No description available.

In this study, the amphipod Corophium volutator and the polychaete Arenicola marina were evaluated as test organisms for use in sediment toxicity tests by adapting standard protocols developed by the EPA/COE and Thain et al. (1994) respectively for conducting 10-day sediment toxicity tests. Although these species have been used to assess the toxicity of marine and estuarine sediments, the detailed ecotoxicologies of these animals are not well documented. In particular, the effects of specific contaminants of known concentrations on this bioassay are not known. Here, I report several experiments carried out using clean intertidal sediment contaminated with the heavy metals copper, zinc and cadmium, and employing the Corophium and the Arenicola bioassay protocol. Concentrations of copper, zinc and cadmium were determined in tissues of Corophium exposed for 4 and 10 days to contaminated sediment using four protocols to allow for any material present in the gut. Significant differences in metal concentrations occurred between the protocols where gut contents were removed and those where they were left intact. These findings have implications for the way in which analyses of metal burdens are carried out for invertebrates in ecotoxicological work. Corophium survival in seawater with dissolved copper, zinc and cadmium was higher in the presence of sediment than without sediment, although the concentrations of these metals in Corophium tissues were the same in both cases. Bioconcentration factors (BCF) were inversely related to seawater concentrations of copper, zinc and cadium, with the lowest exposure concentration, (0.1 mg l-1 for both copper and zinc, 0.01 mg l-1 cadmium) having the highest BCF. Both live amphipods and those that had died accumulated copper, zinc and cadmium in their bodies during the bioassay, and bioconcentration factors were always higher for dead than for living amphipods for each metal.

This research collected surface (<15 cm) sediments from estuarine and coastal zones off southwestern Taiwan. Basic sediment parameters, including grain size, and total organic carbon (TOC) and total inorganic carbon (TIC) concentrations were analyzed. For heavy metals (Fe, Mn, Cd, Cu, Ni, Pb, and Zn), total metal concentrations and metal fractions separated by sequential extraction techniques were determined. This study also obtained several previously collected sediment cores in the Gaoping Canyon area that had been dated by other researchers. Results obtained in this study are used in order to understand the distribution patterns of heavy metals in coastal sediments off southwestern Taiwan, and related to regional environmental changes regarding heavy metals. The distribution of heavy metal fractions and their geochemical significances were studied. Results obtained in this study indicate that physicochemical characteristics of sediments largely affected heavy metal distribution in coastal sediments off southwestern Taiwan. Regional flow patterns contributed to the observed distribution patterns. Higher heavy metal concentrations were found in sediments collected near the Gaoping river mouth, the Gaoping Canyon and its nearby continental slope, and a narrow banded offshore region off the Anping-Tainan urban areas. These results reflect the distribution of fine-grained sediments in the studied area. Vertical profiles of heavy metals in four dated cores showed drastic increases of heavy metal concentrations since 1995-2000, and some extent of decreases during 2003-2006 in two of the cores. Although actions of environmental protection regarding heavy metal pollution had taken place in this region, decreases in sediment heavy metals were mostly attributed to episodic typhoon and possibly sediment slumping events. With the recently intensified landslides and mud flows in the upper reaches of the river that would bring upstream soils and particles to the estuarine region, leading to the decrease of metal concentrations in the Gaoping estuarine sediments, a more significant decreasing trend in sediment metal concentrations can be speculated for the future.

Abstract The aim of this study investigated the metal bioaccumulation in the cetaceans from the Taiwanese coastal waters. The differences of metal concentrations in the small dolphins between species, sex and sampling location were examined. The results were compared to the data all over the world to understand the pollution status in the western Pacific. Accordingly specimens-bank was established. Furthermore, the correlations between the size/age and metal concentrations were investigated in Stenella attenuata, S. longirostris and Neophocaena phocaenoides. This study cooperated with the Cetacean Research Laboratory leading by the Prof. L. S. Chou, Dept. of Zoology, National Taiwan University. The samples included 8 species of 83 individuals accidentally caught and stranded around Taiwan in 1994-1995. The 8 species included Delphinus delphin, Grampus grieus, Lagenodelphis hoseei, Stenella attenuata, S. coeruleoalba, S. longirostris, Steno bredanensis, Tursiops truncatus. In addition, one Kogia simus stranded in 1998 and two Neophocaena phocaenoides accidentaly caught in 2000 were used to examine the variation of metal bioaccumulation in the muscles at different parts of body. The tissues of muscle, liver and lung were used for analysis of Ag, As, Cd , Co, Cu, Fe, total Hg, organic Hg, Mn, Ni, Se and Zn. The flame atomic absorption spectrophotometry (AAS) was used in analysis of Cu, Fe, Mn, Ni and Zn. The cold vapor AAS and graphite furnace AAS were used for determination of Hg and Cd, respectively. ICP-MASS were used in measurements of Ag, As, Co and Se. The differences of metal bioaccumulation in muscles of different species were element ally depend. As, Fe, total Hg, organic Hg, Se and Zn presented significant species differences. Highest Fe (147 mg/Kg wet wt), total Hg (16.9), organic Hg (5.65), and Se (4.62) were found in Lagenodelpnis hosei, whereas highest As (2.92) and Zn (24.1) were found in Grampus griseus and Tursiops truncatus. However, lowest As (0.29), and Se (0.76) were found in Tursiops truncatus. Lowest Fe (90), organic Hg (0.93), total Hg (1.0) and Zn (10.16) were found in Delphinus delphis, Delphinus delphis, Steno bredanensis, and Stenella longirostris. No species differences were found in the muscle concentrations of Ag, Cu, Cd, Co, Mn and Ni. Except organic Hg found highest in muscle. The concentrations of rest elements were found highest in liver and lowest in muscle. There was no significant difference of metal bioaccumulation found in male and female Stenella attenuata. The correlations between the size/age and metal concentrations in muscle were found in Stenella attenuata, S. longirostris and Neophocaena phocaenoides. The relationships were significant in total Hg, oranic Hg and Se of Stenella attenuata, whereas in orangic Hg, Se and Zn of Stenella longirostris and Neophocaena phocaenoides. The metal concentrations found in this study were mostly equal to or lower than those records all over the world. Furthermore, by comparison the total Hg of Stenella attenuata, S. coeruleoalba and Tursiops truncatus with those data found in elsewhere. The total Hg levels in this study were slightly higher than that of eastern Pacific, but much lower than that of Mediterranean of Italy and France, Atlantic and Japan. These findings suggest that the metal concentrations found in this study representing the baseline metal concentration of western Pacific. Based on this, no specific sight of pollution was found in the coastal waters off Taiwan.

Texte remanié de: Thèse de doctorat--Sociologie--Paris 5, ca 2007. / Bibliogr. p. 349-350 et 354-364. Discogr. p.350-353. Webliogr. p. 354. Glossaire.

Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/dieoff- rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates.

Abstract In this study, the removal of Pb(II) from aqueous solutions by tassel powder was studied and optimised. Batch experimentswere conducted on simulated solutions using tassel powder adsorbent and the effects of contact time, pH and concentration on the extent of Pb (II) removalwas studied. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of contact time and concentration at optimum pH 4 and fixed temperature(25 ◦C). The Freundlich model was found to describe the sorption energetics of Pb(II) on tassel more fully than the Langmuir. A maximum Pb(II) loading capacity of 333.3 mg/g on tassel was obtained. The adsorption process could be well described by both the Langmuir and Freundlich isotherms with R2 values of 0.957 and 0.972, respectively. The kinetic parameters were obtained by fitting data fromthe effect of contact time on adsorption capacity into the pseudo-first, pseudo-second-order and intra-particle diffusion equations. The kinetics of Pb(II) on tassel surface was well defined using linearity coefficients (R2) by pseudo-second-order (0.999), followed by pseudo-firstorder (0.795) and lastly intra-particle diffusion (0.6056), respectively. The developed method was then applied to environmental samples taken fromborehole waters contaminated with mine wastewater. The removal of Pb (ND-100%), Se (100%), Sr (5.41–59.0%),U(100%) and V (46.1–100%)was attained using tassel. The uptake of the metals from environmental samples was dependent on pH, ionic strength and levels of other competing species.

A b s t r a c t In this study, the removal of Pb(II) from aqueous solutions by tassel powder was studied and optimised. Batch experimentswere conducted on simulated solutions using tassel powder adsorbent and the effects of contact time, pH and concentration on the extent of Pb (II) removalwas studied. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of contact time and concentration at optimum pH 4 and fixed temperature(25 ◦C). The Freundlich model was found to describe the sorption energetics of Pb(II) on tassel more fully than the Langmuir. A maximum Pb(II) loading capacity of 333.3 mg/g on tassel was obtained. The adsorption process could be well described by both the Langmuir and Freundlich isotherms with R2 values of 0.957 and 0.972, respectively. The kinetic parameters were obtained by fitting data fromthe effect of contact time on adsorption capacity into the pseudo-first, pseudo-second-order and intra-particle diffusion equations. The kinetics of Pb(II) on tassel surface was well defined using linearity coefficients (R2) by pseudo-second-order (0.999), followed by pseudo-firstorder (0.795) and lastly intra-particle diffusion (0.6056), respectively. The developed method was then applied to environmental samples taken fromborehole waters contaminated with mine wastewater. The removal of Pb (ND-100%), Se (100%), Sr (5.41–59.0%),U(100%) and V (46.1–100%)was attained using tassel. The uptake of the metals from environmental samples was dependent on pH, ionic strength and levels of other competing species.

No description available.

No description available.