real urban catchment. The study was based on a hydrodynamic analysis of more than 3000 model catchments. The research plan was developed using Statistica software. On the other hand, the analysis of the results of hydrodynamic simulations was made possible through the use of artificial neural networks designed using the Python programming language. The research also confirmed that parameters such as the total catchment area, the percent of impervious area, and the type of soil within the catchment are crucial in the design process of these facilities. The results of this research can be considered when designing infiltration basins and tanks under Polish conditions. The described algorithm can also be used by other researchers to develop similar models based on different rainfall data. This will contribute to increasing the safety of urban infrastructure. Full article

There has been a large amount of scientific research carried out to date on the impact of salty backwash brine from domestic water softeners (WS) on domestic wastewater treatment plants (DWTPs). Experts and practitioners agree that the impact is harmful and there is still a need to look for new technologies. The study of the effect of an increased sodium chloride (NaCl) concentration after softener regeneration is important from the point of view of the operation of DWTPs and soil properties. This paper presents the results of a field study of the concentration of NaCl at the septic tank (ST) drainage point, into which the grey water from the regeneration of the water softener flowed. During the six-month measurements (recorded every 1 min), an increase in NaCl concentration was observed in the septic tank outflow, from an average NaCl concentration of 1.5 g·L⁻¹—between regenerations—to an average concentration of 4.5 g·L⁻¹—after water softener regeneration. The increased NaCl concentration decreased significantly up to 2 days after the water softener regeneration. Temperature changes in the treated wastewater were also measured—during the winter period, temperature differences of up to 10 °C per day were recorded. In the second part of the study, conducted on a semi-technical scale, the effect of brine from the regeneration of the water softener on the hydraulic conductivity (K_s) of the soil from the infiltration drain of the DWTPs studied was assessed. The K_s was determined by analysing the time it took the water to soak into the soil, using the Van Hoorn equation. The results and statistical analysis indicate an increased salt content in the soil absorbing the brine, which may have been influenced by the reduced absorption and capacity of the drain due to adverse physico-chemical changes. Full article

Harnessing the human immune system as a foundation for therapeutic technologies capable of recognizing and killing tumor cells has been the central objective of anti-cancer immunotherapy. In recent years, there has been an increasing interest in improving the effectiveness and accessibility of this technology to make it widely applicable for adoptive cell therapies (ACTs) such as chimeric antigen receptor T (CAR-T) cells, tumor infiltrating lymphocytes (TILs), dendritic cells (DCs), natural killer (NK) cells, and many other. Automated, scalable, cost-effective, and GMP-compliant bioreactors for production of ACTs are urgently needed. The primary efforts in the field of GMP bioreactors development are focused on closed and fully automated point-of-care (POC) systems. However, their clinical and industrial application has not yet reached full potential, as there are numerous obstacles associated with delicate balancing of the complex and often unpredictable cell biology with the need for precision and full process control. Here we provide a brief overview of the existing and most advanced systems for ACT manufacturing, including cell culture bags, G-Rex flasks, and bioreactors (rocking motion, stirred-flask, stirred-tank, hollow-fiber), as well as semi- and fully-automated closed bioreactor systems. Full article

Low-impact development (LID) structures are widely used to mitigate urbanization impacts on hydrology. The performances of such structures are strongly affected by field conditions, such as the ratio of LID area to drainage area and rainfall properties, such as rainfall intensity. In this study, onsite continuous monitoring was performed at a permeable pavement site and a raingarden site in Taipei, Taiwan, to determine their water retention and groundwater recharge potential under subtropical weather. In addition, the verified Storm Water Management Model (SWMM) was used to illustrate the annual performance on the hydrological cycle. Based on one year of monitoring, data on 41 and 24 rainfall events were obtained at the permeable pavement and raingarden sites, respectively. The ratio of the permeable pavement area to the total drainage area was 36.0%, and this ratio was 15.9% for the raingarden. The results showed that the average runoff reduction rate was 14.7% at the permeable pavement site, and 98.3% of the rainfall was retained in the raingarden and an underground storage tank. The validated model showed that the permeable pavement site experienced 45.3% outflow, 31.6% evaporation, and 23.1% infiltration annually. For the raingarden with an underground storage tank, 91.4% of the annual rainfall infiltrated and was stored, with only 4.1% outflow. According to the observed rainfall event performance and the simulated annual performance, the permeable pavement and raingarden performed well in subtropical regions. Pavement that was approximately 1/3 permeable in a drainage area increased infiltration by approximately 20%, and a raingarden with a sufficient underground storage tank preserved over 90% of the rainfall. Full article

Source facilities can manage stormwater runoff pollutants while also limiting runoff volume in China’s sponge city construction. However, there is no apparent link between source volume control and runoff pollution reduction. This research uses SWMM to develop a model based on the basic data of a city’s catchment zone in northern China in order to statistically examine the response relationship between the initial runoff volume capture of sponge city construction and the reduction effect of stormwater runoff pollution. Based on the dimensionless constant of the runoff pollution control curve, we suggested a novel approach for evaluating runoff pollution control effectiveness. This method was used to examine the response relationship between runoff volume control and runoff pollution control in three typical initial runoff volume capture facilities in the study area, namely bioretention, permeable pavement, rain barrels, and terminal storage tanks, under various design rainfall conditions. The dimensionless constant (Dc) has good practical application value and can quantitatively quantify the control effect of various facilities on stormwater runoff pollution. The Dc value of the source facilities is higher than that of the terminal control facilities, indicating that the source facilities have a higher ability to reduce rainwater runoff pollution than the terminal facilities, particularly the infiltration facilities. The research ideas and evaluation methods proposed in this paper provide an alternative approach for selecting and optimizing facilities during the planning and designing stages of sponge city construction, which can also be used in the monitoring and evaluation stage after completion to carry out a more effective evaluation of sponge facilities’ effects. Full article