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O presente estudo pretendeu avaliar a importância do Oceano para a Comunidade dos Países de Língua Portuguesa (CPLP), com o objetivo de percecionarmos quais os princípios da Literacia do Oceano com mais importância para esta comunidade e quais as áreas com mais interesse que deviam ser mais trabalhadas e intervencionadas. Os dados foram recolhidos através do questionário realizado a indivíduos dentro da comunidade da CPLP que voluntariamente responderam ao mesmo. Os principais resultados mostram que o Princípio 5 “O Oceano suporta uma imensa diversidade de vida e de ecossistemas” e o Princípio 2 “O Oceano e a vida marinha têm uma forte ação na dinâmica da Terra” são os que reforçam a importância das orientações da Literacia do Oceano. E que o problema da poluição por plástico/microplástico são o principal problema que os nossos inquiridos gostariam de ver resolvidos a curto/médio prazo. Este estudo contribui para o conhecimento sobre a literacia científica dentro da comunidade CPLC, promovendo o interesse sobre a investigação científica desenvolvida em prol do Oceano.

Fluorine-based agrochemicals have been benchmarked as the golden standard in pesticide development, prompting their widespread use in agriculture. As a result, fluorinated pesticides can now be found in the environment, entailing serious ecological implications due to their harmfulness and persistence. Microbial degradation might be an option to mitigate these impacts, though environmental microorganisms are not expected to easily cope with these fluoroaromatics due to their recalcitrance. Here, we provide an outlook on the microbial metabolism of fluorinated pesticides by analyzing the degradation pathways and biochemical processes involved, while also highlighting the central role of enzymatic defluorination in their productive metabolism. Finally, the potential contribution of these microbial processes for the dissipation of fluorinated pesticides from the environment is also discussed.

Fishes are one of the most important components of the oceans and are exposed to several anthropogenic pressures, namely microplastic (MP), contaminants that are now ubiquitous worldwide. Taking advantage of the 2020 Circumnavigation Expedition carried by the NRP Sagres tall ship of the Portuguese Navy, fish samples from the southern Atlantic ocean were collected to evaluate possible MP contamination. In a total of 14 weeks of campaign, seven large migratory fishes of commercial interest were collected across the middle Atlantic Ocean and along the South American Atlantic coast. All individuals were contaminated with MPs, with an average of 18 ± 11 MPs/fish. In all fish sampled, both the gastrointestinal tract and gills presented MPs, indicating different contamination pathways including via their preys and from surrounding water, respectively. A total of 124 MPs were observed, where 72 % were fibers and 28 % particles, mostly of blue color (85 %), and with rayon and nylon as the most abundant polymers. This study is an important contribution to increase the scientific knowledge of MP contamination in mesopelagic fishes used for human consumption and collected in the open waters, reinforcing the need for further research regarding MP contamination in top predatory species from high trophic levels.

Concerns regarding plastic pollution, especially microplastics, have increased, as they can be present in different environmental compartments, including estuarine areas and saltmarshes. Although saltmarshes are highly vulnerable to different human activities and pressures, they have the ability to trap/retain contaminants in their vegetated sediments. However, there is still little information regarding the role of saltmarshes in microplastic retention. Thus, the present study aims to investigate the capability of an estuarine saltmarsh to trap microplastics by comparing microplastic concentrations in vegetated (saltmarsh) and non-vegetated sediments. Microplastic content from sediment (vegetated and non-vegetated) samples collected at different sampling sites in Lima River estuary was estimated using previously optimised extraction protocols, and the observed particles were then characterised accordingly to their size, colour, shape, and polymer (by FTIR). Water samples were also collected and analysed for their microplastics content to complement MPs characterisation within the estuarine area. Microplastics were detected in all sediment samples, with fibres being the most common type of microplastic found, followed by fragments/particles. Overall, vegetated sediments, especially those of saltmarsh species Juncus maritimus, presented a higher number of plastic items. These results indicated that microplastics tend to be trapped in vegetated sediments, supporting the fact that saltmarshes have a significant influence on the transport, distribution, and accumulation of MPs in estuarine areas.

The effects of metallic nanoparticles (NPs) on the estuarine biota have mostly been shown for concentrations higher than those actually measured or predicted in these environments. To address this gap, a range of concentrations expected to occur in estuarine environments (from 0.01 to 1 μg g−1) was employed in microcosms studies to assess the impact of Cu NPs in the denitrification pathway. This was achieved by quantifying the gene expression in estuarine sediments exposed to Cu NPs for up to six days and potential denitrification rates. The expression of nitrite (nirS) and nitrous oxide (nosZ) reductase genes was enhanced in a timewise manner upon exposure to Cu NPs

Eutrophication of surface waters caused by toxic cyanobacteria such as Microcystis aeruginosa leads to the release of secondary metabolites called Microcystins (MCs), which are heptapeptides with adverse effects on soil microbiota, plants, animals, and human health. Therefore, to avoid succumbing to the negative effects of these cyanotoxins, various remediation approaches have been considered. These techniques involve expensive physico-chemical processes because of the specialized equipment and facilities required. Thus, implementing eco-technologies capable of handling this problem has become necessary. Indeed, multi-soil-layering (MSL) technology can essentially meet this requirement. This system requires little space, needs simple maintenance, and has energy-free operation and high durability (20 years). The performance of the system is such that it can remove 1.16 to 4.47 log10 units of fecal contamination from the water, 98% of suspended solids (SS), 92% of biological oxygen demand (BOD), 98% of chemical oxygen demand (COD), 92% of total nitrogen (TN), and 100% of total phosphorus (TP). The only reported use of the system to remove cyanotoxins has shown a 99% removal rate of MC-LR. However, the mechanisms involved in removing this toxin from the water are not fully understood. This paper proposes reviewing the principal methods employed in conventional water treatment and other technologies to eliminate MCs from the water. We also describe the principles of operation of MSL systems and compare the performance of this technology with others, highlighting some advantages of this technology in removing MCs. Overall, the combination of multiple processes (physico-chemical and biological) makes MSL technology a good choice of cyanobacterial contamination treatment system that is applicable in real-life conditions, especially in rural areas.

Antibiotics are often applied in aquaculture to prevent fish diseases. These substances can cause disturbances on receiving waters, when not properly eliminated from the aquaculture effluents. In this work, ozone (O

Reusing reclaimed wastewater is needed to fight water scarcity, reduce freshwater consumption and conserve water resources, but one must ensure that hazardous substances are fully removed/eliminate before that reuse. The potential of lab-scale constructed wetlands (CWs) for the removal of chemical and biological contaminants from livestock wastewater, while maintaining nutrient levels for fertilization, was assessed, evaluating changes in microbial communities, with particular focus on potential pathogens. CW microcosms with two different substrates (lava rock or light expanded clay aggregate), both planted with Phragmites australis, were tested. After 15 days of treatment, removal rates were higher than 80% for Cd, Cr, Cu, Fe, Pb and Zn, in general with no significant differences between the two different substrates. Organic matter and nutrients were also removed but their levels still allowed the used of the treated wastewater as a fertilizer Removal of bacterial contamination was estimated through enumeration of cultivable bacteria. High removal rates of fecal indicator bacteria were observed, reaching95% for enterococci and98% for enterobacteria after 15 days of treatment, decreasing hazardous biological contaminants initially present in the wastewater. In addition, the microbial communities in the initial and treated wastewater, and in the plant roots bed substrate, were characterized by using 16SrRNA gene amplicon sequencing. Microbial communities in the CW systems showed a clear shift comparatively with the initial wastewater showing system adaptation and removal potentialities. This also revealed an important removal of the most represented potential pathogenic genus, Clostridium, which relative abundance decreased from 33% to 1% through the treatment. Overall, CWs showed potential to be efficient in removing chemical and biological contaminants, while maintaining moderated levels of nutrients, allowing the reuse of reclaimed water in agriculture, namely as fertilizer. Current results will contribute for the optimization and use of CWs for a sustainable treatment of liquid wastes, promoting the circular economy.

Epoxiconazole (EPO) and fludioxonil (FLU) are two widely used fluorinated pesticides known to be highly persistent and with high ecotoxicological potential, turning them into pollutants of concern. This work aimed to optimize two degrading bacterial consortia, previously obtained from an agricultural soil through enrichment with EPO and FLU, by characterizing the contribution of their corresponding bacterial isolates to the biodegradation of these pesticides using both culture-dependent and independent methodologies. Results showed that a co-culture of the strains Hydrogenophaga eletricum 5AE and Methylobacillus sp. 8AE was the most efficient in biodegrading EPO, being able to defluorinate ca. 80% of this pesticide in 28 days. This catabolic performance is likely the result of a commensalistic cooperation, in which H. eletricum may be the defluorinating strain and Methylobacillus sp. may assume an accessory, yet pivotal, catabolic role. Furthermore, 16S rRNA metabarcoding analysis revealed that these strains represent a minority in their original consortium, showing that the biodegradation of EPO can be driven by less abundant phylotypes in the community. On the other hand, none of the tested combinations of bacterial strains showed potential to biodegrade FLU, indicating that the key degrading strains were not successfully isolated from the original enrichment culture. Overall, this work shows, for the first time, the direct involvement of two bacterial species, namely H. eletricum and Methylobacillus sp., in the biodegradation of EPO, while also offering insight on how they might cooperate to accomplish this process. Moreover, the importance of adequate culture-dependent approaches in the engineering of microbial consortia for bioremediation purposes is also emphasized.

Fluorinated pesticides acquired a significant market share in the agrochemical sector due to the surge of new fluoroorganic ingredients approved in the last two decades. This growing trend has not been accompanied by a comprehensive scientific and regulatory framework entailing all their potential negative impacts for the environment, especially when considering the hazardous properties that may result from the incorporation of fluorine into organic molecules. This review aims to address the safe/hazardous dichotomy associated with fluorinated pesticides by providing an updated outlook on their relevancy in the agrochemical sector and how it leads to their role as environmental pollutants. Specifically, the environmental fate and distribution of these pesticides in the ecosystems is discussed, while also analysing their potential to act as toxic substances for non-target organisms.

Marine litter awareness hands on actions through learning by doing (MALIA) is a funded Erasmus+ project aiming at inclusion of marine conservation practices in the national school curricula. The project is being carried out by four educational centres, three associations and one research centre, from Spain, Italy, Cyprus and Portugal. Its main goal is to improve students and teachers awareness on marine litter problems, tackling the subject in a proactive way. To achieve this, open educational materials are being designed, which can be used in different educational systems. In this paper the materials designed during the first year of the project are presented. The materials include field and bench activities to link the topics to concepts and methods in relevant disciplines, such as geology, biology, chemistry and new digital technologies. In line with educational challenges of the 21st century, they take advantage of the scientific method, and inquiry and problem-based methodologies.

This work aimed to investigate the possible effect of 2 quenchers commonly used in H2O2-based advanced oxidation technologies (AOTs), i.e. catalase and sodium sulphite (Na2SO3), on the analytical signal of 3 detectors coupled to liquid chromatography (LC): tandem mass spectrometry (LC-MS/MS), fluorescence detection (LC-FD) and LC-diode array detection (LC-DAD). The observation of analytical interferences for a group of compounds when studying the removal by continuous mode UV/H2O2 of 26 micropollutants (MPs) from a spiked surface water (SW), for which the residual H2O2 in the samples was quenched by Na2SO3, triggered the need of understanding these effects and thus catalase was used as comparative quencher. From the 26 MPs having a wide range of polarity and pKa, those monitored after electrospray ionization (ESI) under positive ionization (PI) mode and presenting a pKa higher than 5.9 revealed a great signal suppression, but only when using Na2SO3 as H2O2 quencher. In this sense, we further explored this effect by selecting 2 MPs, metoprolol and diclofenac, which had respectively signal suppression and no interference in the LC-MS/MS response. These MPs were analysed before and after addition of H2O2 and catalase or Na2SO3 in reaction vials, using: (i) different detectors coupled to LC, namely LC-MS/MS with ESI under PI and negative ionization (NI) modes, LC-FD and LC-DAD; (ii) different environmental matrices (SW, drinking water, wastewater) and ultrapure water; and (iii) different magnitude levels (0.1–10 mg L−1). The results demonstrated a remarkable signal suppression in LC-MS/MS analyses under PI mode for those compounds with pKa higher than 5.9, confirming the interfering effect of H2O2/Na2SO3. To the best of our knowledge, the analytical interference in the LC-MS/MS analysis, after adding Na2SO3 to quench H2O2 in AOTs experiments was never reported before and the results presented herein support the recommendation to use catalase instead of Na2SO3 as quencher in AOTs studies.

The staff of the XAFS beamline BM30B (FAME) at ESRF, France, and more particularly Dr. D. Testemale, are gratefully acknowledged for their help in performing the XAS experiments.; International audience; Application of anaerobically digested sludges and manure (digestates) to agricultural fields reduces the need for fertilizer application, but might also pose environmental risks due to the introduction of various pollutants –including metal trace elements and pharmaceuticals– to amended soils. The simultaneous presence of different contaminants can affect plant uptake, altering the performance of phytoremediation. This work aims to investigate and compare the single and combined effects of Enrofloxacin (Enro) and Cu on their plant uptake from digestate solutions. Plant uptake experiments were carried out by exposing, for 5 days, Phragmites australis to three different concentrations of a liquid digestate doped with Cu and/or Enro. Contaminant concentrations were afterward determined in both plant tissues and digestate solutions. Contaminant speciation in solution and Cu speciation in plant roots were also assessed. Cu plant uptake (mostly in plant roots, Cu concentration varied between 55 and 254 μg·g−1) was observed, especially at low concentration of digestate. At high digestate concentration, Cu uptake decreased due to the formation of Cu-DOC complexes rendering Cu less bioavailable. The presence of the antibiotic slightly further reduced Cu plant uptake due to the formation of Cu-Enro complexes. Plant roots also accumulated Enro, an accumulation also higher for the lowest concentration of digestate (an increase of 40%), and that slightly increased in the presence of Cu (up to 226 μg·g−1). However, proportion of free Enro in solution decreased (up to 70%) in the presence of Cu due to complexation. Cu speciation in plant roots confirmed the implication of the complexation in the uptake of Cu and Enro when they are simultaneously present in solution. Thus, the presence of amendments (such as digestates) increasing the DOC content, in addition to the interactions between contaminants, should be taken into account for field crop soils as well as for phytoremediation technologies.

This study aimed to evaluate the potential of CWs to remove bacteria, including antibiotic resistant bacteria, and antibiotics from livestock (swine production) wastewater. Microcosms were assembled with Phragmites australis (Cav.) Trin. ex Steud and feed with wastewater spiked or not with 100 µg/L of enrofloxacin or of ceftiofur, alone or as a mixture. Wastewater (spiked or not) was treated during twenty one-week cycles. Treated wastewater was collected at weeks 1, 2, 4, 8, 14, 18 and 20 to evaluate the removal of pollutants, including nutrients, organic matter, metals and added antibiotics, and total cultivable and antibiotic resistant bacteria (enterobacteria and enterococci), which were enumerated in plate culture media. After treatment, a significant reduction in pollutants load (up to 99% depending on the parameter) was observed regardless of the presence of the veterinary antibiotics. Antibiotics were also significantly removed (removal > 90%). High removal rates were achieved for enterobacteria and enterococci bacteria during the experimental period, in the presence or absence of antibiotics (mean removals between 86 and 100%). For antibiotic resistant bacteria initially present in the influent wastewater mean removals > 90% were obtained, and no significant effect of time or of antibiotic presence was observed. This study is, to our knowledge, the first to focus on the removal of enrofloxacin and ceftiofur resistance in faecal bioindicators in CWs fed with livestock wastewater. Results confirm CWs as a green alternative to reduce the risks associated with the release of livestock effluents into the environment.

Estuaries are productive environments used by many fish as nursery grounds. The initial stages of fishes are highly vulnerable to (a)biotic factors, and anthropogenic pressures, influencing fish larvae assemblages along the estuary. Microplastics (MPs 5 mm) are particularly dangerous to early life stages of fishes because their ingestion can induce gut blockage, limiting food intake or exposing organisms to contamination due to MPs capacity to absorb pollutants. Present work aimed to investigate the contamination of an urban impacted estuary (Douro estuary, NW Portugal) by MPs, and study the abundance and distribution of MPs and fish larvae in this estuary. Monthly sampling surveys were performed from December 2016 to December 2017, in nine stations along the estuary. Sub-surface planktonic horizontal trawls were performed to collect fish larvae and MPs. Planktonic samples were sorted, and fish larvae identified. MPs density was determined using a protocol optimized in our laboratory. A total of 1498 fish larvae belonging to 32 taxa were collected, with a mean density of 11.66 fish larvae 100 m

This study aimed to investigate the potential of microbial communities from the rhizosediment of two plants - Phragmites australis and Juncus maritimus - occurring in an estuarine area subjected to a high anthropogenic impact, to biodegrade ENR, a commonly used veterinary antibiotic. An enrichment process with 1 mgL−1 of ENR was conducted during ca. 9 months, using acetate as a co-substrate. After this, the enriched microbial consortia were challenged with higher ENR concentrations of 2 and 3 mgL−1. Microbial cultures enriched with 1 mgL−1 of ENR were capable of biodegrading this antibiotic, though not completely. By the end of the enrichment phase, microbial cultures were defluorinating an average of 50% of the ENR supplemented. Higher ENR concentrations led to lower biodegradation performances, suggesting a possible toxic/inhibitory effect in the microbial cultures. Phylogenetic identification of the microorganisms isolated from microbial cultures enriched with ENR revealed a high taxonomical diversity, with microorganisms belonging mainly to Proteobacteria and Bacteroidetes phyla. Assemblage of the obtained isolated strains (according to the enriched cultures from which they were isolated) revealed that the resulting consortia were also capable of degrading ENR, indicating that the main microbial players in the biodegradation of this antibiotic were isolated. These consortia also showed to be more robust to degrade higher concentrations of ENR than the corresponding enriched cultures. This study shows that microorganisms derived from rhizosediments of the selected plants, exhibit capacity to biodegrade ENR, though not completely for the concentrations tested, and may be further explored for the development of bioremediation strategies for the treatment of this antibiotic.

This work investigated the potential of microbial communities native to an estuarine environment to biodegrade enrofloxacin (ENR) and oxytetracycline (OXY). Sediments collected from two sites in the Douro river estuary (Porto, Portugal) were used as inocula for the biodegradation experiments. Experiments were carried out for one month, during which ENR and OXY (1 mg L−1) were supplemented individually or in mixture to the cultures at 10-day intervals. Acetate (400 mg L−1) was added to the cultures every 3 days to support microbial growth. A series of experimental controls were established in parallel to determine the influence of abiotic breakdown and adsorption in the removal of the antibiotics. Removal of antibiotics was followed by measuring their concentration in the culture medium. Additionally, next-generation sequencing of the 16S rRNA gene amplicon was employed to understand how microbial communities responded to the presence of the antibiotics. At the end of the biodegradation experiments, microbial cultures derived from the two estuarine sediments were able to remove up to 98% of ENR and over 95% of OXY. The mixture of antibiotics did not affect their removal. ENR was removed mainly by biodegradation, while abiotic mechanisms were found to have a higher influence in the removal of OXY. Both antibiotics adsorbed at different extents to the estuarine sediments used as inocula but exhibited a higher affinity to the sediment with finer texture and higher organic matter content. The presence of ENR and OXY in the culture media influenced the dynamics of the microbial communities, resulting in a lower microbial diversity and richness and in the predominance of bacterial species belonging to the phylum Proteobacteria. Therefore, microbial communities native from estuarine environments have potential to respond to the contamination caused by antibiotics and may be considered for the recovering of impacted environments through bioremediation.

One of the most used protocols to extract and quantify MPs is NOAA protocol in aquatic environments. However, there is still no standardized method to extract and quantify MPs in estuarine waters. The aim of this work was to adapt the NOAA protocol to quantify microplastics in estuarine water and provide all the details and changes to improve the efficiency of the method. For that, four types of plastic (PE-LD; PET; PA; PE-HD) were used in artificial samples to test all the steps of the protocol. Several criteria were tested, namely: (i) quantities of H2O2 used for organic matter degradation; (ii) temperatures of drying samples; and (iii) density separation efficacy. With the proposed modifications, the microplastics extraction were above 90%, regardless the type of plastic, with PE-LD reaching 100% of efficiency. The new adapted protocol that we propose will allow a better efficiency in extraction and quantification of microplastics in samples from estuarine environments. • Four different types of plastic (PE-LD; PET; PA; PE-HD) were used to test the efficiency of the protocol • Details as the ideal quantity of H2O2, temperature and exact quantity of NaCl were tested and defined during the experiments • Efficiency of the microplastics extraction were above 90% Method name: Estuarine waters microplastics quantification protocol, Keywords: Microplastics, Estuarine waters, Contamination, Analytical procedure

Contamination derived from maritime transportation is not only linked to petroleum-based substances but also to transportation of other substances such as hazardous and noxious nature (HNS). Over the last decade, the maritime trade of HNS has been augmenting. However, levels of HNS in aquatic environment are still quite unknown. So, an integrative study, combining a chemical and a multi-biomarker evaluation, was done in the NW Atlantic Iberian coast where specimens of Mytilus sp. were collected. Ten HNS were found in the digestive gland of mussels from Vila Cha and Foz, though at generally low levels. Only measurable levels of benzene, trichloroethylene and 1,1,2-trichlorethane were found in other locations. Principal component analysis produced a clear distinction between Vila Cha and Foz and the remaining sampling sites. Biomarkers associated to contamination were the levels of lipid peroxidation (LPO) and activity of glutathione reductase (GR), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes. Correlations between biomarkers and HNS levels highlight the importance of performing biomonitoring campaigns integrating chemical analysis and a biomarker approach to accurately assess the environmental state of aquatic environments.

Contamination by microplastics is increasing steadily worldwide, affecting all environments. Additionally, aquatic organisms are often exposed to mixtures of other contaminants, including various chemicals. Numerous studies reported adsorption of chemicals to microplastics, raising concern about their possible role as vehicles of exposure through transfer to biota. Nevertheless, until recently, the studies on the topic were mostly focused on the marine environment. In the past five years, however, plenty of publications contributed empirical data about freshwater ecosystems, raising the need for a critical appraisal of the information. Herein the scientific literature was reviewed and multivariate data analysis was done. The analysed studies employed widely different experimental designs, endpoints, test species, shapes and concentrations of various polymer types and chemicals, often not relevant for the freshwater environment. Our integrated analytical approach revealed unfathomable research gaps, given the theoretical knowledge available and lessons learned from research about the marine environment. Greater harmonization of laboratory studies investigating this topic is needed, as well as testing conditions reflecting real exposure scenarios. Furthermore, standardized testing protocols are urgently required to guide such experiments and improve the comparability of the results obtained.

The aim of this study focused on the evaluation of constructed wetlands (CWs) microcosms, on a laboratory scale, for the removal of metals from a pig industry effluent while maintaining effluent organic matter and nutrients levels for its later used as a fertilizer. CWs with different macrophytes (Phragmites australis and Typha latifolia) and different substrates (light expanded clay aggregate and lava rock) were tested. Results showed high removals of metals during CWs treatment, with removal rates reaching &gt, 80% for Cd, Cr, Cu, Fe, Mn, and Zn after 2 days of treatment in CWs planted with T. latifolia and &gt, 60% in CWs planted with P. australis. Significant differences were only found between substrates for Fe and Mn in CWs with P. australis. Removal of organic matter (through chemical oxygen demand (COD)) was &gt, 77%, with no significant differences between substrates or plants. Removals of ammonium and phosphate ions ranged between 59&ndash, 84% and 32&ndash, 92%, respectively, in CWs with P. australis and 62&ndash, 75% and 7&ndash, 68% in CWs with T. latifolia, with no significant differences between substrates. Overall, CWs showed potential to be efficient in removing toxic contaminants, as metals, while maintaining moderated levels of nutrients, allowing the use of reclaimed water in agriculture, namely as fertilizer. If one aims for a short CW treatment, CW planted with T. latifolia and expanded clay as substrate could be the more suitable choice.

Effects of metallic nanoparticles (NPs) to the estuarine biota have mostly been shown for concentrations higher than those actually measured or predicted in these environments. To address this gap, a range of concentrations expected to occur in estuarine environments (from 0.01 to 1 μg g-1) was employed in microcosms studies to assess the impact of Cu NPs in the denitrification pathway. That was achieved by quantifying gene expression and the potential denitrification rate in estuarine sediments exposed to Cu NPs for up to six days. Expression of nitrite (nirS) and nitrous oxide (nosZ) reductase genes was enhanced in a timewise manner. For the highest Cu NPs (1 μg g-1) an increase in gene expression could be seen immediately after 1 h of exposure, and continuing to be enhanced up until 7 h of exposure. For the lowest Cu NPs (0.01 μg g-1) an increase in gene expression could only be seen after 4 h or 7 h of exposure; however it continued to rise up until 24 h of exposure. In any case, after 48 h the expression levels were no longer different from the non-exposed control. Concomitantly to increased gene expression the potential denitrification rate was increased by 30 %. Our results suggest that deposition and adsorption of Cu NPs to estuarine sediments promotes the immediate and transient expression of key genes of the denitrification pathway. The long term impact of continuous inputs of Cu NPs into estuaries deserves renewed analysis to account for their effects, not just on the biota, but especially on ecosystems services.Environmental significanceInteractions of metallic nanoparticles with microbial communities of estuarine sediments are poorly characterized and its impact towards ecosystem services even less. By assessing the effect of copper nanoparticles on the expression of key genes of the denitrification pathway, an essential step for nitrogen (N) removal, we were able to show that denitrifying communities are immediately activated after exposure, increasing the denitrification rates in estuaries. The importance of denitrification lies in its release of dinitrogen (N2) to the atmosphere but also in the emissions of N2O (a potent greenhouse gas). The results obtained in this study gather data that contribute information on the denitrification dynamics in estuaries, invaluable for a timely response to the expected upcoming changes in coastal areas.Table of contentsIn estuaries the deposition upon the sediments of copper nanoparticles can contribute to change metal availability and promote the activity of denitrifying bacteria

Biodegradation of two highly persistent fluorinated fungicides, epoxiconazole (EPO) and fludioxonil (FLU), by microbial consortia enriched from estuarine sediment and agricultural soil is reported. After an enrichment period of 6 months, four microbial consortia were able to completely remove and defluorinate the fungicides in co-metabolic conditions. Defluorination was biologically mediated and results suggest it is not a primary catabolic step, as fungicide removal was always faster than its defluorination. Three of the four enriched consortia had similar biodegradation performances in the absence of a co-substrate. Biodegradation kinetics revealed that microbial degradation followed a first-order kinetics, with cultures being capable of biodegrading concentrations up to 10 mg L−1 of EPO or FLU, in a maximum of 21 days. Estimated half-life values for these compounds were significantly lower than those reported in literature, highlighting the unique metabolic performance of the obtained consortia. Analysis of their microbial composition revealed that they integrate several bacterial species belonging to the Proteobacteria phylum, with the most common genera being Pseudomonas, Ochrobactrum and Comamonas. This is the first study providing clear evidence on the biodegradation of EPO and FLU, opening doors for the design of bioremediation technologies for the recovery of ecosystems polluted with such recalcitrant compounds.

Microcystis blooms and the subsequent release of hepatotoxic microcystins (MCs) pose a serious threat to the safety of water for human and livestock consumption, agriculture irrigation, and aquaculture worldwide. Microcystin-LR (MC-LR), the most toxic variant of MCs, has been widely detected in a variety of environments such as water, sediments, plants, and many aquatic organisms. Conventional solutions of water treatment are costly, requiring specific infrastructure, as well as specialized personnel and equipment. Therefore, these solutions are not feasible in many rural areas or in the treatment of large reservoirs. In this regard, low-cost and low-technology solutions, such as constructed wetlands (CWs), are attractive solutions to treat surface waters contaminated with toxic cyanobacteria blooms from lakes, ponds, reservoirs, and irrigation systems. In line with this, the main aim of this work was to evaluate the potential of CWs for the treatment of water contaminated with MC-LR produced by Microcystis aeruginosa&mdash, LEGE 91094. For that, microcosms (0.4 &times, 0.3 &times, 0.3 m) simulating CWs were assembled with Phragmites australis to treat lake water contaminated with Microcystis aeruginosa cells and MCs. Results showed removal percentages of M. aeruginosa cells above 94% and about 99% removal of MC-LR during 1 week treatment cycles. CWs maintained their functions, regardless the presence of MC-LR in the system, and also showed significant removal of nutrients (ammonium ion removal up to 86%) and organic matter (removal reaching 98%). The present work indicates that CWs have the potential for removal of cyanobacterial cells and cyanotoxins, which can be useful for the treatment of eutrophic waters and provide water of sufficient quality to be used, for instance, in agriculture.

Aquaculture is the fastest growing animal food-producing sector. Water is the central resource for aquaculture, and it is essential that its quality be preserved. Micropollutants (MPs) can reach aquaculture through anthropogenic addition or inlet water, and may cause harmful effects such as endocrine disruption and antibiotic resistance, adversely affecting the fish species being farmed. Furthermore, the discharge of aquaculture effluents into the environment may contribute to the deterioration of water courses. In this sense, the implementation of environmentally responsible measures in aquaculture farms is imperative for the protection of ecosystems and human health. The European Commission (EC) has recently launched a guiding document promoting ecological aquaculture practices; however, options for water treatment are still lacking. Conventional processes are not designed to deal with MPs; this review article consolidates relevant information on the application of advanced oxidation technologies (AOTs) and constructed wetlands (CWs) as potential strategies in this regard. Although 161 studies on the application of AOTs or CWs in aquaculture have already been published, only 34 focused on MPs (28 on AOTs and 6 on CWs), whereas the others reported the removal of contaminants such as bacteria, organic matter, solids and inorganic ions. No study coupling both treatments has been reported to date for the removal of MPs from aquaculture waters. AOTs and CWs are prospective alternatives for the treatment of aquacultural aqueous matrices. However, the type of aquaculture activity and the specifications of these available technologies should be considered while selecting the most suitable treatment option.