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Conventional treatments for nutrient removal in wastewater are shifting to Anaerobic Membrane Bioreactors, which produce a high-quality effluent with minimum sludge production. The effluent resulting contains high nitrogen and phosphorus load that can be eliminated by microalgae culture. The aim of this study is to evaluate the ammonium and phosphorus removal rate of different microalgae species in the effluent of an anaerobic treatment. For that, 4 different microalgae species have been tested (Chlamydomonas reinhardtii, Scenedesmus obliquus, Chlorella vulgaris and Monoraphidium braunii) in batch monoculture and mixed conditions. Results indicate that all species are able to eliminate both P and N in the medium with high removal rates. However, a slight interspecies competition may boost these removal rates and productivity values ensuring, the success of the process. [ABSTRACT FROM AUTHOR]

Anaerobic membrane bioreactor (AnMBR) technology has great advantages for treating urban wastewaters, but, when irrigation cannot be applied and the effluent is discharged in a sensitive zone, a post-treatment of this effluent is needed for nitrogen and phosphorus removal. Under this scenario, ion exchange processes represent one of the most promising technologies for treating this effluent. Ion exchange technology allows to meet discharge limits and to recover these nutrients in a highly concentrated stream. In this work, the technical feasibility of using a commercial resin for phosphorus recovery and a natural zeolite (clinoptilolite) for nitrogen recovery was evaluated. Purolite FerrIX A33E resin removed phosphate from the AnMBR permeate within 500 Bed Volumes (BVs) with a maximum adsorption capacity (q max ) of 2,1 mg P-PO 4 /g resin. Regeneration of the resin (2% NaOH 2% NaCl) recovered over 95% of the phosphorous retained, achieving a concentration of 316,7 mg P-PO 4 /L in the regeneration solution. In the absence of a long-term study, the resin showed a stable adsorption capacity during 16 cycles of saturation-regeneration. Clinoptilolite removed nitrogen within 139 BVs obtaining a q max of 3,68 mg N-NH4/g zeolite. 97 % of the retained N-NH 4 was recovered in the regeneration stage (0,8% NaOH) with an average concentration of 577 mg N-NH 4 /L. Continuous exposure of the zeolite to alkaline solutions led to reduction of 50% of the adsorption capacity after 17 cycles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Even when water scarcity and quality issues are not severe in the European Union (EU) countries, the impacts of climate change and external pressures vary across EU nations, leading to different outcomes. Achieving sustainability requires prioritizing the efficient management of water resources and sanitation services. To this end, conducting studies to identify countries needing appropriate measures is essential. This research focuses on evaluating and analysing the situation of water resources and sanitation systems in the European Union, with two specific objectives in mind. The first objective is to compare disparities between Member States (MSs) in a particular year and track their progress over two periods of five and ten years concerning variables related to water resources and sanitation services. By examining these disparities, the study aims to identify which countries have made significant improvements and which require more attention and resources to enhance their water management and sanitation systems. The second objective is to identify the countries best positioned to achieve certain Sustainable Development Goals (SDG 6, SDG 1, SDG 2, SDG 8, SDG 10, SDG 11, SDG 12). The results indicate that the countries best positioned in terms of meeting the SDGs and achieving sustainability in water and sanitation are Luxembourg, the Netherlands, Finland, Sweden, Denmark and Germany. However, in contrast, Romania, Lithuania, and Slovakia face greater challenges, particularly in sanitation. Factors such as economic level and climate change, which impact southern countries more severely (Greece, Spain, Cyprus) where water scarcity is more acute, contribute to these difficulties. Additionally, the lack of information on wastewater management hinders decision-making and the proper management of these wastes. This study analyses the progress and current status of water and sanitation indicators from an environmental perspective for the first time. It introduces variables to assess sustainability in EU countries that are not listed as indicators on the United Nations website, aiming to evaluate compliance with the SDGs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Coastal ecosystems are heavily polluted by human activities. These pollutants reach the aquatic environment and accumulate in the sediment. Among the chemical pollutants, metals represent a notable hazard since they are not biodegradable and have the capability to bioaccumulate, resulting in toxic effects in both the short and long term. In this study, the content of metals and As in marine sediments of the Spanish Mediterranean coast was determined. A total of four annual sampling campaigns were carried out along the Valencian Community coastline, where the presence of eight trace elements (Cr, Cd, Ni, Pb, Cu, Hg, Zn and As) was determined. In this area, the presence of the contaminants is due to both natural and anthropogenic sources. The results obtained allowed, first, to establish nearness Reference Values of the area under study, second, to use several pollution indices (Contamination Factor, Enrichment Factor, Geoaccumulation Factor, Nemerow Pollution Index, and Modified Pollution Index) to determine contamination levels in the area, and finally to select the best index to apply in this coastal zone. The best indices to use in this region are EF and MPI since both take into consideration the natural contributions of the elements studied. The results revealed that according to the index used only two studied zones are classified as Heavily and Severely polluted. The remaining zones (between 25 and 29%) were classified as Moderately or Moderately to Heavily polluted and most of the zones (63% to 100%) were classified as Unpolluted/Low Polluted and Unpolluted/Slightly Polluted. The outcomes obtained with this work indicate that in general, the Valencian coast does not present significant levels of pollution due to the studied trace elements., (Copyright © 2019. Published by Elsevier B.V.)

The Water Framework Directive (WFD, 2000/60/EC) determines that all water bodies must achieve a good ecological status. The solar salterns system of Mata-Torrevieja (Spain) has been designated as Heavily Modified Water Bodies (HMWB). This ecosystem is a transitional water body (TW) largely conditioned by socio-economic management plan and the related human activities that take place. Thus, WFD establishes as obligatory the determination of their ecological potential, and not their ecological status. In order to define the ecological potential, it is necessary to determine previously the chemical and biological conditions of the water body. This paper is focused on the analysis of physical-chemical parameters of a saltern system during 2008-2016, in order to establish a starting point for the implementation process of the WFD in this type of ecosystem (TW-HMWB). The behavior of salinity and physical-chemical parameters (temperature, pH, nutrients) has been studied. Salinity was the most relevant parameter studied to define pressures for these water bodies. However, total phosphorus turned out to be a good potential status indicator. It would be one of the most suitable chemical parameters to propose a methodology for the determination of the ecological potential in the salterns., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Ecosystem-based management is one of the strategies to protect the coastal areas. One of the key elements is phytoplankton community composition since it represents a good indicator of anthropogenic pressures. This identifies the seasonal patterns of phytoplankton, and its alterations by the stress factors induced by human activities are highly valuable. This research represents the first attempt to study that 476 km of western Mediterranean coastal belongs to the Valencian Community (Spain) based on the phytoplankton composition approach. The water samples during a 5-year period (6757 water samples) were taken to determine its phytoplankton group's dynamics and its relationship with anthropogenic stressors by means of a series of plots and statistical analyses. Diatoms are the group that most contribute to the whole community composition with two periods of maximum abundance. The Prasinophyceae and Cryptophyceae show unimodal patterns varying its maximum values depending on the season. The picocyanobacteria group exhibited the clearest and best-defined pattern. Other groups have no clear seasonal pattern and become abundant in areas of higher anthropogenic pressure. Graphical abstract Figure A contains poor quality of text in image. Otherwise, please provide replacement figure file.A new graphical abstract, with higher quality is attached.

A comprehensive study was carried out to evaluate the occurrence, significance of concentrations and spatial distribution of heavy metals (Cr, Cd, Ni, Cu, Pb, Hg, Zn and As) in sediments along the Valencia coastline (Spain). The sampling campaign covered 476 km of the coastline in a 4-year period. The highest concentrations of metals in the sediments were mainly Cr, Ni, Zn and Cd (up to 28.93 mg Cr kg -1 dw, 15.80 mg Ni kg -1 dw, 57.13 mg Zn kg -1 dw and 0.293 mg Cd kg -1 dw), obtained in the northern areas, some central areas and in an isolated area on the southern coastline. The Sediment Quality Guidelines applied reveal that for all metals studied, none of them reached, or exceed, the "effects of median range" or the "probable effect level". The pollution index reveals that 75% of the stretch coastline has a low priority risk level and the rest "medium-low priority risk level". And, lastly, Potential Ecological Risk Index shows that all but one zone have low ecological risk.