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Efficient and sustainable secondary sourcing of Rare-Earth Elements (REE) is essential to counter supply bottlenecks and the impacts associated with primary mining. Recycled electronic waste (E-waste) is considered a promising REE source and hydrometallurgical methods followed by chemical separation techniques (usually solvent extraction) have been successfully applied to these wastes with high REE yields. However, the generation of acidic and organic waste streams is considered unsustainable and has led to the search for “greener” approaches. Sorption-based technologies using biomass such as bacteria, fungi and algae have been developed to sustainably recover REE from e-waste. Algae sorbents in particular have experienced growing research interest in recent years. Despite its high potential, sorption efficiency is strongly influenced by sorbent-specific parameters such as biomass type and state (fresh/dried, pre-treatment, functionalization) as well as solution parameters such as pH, REE concentration, and matrix complexity (ionic strength and competing ions). This review highlights differences in experimental conditions among published algal-based REE sorption studies and their impact on sorption efficiency. Since research into algal sorbents for REE recovery from real wastes is still in its infancy, aspects such as the economic viability of a realistic application are still unexplored. However, it has been proposed to integrate REE recovery into an algal biorefinery concept to increase the economics of the process (by providing a range of additional products), but also in the prospect of achieving carbon neutrality (as large-scale algae cultivation can act as a CO2 sink). Graphical abstract

Shorebirds and seabirds are abundant predators in coastal habitats worldwide, relying upon a high diversity of benthic invertebrates and fish, respectively. While occupying different trophic guilds, they are differently exposed to element contamination entering the coastal food web. Therefore, these birds have been used as bioindicators of environmental contamination in marine ecosystems. We analysed the concentration of trace elements in blood samples of 16 shorebird and seabird migratory species in a major non-breeding site, the Bijagós Archipelago, in regard to their trophic ecology. Overall, our study shows low exposure of this bird community to toxic elements, except for Hg. Most species presented Hg burdens within the moderate toxicity threshold, but one species (Dunlin) presented values at a potential high Hg toxicity risk. We found a positive relationship between Se and Ni concentrations and δ

Sorption has been proposed as a promising approach towards a sustainable water decontamination and recently to the recycling of rare earth elements (REE). Although living seaweed have been shown to be capable of removing REE from contaminated solutions, no studies have yet compared the effects of REE competition on sorption onto different groups of seaweed. These effects were analysed in the present study by exposing six living seaweeds (Ulva lactuca, Ulva intestinalis, Fucus spiralis, Fucus vesiculosus, Gracilaria sp. and Osmundea pinnatifida) (3 g/L, fresh weight) to mono-element and multi-element solutions of Y, La, Ce, Pr, Nd, Eu, Gd, Tb and Dy (1 μmol/L). Results show a preference towards light REE in mono-element solutions, which is reduced when in competition with other REE. The competitive effect is less pronounced in heavy REE indicating that these are still able to bind to the macroalgae despite the presence of competing ions. Contrary to water content (%), seaweed specific surface area (cm2/g) shows to be an important factor in the sorption of REE, since larger surface area is associated with higher removal and larger competitive effect.

We report the concentration of 13 elements in the muscle and liver of 17 coastal fish species of the Bijagós Archipelago, Guinea-Bissau, and link element concentrations to trophic ecology as assessed by carbon (δ

The Amazon has been jointly glimpsed as a space where a wide range of differences emerge, both within and outside the region. Establishing ways to measure these diversities through the prism of the quality of life and well-being of their populations is an urgent initiative to be satisfied. Thus, this article presents the application of the PICOC methodology for mapping the indicators from the actions that represent the quality of life and welfare of the population of the Brazilian Amazon. A systematic mapping was carried out in five scientific databases in order to map works published in the period from 2017 to 2021. As results, 31 indices related to quality of life and well-being were found arranged in the dimensions of environment, health, education, governance, social programs, and income. The dimensions of environment, health, education, governance, and social programs and income are the main recurrences. The findings allowed as contributions: (i) quantify and qualify the works, listing their sources, year of publication, area of application and repository of origin; (ii) identify the most recurrent dimensions of the indicators found; (iii) relate the indexes to the quantities of dimensions that compose them.

Mercury is a potential contaminant of the aqueous systems that needs to be removed from wastewaters even in trace concentrations due to its hazardous effects on environment and human health. Agricultural and industrial wastes are produced in abundance in many agro-industrial activities and have no commercial costs associated with them. The Hg(II) ions can establish bonds with the functional groups present on lignocellulosic biomasses, making the use of these types of biosorbents excellent alternatives to remove mercury in water treatments, while promotes their recycling and valuation. In this work, six biosorbents (banana and potato peels, eggshells, Eucalyptus globulus bark, water hyacinth, and coffee waste) were tested and compared under the same batch conditions with an initial mercury concentration of 50 µg dm−3 in order to determine their removal performances. Several reaction- and diffusion-based models were adjusted to the experimental data to analyze the limiting sorption mechanisms. Sorption experiments and modelling results evidenced distinct affinities of those biosorbents to Hg(II), banana peels being the best alternative due to the fast removal kinetics and capacity. This biosorbent was able to remove more than 90 % of the Hg(II) initially in solution after 72 h of exposure, being more than 80 % removed in the first 10 h. Chemical and physical characteristics of the solids are involved in Hg(II) elimination, as reported by FTIR-ATR and SEM studies.

The present study reports the quantity, shape, colour and chemical properties of microplastics (MP) and MP-like in whole soft tissues of the mussel Mytilus spp. collected in January and February 2019 from four natural banks in the Portuguese coast. Three sites are located in estuarine areas influenced by anthropogenic pressures and freshwater discharges, and one in the coast far from urbanised areas. An alkaline digestion (KOH) of biological tissues was used and a polymeric identification of 20% of the visually sorted particles was achieved using the Fourier-transform mid-infrared spectroscopy (FT-MIR). MP and MP-like concentrations ranged from 0.54 to 3.0 items g−1 without significant differences among the sites. Particle size varied from 36 to 4439 μm, being fibers the most abundant shape (50%) followed by films (22%) and spherules (18%). FT-MIR revealed that 69% of the analysed particles were plastic, being identified six polymers and two polymeric blends, and 32% were cellulose-based materials. Fibers identified in mussel tissues were mainly composed of cotton and viscose (77%). This study emphasizes the importance of the polymer's spectroscopic identification after microscopic observation to recognise MP.

This study examined the mechanism of incorporation of the rare earth elements (REEs), La, Ce, Nd, Eu, Gd, Tb, Yb, into green (Codium tomentosum, Ulva rigida), red (Gracilaria gracilis, Osmundea pinnatifida, Porphyra sp), and brown seaweeds (Saccorhiza polyschides, Undaria pinnatifida) collected from a single site near the coastline of the Cape Mondego, western Portugal. The concentrations of REEs, Mg, Ca, Al, Fe, Zn, and Cu in the biomasses were determined by inductively-coupled plasma mass spectrometry (ICP-MS). The species showed differences in their incorporation and fractionation of REEs from the same environment: the sum of REEs was higher in U. rigida, C. tomentosum, G. gracilis, and O. pinnatifida (0.7-1.7 μg g-1) than in Porphyra sp., S. polyschides, and U. pinnatifida (0.1-0.2 μg g-1). Ratios of Ce/Yb ranged from 13 (in S. polyschides) to 103 (in U. rigida), indicating different proportions of light and heavy REEs among species. Good correlations were found between Al and Fe (R2 = 0.98), and between these elements and La, Ce, Nd, Gd (R2 = 0.88-0.97) and Yb (R2 = 0.66-0.71) for all species except C. tomentosum and G. gracilis. Profiles of REE values normalised to average upper-continental crust composition indicated positive anomalies of Eu and Tb that reinforced the singularity of these elements in the REE group. Correlations between the REEs and Al or Fe suggest that detrital terrigenous particles, adhered to seaweed walls, may be an important mechanism for the incorporation of REEs by seaweeds. Different patterns for C. tomentosum and G. gracilis may also be indicative of the higher influence of cell wall composition on REE incorporation.

Current environmental policies aim to reduce the levels of toxic substances in aquatic ecosystems and to promote the water reuse after appropriate treatment of wastewater. Chromium is a hazard element present in effluents of various industries that should be reduced to achieve the objectives of those policies. Most of the results reported in the literature concern the use of nanomaterials for chromium sorption dissolved either in synthetic or mono-elemental spiked solutions. The present work reviews the results of research undertaken in the last decade on the application of various nanomaterials to decrease chromium concentrations in contaminated waters. Major factors influencing the removal efficiency were examined. Because most of the published studies are based on simple experiments with deionised water and mono contamination further studies are suggested focused on effects of natural and artificial chelators, interferences of other trace elements competing with chromium sorption, reduction the sorbent mass per water volume. published

Plastic debris becomes a persistent contaminant in aquatic systems. The adherence of abiotic and biotic materials to plastics may potentiate structural changes and their degradation. How the major and minor elements present in sea water interact with polymers is largely unknown. Nuclear microprobe clusters PIXE and RBS techniques, which offer unique possibilities to characterize the materials deposited on the surface of plastics rejected to the aquatic environment. In particular, these techniques enable to examine the penetration of elements in deposits into the plastic structure. Food packaging polymers, high-density polyethylene (HDPE) and polyethylene terephthalate (PET) exposed to turbid water of the Tagus estuary were studied. The deposition mosaic contained clastic, biota and saline components. A major finding was the diffusion of the ion Cl- in the polymer matrix. This was possible by examining elemental profiles taken in transversal sections of the polymers. The depth structure of deposits was estimated using RBS and PIXE data applying the programs OMDAQ2007 and WiNDF, which illustrate the capabilities of these analytical tools in the micro-scale analysis of deposits. The results obtained pointed out for a multilayer depth structure which can decode the complex arrangement of cellular and sediment materials deposited on the polymer’s surface. In addition, it was possible to identify sources of uncertainties in simulating the interface and the changeable polymer matrix in sub-surface layers.

A obesidade é atualmente um dos principais problemas de saúde pública no Brasil e no mundo que gera várias outras comorbidades. O objetivo deste estudo foi analisar a composição corporal e as características dermatoglíficas de obesas mórbidas com o intuito de uma melhor orientação, prescrição e acompanhamento do treinamento físico. A amostra foi composta por 23 mulheres com valores médios com idade de 34,8 ± 3,6; massa corporal total de 118,6 ± 18,9 kg; estatura de 1,58 ± 0,06 metros e IMC de 47 ± 4,27 kg/m2. Os resultados do IMC = 47% classificaram as pacientes como obesas e a análise por segmentos, apresentaram aumento da gordura na parte central 48,2%, diminuição da massa livre de gordura 47,7% e água corporal total 41,7%. Concluiu-se, com os resultados deste estudo que, a partir do conhecimento da composição corporal é possível prescrever e acompanhar um treinamento físico através de dados dermatoglíficos. ABSTRACT Analysis of the profile of the corporal and dermatoglyphic composition of morbid obese women Obesity is currently one of the main public health problems in Brazil and in the world that’s generates several other comorbidities. The aims of this study was to analyze the body composition and the dermatogliphyc characteristcs of morbid obese with aim of better orientation, prescriptiion and follow up of the physical training. The sample consisted of 23 women with mean values of 34.8 ± 3.6; total body mass of 118.6 ± 18.9 kg; height of 1.58 ± 0.06 meters and BMI of 47 ± 4.27 kg / m2. The results of BMI = 47% classified the patients as obese and the analysis by segments, showed a fat increase in the central part 48,2%, decrease in fat free mass, and total body water 41,7%. It was concluded, with the results of this study that, from the aknowledge of the body composition it´s possible to prescribe and follow a physical training through dermatoglypic data.

The Manila clam Ruditapes philippinarum is an invasive bivalve in Europe, widely distributed, with a great ability to tolerate a broad range of environmental conditions. Despite the ability to reflect contamination, its suitability as bioindicator is not consensual. This study provided clarification on this issue by evaluating the ability of R. philippinarum to signalise trace element contamination in an estuary chronically impacted by metals and metalloids (Tagus estuary, Portugal). A multidimensional approach was carried out in two differently contaminated sites (Barreiro – BAR; Alcochete – ALC) in warm and cold periods, combining sediment contamination, bioaccumulation of trace elements (As, Cd, Pb and Hg), and a battery of oxidative stress biomarkers in two R. philippinarum organs (digestive gland and gills). Sediments from BAR exhibited higher concentrations of all the elements than those from ALC, in line with the anthropogenic pressures identified for both estuarine areas. Likewise, clams from BAR showed higher concentrations of As and Pb in the digestive gland (cold period) and Pb in the gills (warm and cold periods) in comparison with ALC. These results suggest the capacity of R. philippinarum to reflect external levels of exposure to those elements into tissue loads. However, an opposite spatial variation was consistently found for Hg accumulation in the digestive gland and gills in both periods, as well as for Cd in the gills in the warm season. The results reinforce the idea that trace element accumulation patterns depend not only on the external bioavailability, but also on the toxicokinetics that is trace element-specific. Despite the two contrasting patterns found for bioaccumulation in R. philippinarum (mainly Pb vs. Hg), oxidative stress parameters were able to signalise BAR as the most impacted area. In fact, the digestive gland of BAR clams exhibited higher GST activity and GSHt levels (in both sampling periods) and SOD activity (warm season), presumably to cope with the enhanced accumulation of Pb and As. Moreover, variations of gills’ CAT and SOD activities (warm period) agreed with the elevated accumulation of Pb at BAR. Overall, the characteristics of this invasive species could lead to a biased interpretation of the environmental quality status, particularly when based on trace element bioaccumulation only, reinforcing the need to adopt a multi-level/-species approach on environmental assessment studies.

Marine bivalves are bioindicators of coastal environmental pollution, integrating monitoring programs worldwide. Nonetheless, the choice of particular species as an indicator requires validation, achieved by understanding the differences in element concentrations among and within species. The present study compares the chemical composition of whole body soft tissues of four common bivalve species from the Bijagos Archipelago, a pristine region of West Africa. Significant differences were recorded in the concentrations of various elements among studied species, which likely arise from species-specific uptake and bioaccumulation processes. Overall, there was a segregation between a group including the bloody cockle Senilia senilis and oyster Crassostrea tulipa (with high Cd and Zn concentrations) versus the two other species, Austromacoma nymphalis (with low Cu and high Mn, Se, Hg, Pb concentrations) and Diplodonta spp. (with high values of Cu, Al, Fe, V, Cr, Hg, Pb). C. tulipa was sampled in two different substrates (rock beds and mangrove roots), and the two groups revealed different chemical profiles, with significantly higher concentrations of P, Si, Zn and Cr and lower Cu in specimens fixed in mangrove roots. These results strongly suggest the influence of small-scale environmental variability on the accumulation of particular elements. We found extremely high Cd concentrations in S. senilis (27.1 ± 7.53 μg g−1 DW) and identified C. tulipa as another high Cd-accumulating species (ca. 10 μg g−1 DW). Our results suggest a detoxifying mechanism linked with the presence of Se to reduce the potential toxic effects of Cd in these two species. Cadmium concentrations reported for some bivalve species in this area largely exceed the maximum values proposed by the European Union, emphasizing the need for a regular contamination assessment.

The release of potentially toxic elements into the environment, and their effects on aquatic ecosystems still present a real threat. To avoid such contamination, the use of biological sorbents as an alternative to conventional and expensive water remediation techniques has been proposed. The present study evaluated the potential of 0.5 g L−1 of peanut, hazelnut, pistachio, walnut, and almond shells to remove the requisite concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) from contaminated water. Hazelnut shells were identified as the sorbent with the highest potential and were evaluated in mono- and multi-contaminated mineral water. The influence of sorbent-intrinsic and solution-intrinsic characteristics were assessed. Differences among sorbents were attributed to varying percentages of their main components: cellulose, hemicellulose, and lignin. Matrix complexity increase caused a decrease in Cd removal, presumably due to the diminution in electrostatic interaction, and complexation with anions such as Cl-. When simultaneously present in the solution, contaminants competed, with Pb showing higher affinity to the sorbent than Hg. High efficiencies (&gt, 90%) obtained for hazelnut shells for all elements in ultrapure water and for Pb and Hg in mineral water) reveals the high potential of this low-cost and abundant waste for use in the remediation of contaminated waters (circular economy).

The simultaneous determination of major, trace, and rare earth elements in sediments requires the development of specific procedures to prevent interfer- ences. A single digestion method adapted from the EPA method 3051A is proposed for the quantification of 42 elements in sediments by inductively coupled plasma techniques associated with optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP- MS). A combination of different acids and microwave- assisted acid extraction following hot plate extraction was tested. Evaluation of applicability range, linearity, limits of detection and quantification, selectivity, repeat- ability, intermediate precision, and trueness showed the accurate determination of all elements. Selectivity, pre- cision, and trueness values were below the criteria established by the laboratory. The applicability of the proposed method was tested in real sediment samples. For each element, difference between duplicates was lower than the corresponding repeatability limit, with the coefficients of variation ranging between 1.7 and 14%. These results point to the usefulness of this meth- od in multi-element determination of major, minor, trace, and REE in sediment samples, showing its appli- cability in environmental studies related, namely to sediment characterization, monitoring programs, assess- ment of environmental impacts, sediment provenance, and post-depositional mechanisms. This work was developed within the scope of the projects LAQV-REQUIMTE (UIDB/50006/2020), CICECO (UIDB/50011/2020+UIDP/50011/2020), CESAM (UIDB/50017/2020+UIDP/50017/2020), and CIIMAR (UID/Multi/04423/2019), funded national funds through the FCT/ MEC, and co-funded by the FEDER, within the PT2020 Partnership Agreement and COMPETE2020. Authors thank to Euromargins MVSeis Project (01-LEC-EMA24F; PDCTM72003/DIV/40018). Rui Monteiro also acknowledges FCT– Fundação para a Ciência e a Tecnologia, I.P., for his grant (SFRH/BD/108535/2015), A. T. Reis for her grant (SFRH/BPD/ 122112/2016), and Bruno Henriques his Research position funded by national funds (OE), through FCT, in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/ 2017, of July 19. info:eu-repo/semantics/publishedVersion

Mercury is a very toxic metal that persists and accumulates in the living organisms present in the aquatic systems and its elimination is an urgent need. Two green (Ulva intestinalis and Ulva lactuca), brown (Fucus spiralis and Fucus vesiculosus), and red (Gracilaria sp. and Osmundea pinnatifida) marine macroalgae were tested for mercury removal from saline waters. The ability of each species was evaluated to the initial mercury concentrations of 50, 200, and 500 μg dm-3 along 72 h. In general, all species exhibited good performances, removing 80.9–99.9% from solutions with 50 μg dm-3, 79.3–98.6% from solutions with 200 μg dm-3, and 69.8–97.7% from solutions containing 500 μg dm-3 of mercury. Among the macroalgae, Ulva intestinalis showed the highest affinity to mercury and it presented an uptake ability up to 1888 μg g-1 of Hg(II) and bioconcentration factors up to 3823, which proved its promising potential on Hg removal.

Water is an essential resource on Earth and the maintenance of its quality led to the incentive of water reuse programmes. Among the most relevant contaminants, mercury is recognized for its toxicity and biomagnifications along the food chain, reason why its removal from aqueous solutions was studied in this essay using two microporous materials for the first time. The ability of a niobium silicate, called AM-11 (Aveiro-Manchester No 11), and of a vanadium silicate, AM-14 (Aveiro-Manchester No 14), were assessed under batch conditions, at fixed temperature and pH. These microporous materials were synthesized and characterized by SEM, PXRD, ICP-OES, TGA and elemental analysis. Because of their excellent ion exchange properties, equilibrium and kinetics assays were performed using only a few mg dm−3 of material. The most relevant two- and three-parameter isotherms were used to fit the experimental data. Langmuir isotherm adjusted better the AM-11 data (deviation of 3.58 %, R adj 2 =0.980, AIC =52.8), predicting a maximum uptake of 161 mg g−1, while the AM-14 data were better fitted by the Temkin model (deviation of 3.92 %, R adj 2 =0.985, AIC =54.2). The kinetic study was performed using Elovich, pseudo-first order and pseudo-second order models. The pseudo–second order and Elovich equations provided the best fits for both materials. The Elovich equation achieved a better correlation in the initial branch while the pseudo-second order expression was more efficient for the horizontal branch. The intraparticle diffusivities of counter ions were also assessed using a kinetic model based on the Nernst-Plank equations. Performance of these two microporous materials to remove mercury has been compared with other sorbents, highlighting their potential as ion exchangers.

Marine toxins in bivalves pose an important risk to human health, and regulatory authorities throughout the world impose maximum toxicity values. In general, bivalve toxicities due to paralytic shellfish toxins (PSTs) above the regulatory limit occur during short periods, but in some cases, it may be extended from weeks to months. The present study examines whether cockles (Cerastoderme edule), mussels (Mytilus galloprovincialis) and razor shells (Solen marginatus) naturally exposed to a bloom of Gymnodinium catenatum activated or suppressed biochemical responses as result of the presence of PSTs in their soft tissues. Toxins (C1+2, C3+4, GTX5, GTX6, dcSTX, dcGTX2+3 and dcNEO) and a set of biomarkers (ETS, electron transport system activity; GLY, glycogen; PROT, protein; SOD, superoxide dismutase; CAT, catalase; GPx, glutathione peroxidase; GST, glutathione S-transferases; LPO, lipid peroxidation; reduced (GSH) and oxidized (GSSG) glutathione contents and AChE, acetylcholinesterase activity) were determined in the three bivalve species. Specimens were harvested weekly in Aveiro lagoon, Portugal, along thirteen weeks. This period included three weeks in which bivalve toxicity exceeded largely the regulatory limit and the subsequence recovery period of ten weeks. Biochemical performance of the surveyed species clearly indicated that PSTs induce oxidative stress and neurotoxicity, with higher impact on mussels and razor shells than in cockles. The antioxidant enzymes CAT and GPx seemed to be the biomarkers better associated with toxin effects.

The present study tested under laboratorial conditions the sorption of okadaic acid (OA), a lipophilic toxin produced by marine phytoplankton, onto 6-mm plastic circular fragments. Fragments (4 g L−1) of polyethylene terephthalate (PET), polypropylene (PP), expanded polystyrene (EPS) and non-expanded polystyrene (PS) were exposed for 96 h to seawater spiked with 10 ng mL−1 of OA. Results of the experiments showed a broad percentage of OA removed from the water by plastics after 48 h of exposure: 30 ± 5.1% (PET), 37 ± 9.5% (PP), 62 ± 7.1% (EPS) and 83 ± 1.9% (PS). Sorption appears to be highly influenced by polymer's characteristics, such as polarity and degree of crystallinity. Further studies are needed to clarify the effect of the contact area on sorption by expanded plastics. These results point to the plausible interaction of OA and plastics in coastal waters.

Concentrations of 16 elements (K, Na, Mg, Ca, Fe, Zn, Hg, Se, As, Cu, Cd, Mn, Ni, Cr, Pb and Co) were determined in dorsal white and dark muscle of Xiphias gladius, sampled at various positions of a single swordfish and at the same position of eight specimens. Hg was quantified by thermal decomposition atomic absorption spectrometry (LECO AMA-254) and the rest of the elements by inductively coupled plasma optical emission spectrometry (ICP OES) or mass spectrometry (ICP MS). Element partitioning differed in dark and white muscle. Dark muscle was particularly enriched in Fe (median 13 times) and Cu (9) and moderately enhanced in Se, Mn, Zn and Cd (2.8–4.0). Dark:white ratios of the potentially toxic elements (As, Cr, Hg, Ni and Pb) varied from 0.9 to 1.4, pointing to a similar distribution between the two muscles types and indicating no additional risk in the consumption of dark muscle.

Mercury (Hg) removal by six different living marine macroalgae, namely, Ulva intestinalis, Ulva lactuca, Fucus spiralis, Fucus vesiculosus, Gracilaria sp., and Osmundea pinnatifida was investigated in mono and multi-contamination scenarios. All macroalgae were tested under the same experimental conditions, evaluating the competition effects with all elements at the same initial molar concentration of 1 μmol dm−3. The presence of the main potentially toxic elements (Cd, Cr, Cu, Ni, and Pb) and rare earth elements (La, Ce, Pr, Nd, Eu, Gd, Tb, and Y) has not affected the removal of Hg. Characterizations of the macroalgae by FTIR before and after the biosorption/bioaccumulation assays suggest that Hg was mainly linked to sulfur-functional groups, while the removal of other elements was related with other functional groups. The mechanisms involved point to biosorption of Hg on the macroalgae surface followed by possible incorporation of this metal into the macroalgae by metabolically active processes. Globally, the green macroalgae (Ulva intestinalis, Ulva lactuca) showed the best performances for Hg, potential toxic elements and rare earth elements removal from synthetic seawater spiked with 1 μmol dm−3 of each element, at room temperature and pH 8.5.

Spinel ferrite particles (Fe3O4, MnFe2O4, and CoFe2O4) were investigated as magnetic nanosorbents for removing arsenic from spiked water samples. The nanosorbents were collected via magnetic separation from aqueous solutions spiked with an arsenic concentration that mimics the amount of this contaminant in real water samples. This research shows that using amounts of CoFe2O4 or MnFe2O4 as low as 40 mg/L, the arsenic content in the contaminated water decreased for levels below the maximum admitted value by the World Health Organization for drinking waters (10 μg/L). Moreover, these magnetic nanosorbents also showed good performance for As(V) sorption, when applied to aqueous matrices with variable ionic strength and in the mixtures of other several hazardous contaminants. The good performance observed for the MnFe2O4 and CoFe2O4 ferrites contrasts with the one observed for Fe3O4 nanosorbent, whose efficiency is lower in the removal of As(V) from water, nevertheless increased with the presence of other elements in solution.

Different experimental conditions were tested in order to optimize the Hg(II) removal by Eucalyptus globulus bark. Response surface methodology was applied to extract information about the significance of the factors and to obtain a model describing the sorption. The results were generated through the design of experiments by applying the methodology of a three-factor and three-level Box&ndash, Behnken design. The factors tested were pH (4.0, 6.5, and 9.0), salinity (0, 15, and 30), and biosorbent dosage (0.2, 0.5, and 0.8 g dm&minus, 3) to evaluate the Hg(II) removal using realistic conditions, such as contaminated natural waters with an initial Hg(II) concentration of 50 &micro, g dm&minus, 3. The optimum response provided by the model was 81% of the metal removal under the optimal operating conditions: a pH value of 6.0, no salinity, and a biosorbent dosage of 0.55 g dm&minus, 3. Concerning the kinetic, the pseudo-second-order equation fitted better to the experimental results with R 2 between 0.973 and 0.996. This work highlights the promising valorization of this biomass, which is an industrial byproduct and makes available information about the influence of the variables for Hg(II) removal in water treatment processes.

The growing economic interest in the exploitation of mineral resources on deep-ocean beds, including those in the vicinity of sensitive-rich habitats such as hydrothermal vents, raise a mounting concern about the damage that such actions might originate to these poorly-know ecosystems, which represent millions of years of evolution and adaptations to extreme environmental conditions. It has been suggested that mining may cause a major impact on vent ecosystems and other deep-sea areas. Yet, the scale and the nature of such impacts are unknown at present. Hence, building upon currently available scientific information it is crucial to develop new cost-effective technologies embedded into rigorous operating frameworks. The forward-thinking provided here will assist in the development of new technologies and tools to address the major challenges associated with deep sea-mining; technologies for in situ and ex situ observation and data acquisition, biogeochemical processes, hazard assessment of deep-sea mining to marine organisms and development of modeling tools in support of risk assessment scenarios. These technological developments are vital to validate a responsible and sustainable exploitation of the deep-sea mineral resources, based on the precautionary principle.

The photodegradation kinetics of the neonicotinoid insecticide acetamiprid (ACT) was investigated under different conditions of pH, salinity and dissolved organic matter (DOM). Photodegradation of ACT in saline and freshwaters followed pseudo-first-order kinetics. Varying pH from 5 to 9 did not significantly affect the photodegradation rate constants (kp) of ACT. Addition of chloride ions increased significantly the value of kp. In the presence of AHA, 10 mg L−1, kp was reduced to approximately 34% of that in sodium chloride solutions 35 g L−1 The observed inhibition may be a consequence of the antioxidant properties of DOM and/or the shading of DOM in the solution. In coastal waters, kp showed a tendency to increase with increasing of salinity and to decrease in the presence of DOM. This is an important outcome since coastal lagoons are important and dynamic systems that are likely to be highly influenced by global climate changes. info:eu-repo/semantics/publishedVersion

Sixty sediment samples from four sites in the Bijagos archipelago were characterized for fine fraction, loss on ignition, major, minor and trace elemental composition (Al, Fe, Ca, Mg, Ti, P, Zr, Mn, Cr, Sr, Ba, B, V, Li, Zn, Ni, Pb, As, Co, U, Cu, Cs and Cd), and the elements of the La–Lu series. Element concentrations were largely explained by the Al content and the proportion of fine fraction content, with the exception of Ca and Sr. Sediments showed enhanced Ti, U, Cr, As and Cd concentrations with respect to estimated upper crust values, most likely mirroring a regional signature. Rare earth elements were in deficit relatively to the North American Shale Composite (NASC), mainly in coarser material. No pronounced Ce-anomaly was observed, while Eu-anomalies were positive in most analyzed sediments.

The experiments performed in this work proved the ability of Gracilaria gracilis to concentrate and recover Critical Rare Elements (CRE) from contaminated waters. The importance of recycling these elements is related to their very limited sources in Nature and progressive use in technologies. Moreover, their mining exploitation has negative environmental impact, and recent studies point them as new emerging pollutants. To the best of our knowledge, this is the first report on the application of living macroalgae for the removal and recovery of CRE. G. gracilis (2.5gL-1, fresh weight) was exposed to mono- and multi-element saline solutions of 500μgL-1 of Y, Ce, Nd, Eu and La. Removal was up to 70% in 48h, with bioaccumulation following Elovich kinetic model. In multi-element solutions, selectivity was not observed although removal of lanthanides improved comparatively to single-element solutions. No mortality or adverse effect on growth was registered. The subsequent macroalgae digestion allowed collecting virtually 100% of all elements in a 300-fold more concentrated solution. The overall results suggest the application of living macroalgae as a simple and effective alternative technology for removing and recovering CRE from wastewaters, contributing to an improvement of water quality and CRE recycling.

The influence of nutritional regime and water temperature on depuration rates of OA-group toxins in the wedge shell Donax trunculus was examined by exposing naturally contaminated specimens to three nutritional regimes (microalgae, commercial paste of microalgae, and starvation) for 14 days at 16 °C and 20 °C. Total OA was quantified in the whole soft tissues of the individuals collected in days 2, 4, 6, 8, 10, 12 and 14. Mortality, dry weight, condition index, gross biochemical composition and gametogenic stages were surveyed. Low variation of glycogen and carbohydrates during the experiments suggest that wedge shells were under non-dramatic stress conditions. Wedge shells fed with non-toxic diets showed similar depuration rates being 15 and 38% higher than in starvation, at 16 and 20 °C, respectively. Depuration rates under non-toxic diets at 20 °C were 71% higher than at 16 °C. These results highlight the influence of water temperature on the depuration rate of total OA accumulated by D. trunculus, even when the increase is of only 4 °C, as commonly observed in week time scales in the southern Portuguese coastal waters. These results open the possibility of a faster release of OA in harvested wedge shells translocated to depuration systems when under a slight increase of water temperature.

Mud volcanoes are feature of the coastal margins where anaerobic oxidation of methane triggers geochemical signals. Elemental composition, percentage of fine particles and loss on ignition were determined in sediment layers of eleven gravity cores retrieved from four mud volcanoes (Sagres, Bonjardim, Soloviev and Porto) and three undefined structures located on the deep Portuguese margin of the Gulf of Cadiz. Calcium was positively correlated to Sr and inversely to Al as well as to most of the trace elements. Vertical profiles of Ba, Cd and As concentrations, and their ratios to Al, in Porto and Soloviev showed pronounced enhancements in the top 50-cm depth. Sub-surface enhancements were less pronounced in other mud volcanoes and were absent in sediments from the structures. These profiles were interpreted as diagenetic enrichments related to the anaerobic oxidation of methane originated from upward methane-rich fluxes. The observed barium fronts were most likely caused by the presence of barite which precipitated at the sulphate-methane transition zone. Cd and As enrichments have probably resulted from successive dissolution/precipitation of sulphides in response to vertical shifts of redox boundaries.

Wild fish (Cyprinus carpio, Mugil cephalus, Platichthys flesus) from an estuary of the NE Atlantic coast were investigated for plastic contamination (N = 128). From the 1289 particles recovered from fish samples, 883 were plastics. Among these, 84% were fibres and 97% were microplastics. Thirty-six polymers were identified. The number of microplastics (mean ± SD) per individual fish (MP/fish) was 8 ± 6 in C. carpio, 10 ± 9 in M. cephalus and 2 ± 2 in P. flesus. The means of MP/fish per body site were 6 ± 7 in gastrointestinal tract, 0.5 ± 1.1 in gills, 0.3 ± 0.7 in liver and 0.6 ± 1.2 in muscle samples. A few large fibres in liver (≤ 4841 μm) and muscle (≤ 5810 μm) samples were found. The results evidence the existence of high fish contamination by microplastics and reinforce the need of further research on plastic pollution in estuaries.