Chemicals In Seawater Research Articles

The microbial contribution to reactive oxygen species dynamics in marine ecosystems.

This review surveys the current state of knowledge of the concentrations, sources and sinks of reactive oxygen species (ROS) in the ocean. Both abiotic and biotic factors contribute to ROS dynamics in seawater, and ROS can feature prominently in marine microbe-microbe interactions. The sun plays a key role in the production of ROS in the ocean, and consequently ROS concentrations are typically maximal in the sun-exposed surface. However, microbes can also contribute significantly to extracellular ROS. Production of superoxide is widespread within the microbial community, and may benefit the producers as antimicrobial agents or perhaps more generally, as a means of nutrient scavenging. Decomposition of hydrogen peroxide is a community-wide activity, though some members may play less significant roles in this process. The more reactive forms of ROS, singlet oxygen and the hydroxyl radical, may be less important as microbial stressors, as they tend to react with the chemicals in seawater before they can contact the cells. However, exceptions may exist for microbes attached to singlet oxygen-generating sinking particulate matter. Extracellular ROS thus plays an important role in the ecology of marine microbes, the full extent to which we are only beginning to appreciate.

Solid Phase Microextraction (SPME) Fibers: in situ Measurements of Endocrine Disrupting Chemicals in Seawater

Solid Phase Microextraction (SPME) Fibers: in situ Measurements of Endocrine Disrupting Chemicals in Seawater

Evaluation of coexposure to inorganic arsenic and titanium dioxide nanoparticles in the marine shrimp Litopenaeus vannamei.

The acute toxicity of titanium dioxide nanoparticles (nTiO2) that occur concomitantly in the aquatic environment with other contaminants such as arsenic (As) is little known in crustaceans. The objective of the present study is to evaluate whether coexposure to nTiO2 can influence the accumulation, metabolism, and oxidative stress parameters induced by arsenic exposure in the gills and hepatopancreas of the shrimp Litopenaeus vannamei. Organisms were exposed by dissolving chemicals in seawater (salinity = 30) at nominal concentrations of 10μg/L nTiO2 or As(III), dosed alone and in combination. Results showed that there was not a significant accumulation of As in either tissue type, but the coexposure altered the pattern of the metabolism. In the hepatopancreas, no changes were observed in the biochemical response, while in the gills, an increase in the glutamate-cysteine-ligase (GCL) activity was observed upon exposure to As or nTiO2 alone, an increase in the reduced glutathione (GSH) levels was observed upon exposure to As alone, and an increase in the total antioxidant capacity was observed upon exposure to nTiO2 or nTiO2 + As. However, these modulations were not sufficient enough to prevent the lipid damage induced by nTiO2 exposure. Our results suggest that coexposure to nTiO2 and As does not alter the toxicity of this metalloid in the gills and hepatopancreas of L. vannamei but does alter its metabolism, favoring its accumulation of organic As species considered moderately toxic.

Autonomous In-situ Raman Sensor, Suitable for Surface Enhanced Raman Spectroscopy (SERS) for Detection of Chemicals in the Sea

An autonomous in-situ Raman/SERS sensor for the detection of chemicals in seawater has been constructed and successfully tested in the harbor and offshore under harsh field conditions, during October - January 2012-2013. Applying integration time of typically only 10 s, the sensor was able to detect various PAHs in situ, such as fuoranthene, biphenyl, phenanthrene and fluorine in the Mediterranean Sea.

Design and Implementation of the Simulation Information System of Marine Oil Spill

Migration and diffusion of oil spill in sea is an extremely complex issue by the impact of the oil features and a variety of environmental factors, undergoing expansion, drift, evaporation, dispersion, emulsification, dissolution, photo-oxidation, biodegradation and their interactionsand many other processes ，at the same time has a direct relationship with the local meteorological conditions and law motionofseawater. Marine oil spill behavior analysis and research of the system, using VB technology and C#technical design and development of a marine oil spill simulation system based on Geographic Information System (GIS). The system using cloud-based GIS for a platform, using the Monte-Carlo method to simulate the behavior of chemicals in seawater on the system of cloud computing, the organic integration of GIS system application model

Application of calixarene to high active surface‐enhanced Raman scattering (SERS) substrates suitable for in situ detection of polycyclic aromatic hydrocarbons (PAHs) in seawater

The characteristics of the sol–gel matrix embedding Ag nanoparticles functionalized with 25,27‐dimercaptoacetic acid‐26,28‐dihydroxy‐4‐tert‐butylcalix[4]arene (DMCX) suitable for the in situ detection of polycyclic aromatic hydrocarbons (PAHs) in seawater is presented. The DMCX‐functionalized silver nanoparticles were produced by the thermal reduction method in xerogel film. The silver colloid blocks were formed in the sol–gel matrix, with a diameter ranging from 50 to 120 nm. DMCX forming the monolayer on the silver nanoparticle surface contributes to the surface‐enhanced Raman scattering (SERS) activity due to the aggregation of silver nanoparticles and the preconcentration of PAH molecules within the zone of electromagnetic enhancement. When selected, PAH molecules e.g. pyrene and naphthalene were adsorbed onto the SERS substrate; Raman band positions of PAH were slightly shifted. A calibration procedure reveals that this type of SERS substrate has a limit of detection of 3 × 10−10 mol/l for pyrene and 13 × 10−9 mol/l for naphthalene in artificial seawater. The Raman signal response on a pyrene concentration change in artificial seawater was evaluated using a 671‐nm Raman setup with a flow‐through cell. This type of SERS substrate will be suitable for the in situ trace detection of pollutant chemicals in seawater. Copyright © 2012 John Wiley & Sons, Ltd.

Operational Device and Procedure to Test the Initial Dissolution Rate of Chemicals After Ship Accidents: the Cedre Experimental Column

This paper describes an experimental procedure recently developed to simulate and study the behaviour of various chemicals in seawater during their transfer in a 5 m deep water column. Since chemical pollution can be harmful to the environment, anticipating the evolution of a chemical spill is important for authorities, so that they can act rapidly and efficiently after a spill. In the case of a sunken wreck containing chemicals with a lower density than seawater in its leaking tanks, it could be useful to estimate the quantity of chemicals that should be found at the sea surface. On the other hand, in the case of a spill occurring at the sea surface, the mass of chemicals liable to sink and accumulate on the seabed without being dissolved during sinking is an important piece of information required to choose the most suitable response strategy.

Seawater Quality, Suspended Solids, and Settling Particles in the Wood Pool Area of Shimizu Port, Japan

Abstract The transport and contamination of suspended solids in a wood pool were quantitatively studied as a case study for the environmental assessment of an enclosed sea area. To assess the present contamination of Shimizu Port (Japan), seawater, suspended solids, and settling particles were collected from three rivers, the wood pool, and Shimizu Port. Physical and chemical properties of the samples were analyzed. In addition, tidal currents were observed to investigate the transport process of chemical substances by suspended solids. The results showed that the amount of lithogenic particles discharged into Shimizu Port was approximately 12 000 kg/day. Suspended solids discharged from rivers and the biological particles produced in the port caused a reduction in seawater transparency and an increase in chemical oxygen demand. Trace metals, such as Mn, Co, and Pb, were highly concentrated in suspended solids. Tributyltin adsorbed onto settling particles was approximately 300 µg/kg. Concentration factors for Mn, Fe, Cd, and Pb from water and settling particles are comparable to those of plankton. Hydroxides were found in suspended solids from the wood pool, which locates in the inner part of Shimizu Port. The results showed that these suspended particles could accumulate metals from seawater as effectively as biogenic particles. After particle deposition, trace metals are regenerated into seawater under anaerobic conditions. This process plays an important role in the accumulation of chemicals in seawater and sediments, especially in enclosed sea areas.

Degradation of Five Selected Endocrine-Disrupting Chemicals in Seawater and Marine Sediment

We studied degradation of five endocrine-disrupting chemicals (EDCs), namely bisphenol A (BPA), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), 4-tert-octyl phenol (4-t-OP), and 4-n-nonyl phenol (4...

Surface-enhanced Raman scattering (SERS) system for continuous measurements of chemicals in sea-water

A laboratory-based system for measurement of chemicals in sea-water with sol–gel-derived surface-enhanced Raman scattering (SERS) substrates is presented. The motivation behind this work was the development of a marinized prototype sensor. A long-term spectral stability of better than 1 cm−1 over a period of several months was observed. Photodegradation of the SERS layer was avoided by the choice of optical components and layout. Dielectric edge filters and holographic notch filters were compared. Coated fibres were tested and results are discussed in terms of fibre choice, reduction of background signal, sensitivity and time response. Continuous analysis was performed with two flow-through cells, the first a modification to a standard glass cuvette and the second an improved in-house-constructed aluminium cell. SERS investigations on samples whose turbidity ranged from 0 to 400 NTU were performed with both cells. These tests show the suitability of the developed system for continuous monitoring of real samples and possible application in on-line process control. Copyright © 2000 John Wiley & Sons, Ltd.

Use of sol-gel techniques in the development of surface-enhanced Raman scattering (SERS) substrates suitable for in situ detection of chemicals in sea-water

The development of surface-enhanced Raman scattering substrates suitable for in situ environmental analysis in sea-water is presented. Substrates consist of metal colloids encapsulated in a sol-gel-derived xerogel layer. Control of the gel parameters, such as porosity, pore size, and polarity, enables tailoring of sensitivity to different analyte groups. Gold and silver colloids were used along with tetraethoxysilane (TEOS) and methyltriethoxysilane (MTEOS) precursors. Substrates are characterised by measurement of optical spectra and use of scanning electron microscopy (SEM). Activity is discussed in terms of the choice of precursor and choice of metal colloid. Spectra were obtained for a range of substituted benzene derivatives with limits of detection (LODs) of 100 ppb and 10 ppb for chlorobenzene and phenylacetylene, respectively. Substrate selectivity is shown by the contrasting response of a single substrate type to similar molecules, in particular phenylacetylene and benzonitrile. Details of mechanical and chemical stability tests on the substrates are also included.

海藻を供試生物とした都市下水処理水の生物検定

Bioassay techniques for testing treated waste water (sewage effluent) and toxic chemicals in seawater by monitoring the growth of seaweed were reviewed in this paper. Waste waters have been tested by seaweeds were classified into indusrial waste water, sewage effluent, night-soil effluent, antifouling chemicals in sea-water and other toxic chemicals in seawater. Porphyra tenera or yezoensis (nori) in Japan and Macrocystis pyrifera (giant kelp) have mostly been used for biological testing in past researches. P. tenera or yezoensis and M. pyrifera were chosen for toxicity bioassays of treated sewage effluent due to their biological and socio-economic effectiveness and significances. Bioassay techniques such as the life stages of specimens and test periods required, methods of detecting adverse effects of effluent on specimens, culture methods, culture conditions, culture media and effluent sampling times were described. Chemical substances which promote or hinder the growth of seaweeds are contained in the treated sewage effluent and chemical substances and their concentrations change daily and weekly. Lower salinity intensify the adverse effects of effluent on growth of seaweeds. Therfore, variables such as effluent concentration, salinity of culture media and dayly and weekly changes of effluent must taken into account. It was clarified by the proposed bioassay techniques that the strongest toxic substance on the growth of P. yezoensis was monochloramine resulting from chlorinated sewage effluent. P. yezoensis is considered to be the appropriate seaweed for toxicity bioassay of treated sewage effluent for the biological and socio-economic effectiveness and significances in Japan.

A comparative study of test methods for assessment of the biodegradability of chemicals in seawater—Screening tests and simulation tests

A comparative study has been performed on test methods for assessing the biodegradability of chemicals in seawater environments. A simple shake flask die-away test with natural seawater and 14C-labeled chemicals added in μg/liter concentrations is proposed as a “simulation” test. The analytical parameter used in this test is residual dissolved 14C activity. The performance of the simulation test has been compared with the performance of similar screening tests with dissolved organic carbon analysis and test compounds added in mg/liter concentrations to nutrient-enriched seawater. All chemicals investigated that passed the screening tests were also degradable in the simulation test and some results with simulation tests were positive; even screening tests were negative, while some compounds, including maleinhydrazide, known to be degradable in soil, remained undegraded in either type of test. Disappearance times after the ended lag time were smaller in screening tests than in simulation tests, but the rates of biodegradation cannot be meaningfully compared, as zero-order kinetics in combination with an exponentially growing population of degraders prevail in screening tests, while first-order kinetics and frequently a constant activity of degraders (cooxidation) prevail in simulation tests where the test material is a secondary substrate only. In screening tests, lag times are sometimes excessively long and highly variable. Whether the lag times could be decreased and their variability narrowed by supplementation with a cosubstrate (yeast extract) or by inoculation with seawater that had been preadapted to the test material was investigated. In most experiments such test modifications had no significant effect but in one experiment with 4-nitrophenol, inoculation with 1% preadapted seawater decreased the lag phase from >35 to 9 days.

Screening methods for assessment of biodegradability of chemicals in seawater—Results from a ring test

An international ring test involving 14 laboratories was organized on behalf of the Commission of the European Economic Communities (EEC) with the purpose of evaluating two proposed screening methods for assessment of biodegradability in seawater: (a) a shake flask die-away test based primarily on analysis of dissolved organic carbon and (b) a closed bottle test based on determination of dissolved oxygen. Both tests are performed with nutrient-enriched natural seawater as the test medium and with no inoculum added other than the natural seawater microflora. The test methods are seawater versions of the modified OECD screening test and the closed bottle test, respectively, adopted by the Organization for Economic Cooperation and Development (OECD) and by the EEC as tests for “ready biodegradability.” The following five chemicals were examined: sodium benzoate, aniline, diethylene glycol, pentaerythritol, and 4-nitrophenol. Sodium benzoate and aniline, which are known to be generally readily biodegradable consistently degraded in practically all tests, thus demonstrating the technical feasibility of the methods. Like in previous ring tests with freshwater screening methods variable results were obtained with the other three compounds, which is believed primarily to be due to site-specific differences between the microflora of the different seawater samples used and to some extent also to differences in the applied concentrations of test material. A positive result with the screening methods indicates that the test substance will most likely degrade relatively rapidly in seawater from the site of collection, while a negative test result does not preclude biodegradability under environmental conditions where the concentrations of chemicals are much lower than the concentrations applied for analytical reasons in screening tests. Nevertheless, the screening tests are considered useful and cost-effective tools for an initial assessment of biodegradability in marine environments.

Metals and synthetic organic compounds in plankton from the estuary and harbor area in Osaka City.

This study was made in order to evaluate the feasiblity of net plankton analysis for monitoring pollution due to heavy metals and synthetic chemicals in seawater. Plankton was collected by using a phytoplankton net in the harbor area of Osaka City, Japan. Heavy metals, organochlorine and organophosphorus compounds in the net plankton and also in the corresponding seawater were determined. The heavy metal concentration in the seawater increased in the order of, Hg<Cd<Pb<Cu, Cr<Ni<Zn<Mn<Fe. In the net plankton, the order was follwes; Hg<Cd<Ni, Cr, Pb<Cu, Mn<Zn<Fe. Except for Ni and Mn, the meatal levels in the net plankton corresponded to those in the seawater, and their bioconcentration factors (BCF) were 1 to 5×104, but in Ni and Mn the factors were 0.4to 0.5×104. Organochlorine compounds such as PCBs and HCH were clearly noticed in net plankton and the levels ranged form 1 to 5 μg/g and from 0.1 to 0.2 μg/g in dry basis, respectively. These values were entirely dependent on the seawater levels and the BCF of PCBs was 11×104 and 0.4×104 in HCH. Organophosphorus pesticides including diazinon, IBP and fenitorthion were almost always found in the seawater. There compounds, however, were never detected in the net plankton. These results indicate the feasibilty of plankton analysis for monitoring approximate pollution in water, but some problems observed in certain metals and organophosphorus compounds still remain to be studied.