Age-related change and distribution of cadmium and zinc concentrations in the Steller sea lion (Eumetopias jubata) from the coast of Hokkaido,Japan

Tissue cadmium and zinc levels in Steller sea lions have been analysed to elucidate the body distribution of these metals and their age-related accumulation. A significant correlation between age (0.7–8.8 year old) and renal and hepatic cadmium concentration was noted. Of the tissues examined, the kidney manifested the highest cadmium content (mean: 20.9 μg g^?1 dry wt). A similar zinc distribution pattern was observed; its concentration was more uniform among tissues than that of cadmium. The tissue cadmium concentration in the Steller sea lion was lower than in other pinnipeds from various areas, possibly due to their feeding habits which may represent a major pathway of metal accumulation.     

Inhibition Concentration of Phenolic Substances under Different Cultivation Conditions. Part I: Phenol Oxidation by Mixed Microbial Population in a Model System

The effects of oxygen supply rate and the presence or absence of nutrients on the kinetics of phenol degradation and oxygen consumption by a mixed microbial population were tested in a model system. The values for the maximum specific rate of phenol degradation (q_Smax), the saturation constant (K_S), and the inhibition concentration (S_CR) were determined for unlimited growth (K_La = 340 h^?1, growth medium) with 1.7 mmol g^?1 h^?1, 65 mg L^?1, and 190 mg L^?1. Under limitation conditions, alterations occur depending on the type of limitation. Nutrient limitations lead to values of 0.8 mmol g^?1 h^?1, 45 mg L^?1, and 160 mg L^?1, and oxygen limitations lead to 1.2 mmol g^?1 h^?1. 30 mg L^?1, and 120 mg L^?1, respectively. The results suggest that with excess oxygen, the rate of phenol degradation was higher and the inhibition effect of phenol was suppressed to some extent. Under the same high oxygen supply rate, the presence of nutrients in the model water significantly supported the phenol degradation rate.     

Flame Atomic Absorption Spectrometry Determination of Trace Amounts of Cadmium and Zinc in Water Samples after Preconcentration onto Modified Amberlite XAD‐4 Resin

In the present article, a procedure for the simultaneous separation and preconcentration of trace amounts of cadmium and zinc is proposed. It is based on the adsorption of cadmium and zinc ions onto a column of Amberlite XAD‐4 resin loaded with aluminon reagent. Cadmium and zinc ions are quantitatively retained on the column in the pH range from 6.5–7.5, at a flow rate of 2 mL min^–1. The cadmium and zinc ions are eluted with 5.0 mL of 5 mol L^–1 HNO₃ solution. Cadmium and zinc are measured by flame atomic absorption spectrometry (FAAS). In the present case, 0.1 μg of cadmium and 0.5 μg of zinc can be concentrated in the column from 1000 mL of aqueous sample, where their concentrations are as low as 0.1 and 0.5 ng mL^–1, respectively. The relative standard deviations, for seven replicated determinations of 1.0 μg mL^–1 of cadmium and zinc, are 1.2 and 1.1%, respectively. The detection limits for cadmium and zinc in the original solution are 0.02 and 0.11 ng mL^–1, respectively. The interference of a large number of anions and cations has been studied and the optimized conditions are utilized for the determination of trace amounts of cadmium and zinc in different environmental and standard samples.     

Stable isotopes and metal contamination in caged marine mussel Mytilus galloprovincialis

Metal concentrations and isotopic composition were measured in different tissues of the mussel Mytilus galloprovincialis in waters of the Balearic Islands (Western Mediterranean) in order to assess pollution levels. The isotopic composition was correlated with lead, cadmium, selenium and nickel obtained from the digestive gland and foot of the mussels. Significant negative correlations were found between cadmium, selenium and zinc and the mussel foot, mainly for ¹³C. Significant correlations were also found between lead and cadmium and the digestive gland. Pearson correlations indicated that the ¹³C isotopic signal in foot is a good proxy for the concentration of metals such as lead, cadmium, selenium and zinc. Similarly, ¹⁵N isotopic signatures in the digestive gland reflected the lead and cadmium concentration.     

Differentiation of the sensitivity to copper and cadmium in different life stages of a copepod

Copper is more toxic to all life stages of the copepod Tisbe than cadmium. The most sensitive life stage of Tisbe to both copper and cadmium is the one-day-old nauplius. The resistance of larval stages of Tisbe increases with age (one-day-old nauplii 48h $\text{lc}{}_{50}\text{=0.3142}$ mg Cu l^?1. and 0.5384 mg Cd l^?1, 0.3415 mg Cu l^?1. and 0.645 mg Cd l^?1. for five-days-old nauplii and 0.5289 mg Cu l^?1. and 0.9061 mg Cd l^?1. for ten-days-old nauplii. The two reproductive stages of Tisbe tested (females with ovigerous bands and females bearing the first ovigerous sac) demonstrated an increased sensitivity to metals and proved more sensitive than the ten-days-old copepodids (only females with ovigerous bands had a similar sensitivity to copper with the ten-days-old copepodids).     

Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico

Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01 μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn > Se > Ni > Cu > Mn > Cd > Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.     

Heavy metals in surface sediment and epibenthic macroinvertebrates from the coastal zone and continental slope of Kenya

In surface sediments, a statistically significant increase was measured in the concentration of copper and cadmium along all transects, and of zinc along only the most southern (Gazi) transect, radiating into the Indian Ocean perpendicular to the Kenyan coast. Mean copper and cadmium increased from 5 to 30 μg g⁻¹ dry wt and from 0.01 to 0.34 μg g⁻¹ dry wt in shallow coastal (±20 m depth) to deep-sea stations (±2000 m depth), respectively. These gradients were found both during the south-east monsoon and north-east monsoon period. The shallow estuarine zone of the Sabaki river mouth showed significantly enhanced levels of total organic carbon and nitrogen and all metals analysed, except cadmium.In crustaceans, the concentration of copper and particularly cadmium was significantly above baseline levels, varying from 45 to 90 μg g⁻¹ dry wt and 1.0 to 8.5 μg g⁻¹ dry wt, respectively. Zinc levels (49–102 μg g⁻¹ dry wt) were at about baseline levels or a little elevated. On the contrary, lead showed very low concentrations, varying from 0.1 to 0.6 μg g⁻¹ dry wt. Other species generally showed the same pattern.     

Removal of Copper,Nickel, and Zinc Ions from Electroplating Rinse Water

Removal of copper, nickel, and zinc ions from synthetic electroplating rinse water was investigated using cationic exchange resin (Ceralite IR 120). Batch ion exchange studies were carried out to optimize the various experimental parameters (such as contact time, pH, and dosage). Influence of co‐existing cations, chelating agent EDTA on the removal of metal ion of interest was also studied. Sorption isotherm data obtained at different experimental conditions were fitted with Langmuir, Freundlich, Redlich–Peterson, and Toth models. A maximum adsorption capacity of 164 mg g^?1 for Cu(II), 109 mg g^?1 for Ni(II), and 105 mg g^?1 for Zn(II) was observed at optimum experimental conditions according to Langmuir model. The kinetic data for metal ions adsorption process follows pseudo second‐order. Presence of EDTA and co‐ions markedly alters the metal ion removal. Continuous column ion exchange experiments were also conducted. The breakeven point of the column was obtained after recovering effectively several liters of rinse water. The treated rinse water could be recycled in rinsing operations. The Thomas and Adams–Bohart models were applied to column studies and the constants were evaluated. Desorption of the adsorbed metal ions from the resin column was studied by conducting a model experiments with Cu(II) ions loaded ion exchange resin column using sulfuric acid as eluant. A novel lead oxide coated Ti substrate dimensionally stable (DSA) anode was prepared for recovery of copper ions as metal foil from regenerated liquor by electro winning at different current densities (50–300 A cm^?2).     

A Study: Removal of Cu(II), Cd(II), and Pb(II) Ions from Real Industrial Water and Contaminated Water Using Activated Sludge Biomass

This study aims to remove of Cu²⁺, Cd²⁺, and Pb²⁺ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion‐exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (q_max) were calculated as 0.478, 0.358, and 0.280 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺, respectively, and the adsorption equilibrium time was found as 60 min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25 mmol L^?1 metal concentration was determined as 0.200, 0.167, and 0.155 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282 mmol g^?1 for Cu²⁺, Cd²⁺, and Pb²⁺ ions, respectively, when initial metal concentration was 0.50 mmol L^?1. In the multi‐metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu²⁺ > Cd²⁺ > Pb²⁺. In the presence of 100 mmol L^?1 H⁺ ion, the order of ion‐exchange affinity with H⁺ was found as Cu²⁺ > Cd²⁺ > Pb²⁺. The adsorption kinetics were also found to be well described by the pseudo‐second‐order and intraparticle diffusion models. Two different rate constants were obtained as k_i1 and k_i2 and k_i1 (first stage) was found to be higher than k_i2 (second stage).     

Cumulation of Zinc,Cadmium and Mercury on the Alga Scenedesmus obliquus

In batch experiments with the metals labelled with their radionuclides the cumulation of zinc, cadmium and mercury on Scenedesmus obliquus in dependence on the pH-value is measured, because the original pH-value of the solution is changed by the algae due to their absorption of hydrogen-ions. For the uptake of zinc and cadmium the logarithm of the cumulation factor in the range of 2 … 5 is a linear function of the pH-value in the range of 5 … 9, cumulation increasing with rising pH-value. In contrast, the mercury cumulation is pH-independent. If the changed pH-value is taken into account, the cumulation factors are independent of the metal concentration in the range = 10^?4 mol/l. The degree of cumulation is not changed by the presence of other metals. The cumulation factor is reduced by substances forming negatively charged complexes with the metals.     

Toxicities of ten metals to Crassostrea gigas and Mytilus edulis embryos and Cancer magister larvae

Pacific oyster (Crassostrea gigas Thunberg) embryos, bay mussel (Mytilus edulis Linnaeus) embryos, and Dungeness crab (Cancer magister Dana) zoea I stage larvae were exposed to arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and zinc salts. The two bivalve species were exposed through the completion of embryogenesis (48 h), and the effects of the metals upon abnormal development were monitored. The crab larval stages were exposed to the metal solutions for 96 h. Concentrations (μg l_.^?1 as metal) which caused 50% abnormal development in the two species of bivalve larvae and which were fatal to 50% of the crab larvae ranged from 5.3 (oyster) to 49 (crab) for copper; 5.8 (mussel) to 8.2 (crab) for mercury; 14 (mussel) to 55 (crab) for silver; 119 (oyster) to 456 (crab) for zinc; 232 (crab) to 3000 (mussel) for arsenic; 247 (crab) to 1200 (mussel) for cadmium; 349 (oyster) to 4360 (crab) for nickel; 476 (mussel) to 758 (oyster) for lead; 3440 (crab) to 4538 (oyster) for hexavalent chromium; and selenium greater than 10 000 for the three species. The acute toxicity testing of C. gigas embryo together with two California native species confirmed its usefulness for predicting toxicity to the latter species.     

Embryotoxic and genotoxic effects of heavy metals and pesticides on early life stages of Pacific oyster (Crassostrea gigas)

This study evaluated embryotoxicity and genotoxicity of two dissolved metals copper and cadmium (Cu and Cd) and two pesticides (metolachlor and irgarol) occurring in Arcachon Bay (SW France) in Pacific oyster (Crassostrea gigas) larvae and investigated the relationship between those two endpoints. Embryotoxicity was measured by calculating the percentage of abnormal D-shaped larvae and genotoxicity was evaluated with DNA strand breaks using the comet assay. After 24 h exposure, significant increases of the percentage of abnormal D-larvae and the DNA strand breaks were observed from 0.1 μg L⁻¹ for Cu, 10 μg L⁻¹ for Cd and 0.01 μg L⁻¹ for both irgarol and metolachlor in comparison with the controls. A strong positive relationship between embryotoxicity and genotoxicity was recorded for Cu, Cd and metolachlor. The current study suggests that copper, irgarol and metolachlor can induce larval abnormalities and DNA damage in a population of exposed oysters at environmentally relevant concentrations.     

Toxicity of Interactions of Zinc —Nickel,Copper —Nickel and Zinc —Nickel —Copper to a Freshwater Teleost,Lebistes reticulatus (PETERS)1

The lethal toxicity of mixtures of Zn²⁺ —Ni²⁺, Cu²⁺ —Ni²⁺ and Zn²⁺ —Cu²⁺ —Ni²⁺ to common guppy at 21£C in hard water (total hardness = 260 mg/l as CaCO₃) was studied under static bioassays test conditions with renewal of the test solutions every 24 h. The heavy metals were tested separately and in mixtures. The 48 h median lethal concentrations (LC₅₀) for individual salts were 75 mg/l Zn²⁺, 37 mg/l for Ni²⁺ and 2.5 mg/l for Cu²⁺. Concentrations were expressed in “toxic units” by taking them as proportions of LC₅₀ values. Experiments showed that in the Zn²⁺-Ni²⁺ mixture, when Ni²⁺ was more in proportion, the toxicity was more than additive. The 48 h LC₅₀ value and 95% confidence limits in the Ni²⁺-Cu²⁺ mixture were 0.684 (0.484 … 0.807) toxic units and the mixture produced more than the additive toxicity (synergism.). The LC₅₀ value and its 95% confidence limits in a Zn²⁺?Cu²⁺?Ni²⁺ mixture also suggested that the mixture was again strictly additive. The results indicate that heavy metallic mixtures would pose a greater toxicological danger to fish than the respective individual metals.     

Equilibrium Uptake and Bioaccumulation of Basic Violet 14 Using Submerged Macrophyte Hydrilla verticillata

The percentage removal and uptake capacity of Basic Violet 14 using Hydrilla verticillata with living biomass was studied under batch conditions. The survival of H. verticillata was studied using the chlorophyll content in the living biomass. Bioaccumulation of Basic Violet 14 using H. verticillata was tested by varying the wet sorbent dosage (0.5–2.5 g), initial pH (3–8), and initial dye concentrations (5–25 mg L^?1). The results show that the plant was effectively accumulating the Basic Violet 14 dye. The uptake capacity of Basic Violet 14 dye was observed as 5.9 and 21.3 mg g^?1 at the initial dye concentration of 5 and 25 mg L^?1, respectively, for a biomass of 5 g L^?1 (wet weight) at pH 7.0 for 144 h. In general, the plant growth was found to be normal at lower concentrations and showed higher removal efficiency. It was also observed that removal efficiency of H. verticillata was found to decrease with increase in initial dye concentration. The biomass sample surface was analyzed using SEM imaging and functional groups present in the biomass were analyzed using FTIR. The equilibrium uptake capacity was analyzed by Langmuir and Freundlich isotherms. The equilibrium data was found to be fit well to both Langmuir and Freundlich isotherm models with higher coefficient of determination.     

Biosorption of Nickel from Synthetic and Electroplating Industrial Solutions using a Green Marine Algae Ulva reticulata

The present work investigated the biosorption of nickel from synthetic and electroplating industrial effluents using a green marine algae Ulva reticulata. Preliminary batch results imply that pH 4.5 was optimum for nickel uptake and the isotherm experiments conducted at this pH condition indicated that U. reticulata can biosorb 62.3 mg g^–1 nickel ions from synthetic solutions, according to the Langmuir model. Desorption was effective and practical using 0.1 M CaCl₂ (pH 2.5, HCl) and the biomass was regenerated and reused for three cycles. Continuous biosorption experiments were performed in an upflow packed column (2 cm I.D and 35 cm height). Among the two electroplating effluents used, effluent‐1 is characterized by excess co‐ions and high nickel ion content. This influenced the column nickel uptake with U. reticulata exhibiting 52.1 mg g^–1 in the case of effluent‐1 compared to 56.5 mg g^–1 in the case of synthetic solution. On the other hand U. reticulata performed well in effluent‐2 with uptakes of 53.3 and 54.3 mg g^–1 for effluent‐2 and synthetic solution, respectively. Mathematical modeling of column experimental data was performed using nonlinear forms of the Thomas‐ and modified dose‐response models, with the latter able to simulate breakthrough curves with high correlation coefficients.     

Transformation of Tobacco with ScMTII Gene‐Enhanced Cadmium and Zinc Accumulation

Genetic transformation is gaining importance for developing plant types suitable to metal accumulate and/or hyperaccumulate. In this study, the transgenic tobacco plant which transferred the ScMTII gene from Saccharomyces cerevisiae to wild type tobacco cultivar Petite Havana (SR1) was grown on soils with low and high cadmium (Cd) and zinc (Zn) concentrations in a growth chamber for 6 weeks and compared to wild type tobacco for Cd and Zn accumulation. Cadmium and Zn accumulations in the transgenic and wild type tobacco plants were increased with the increasing Cd and Zn concentrations. Unlike Zn, the transgenic plant accumulated significantly higher amount of Cd compared to the wild type control plants. Shoot Cd concentrations of transgenic tobacco in higher Cd dosages reached the above the hyperaccumulation threshold value of 100 mg Cd kg^?1 in the dry weight (DW). Transgenic tobacco accumulated 354, 400, 372, and 457 mg Cd kg^?1 DW, for 10, 20, 40, and 80 mg Cd kg^?1 soil treatments, respectively. These values are 3.5–4.5‐fold higher than that of Cd hyperaccumulation threshold value. With 10 mg kg^?1 Cd treatment, the bioconcentration factor (BCF) of transgenic tobacco plants for Cd reached up to 35 in which the threshold value for BCF should be at least 10. Our results showed that the transgenic tobacco may be used as a good Cd hyperaccumulator plant and for phytoextraction of Cd contaminated soils, but not for Zn.     

Adsorption of Cationic Dyes from Aqueous Solution by Termite Feces,a Non‐Conventional Adsorbent

The adsorption of three cationic dyes (rhodamine B, RB; crystal violet, CV; and malachite green, MG) onto termite feces, a low‐cost adsorbent, was investigated. The adsorbent was characterized by IR spectroscopy, point of zero charge measurement, and the Boehm titration method. The adsorption follows the pseudo‐second‐order kinetic model and the Langmuir–Freundlich isotherm with maximum adsorption capacities of 95.53 mg g^?1 (RB), 75.71 mg g^?1 (CV), and 44.78 mg g^?1 (MG). The study of thermodynamics showed that the adsorption is a spontaneous and endothermic process. This works suggest that termite feces can be used as a new low‐cost adsorbent for cationic dye removal.     

Fluxes of selected trace metals from the Seine estuary to the eastern English Channel during the period August 1994 to July 1995

Two sampling cruises conducted in the Seine estuary (France) under low-water and flood conditions produced high resolution profiles for dissolved cadmium, lead, copper, zinc and nickel concentrations versus salinity. The distribution of dissolved trace metals differed depending on hydrologic conditions, partly because of the dilution of upstream inputs during flood periods. Daily fluxes of these dissolved trace metals were estimated for the two sampling periods (September 1994 and February 1995) by extrapolating the dilution lines observed in higher salinity waters to salinity=0 and then multiplying the effective freshwater concentrations thus obtained by the corresponding freshwater flow. Several procedures were subsequently applied to deduce each daily flux for the year studied from data for these two periods. A consensus was found among these procedures, allowing the determination of net fluxes of dissolved trace metals with a precision of 20–35%. The net fluxes thus estimated were 4 T yr⁻¹ for Cd, 4 T yr⁻¹ for Pb, 40 T yr⁻¹ for Cu, 130 T yr⁻¹ for Zn and 50 T yr⁻¹ for Ni.     

Biologischer Abbau von 2,4-Dinitrotoluol in einer kontinuierlich betriebenen Versuchsanlage und kinetische Untersuchungen

Biological Degradation of 2,4-Dinitrotoluene in a Continuous Bioreactor and Kinetic Studies Experimental results on the aerobic biological degradation with complete mineralization of 2,4-dinitrotoluene (2,4-DNT) are presented. A culture of Pseudomonas sp. DNT from Spain and Nishino was used. The degradation was examined with batch cultures for the determination of kinetic and stoichiometric coefficients. Further experiments were carried out with a continuous culture in a fixed-bed reactor with recirculation in order to obtain high degradation rates. The reactor was packed with ceramic Raschig rings (55 mL) and had a liquid reaction volume of 160 mL. The minimal salt media from Spanggord et al. with and without (NH₄)₂S)₄ as nitrogen source was used as substrate. 2,4-DNT was the sole source of carbon and energy. From batch experiments a yield coefficient Y_B/S = (0.30 ± 0.05) g g^?1 was calculated from a mass balance of the elements. This result was confirmed by calculations using literature data. Fitting the experimental data to the Monod equation, μ_max = 0.1 h^?1 and K_S = 0.01…0.03 mmol L^?1 were obtained. It was demonstrated by batch experiments that 2,4-DNT is not only used as the source of carbon and energy but also as the nitrogen source. In the fixed-bed reactor, a degradation of 92…97% was reached with a maximal 2,4-DNT load of 95 mg L^?1 h^?1. The rate of continuous degradation could be described by a pseudo-first-order reaction (k = 9.73 h^?1). The complete mineralization of 2,4-DNT was verified by the measurement of DOC and the formed nitrite and nitrate. The formed nitrite was nitrified simultaneously. It was demonstrated by these experiments that large scale biological treatment of industrial effluent containing 2,4-DNT may be successful.     

Trace metals in corals from the Great Barrier Reef

Various octocorallian and scleractinian corals from within the Great Barrier Reef Province were analysed for zinc, copper, cadmium, nickel and lead by atomic absorption spectroscopy. Of the two coral groups, the octocorals accumulated significantly greater amounts of all detectable metals. The soft coral, Sarcophyton sp., revealed distinct inter-locational differences for zinc, copper and cadmium. The potential of this genus for monitoring trace metal pollution in tropical reef waters is briefly discussed.