Colloidal Metals in the Tamar Estuary and their Influence on Metal Fractionation by Membrane Filtration

2006 ◽  
Vol 3 (3) ◽  
pp. 199 ◽  
Author(s):  
Kate A. Howell ◽  
Eric P. Achterberg ◽  
Alan D. Tappin ◽  
Paul J. Worsfold
Keyword(s):  
Trace Metals ◽  
Membrane Filtration ◽  
Aquatic Organisms ◽  
Sample Volume ◽  
Water Sampling ◽  
Dissolved Metals ◽  
Tamar Estuary ◽  
And Function ◽  
Colloidal Fraction ◽  
Colloidal Metal

Environmental Context. Trace metals play an essential role in the growth and function of aquatic organisms; however, enhanced metal concentrations can have detrimental effects on ecosystems. The distribution of metals between filterable and filter-retained phases is key to their bioavailability and biogeochemical cycling. Studies on rivers have shown that separating dissolved metals from particle-associated metals may introduce significant artefacts in the resulting filtrate concentrations. Comparable studies on turbid estuarine waters are necessary to improve the design of water sampling programmes. Abstract. Total filterable and colloidal metals were measured in the Tamar Estuary. The colloidal fraction (Mc) was highly variable for each metal, both spatially and temporally. In April 2001, Alc and Coc were higher in the river than the estuary, Cdc, Crc and Pbc were lower, and Mnc and Uc were similar. In September 2001, Cdc was higher in the river than the estuary. Colloidal Al and Mn were positively correlated with concentrations of suspended particles, whereas the colloid contents of the other metals were primarily determined by additional factors. The effect of the colloidal metal content on resultant metal filtrate concentrations, as a function of sample volume filtered, was examined. The amount of Al, Cd, Cu, Pb, and U in the filtrate decreased significantly in at least one case, whereas Mn initially increased in some cases. There was no change for Co, Cr, and Zn. The implications of these results for the study of trace metals in moderately turbid estuaries are discussed.

Nanomaterial Surface Modifications for Enhancement of the Pollutant Adsorption From Wastewater

2019 ◽  
pp. 143-170 ◽  
Author(s):  
Hamidreza Sadegh ◽  
Gomaa A. M. Ali ◽  
Hamid Jafari Nia ◽  
Zahra Mahmoodi
Keyword(s):  
Membrane Filtration ◽  
Organic Dyes ◽  
Low Cost ◽  
Aquatic Organisms ◽  
Chemical Degradation ◽  
Photochemical Degradation ◽  
Dye Wastewater ◽  
Biological Degradation ◽  
Operation Costs ◽  
Global Concern

With the development of dyeing, textile, leather, paper, and other chemical industries, an increasing amount of dye wastewater containing refractory organic dyes is discharged. Undoubtedly, much high content dye wastewater will lead to serious environmental issues such as color pollution, light penetration interference, and virulence to aquatic organisms, even endanger human health. Therefore, it is an imminent problem and has become a global concern to degrade dye wastewater efficiently. So far, many techniques have been used to degrade dyeing wastewater, such as chemical degradation, biological degradation, photochemical degradation, coagulation, membrane filtration, and combined methods. These methods have certain impacts on the degradation of dye wastewater, but usually with slow degradation rate, complex and high operation costs, as well as easily causing secondary pollution. The adsorption process is a simple, effective, and low-cost way to remove dyes.

Mathematical Modeling and Assessment of Microbial Migration during the Sprouting of Alfalfa in Trays in a Nonuniformly Contaminated Seed Batch Using Enterobacter aerogenes as a Surrogate for Salmonella Stanley

2007 ◽  
Vol 70 (11) ◽  
pp. 2602-2605 ◽  
Author(s):  
BIN LIU ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Irrigation Water ◽  
Membrane Filtration ◽  
Microbial Contamination ◽  
Food Poisoning ◽  
Enterobacter Aerogenes ◽  
Probability Of Detection ◽  
Microbial Populations ◽  
Water Sampling ◽  
The Past ◽  
Low Concentrations

Raw seed sprouts have been implicated in several food poisoning outbreaks in the past 10 years. The U.S. Food and Drug Administration recommends that sprout growers use interventions (such as testing of spent irrigation water) to control the presence of pathogens in the finished product. During the sprouting process, initially low concentrations of pathogen may increase, and contamination may spread within a batch of sprouting seeds. A model of pathogen growth as a function of time and distance from the contamination spot during the sprouting of alfalfa in trays has been developed with Enterobacter aerogenes. The probability of detecting contamination was assessed by logistic regression at various time points and distances by sampling from sprouts or irrigation water. Our results demonstrate that microbial populations and possibility of detection were greatly reduced at distances of ≥20 cm from the point of contamination in a seed batch during tray sprouting; however, the probability of detecting microbial contamination at distances less than 10 cm from the point of inoculation was almost 100% at the end of the sprouting process. Our results also show that sampling irrigation water, especially large volumes of water, is highly effective at detecting contamination: by collecting 100 ml of irrigation water for membrane filtration, the probability of detection was increased by three to four times during the first6hof seed germination. Our findings have quantified the degree to which a small level of contamination will spread throughout a tray of sprouting alfalfa seeds and subsequently be detected by either sprout or irrigation water sampling.

A review of marine water sampling methods for trace metals

2020 ◽  
Vol 21 (3-4) ◽  
pp. 267-290 ◽  
Author(s):  
A. E. Noble ◽  
C. B. Tuit ◽  
J. P. Maney ◽  
A. D. Wait
Keyword(s):  
Trace Metals ◽  
Sampling Methods ◽  
Marine Water ◽  
Water Sampling

scholarly journals Propensity of undulatory swimmers, such as worms, to go against the flow

2015 ◽  
Vol 112 (12) ◽  
pp. 3606-3611 ◽  
Author(s):  
Jinzhou Yuan ◽  
David M. Raizen ◽  
Haim H. Bau
Keyword(s):  
Control Strategies ◽  
Aquatic Organisms ◽  
Life Cycles ◽  
Environmental Cues ◽  
Mechanical Forces ◽  
C Elegans ◽  
The Subject ◽  
And Function ◽  
First Time

The ability to orient oneself in response to environmental cues is crucial to the survival and function of diverse organisms. One such orientation behavior is the alignment of aquatic organisms with (negative rheotaxis) or against (positive rheotaxis) fluid current. The questions of whether low-Reynolds-number, undulatory swimmers, such as worms, rheotax and whether rheotaxis is a deliberate or an involuntary response to mechanical forces have been the subject of conflicting reports. To address these questions, we use Caenorhabditis elegans as a model undulatory swimmer and examine, in experiment and theory, the orientation of C. elegans in the presence of flow. We find that when close to a stationary surface the animal aligns itself against the direction of the flow. We elucidate for the first time to our knowledge the mechanisms of rheotaxis in worms and show that rheotaxis can be explained solely by mechanical forces and does not require sensory input or deliberate action. The interaction between the flow field induced by the swimmer and a nearby surface causes the swimmer to tilt toward the surface and the velocity gradient associated with the flow rotates the animal to face upstream. Fluid mechanical computer simulations faithfully mimic the behavior observed in experiments, supporting the notion that rheotaxis behavior can be fully explained by hydrodynamics. Our study highlights the important role of hydrodynamics in the behavior of small undulating swimmers and may assist in developing control strategies to affect the animals’ life cycles.

Comparison of pore water sampling techniques for trace metals

1995 ◽  
Vol 29 (9) ◽  
pp. 2051-2054 ◽  
Author(s):  
Steven E. Bufflap ◽  
Herbert E. Allen
Keyword(s):  
Trace Metals ◽  
Pore Water ◽  
Sampling Techniques ◽  
Water Sampling

scholarly journals Hydrothermal trace metal release and microbial metabolism in the northeastern Lau Basin of the South Pacific Ocean

2021 ◽  
Vol 18 (19) ◽  
pp. 5397-5422
Author(s):  
Natalie R. Cohen ◽  
Abigail E. Noble ◽  
Dawn M. Moran ◽  
Matthew R. McIlvin ◽  
Tyler J. Goepfert ◽  
...  
Keyword(s):  
Trace Metals ◽  
Pacific Ocean ◽  
Hydrothermal Vents ◽  
Spreading Center ◽  
Marine Microorganisms ◽  
Dissolved Metals ◽  
Lau Basin ◽  
Southwest Pacific ◽  
South Pacific Ocean ◽  
Close Proximity

Abstract. Bioactive trace metals are critical micronutrients for marine microorganisms due to their role in mediating biological redox reactions, and complex biogeochemical processes control their distributions. Hydrothermal vents may represent an important source of metals to microorganisms, especially those inhabiting low-iron waters, such as in the southwest Pacific Ocean. Previous measurements of primordial 3He indicate a significant hydrothermal source originating in the northeastern (NE) Lau Basin, with the plume advecting into the southwest Pacific Ocean at 1500–2000 m depth (Lupton et al., 2004). Studies investigating the long-range transport of trace metals associated with such dispersing plumes are rare, and the biogeochemical impacts on local microbial physiology have not yet been described. Here we quantified dissolved metals and assessed microbial metaproteomes across a transect spanning the tropical and equatorial Pacific with a focus on the hydrothermally active NE Lau Basin and report elevated iron and manganese concentrations across 441 km of the southwest Pacific. The most intense signal was detected near the Mangatolo Triple Junction (MTJ) and Northeast Lau Spreading Center (NELSC), in close proximity to the previously reported 3He signature. Protein content in distal-plume-influenced seawater, which was high in metals, was overall similar to background locations, though key prokaryotic proteins involved in metal and organic uptake, protein degradation, and chemoautotrophy were abundant compared to deep waters outside of the distal plume. Our results demonstrate that trace metals derived from the NE Lau Basin are transported over appreciable distances into the southwest Pacific Ocean and that bioactive chemical resources released from submarine vent systems are utilized by surrounding deep-sea microbes, influencing both their physiology and their contributions to ocean biogeochemical cycling.

scholarly journals SUSCEPTIBILITY PROFILES TO ANTIBIOTICS IN STRAINS OF THE GENUS BACILLUS ISOLATED FROM EXTREME AQUATIC ENVIRONMENTS OF ECUADOR

2021 ◽  
pp. 27-34
Author(s):  
Marco González ◽  
Francisco Viteri ◽  
Luis Villacís ◽  
Jessica Escobar ◽  
Liliana Araujo ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Sample Volume ◽  
Diffusion Method ◽  
Bacillus Species ◽  
Natural Environments ◽  
Biochemical Tests ◽  
Volcanic Lake ◽  
Antibiotic Resistance Profile ◽  
High Concentrations ◽  
Susceptibility Profiles

Introduction. The water of aquatic ecosystems considered extreme, given the values of its physicochemical and chemical parameters, such as high concentrations of salts, oligotrophic environments, extreme pH, high radiation and extreme temperatures, there is a bacterial population that has adapted to these conditions and that they can be an important reservoir of natural resistomes. Objective. The objective of the present work was to know the profiles of susceptibility to various antibiotics in strains of the Bacillus genus isolated from mineromedicinal water spas and water from a volcanic crater lake in Ecuador. Materials and methods. A total of 16 mineromedicinal water samples and 32 samples of crater volcanic lake water were analyzed. The isolation of the Bacillus colonies was carried out by the membrane filtration technique, using Millipore filters of 0.45 μm pore, a sample volume of 100 mL and R2A agar. The isolated strains were identified following the schemes of MacFaddin (2004), complemented with the biochemical tests of the Microgen galleries for Bacillus. The antibiotic resistance profile was determined by the plate diffusion method of Kirby and Bauer (1966), interpreted according to the CLSI (2019). Results. 19 Bacillus strains were identified. Most of the strains were resistant and multi-resistant to the antibiotic clindamycin, erythromycin, gentamicin, oxacillin, and penicillin. Conclusions. The results indicate the presence of Bacillus species and resistomes associated with this genus in the water of extreme natural environments in Ecuador, which suggests that these environments may be an important reservoir of bacteria resistant to antibiotics.

scholarly journals Characterising the surface microlayer in the Mediterranean Sea: trace metals concentration and microbial plankton abundance

2019 ◽  
Author(s):  
Antonio Tovar-Sánchez ◽  
Araceli Rodríguez-Romero ◽  
Anja Engel ◽  
Birthe Zäncker ◽  
Franck Fu ◽  
...  
Keyword(s):  
Trace Metals ◽  
Mediterranean Sea ◽  
Surface Waters ◽  
Bacterial Community Composition ◽  
Western Mediterranean ◽  
Surface Microlayer ◽  
Dissolved Metals ◽  
Western Mediterranean Sea ◽  
Sea Surface Microlayer ◽  
The Mediterranean

Abstract. The Sea Surface Microlayer (SML) is known to be enriched in trace metals relative to the underlaying water and to harbor diverse microbial communities (i.e. neuston). However, the processes linking metals and biota in the SML are not yet fully understood. In this study, we analyzed the metal (Cd, Co, Cu, Fe, Ni, Mo, V, Zn and Pb) concentrations in aerosol samples, SML (dissolved and total fractions) and in subsurface waters (SSW; dissolved fraction at ~ 1 m depth) from the Western Mediterranean Sea during a cruise in May–June 2017. The bacterial community composition and abundance in the SML and SSW, and the primary production and Chl-a in the SSW were measured simultaneously at all stations during the cruise. Residence times of particulate metals derived from aerosols deposition ranged from a couple of minutes for Co (2.7 ± 0.9 min; more affected by wind conditions) to a few hours for Cu (3.0 ± 1.9 h). Concentration of most dissolved metals in both, the SML and SSW, were well correlated with the salinity gradient and showed the characteristic eastward increase in surface waters of the Mediterranean Sea (MS). Contrarily, the total fraction of some reactive metals in the SML (i.e. Cu, Fe, Pb and Zn) showed negative trends with salinity, these trends of concentrations seem to be associate to microbial uptake. Our results suggest a toxic effect of Ni on neuston and microbiology community’s abundance of the top meter of the surface waters of the Western Mediterranean Sea.

scholarly journals Acute and chronic toxicity of mixtures of bisphenol A and trace metals (Cd and Pb) to micro-crustacean, Daphnia magna

2022 ◽  
Vol 964 (1) ◽  
pp. 012012
Author(s):  
V T Nguyen ◽  
A T Huynh ◽  
T S Dao
Keyword(s):  
Trace Metals ◽  
Bisphenol A ◽  
Daphnia Magna ◽  
Aquatic Ecosystems ◽  
Life History Traits ◽  
Feeding Rate ◽  
Aquatic Organisms ◽  
Antagonistic Effect ◽  
Ecological Impacts ◽  
Plastic Materials

Abstract The occurrence of plastic additives and their ecological impacts have attracted much attention in recent years globally. Among plastic additives, the trace metals (e.g., Cd, Pb) are widely used as color pigments and stabilizers, whereas bisphenol A (BPA) is added to enhance the desired physical characteristics of plastic products. However, these additives can easily leach out of plastic materials and enter the aquatic environment causing risks to aquatic ecosystems. Although the toxicity of a single additive on various aquatic organisms has been studied, the responses of zooplankton exposed to the mixed plastic additives have not been fully understood. Therefore, this study aims to evaluate the effects of the binary mixtures (BPA+Cd, BPA+Pb) and trinary mixture (BPA+Pb+Cd) at the metal concentrations of 5 µg/L and BPA level of 50 µg/ L on the life history traits and food feeding rate of the freshwater micro-crustacean, Daphnia magna. The results showed exposures to these mixtures for 24h could significantly enhance the food feeding rate of D. magna from 2.5 – 5.8 times higher than the control. The survival rate was decreased from 50 – 90% in the organisms exposed to these mixtures after 18 incubated days. We found a synergistic effect of BPA+Pb but an antagonistic effect of BPA+Pb+Cd on the survivorship of D. magna. Similarly, the organisms in the exposures delayed their maturity age and reduced their reproduction. The potent impact order of the mixtures on D. magna was BPA+Cd > BPA+Pb+Cd > BPA+Pb. Our results evidenced the adverse effects of plastic additive mixtures on aquatic organisms. Therefore, the use and disposal of plastic materials and plastic additives should be paid more attention to protect the environment, ecosystem, and human health. Moreover, our findings proved that the toxicity of multi-contaminants on organisms could be unpredictable even the toxicity of a single contaminant is known.

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