Coastal and marine environments are being impacted by the significant presence of marine debris, particularly plastics. Plastic pellets (small beads/spherules of polymer resins produced from chemical processing for the base plastic industry) serve as an example of materials or waste that may be inadvertently released into the environment during manufacturing, transportation, and storage processes. This study aimed to develop a preliminary assessment of the presence and dispersion of plastic pellets on beaches in the Bay of All Saints (BAS). Eight beaches within the BAS were selected, with six located within the bay and two facing the Atlantic Ocean. These beaches were chosen because many are close to sources of pellet emissions, such as ports and plastic-producing industries, as well as oil and petrochemical platforms. The research methods employed included bibliographic research, cartographic analysis, and fieldwork conducted during the winter of 2023. A total of 74 sampling points were established across the eight beaches in the BAS for sand collection. The results indicate the presence of pellets on seven of the eight studied beaches. Starting from ports and industries as the primary sources of emissions, a correlation was observed between the distance from these sources and the beaches, the occurrence of meteorological-oceanographic events (storm surges), spatial distribution, and general characteristics, with the highest concentration gradients observed at Praia do Farol da Barra, Praia da Costa, Barra Grande, Cabuçu, Praia do Sol, Itaparica, and São Tomé de Paripe. No pellets were found at Praia de São Francisco do Conde.

Waste reduction and recycling are two of the main strategies which have favorable effects in terms of a circular economy, and they are one of several environmental remedies included in the European Union's (EU) Green Deal. Also, the EU Blue Deal is aimed at the protection of vulnerable freshwater resources and includes recommended water reuse applications. Biochar is an innovative and effective technology for several environmental applications. From this point of view, malt dust, which is a by-product of the brewery industry, has been used as a biochar feedstock for the treatment of municipal wastewater in order to achieve a reclaimed water quality. A techno-economic performance assessment was carried out to reclaim water using this novel adsorbent. This paper mainly aimed to obtain reclaimed water using biochar application, with an aim of contributing to a circular economy. An average reduction of 41.4% in operational costs was reported compared to an activated sludge system. Turbidity, Biological Oxygen Demand (BOD₅), Total Suspended Solid (TSS), and E. coli analyses were performed to determine the effluent quality. In the end of the biochar adsorption process, a Class B reclaimed water quality according to EU legislation was obtained. This study validated that malt-dust-derived biochar is an efficient and low-cost adsorbent and can achieve a high quality of reclaimed water.

Floating Treatment Wetland (FTW) is a technique that can be used for the restoration of water bodies based on phytoremediation processes. FTW simulates the natural wetland environment and accelerates the processes that occur there, contributing to ecosystem conservation, pollution, and erosion reduction. Briefly, a typical FTW is composed of a floating structure and plants that interact with microorganisms, water, and the surrounding environment to remove contaminants. In the Brazilian semi-arid region, characterized by natural drought processes, the use of this technology helps mitigate challenges related to water security and quality. This study conducted a survey of selected plant species that can be used in the development of FTW projects in the Brazilian semi-arid region. Through the Web of Science and Google Scholar platforms, 12 publications were collected using the keywords Wetlands, Floating Treatment Wetlands, Phytoremediation, and Brazilian Semi-arid. The species Cyperus papyrus (33%), Canna x generalis (33%), Tradescantia zebrina (25%), Eichornia crassipes (25%), and Iris pseudacorus (25%) had the highest number of applications and best adaptation; 17% of the studies utilized the species Typha domingensis, Solms and Chrysopogon zizanioides. The results indicate that FTW needs to be further explored through studies on native plants and specific analyses focused on their evaluation.

Acknowledgments: Batista, G. S. is thankful the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001.

Per- and polyfluoroalkyl substances (PFAS) is currently becoming a concern for the adverse health effects in mammals for health scientists and environmental technocrats. PFAS can be found in various type of waters like groundwater, drinking water, surface water, wastewater and in soil and dust from the household. The sources of PFAS can be various that includes but not limited to cleaning products, water resistant fabrics, cookware, personal care products and others. This PFAS contaminated soil and water can get into the bodies of animals and humans and cause various and chronic diseases which can be life threatening at times. There have been various methods of treating this PFAS from water -most of these methods rely on heavy chemical treatments and/or expensive filtration methods. In this review we tried to investigate the possibility for using bioremediation of PFAS by bacteria. Different microbial species have the ability of biodegrade or bio sequester different chemicals from the environment which otherwise be harmful to living species. Different bacterial species including Desulfovibrio aminophilus and Sporomusa sphaeroides that have been isolated from the nature have proven strong enough to cut the PFAS’ chlorine-carbon bond. In turn, that starts a chain of reactions that destroy the structures, rendering PFAS compounds harmless. Some fungal species have also shown enough evidence of degrading the PFAS. Some drawbacks of these research include the lack of data for long term studies. Most of the microbial species that have been used for treating PFAS show slow results for the process. Future aspects of these studies can be expanded for coupling various microorganisms together through batch reactor studies, aiming for a viable biological based solution for treating PFAS from urban water.

Floating wetland islands (FWIs) are innovative nature-based solutions designed to enhance water quality in various aquatic environments, including lakes, ponds, and reservoirs, while restoring their ecological functions. In recent years, FWIs have gained popularity due to their effectiveness, low cost, and low maintenance needs. These systems provide a range of valuable ecosystem services, such as boosting biodiversity, enhancing aesthetic appeal, and improving water quality through phytoremediation. The plants on FWIs absorb excess nutrients like nitrogen and phosphorus, mitigating nutrient pollution, reducing eutrophication, and preventing water body degradation. Additionally, the microorganisms associated with plant roots and floating mats decompose organic matter, while the plants facilitate oxygen transfer into the water. Moreover, FWIs provide essential habitats for wildlife such as birds and insects, thereby enriching local biodiversity.

This study aimed to showcase the implementation of an FWI composed of a polyculture of Iris germanica, Acorus gramineus, Caltha palustris, and Typha latifolia, established on a cork agglomerate platform in a freshwater pond. The FWI was installed in 2018, with ongoing monitoring to evaluate improvements in local biodiversity and to assess the long-term effectiveness of the buoyancy in supporting plant growth.

Acknowledgments: Calheiros C.S.C. is thankful for the Strategic Funding UIDB/04423/2020, UIDP/04423/2020, and LA/P/0101/2020 through national funds provided by Fundação Ciência e Tecnologia (FCT). S.I.A. Pereira is thankful to the scientific collaboration of FCT project UIDB/ 50016/2020.

Oil spills are a serious hazard to coastal ecosystems and communities, with severe socio-economic and biological consequences. In Greece, with a coastline of more than 15,000 km and exceptionally active maritime traffic, there is a high possibility of accidents that could cause oil spills. In this paper, three different oil spill scenarios of different severities were modeled using GNOME (General NOAA Operational Modeling Environment), a set of modeling tools for predicting the trajectory and fate of marine pollutants and determining which coastlines would be mos affected by an accident. The incidents modeled occurred in Saronikos Gulf, Thermaikos Gulf, and near the island of Kithira. Additionally, wind and current data were incorporated into the process to predict the trajectory and impact of the spills. An Environmental Sensitivity Index (ESI) was used to assess which parts of the affected areas were most vulnerable to the pollution using the socio-economic, physical, and biological characteristics of the coastline. The model outputs were finally compared to the Environmental Sensitivity Index to delineate areas where high oil concentrations overlapped with those of high vulnerability.

The oil spill modeling showed that in Saronikos Gulf, high concentrations of oil reached vulnerable and non-vulnerable areas. For Kithira, oil reached Antikithira Island, although with a minimal impact. In Thermaikos Gulf, low concentrations of oil reached the vulnerable coastline of the beach close to Katerini. These results showed that the proposed methodology was able to assess the impact of an oil spill on the coastline by modeling its fate and identifying the vulnerability of the area. The presented methodology could help to improve emergency response strategies, as well as dealing with the impact of marine pollution.

Instead of the simplified “optimization procedure,” multicriteria analysis, which also incorporates optimization theory, is an integrated tool that encompasses all aspects of decision-making. The field of water resources management is particularly well suited for applying multicriteria problems due to the various dimensions of water systems. This work emphasizes comparing alternatives and aggregating several criteria with different natures and metrics. Furthermore, the lack of knowledge or ill-defined information and the qualitative responses of experts necessitate the use of fuzziness. Hence, this article examines the use of hybrid multicriteria methods for the final ranking of alternatives. Fuzziness is employed to express data uncertainty, uncertainty during binary comparisons, and the final aggregation of criteria. It is worth noting that fuzziness is used not only to quantify uncertain information but also to justify the decision-making scheme. Even if the best multicriteria method "is a very elusive goal and this quest may never be answered," the “French school” of multicriteria could incorporate many concepts of fuzziness due to its sophisticated background. Therefore, two hybrid fuzzy outranking methods oriented towards water resource management are proposed, based on the ELECTRE and PROMETHEE methods, and useful comparisons are made. A challenge is to ensure a commensurate solution in the final decision and to avoid full compensation among the criteria by using the non-discordance principle. Additionally, ideas on how this principle can be transferred to the modified PROMETHEE method are presented.

Water appeared to be fundamental to human settlement. Traditional water systems can be understood as a complex, diverse, and intricate regime of water structures that were designed to support the population as it grew. These structures are also called water architecture in India, constituting a broad category of natural as well as human-made infrastructure. With the passage of time in a fast-forward mode and with rapid urbanisation, the ponds—natural catchment areas which helped mitigate the seasonal flooding due to heavy rains in the past—have become either defunct or non-existent today in the urban areas, which is a current matter of concern. This paper attempts to revisit the traditional water systems and knowledge to bring out solutions to these problems by means of traditional wisdom, which is ever more relevant today, as we face the climate crisis. Solutions which are basic, simple and logical and which can be implemented without extensive use of technology may pave the way forward to revive the ponds in water-scarce yet flood-prone areas of Gurugram in Haryana. Historical and interpretative research techniques, such as literature analysis, comparative analysis, case investigations, reasonable significance, qualitative analysis, and location-specific building studies are used in relation to traditional water systems, especially in the case of Haryana. A relevant field study is undertaken to identify the issues and challenges faced in the context of the non-existence of the natural ponds, and their conditions in specific areas are analysed using secondary sources and primary observations wherever deemed necessary.

Floating Wetland Islands (FWIs) are innovative, nature-based solutions designed to improve water quality and enhance biodiversity in aquatic environments. These artificial islands float on water bodies and are typically constructed using buoyant materials like recycled plastics, foam, or natural substances such as cork. The surfaces of FWIs are planted with a variety of aquatic and semi-aquatic plants, creating a floating garden that mimics natural wetlands. The plants and associated microorganisms play a crucial role in phytoremediation, providing water depuration when contaminants are present, such high concentrations of nitrogen and phosphorus, heavy metals, and others.

In port marinas, FWIs can be particularly valuable. These environments often face challenges such as water pollution from boat traffic and runoff containing hydrocarbons and other contaminants. By installing FWIs, marinas can improve water quality and create more attractive and ecologically rich spaces. The research and development of FWIs is expanding, with ongoing studies focusing on optimizing plant species selection, island design, and placement to maximize ecological and aesthetic benefits. As a versatile and sustainable tool, FWIs are gaining recognition for their potential to enhance ecosystem services in various aquatic environments, from freshwater lakes to saline coastal areas. Acknowledgments: Authors are thankful to Strategic Funding UIDB/04423/2020, UIDP/04423/2020 and LA/P/0101/2020 through national funds provided by FCT.

Chromium (Cr) is a potentially toxic metal considered 17^th in the toxicity profile of the Agency for Toxic Substances and Disease Registry (ATSDR). Thus, this study focused on the performance of natural bituminous coal (NBC) from Ethiopia in the uptake capacity of Cr (VI) from aqueous solutions. Batch and column adsorption experiments were performed in order to examine the removal process under various parameters. The parameters were optimized using the one-factor-at-a-time method. Parameters considered at the batch scale include contact time, pH, initial concentration, adsorbent dose, and temperature. These parameters (e.g., pH(2-9), contact time (30-180 min.), dose of the adsorbent (0.25-2 g), initial Cr (VI) concentration (3-150 mg/L), and temperature (20-45 °C), were optimized in triplicate. Similarly, at the column stage, parameters including column height, flow rate, dose, and initial concentration were considered. The adsorbent coal samples were collected from five sites in Delbi, Ethiopia, and composite samples were used for the adsorptive analysis. The adsorbent was then characterized using FTIR and XRF. The results of the study suggested that Cr (VI) ion uptake was pH-dependent and reached its optimum potential at pH 3.0 in the batch process. The capacity of NBC at equilibrium was estimated to be 11.54 mg/g from the Freundlich isotherm model. The isotherm study revealed that Freundlich isotherms explained the adsorption process. It was determined that removal of Cr (VI) was well fitted by second-order reaction kinetics over pseudo-first-order reaction kinetics. The thermodynamics of the adsorption of Cr (VI) were found to be negative, indicating an exothermic adsorption process. The results of the column experiments indicated that NBC could be suitable for treating water contaminated with low concentrations of Cr (VI) at a slow flow rate of 1.25 mL/min. Therefore, the batch and column studies showed that NBC is a favorable adsorbent for the removal of Cr (VI) from an aqueous solution.