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1.
Chemosphere ; 242: 125268, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896175

RESUMO

This study investigated chlorinated transformation products (TPs) and their parent micropollutants, aromatic pharmaceuticals and personal care products (PPCPs) in the urban water bodies of two metropolitan cities. Nine PPCPs and 16 TPs were quantitatively or semi-quantitatively determined using isotope dilution techniques and liquid chromatography-tandem mass spectrometry. TPs and most PPCPs were effectively removed by conventional wastewater treatments in a wastewater treatment plant (WWTP). Chlorinated parabens and all PPCPs (at concentrations below 1000 ng/L) were present in the waters receiving treated wastewater. By contrast, the waters receiving untreated wastewater contained higher levels of PPCPs (up to 9400 ng/L) and more species of chlorinated TPs including chlorinated parabens, triclosan, diclofenac, and bisphenol A. The very different chemical profiles between the water bodies of the two cities of similar geographical and climatic properties may be attributed to their respective uses of chemicals and policies of wastewater management. No apparent increase in the number of species or abundances of TPs was observed in either the chlorinated wastewater or the seawater rich in halogens. This is the first study to elucidate and compare the profiles of multiple TPs and their parent PPCPs in the water bodies of coastal cities from tropical islands. Our findings suggest that chlorinated derivatives of bisphenol A, diclofenac, triclosan, and parabens in the surface water originate from sources other than wastewater disinfection or marine chlorination. Although further studies are needed to identify the origins, conventional wastewater treatments may protect natural water bodies against contamination by those chlorinated substances.


Assuntos
Desinfecção/métodos , Monitoramento Ambiental/métodos , Água do Mar/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Cromatografia Líquida , Cidades , Cosméticos/análise , Halogenação , Preparações Farmacêuticas/análise , Taiwan
2.
Chemosphere ; 240: 124821, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31546185

RESUMO

Anthropogenic CO2 emissions lead to seawater acidification that reportedly exerts deleterious impacts on marine organisms, especially on calcifying organisms such as mussels. A 21-day experiment focusing on the impacts of seawater acidification on the blue mussel, Mytilus edulis, was performed in this study, within which two acidifying treatments, CO2 enrichment and HCl addition, were applied. Two acidifying pH values (7.7 and 7.1) and the alteration of the key physiological processes of ingestion and digestion were estimated. To thoroughly investigate the impact of acidification on mussels, a histopathological study approach was adopted. The results showed that: (1) Seawater acidification induced either by CO2 enrichment or HCl addition impaired the gill structure. Transmission electron microscope (TEM) results suggested that the most obvious impacts were inflammatory lesions and edema, while more distinct alterations, including endoplasmic reticulum edema, nuclear condensation and chromatin plate-like condensation, were placed in the CO2-treated groups compared to HCl-treated specimens. The ciliary activity of the CO2 group was significantly inhibited simultaneously, leading to an obstacle in food intake. (2) Seawater acidification prominently damaged the structure of digestive glands, and the enzymatic activities of amylase, protease and lipase significantly decreased, which might indicate that the digestion was suppressed. The negative impacts induced by the CO2 group were more severe than that by the HCl group. The present results suggest that acidification interferes with the processes of ingestion and digestion, which potentially inhibits the energy intake of mussels.


Assuntos
Ácidos/efeitos adversos , Dióxido de Carbono/efeitos adversos , Ácido Clorídrico/efeitos adversos , Mytilus edulis/efeitos dos fármacos , Água do Mar/química , Ácidos/química , Animais , Dióxido de Carbono/farmacologia , Homeostase/efeitos dos fármacos , Ácido Clorídrico/farmacologia
3.
Chemosphere ; 240: 124883, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726606

RESUMO

A coupled algal-osmosis membrane treatment system was studied for recovering potable-quality water from municipal primary effluent. The core components of the system included a mixotrophic algal process for removal of biochemical oxygen demand (BOD) and nutrients, followed by a hybrid forward osmosis (FO)-reverse osmosis (RO) system for separation of biomass from the algal effluent and production of potable-quality water. Field experiments demonstrated consistent performance of the algal system to meet surface discharge standards for BOD and nutrients within a fed-batch processing time of 2-3 days. The hybrid FO-RO system reached water productivity of 1.57 L/m2-h in FO using seawater as draw solution; and permeate flux of 3.50 L/m2-h in brackish water RO (BWRO) and 2.07 L/m2-h in seawater RO (SWRO) at 2068 KPa. The coupled algal-membrane system achieved complete removal of ammonia, fluoride, and phosphate; over 90% removal of calcium, sulfate, and organic carbon; and 86-89% removal of potassium and magnesium. Broadband characterization using high resolution mass spectrometry revealed extensive removal of organic compounds, particularly wastewater surfactants upon algal treatment. This study demonstrated long-term performance of the FO system at water recovery of 90% and with membrane cleaning by NaOH solution.


Assuntos
Reatores Biológicos/microbiologia , Água Potável/análise , Membranas Artificiais , Rodófitas/crescimento & desenvolvimento , Purificação da Água/métodos , Filtração/métodos , Compostos Orgânicos/análise , Osmose , Águas Salinas/química , Água do Mar/química , Águas Residuárias/química , Poluentes Químicos da Água/análise
4.
Chemosphere ; 238: 124560, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31437632

RESUMO

Plastics are the most abundant marine debris globally dispersed in the oceans and its production is rising with documented negative impacts in marine ecosystems. However, the chemical-physical and biological interactions occurring between plastic and planktonic communities of different types of microorganisms are poorly understood. In these respects, it is of paramount importance to understand, on a molecular level on the surface, what happens to plastic fragments when dispersed in the ocean and directly interacting with phytoplankton assemblages. This study presents a computer-aided analysis of electron paramagnetic resonance (EPR) spectra of selected spin probes able to enter the phyoplanktonic cell interface and interact with the plastic surface. Two different marine phytoplankton species were analyzed, such as the diatom Skeletonema marinoi and dinoflagellate Lingulodinium polyedrum, in absence and presence of polyethylene terephthalate (PET) fragments in synthetic seawater (ASPM), in order to in-situ characterize the interactions occurring between the microalgal cells and plastic surfaces. The analysis was performed at increasing incubation times. The cellular growth and adhesion rates of microalgae in batch culture medium and on the plastic fragments were also evaluated. The data agreed with the EPR results, which showed a significant difference in terms of surface properties between the diatom and dinoflagellate species. Low-polar interactions of lipid aggregates with the plastic surface sites were mainly responsible for the cell-plastic adhesion by S. marinoi, which is exponentially growing on the plastic surface over the incubation time.


Assuntos
Diatomáceas/metabolismo , Dinoflagelados/metabolismo , Microalgas/crescimento & desenvolvimento , Fitoplâncton/metabolismo , Plásticos/metabolismo , Polietilenotereftalatos/metabolismo , Ecossistema , Espectroscopia de Ressonância de Spin Eletrônica , Microalgas/metabolismo , Oceanos e Mares , Água do Mar/química , Resíduos/análise
5.
Sci Total Environ ; 700: 134464, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31689648

RESUMO

Ocean acidification (OA) and warming currently threaten coastal ecosystems across the globe. However, it is possible that the former process could actually benefit marine plants, such as seagrasses. The purpose of this study was to examine whether the effects of the seagrass Thalassia hemprichii can increase the resilience of OA-challenged coral reef mesocosms whose temperatures were gradually elevated. It was found that seagrass shoot density, photosynthetic efficiency, and leaf growth rate actually increased with rising temperatures under OA. Macroalgal growth rates were higher in the seagrass-free mesocosms, but the calcification rate of the model reef coral Pocillopora damicornis was higher in coral reef mesocosms featuring seagrasses under OA at 25 and 28 °C. Both the macroalgal growth rate and the coral calcification rate decreased in all mesocosms when the temperature was raised to 31 °C under OA. However, the variation in gross primary production, ecosystem respiration, and net ecosystem production in the seagrass mesocosms was lower than in seagrass-free controls, suggesting that the presence of seagrass in the mesocosms helped to stabilize the metabolism of the system in response to simulated climate change.


Assuntos
Antozoários/fisiologia , Recifes de Corais , Hydrocharitaceae/fisiologia , Animais , Mudança Climática , Concentração de Íons de Hidrogênio , Água do Mar/química , Temperatura Ambiente
6.
Sci Total Environ ; 701: 134794, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31715479

RESUMO

Multiple lines of evidence, ranging from time series field observations to climate change stimulation experiments demonstrate the negative effects of global warming and ocean acidification (OA) on bivalve molluscs. The impact of global warming on bivalve aquaculture has recently been reviewed. However, the impact of OA on bivalve aquaculture has received relatively less attention. Although there are many reports on the effects of OA on bivalves, this information is poorly organized and the connection between OA and bivalve aquaculture is unclear. Therefore, understanding the potential impact of acidification on ecosystems and bivalve aquaculture is of prime importance. Here, we provide a comprehensive scientific review of the impact of OA on bivalves and propose mitigation measures for future bivalve farming. This information will help to establish aquaculture and fisheries management plans to be implemented in commercial fisheries and nature conservation. In general, scientific evidence suggests that OA threatens bivalves by diminishing the availability of carbonate minerals, which may adversely affect the development of early life stages, calcification, growth, byssus attachment and survival of bivalves. The Integrated multi-trophic aquaculture (IMTA) approach is a useful method in slowing the effects of climate change, thereby providing longer adaptation period for bivalves to changing ocean conditions. However, for certain regions that experience intense OA effects or for certain bivalve species that have much longer generational time, IMTA alone may not be sufficient to protect bivalves from the adverse effects of climate change. Therefore, it is highly recommended to combine IMTA and genetic breeding methods to facilitate transgenerational acclimation or evolution processes to enhance the climate resilience of bivalves.


Assuntos
Aquicultura/métodos , Bivalves , Animais , Aquecimento Global , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar/química
7.
Chemosphere ; 238: 124641, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31466001

RESUMO

Seawater reverse osmosis (SWRO) brine contain many valuable resources. In this study, fractional-submerged membrane distillation crystallizer (F-SMDC) was used to recover sodium sulfate (Na2SO4) from SWRO brine. The concentration/temperature gradient (CG/TG) in the reactor enhanced water recovery utilizing MD and Na2SO4 crystallization via a crystallizer. Crystals were not obtained at the bottom section of the F-SMDC due to: firstly, calcium sulfate crystallization occurring on the membrane surface; and secondly, low temperature-sensitivity solubility component such as NaCl exerting a negative influence. In order to obtain supersaturation, a sulfate-rich scenario was created in the reactor through the addition of the following three components: Na2SO4, MgSO4 and (NH4)2SO4. When Na2SO4 and MgSO4 were added, a larger concentration was observed at the top section, resulting in a low concentration gradient (CG) ratio, i.e. around 1.7. Conversely, the addition of (NH4)2SO4 achieved faster Na2SO4 crystallization (VCF 1.42) at the bottom section with a greater CG ratio of more than 2.0. Total water recovery ratio of 72% and 223.73 g Na2SO4 crystals were successfully extracted from simulated SWRO brine using laboratory scale F-SMDC.


Assuntos
Destilação/métodos , Sais/química , Sulfatos/isolamento & purificação , Cristalização , Membranas Artificiais , Osmose , Água do Mar/química , Solubilidade , Temperatura Ambiente
8.
Chemosphere ; 239: 124696, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726529

RESUMO

Brine disposal is a major drawback for seawater desalination. Membrane distillation (MD) is an emerging technology to treat a high saline water including brine disposal instead of reverse osmosis, multi-stage flash and multi-effect distillation. This study investigated a pilot scale of a spiral-wound air gap MD (AGMD) module and evaluated its efficiency. A pilot-scale AGMD module with design production capacity of 10 m3/d was operated. Experiments with varying flow velocity showed increasing trend of water vapor flux as flow velocity increases. The temperature is one of the significant points in maximizing water permeate vapor flux in MD. Increasing temperature from 65 °C to 75 °C in evaporator channel has increased flux from 0.59 to 1.15 L/m2/h. Under various conditions, specific thermal energy consumption (STEC) and gained output ratio (GOR) was used to analyze energy efficiency. The pilot plant showed high GOR value in spite of a limited heating and cooling source available at the site. The highest GOR achieved was 3.54 with STEC of 182.78 kWh/m3. This study provides an overview of operation experience and its data analysis related to temperature, concentration, flow rate and energy supply.


Assuntos
Destilação/métodos , Membranas Artificiais , Sais/análise , Purificação da Água/métodos , Destilação/instrumentação , Temperatura Alta , Osmose , Projetos Piloto , Água do Mar/química , Água/química
9.
Environ Monit Assess ; 192(1): 14, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811395

RESUMO

The potential influence of short-period (May-June 2012) dredging activities (for the installation of a submarine gas pipeline) on physical properties of the marine environment of two shallow-water sites in the Aliveri and Varnavas areas of South Euboean Gulf (Greece) has been evaluated. During the dredging operation in Varnavas, the induced dredge plume traveled up to ~ 750 m from the shoreline, featured by light attenuation coefficient (cp) maxima of 4.01-4.61 m-1 and suspended particulate matter (SPM) concentrations up to 6.01 mg L-1. After dredging the previous parameters reduced to the ambient seawater condition, ~ 0.45 m-1 and < 2.8 mg L-1 on average, respectively. Likewise in Aliveri, the dredging-associated sediment plume drifted offshore up to ~ 400 m from the shoreline, characterized by cp maxima of 2.11-4.86 m-1 and SPM concentrations up to 13.07 mg L-1. After the completion of the excavation and trenching activities, the cp and SPM values were restored to the pre-disturbance condition, ~ 0.6 m-1 and < 2.2 mg L-1 on average, respectively. The migration of the dredge plume in both dredging sites was accomplished through the formation of intermediate and benthic nepheloid layers, whose development and evolution were governed by seawater stratification and flow regime. The dredging-derived SPM levels appeared to increase within a distance of no more than 300 m from the shoreline (near-field zone). Based on data from the literature, this SPM enhancement together with the deposition of a post-dredging residual mud veneer in the near-field zone could deteriorate local marine biota, but in a reversible way.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Material Particulado/análise , Água do Mar/química , Grécia , Mar Mediterrâneo , Indústria de Petróleo e Gás/normas , Navios , Tempo , Poluentes Químicos da Água/análise
10.
Environ Pollut ; 255(Pt 3): 113363, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31614247

RESUMO

Microplastics can adsorb chemical pollutants such as metals or pharmaceuticals, and transferred them along the food chain. In this work, an investigation of the adsorption of Cd, Co, Cr, Cu, Ni, Pb and Zn by five different types of microplastics was performed in Milli-Q water and natural waters (seawater, urban wastewater and irrigation water) via a series of batch adsorption experiments. The effects of concentration of metals and physicochemical characteristics of polymers were particularly studied. Results revealed a significant adsorption of lead, chromium and zinc on microplastics, especially on polyethylene and polyvinyl chloride. In the case of polyethylene terephthalate, it showed little adsorption capacity. Specific surface, porosity and morphology are characteristics that affect the molecular interactions. The adsorption isotherms were better described by Langmuir model, which indicates that the main adsorption mechanism might be chemical adsorption. Finally, results obtained in natural waters indicated that dissolved organic matter may play a major role on metal adsorption on microplastics. Results showed an enhancement of metal adsorption in waters with high chemical and biological oxygen demands as urban wastewater and irrigation water.


Assuntos
Metais Pesados/química , Poluentes Químicos da Água/química , Adsorção , Cromo , Poluentes Ambientais , Metais Pesados/análise , Compostos Orgânicos , Plásticos , Água do Mar/química , Águas Residuárias , Água/química , Poluentes Químicos da Água/análise , Zinco
11.
Sci Total Environ ; 693: 133469, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31635008

RESUMO

To make robust projectios of the impacts of climate change, it is critical to understand how abiotic factors may interact to constrain the distribution and productivity of marine flora and fauna. We evaluated the effects of projected end of the century ocean acidification (OA) and warming (OW) on the thermal tolerance of an important living marine resource, the sea urchin Loxechinus albus, a benthic shallow water coastal herbivore inhabiting part of the Pacific coast of South America. After exposing young juveniles for a 1-month period to contrasting pCO2 (~500 and 1400 µatm) and temperature (~15 °C and 20 °C) levels, critical thermal maximum (CTmax) and minimum (CTmin) as well as thermal tolerance polygons were assessed based on self-righting success as an end point. Transcription of heat shock protein 70 (HSP70), a chaperone protecting cellular proteins from environmental stress, was also measured. Exposure to elevated pCO2 significantly reduced thermal tolerance by increasing CTmin at both experimental temperatures and decreasing CTmax at 20 °C. There was also a strong synergistic effect of OA × OW on HSP70 transcription levels which were 75 times higher than in control conditions. If this species is unable to adapt to elevated pCO2 in the future, the reduction in thermal tolerance and HSP response suggests that near-future warming and OA will disrupt their performance and reduce their distribution with ecological and economic consequences. Given the wider latitudinal range (6 to 56°S) and environmental tolerance of L. albus compared to other members of this region's benthic invertebrate community, OW and OA may cause substantial changes to the coastal fauna along this geographical range.


Assuntos
Monitoramento Ambiental , Ouriços-do-Mar/fisiologia , Água do Mar/química , Estresse Fisiológico , Animais , Mudança Climática , Concentração de Íons de Hidrogênio , Invertebrados , Oceanos e Mares , América do Sul , Temperatura Ambiente
12.
World J Microbiol Biotechnol ; 35(11): 167, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31650344

RESUMO

Codium tomentosum, as all organisms, hosts transiently and permanently numerous microorganisms. These holobionts can undergo environmental pressures influencing both partners creating modifications/imbalances within the associations, which may directly influence their physiological status by selecting tolerant bacteria. Furthermore, the capability of remediation of the associated bacterioflora, in particular of metallic trace elements, may provide the host with survival potential in polluted environments. In this context, we incubated C. tomentosum thalli in the presence of copper and studied its influence on the reference bacteriome. Whatever the concentration of copper, no shift was evidenced on the bacteriome at the phylum level. However, a high copper concentration enriched the bacteriome of C. tomentosum in both the genera Clostridium and Pseudolteromonas.


Assuntos
Bactérias/classificação , Bactérias/efeitos dos fármacos , Clorófitas/microbiologia , Cobre/toxicidade , Microbiota/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodiversidade , Microbiota/fisiologia , Água do Mar/química , Água do Mar/microbiologia , Alga Marinha/microbiologia , Oligoelementos , Poluentes da Água
13.
Nat Commun ; 10(1): 4742, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628346

RESUMO

Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins - but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean's largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval Antarctic krill.


Assuntos
Biomassa , Euphausiacea/fisiologia , Cadeia Alimentar , Spheniscidae/fisiologia , Baleias/fisiologia , Animais , Regiões Antárticas , Carbono/metabolismo , Ciclo do Carbono , Euphausiacea/crescimento & desenvolvimento , Água do Mar/química
14.
Bull Environ Contam Toxicol ; 103(6): 770-775, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31620816

RESUMO

Little is known about the presence and effects of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in Puerto Rico's waters. Four coastal aquatic systems were investigated using low-density polyethylene passive sampling for PCBs and OCPs in water and its overlying air. The highest total freely dissolved and gaseous concentrations of PCBs were found in Guánica Bay, with 4000 pg/L and 270 pg/m3, respectively. Five OCPs were detected, mainly in water, with greatest concentrations (pg/L) in Guánica Bay: α-HCH (7400), p,p'-DDE (390), aldrin (2000), dieldrin (420), and endrin (77). The compound α-HCH was also measured at elevated water concentrations in Condado Lagoon (5700 pg/L) and Laguna Grande (2900 pg/L). Jobos Bay did not show values of concern for these persistence organic pollutants. Levels of PCBs and OCPs in water, particularly in Guánica Bay, exceeded USEPA ambient water quality criteria values representing a human health risk regarding consumption of aquatic organisms.


Assuntos
Baías/química , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Humanos , Projetos Piloto , Bifenilos Policlorados/análise , Porto Rico
15.
Ecotoxicol Environ Saf ; 186: 109746, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31606641

RESUMO

In this paper, polypropylene (PP) nanofibers were prepared using the melt forcespinning technology by a handmade device. Then, the surface of PP nanofibers was grafted through the high energy electron beams (EB) pre-irradiation method by acrylonitrile and methacrylic acid monomers with grafting percentage of 145.55%. The 92% of grafted cyano functional groups on nanofibers were converted to amidoxime groups, then modified by an alkaline solution. Characterization and surface morphology of nanofibers were investigated by Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The produced adsorbent was used to adsorb U(VI) ions from simulated seawater. The maximum adsorption was 83.24 mg/g in the optimal time of 60 min and optimal pH of 4. The optimum desorption efficiency was 80% in HCl 0.5 M. The kinetic data in optimum conditions showed that the adsorption followed an S-shaped kinetic model. The Adsorption equilibrium studies presented S-shape isotherm model that confirmed the adsorption occurs both on the adsorbent surface and in its pores The thermodynamic studies indicated spontaneous adsorption of uranyl ions and the higher efficiency adsorption at higher temperatures. The selectivity of adsorbent for metal ions followed the order V(V)>U(VI)>CO(II)>Ni(II)>Fe(II). These results shows that the prepared and modified nanofibers in this work can be considered as an effective and promising adsorbents for removal of uranium ions from seawater with high efficiency.


Assuntos
Recuperação e Remediação Ambiental/métodos , Nanofibras/química , Polipropilenos/química , Água do Mar/química , Urânio/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
16.
Mar Pollut Bull ; 145: 118-125, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590767

RESUMO

The effects of short-term (7 days) experimental ocean acidification (-0.4 pH units) and warming (+5 °C) on anti-predator defenses of two sympatric Mytilus species from China, M. coruscus and M. edulis, in the presence and absence of predator cues were investigated. Results suggested species-specific independent negative effects of acidification and warming on the number and weight of byssal threads, the force of thread attachment, and total thread plaque area. Similar negative effects were observed for clustering behaviour, with acidification and warming independently increasing the number of solitary individuals and decreasing the percentage of mussels in clusters. Acidification effects on byssus were strongly exacerbated when predators were present. Ultimately, this study suggests that short-term exposure to experimental warming and acidification can negatively impact anti-predator defense strategies in mussels with potential ramifications for predator-prey interactions and ecological functioning in systems where mussel beds play a key ecological role.


Assuntos
Mytilus/fisiologia , Água do Mar/química , Temperatura Ambiente , Animais , Comportamento Animal , China , Concentração de Íons de Hidrogênio , Mytilus/classificação , Especificidade da Espécie
17.
Mar Pollut Bull ; 145: 14-22, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590770

RESUMO

The anthropogenic alteration of the nitrogen cycle results in the modification of the whole food web. And yet, the impact caused on nitrogen dynamics in marine systems is still very uncertain. We propose a workflow to evaluate changes to coastal nitrification by modelling nitrite dynamics, the intermediary compound. Nitrite concentrations were estimated with a simple steady state nitrification model, which was calibrated in 9 NW Mediterranean coastal sites with different anthropogenic pressures, located within 250 km. The results obtained indicate that nitrite peaks are observed in winter and explained by nitrification response to temperature, but these dynamics are altered in impacted coastal waters. We found the second step of nitrification to be more sensitive to temperature, which entails a significant impact of climate change on the decoupling of the two steps of nitrification. The results could be extrapolated to numerous coastal regions of the Mediterranean Sea with similar characteristics.


Assuntos
Nitrogênio/química , Água do Mar/química , Mar Mediterrâneo , Nitrificação , Nitritos/química , Ciclo do Nitrogênio , Estações do Ano , Temperatura Ambiente
18.
Mar Pollut Bull ; 145: 153-160, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590772

RESUMO

As a global pollutant, microplastics have attracted attention from the public and researchers. However, the lack of standard and time-saving methods for analysis has become one of the bottlenecks in microplastics research. Here, we demonstrate TGA coupled to FTIR to identify and quantify certain microplastics in environment. Samples were pyrolyzed in TGA and the pyrolysis gases were analyzed by FTIR. Combining TGA and FTIR data adds discriminatory power as temperature profiles and absorption spectra differ among several common plastics. To quantify on a mass basis, we calibrated on characteristic IR peaks at temperatures of maximum weight loss for individual polymers. The method can distinguish PVC, PS and was validated by spiking samples with known quantities of microplastics. The result of field sample experiments showed that TGA-FTIR can be used to identify and quantify PVC and PS in bivalves, seawater and soil. And the method may be applicable to environmental samples.


Assuntos
Plásticos/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Termogravimetria/métodos , Poluentes Químicos da Água/análise , Animais , Bivalves/química , China , Monitoramento Ambiental/métodos , Plásticos/química , Polímeros/análise , Polímeros/química , Reprodutibilidade dos Testes , Água do Mar/química , Poluentes do Solo/análise , Poluentes do Solo/química , Poluentes Químicos da Água/química
19.
Mar Pollut Bull ; 145: 306-315, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590792

RESUMO

Understanding the fate of spilled oil in cold environments is essential for oil spill response in Arctic areas. The potential for oils to adhere to sea ice and mechanical skimmers can significantly impact the success of oil spill response and influence the fate of oil in the marine environment. Therefore, the affinity of oil to sea ice and skimmer material was quantified experimentally for three different types of oils at various degrees of weathering. Contact angle measurements of crude oil droplets were performed on the top of and under sea ice and polyethylene-based skimmer material, being submerged in seawater (-2 °C). In addition, "dip- and refloat" tests were performed to quantify the adhesion and study the re-floating process of oil from sea ice at -2 °C (moist ice) and -20 °C (cold dry ice), and from a skimmer material prior to and subsequently to its submersion in seawater (-2 °C). The results indicated limited interaction of oils with sea ice submerged in seawater, but a strong affinity of oils towards polyethylene-based skimmer material.


Assuntos
Camada de Gelo/química , Petróleo , Polietileno/química , Água do Mar/química , Poluentes Químicos da Água/química , Regiões Árticas , Poluição por Petróleo/análise
20.
Mar Pollut Bull ; 145: 377-389, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590800

RESUMO

In the current study, ecological risk of potentially toxic elements (PTEs) in sediments, seawater, wastewater, soft tissues and shell of a major fouling species Callista florida (C. florida) and soft tissue of rocky oyster, Saccostrea cucullata (S. cucullata) are investigated. For this purpose, 25 sediment samples, 24 seawater samples, 28 wastewater samples, and 100 bivalve samples were collected for PTEs analysis. Risk index (RI) and sediment quality guidelines along with calculated enrichment factors (EF) and PTEs profiles revealed that Musa Estuary is threatened by contamination, especially with respect to Hg, Cu, and Zn. The decreasing trend of average element enrichment factor is: Hg > Cu > Ni > Cd > Zn > Co > Cr > Mn > Fe > As > Pb > Mo > Sb. Among the investigated elements, Hg indicated the highest potential ecological risk factor in sediment (RI and EF are 1341.6 and 214.66 close to the industrial area). The Ficklin chart results demonstrated that seawater samples almost plot in regions with high metal load and pH values were the same. Mean concentrations of PTEs in water samples were 1.2 (for Cu) to 6565 (for Hg) times higher than world seawater. Regarding wastewater, pH values changed from very acidic to alkaline while PTEs load ranged from low to high load. In general, PTEs concentration in water samples was higher compared to those of the world seawater. Based on the results obtained in this biomonitoring study, elevated concentrations of Al, Fe, Cu, and Zn were found in soft tissue of C. florida and S. cucullata. Statistical analysis revealed significant differences in PTEs concentration between the two studied species. Generally, most PTEs concentration including Al, Co, Cr, Fe, Mn, Ni, Pb, and Sb in soft tissue fall between water and sediment samples i.e., sediment > biota > water.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Poluentes do Solo/toxicidade , Águas Residuárias/análise , Poluentes Químicos da Água/toxicidade , Animais , Bivalves/química , Bivalves/efeitos dos fármacos , Oceano Índico , Mercúrio/análise , Mercúrio/toxicidade , Metais Pesados/análise , Metais Pesados/toxicidade , Água do Mar/química , Poluentes do Solo/análise , Poluentes Químicos da Água/análise
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