The coastal sediment supply of insular basins involves a dynamic process influenced by intermittent rivers and has a crucial role in shaping beaches. In the Mediterranean, many areas are semi-arid and have intermittent rivers with low sediment regimes. The nature of sediment delivery from these rivers influences coastal stability and ecosystem services. The coastal area of Coral Bay, Potamia, west Cyprus (~10 km in length) is a tourist zone facing coastal erosion issues, according to previous studies. The sediment budget depends on four small intermittent rivers that flow into this coastal zone, covering a total drainage area of ~66.0 km². Human actions impact the sediment balance; for example, the Mavrokolympos stream has been dammed upstream, trapping sediments in the reservoir. Estimating the amount of sediment transported from the watershed to rivers is vital for evaluating catchment erosion, as well as for understanding the supply dynamics to the adjacent coastal zone. This study uses the empirical method of USLE (Universal Soil Loss Equation) to estimate soil erosion from basins to rivers. Subsequently, the SDR (Sediment Delivery Ratio) module estimates river sediment supply to their outlet. Sediment yield is of particular importance because it is directly related to the quantity of sediment that is transported and accumulated on the beach. The annual soil loss for the basin is 9.23 t ha⁻¹ yr⁻¹, and the annual sediment yield deposited at the basin’s outlet is 325 t km⁻¹ yr⁻¹. The results reveal the relationship between watershed processes and coastal zones in terms of sediment transport and coastal conservation. By balancing sediment supply, we can mitigate negative impacts and promote sustainable development in coastal and riverine environments.

Microplastics, plastic particles of < 5 mm, are well-known emergent pollutants, ubiquitous in all ecosystems on the planet. They are considered a global threat, being aquatic ecosystems the most affected by them and inland freshwater ecosystems less studied in regards to this matter. When microplastics enter the ecosystems, they produce a wide range of impacts on biodiversity, ecosystem functions, production and animal health. Microplastics enter these ecosystems mainly due to the human activity, for this reason, in this research, the comparison of the microplastic content of sixteen wetlands from Spain and United Kingdom with two different land uses in their catchment basin was carried out: agricultural-livestock and forestry. In the process, two filter sizes were compared to demonstrate which one is more suitable for these studies, which is a smaller pore size filter. Microplastics were found in fifteen wetlands, although no significant difference was found between the ponds of the United Kingdom, nor comparing them with the Spanish. However, in Spain it was evident that agriculture, especially olive groves, causes an outstanding microplastic pollution in wetlands, likely due to the intensification of this cultivation, more use of plastic and more waste caused by olive farmers and higher erosion of the soil. Lastly, some measure to minimize microplastics inputs are suggested.

Rainwater is increasingly being used as an alternative water source for households and industries. It can be used for a variety of purposes such as watering plants, rinsing surfaces, and, after proper treatment/disinfection, flushing toilets. Constantly decreasing freshwater resources and climate change encourage the installation of systems for collecting and using rainwater. However, it is crucial to properly select the available solutions on the market to meet consumer needs while considering maintaining the appropriate quality of collected water. This research aimed to assess the quality of rainwater collected from roof surfaces in open and closed above-ground and underground tanks. The tanks, with a capacity of 300 L, were made of polyethylene and equipped with drain valves and an opening flap. Water samples were subjected to physicochemical, chromatographic, and toxicological analyses immediately after collection and after a given period of water storage in tanks. Samples were taken every two days over four months.

It was shown that the residence time of water in retention reservoirs significantly affects the deterioration of their quality in both above-ground and underground reservoirs. It was recorded that the pH of water decreases from 7.6 to 4.3 over time. Moreover, an increase in TOC concentration was observed in both covered and open above-ground tanks. The chromatographic analysis of rainwater samples that was performed immediately after the rainfall was collected in the tanks and after a given storage period showed the presence of organic micropollutants that gradually decompose. The presence of decomposition intermediates was particularly clearly observed in outdoor tanks exposed to solar radiation. The toxicological analysis showed a change in the water from a non-toxic to a low toxic level.

Acknowledgments: This research was financed by the National Centre for Research and Development, No. LIDER13/0126/2022

The wide-scale management and treatment of urban stormwater is a promising technological advancement to address the ongoing global potable water crisis. About 26% of the global population have unsafe drinking water and 46% have no safely managed water for sanitation. However, the lack of a regulatory framework for urban stormwater usage and the uncertainty in water quality pose significant threats to its wide-scale application. Emerging conversion technologies provide a more efficient and cost-effective means to convert urban stormwater to potable water. Urban stormwater management such as capture in large cisterns and run-off capture provides the necessary means to properly collect and manage stormwater, while engineered stormwater treatment systems such as stormwater biofilters provide high reliability and performance while having zero energy consumption for the treatment of collected stormwater. By utilizing an efficient urban stormwater management system and appropriate treatment technologies, urban stormwater can be used to alleviate the problems with potable water scarcity. This study delves into utilizing urban stormwater for the generation of potable water, evaluates conversion technologies, and presents its application to mitigate the global potable water crisis. Urban stormwater management systems are thoroughly examined and treatment processes are investigated, highlighting the importance of using appropriate technologies in potable water generation. Through conversion technologies, high-volume urban stormwater can be transformed into potable drinking water, addressing water resource management problems and the ongoing global potable water crisis. This systematic review will identify existing conversion technologies and research gaps, and pave the way to more efficient and cost-effective conversion technologies that will use high-volume urban stormwater for the production of potable water.

Sustainable agriculture requires effective managment of environmental challenges, and one such challenge is pond waste. In Pakistan, vast networks of freshwater ponds (approximately 60,470 hectares) are used for fish farming. While this practice produces valuable food, the resulting nutrient-rich wastewater is often discarded, creating a potential environmental burden. However, this very waste holds immense potential for agriculture.

A groundbreaking solution has emerged from NIBGE (a research institution). Their innovative method tackles pond waste using a unique combination of floating wetlands and electrolysis. Floating wetlands act as miniature ecosystems within the ponds. These plant-based systems filter and purify the water by absorbing pollutants and fostering the growth of beneficial microorganisms. Electrolysis takes things a step further by using electricity to break down remaining contaminants and potentially even harvest valuable minerals.

This two-pronged approach offers a dual benefit. First, the process transforms pond waste into a usable, nitrogen-rich sludge. Nitrogen is a vital element for plant growth, making this sludge a valuable organic fertilizer. By replacing synthetic fertilizers, this method reduces reliance on potentially harmful chemicals and promotes sustainable agricultural practices. Second, the method simultaneously cleans and polishes the wastewater, removing impurities and achieving crystal clarity. This treated water becomes a valuable resource, suitable for reuse in irrigation or replenishing aquaculture systems. This not only promotes water conservation but also minimizes the environmental impact of agriculture by reducing reliance on freshwater sources.

By addressing both aspects of pond waste management, NIBGE's innovative method positions itself as a promising solution for sustainable agriculture in Pakistan. This approach promotes organic practices, reduces dependence on chemical fertilizers, conserves water, and minimizes environmental impact. This paves the way for a more sustainable future for Pakistani agriculture.

The world is facing increasing pressure over the water resources. One of the main water uses is agricultural irrigation. Therefore, the ever-increasing demand for food, coupled with the effects of climate change, is putting increasing pressure on the water resources used for irrigation. Traditional design methods used for irrigation networks only look for economical optimization. This study presents a methodology for the evaluation of the resilience of irrigation networks. It uses two indicators of resilience: RSYS and PHRI indicators. These indicators will be calculated for a pressurized irrigation network that was designed using an optimization method based on dynamic programming, known as the Granados optimization method. The network was operated using the on-demand scheme and the Clément's formulation for demands was used. The values of the supply guarantee (probability of non-exceedance) of the network were modified, allowing us to know its influence on the results of the indicators.

The decision variables in the design problem were the size of the pipes and the objective function, the capital cost of the project, etc. The methodology was applied to an irrigation network in Ecuador, and the resilience indicators at the level of both pressures and demands measured the behavior of the network in the face of disruptive events. The results of the research indicate that the implementation of resilience indicators in irrigation networks allows the irrigation network to be efficiently managed when the operational conditions differ from the design parameters. A suitable combination of economy and resilience during the design process can be an effective strategy when using optimization algorithms. This work evidences this statement.

In the context of contemporary challenges in urban water management, particularly in relation to the scarcity of high-quality water and the amplification of urban floods, the implementation of an innovative approach to rainwater utilization becomes imperative. This approach serves as an alternative water source, mitigating the strain on tap water resources. Embracing rainwater presents an opportunity to diminish dependency on conventional water sources, while fortifying the urban water supply infrastructure in a sustainable and adaptable manner.

An extensive water quality assessment was conducted in outdoor swimming pools to examine the impact of precipitation on water quality within the pool environment. Two public bathing facilities located in Poland were examined. One of the pools under study was equipped with a closed-circuit water treatment system, while the other operated without such a sophisticated setup. The research spanned three summer months, aligning with the annual operating period for outdoor swimming pools in Poland, owing to the region's specific climatic conditions. The research encompassed a detailed analysis of the primary parameters of swimming pool water quality, as outlined in the Regulation of the Polish Minister of Health dated November 9, 2015, pertaining to the specified standards for swimming pool water. Moreover, the analysis extended to supplementary water quality indicators, encompassing, among others, total organic carbon (TOC), conductivity, and the presence of micropollutants (including contaminants of emerging concern).

The research results represent a foundational cornerstone for subsequent inquiry aimed at formulating an innovative methodology permitting the deliberate integration of rainwater into public swimming pools as a primary water source, thereby supplanting conventional tap water usage.

Acknowledgments: This research was financed by the Ministry of Education and Science as part of the "Implementation Doctorate 2023" program, No. DWD/7/0339/2023, and by the National Centre for Research and Development, No. LIDER13/0126/2022.

Impellers within turbomachinery face critical challenges related to material wear, maintenance costs, performance, and efficiency. The optimization of impellers has been extensively studied to address these issues across components such as turbines, pumps, compressors, fans, and mixers. The objective of this comprehensive review is to explore current state-of-the-art techniques for resolving these problems in the field of additive manufacturing (AM) and optimization methods. We conducted an exhaustive search of scientific articles in major databases, meticulously filtering relevant information from high-quartile sources. The study reveals various AM techniques applied to impellers and adjacent elements, along with diverse materials used in functional system components. Additionally, we describe the positive effects of optimization methods, including Multi-objective Optimization (MO), Artificial Neural Networks (ANN), Response Surface Method (RSM), and Genetic Algorithm (GA), on turbomachinery part design. Recent trends indicate increased variability in optimization approaches, often combining multiple techniques or optimization models for optimal results. Regarding AM, evidence suggests that Fused Deposition Modeling (FDM) and powder bed fusion technology are the most widely used methods in this field. The materials used in AM processes are very varied and depend on their applications and can be metals (Ti-6Al-4V, Inconel 718, AISI316L, 17-4 PH), polymers (ABS, nylon, PLA, PU), resins and ceramics.

Introduction: Bangladesh faces severe climate change impacts exacerbated by its vulnerability to disasters. The Climate Vulnerability Index-2023 ranks Bangladesh as the seventh most disaster-risk-prone country globally. Poor and developing countries like Bangladesh bear disproportionate impacts from climate change, with significant vulnerabilities identified, including sea-level rise, erratic rainfall, and water security issues.

Methods: This study focuses on a commercial high-rise building on Gulshan Avenue, Dhaka, which is recognized for achieving 50% water efficiency compared to similar-sized buildings. The building employs rainwater harvesting, wastewater recycling, and advanced treatment technologies and integrates innovative water grid systems. It is LEED Platinum-certified by the U.S. Green Building Council, marking it as a pioneer in sustainable construction in Dhaka. Data were collected through on-site observations, interviews with the building architects, and a review of LEED certification documentation.

Results: The commercial building at Gulshan Avenue demonstrates substantial water efficiency gains through innovative strategies. Rainwater harvesting, wastewater recycling, and low-flow fixtures supported by innovative water grid systems significantly reduce reliance on groundwater and mitigate water quality issues from contaminated surface sources. The building's LEED certification underscores its leadership in sustainable practices, achieving the highest environmental standards in Bangladesh's commercial building sector.

Conclusion: The case study highlights the importance of rainwater harvesting, wastewater recycling, and intelligent water grid systems in enhancing water efficiency in Dhaka's commercial buildings. The success of the Gulshan Avenue building underscores the feasibility and benefits of adopting comprehensive water management strategies amidst growing water scarcity and pollution challenges. Further promotion and implementation of such integrated systems are crucial for mitigating water-related risks and advancing urban sustainability.

Green roofs are one of the nature-based technologies most largely used in the construction sector. Besides their aesthetical benefits, this technology can also be considered a decentralized solution for climate adaptation and flood mitigation, since it can contribute to reducing and delaying the peak flow in rainwater systems. However, even if it can be considered a mature technology, there are no consolidated design standards or guidelines particularly describing how to estimate rainwater volume retention in green roofs at national and international levels. So, the goal of this study is to analyze the hydraulic effect of green roofs on rainwater management based on experimental outflow rate monitoring. The experimental setup was installed at Ballerup in Denmark and consisted of three pitched roofs, each one with 25 m² of surface area and monitored over 1 year. Meteorological data were obtained using a weather station located just on the side of the pilots. The water outflow of the green roofs was monitored by measuring the rainwater flow rate in the pipe that collects water in each green roof. The green roofs presented variations in annual rainwater retention capacity, ranging from 35% to 50%. In terms of peak flow attenuation, it varied from 10% to 90% in both green roofs, depending on rain intensity and the duration of dry periods. The results obtained outline quantitatively the differences between green roof types in terms of water retention. These findings can be used to support future studies addressing green roof design optimization.