Ethylenediamine-N,N′-diacetic acid complexes with divalent manganese, zinc, cadmium, and lead: a thermodynamic study

1979 ◽  
Vol 57 (1) ◽  
pp. 113-118 ◽  
Author(s):  
R. J. Gualtieri ◽  
W. A. E. McBryde ◽  
H. K. J. Powell
Keyword(s):  
Protonation Constants ◽  
Thermodynamic Study ◽  
Diacetic Acid ◽  
Calorimetric Data ◽  
Nmr Studies ◽  
Aqueous Acid ◽  
Manganese Zinc ◽  
Proton Dissociation ◽  
Zinc Cadmium ◽  
Cadmium And Lead

The four protonation constants are reported for the dianion of ethylenediamine-N,N′-diacetic acid(H2L),25°C, I = 0.10 M(KNO3), (log ki = 9.60, 6.51, 2.12, 1.3). log K(potentiometric) and ΔH(calorimetric) data are reported for the formation of the complexes [ML], M = Mn2+, Zn2+, Cd2+, and Pb2+ (log K = 6.87, 10.99, 9.16, and 10.66; ΔH = −2.9, −24.4, −16.7, and −28.0 kJ mol−1 respectively). The complexes [ZnL] and [PbL] undergo (aqua) proton dissociation reactions, [Formula: see text] log KD = −10.56 and −11.02, ΔHD = +60.7 and +38.5 kJ mol−1, respectively. Potentiometric and nmr studies indicate that the ligand undergoes a slow (metal catalysed) hydrolysis or rearrangement in aqueous acid.

Reactions of triethylenetetramine with protons and bivalent zinc, cadmium, and lead in aqueous solution and aqueous dioxane (50% v/v)

1979 ◽  
Vol 57 (14) ◽  
pp. 1785-1791 ◽  
Author(s):  
W. A. E. McBryde ◽  
H. K. J. Powell
Keyword(s):  
Aqueous Solution ◽  
Aqueous Dioxane ◽  
Calorimetric Data ◽  
Electrostatic Effects ◽  
Solvation Effects ◽  
Zinc Cadmium ◽  
Cadmium And Lead

The reactions of triethylenetetramine with protons and with bivalent Zn, Cd, and Pb have been studied in aqueous solution and in 50% (v/v) aqueous 1,4-dioxane, 25 °C, I = 0.10 M KNO3. log K (potentiometric) and ΔH (calorimetric) data are interpreted in terms of electrostatic effects and solvation effects operative in the two solvents.Protonation constants are higher by 0.2–0.6 log units in aqueous solution. Stepwise enthalpies of protonation −ΔHn (n = 2,3,4) are significantly higher, and the corresponding entropies lower, in aqueous solution. The complexes [ML]2+ are of similar stability in the two solvents but −ΔH is ca. 10–20% lower in aqueous dioxane.

scholarly journals Environmental Impacts of an Old Mine Tailings Deposit – Metal Concentrations and Water Pathways

1987 ◽  
Vol 18 (4-5) ◽  
pp. 301-312 ◽  
Author(s):  
P. Sandén ◽  
S. Karlsson ◽  
U. Lohm
Keyword(s):  
Environmental Impacts ◽  
Mine Tailings ◽  
Water Bodies ◽  
Contaminated Water ◽  
Surrounding Area ◽  
Metal Concentrations ◽  
Principal Source ◽  
Zinc Cadmium ◽  
Copper Zinc ◽  
Cadmium And Lead

Variations in metal concentrations in a heavily polluted stream receiving acidic leachates from an old mine tailings deposit are analysed from a hydrological perspective. From an extensive data material, collected during three years, the variations in concentrations of four metals (copper, zinc, cadmium and lead) are discussed. The deposit is the principal source for these metals in the watershed. The variation in metal concentrations in the vicinity of the deposit can to a large extent be explained by simple dilution of contaminated water with uncontaminated water from the surrounding area. Further downstream the deposit, other processes become increasingly important for the metal concentrations in the water bodies.

Copper substitution alone and in the presence of chromium, zinc, cadmium and lead in goethite (α-FeOOH)

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 293-310 ◽  
Author(s):  
N. Kaur ◽  
B. Singh ◽  
B. J. Kennedy
Keyword(s):  
Dissolution Rate ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
General Sequence ◽  
Cell Parameters ◽  
Molar Ratios ◽  
Zinc Cadmium ◽  
Cadmium And Lead ◽  
Copper Substitution

AbstractA series of Cu-substituted goethites, single and co-substituted with Cr, Zn, Cd and/or Pb was prepared, having molar ratios equal to 2.00, 3.33 and 5.00 mol%. All the samples contained only goethite, except Cu-, (Cu,Zn)- and (Cu,Pb)-samples synthesized at 5.00 mol% where hematite was also formed. The presence of Cr/Cd suppressed the hematite-forming effects of Cu. The general sequence of metal entry into the single-metal-substituted goethites was Zn = Cr > Cd > Cu > Pb and in di- (5.00 mol%) and tri- (3.33 mol%) metal-substituted goethites was Cu > Zn > Cd > Cr >> Pb. Cu incorporation increased all the unit-cell parameters in single-metal-substituted goethite, and these parameters increased in combination with other metals as follows: Cd > Zn > Cr > Pb in the multimetal-substituted goethites. The Cu-substituted goethite dissolved faster than pure goethite. Co substitutions of Cr/Pb reduced the dissolution rate (kFe), while substitutions of Cd/Zn increased kFe.

Zinc concentrations in juvenile flatfish

1979 ◽  
Vol 59 (3) ◽  
pp. 761-775 ◽  
Author(s):  
N. J. Milner
Keyword(s):  
Sea Water ◽  
Chemical Properties ◽  
Estuarine Fish ◽  
Physico Chemical ◽  
Zinc Cadmium ◽  
Iron And Zinc ◽  
Lead Levels ◽  
Zinc Concentrations ◽  
High Concentrations ◽  
Cadmium And Lead

In most demersal and some pelagic marine fish O- and I-group stages are found on inshore nursery grounds which are often situated in coastal indentations and estuarieswhere flushing rates are low and the build up of persistent pollutants can be correspondingly high. Their movements are restricted, only leaving the nursery areas towards the end of their second year (Lockwood, 1974; Riley, 1973). This, coupled with the fact that juveniles may be more susceptible than adults to pollutants, makes them particularly vulnerable to the potential hazards of inshore pollution.The physico-chemical properties of most trace metals, however, generally preclude their occurrence at high concentrations in sea water itself. Instead, most of the metal is transferred to the particulate phase of the water mass and to sedimentary reservoirs (Renfro, 1973) so that concentrations of metals in sea water very rarely reach levels which are known to be acutely toxic to fish. The main risk from direct effects of metals lies in poisoning resulting from internal accumulation.Little information is available on metal concentrations occurring in young fish. Hardisty et al. (1974) and Hardisty, Kartar & Sainsbury (1974) have examined zinc, cadmium and lead levels in O-group and older flounders from the Bristol Channel. Andersen, Dommasnes & Hesthagen (1973) found high concentrations of zinc in O- and I-group herring and sprat from Oslo Fjord, Cross & Brooks (1973) reported on manganese, iron and zinc concentrations in juvenile estuarine fish. Pentreath (1973 b) has reported on zinc concentrations in the organs of I-group plaice.

Influence of Nitrilotriacetate on the Elimination of Metal Ions by Coprecipitation with Ferric Hydroxide

1987 ◽  
Vol 19 (5-6) ◽  
pp. 1013-1019 ◽  
Author(s):  
F. H. Frimmel ◽  
J. Geywitz
Keyword(s):  
Conditional Distribution ◽  
Ferric Hydroxide ◽  
Distribution Coefficients ◽  
Metal Species ◽  
Batch Experiments ◽  
Reaction Conditions ◽  
Low Concentrations ◽  
Zinc Cadmium ◽  
Copper Zinc ◽  
Cadmium And Lead

The elimination of dissolved copper, zinc, cadmium and lead by coprecipitation with iron(III) hydroxide was investigated. The reaction conditions of the batch experiments were adopted from water treatment. Conditional distribution coefficients show the order Cd < Zn < Cu < Pb for increasing interaction of the metals with the ferric hydroxide. The presence of nitrilotriacetate (NTA) decreases the efficiency of the metal elimination. NTA is also able to remobilize metals from the metal enriched precipitation. There is a significant effect, even at low concentrations of a few µmol/l. Remobilization of Cu, Zn and Cd increases, remobilization of Pb decreases with reaction time. The “ageing” of the precipitation plays an important role for the yield of the reactions. From a broad application of NTA in detergents an increase of the concentration of dissolved metal species has to be expected.

scholarly journals Biotoxicity of heavy metal salts to Bacillus subtilis and their sorption properties

2020 ◽  
Vol 157 ◽  
pp. 02012
Author(s):  
Aleksey Sizentcov ◽  
Elena Sal’nikova ◽  
Elena Barysheva ◽  
Yaroslav Sizentcov ◽  
Veronika Sal’nikova
Keyword(s):  
Heavy Metal ◽  
Bacillus Subtilis ◽  
Strain Differences ◽  
Scientific Development ◽  
Biological Origin ◽  
Metal Compounds ◽  
Zinc Cadmium ◽  
Probiotic Strains ◽  
Cadmium And Lead ◽  
High Level

The prospect of the use of microorganisms in medical and veterinary practice at the present stage of scientific development has high potential based on natural mechanisms of protection and adaptation of organisms to the effects of adverse factors. The biological adaptation potential of microorganisms to the effects of heavy metals found its practical application in studies of soil and water bioremediation. Based on the above, we set the aim to assess inhibitory characteristics of various heavy metal compounds, the extent of their impact on the growth of populations of probiotic strains Bacillus subtilis, and to study biosorption criteria of the strains. To achieve this aim, we used isolated cultures of probiotic strains B. subtilis 534 and B. subtilis 10641 extracted from drugs Sporobacterin and Vetom 1.1, respectively. Various chemical compounds of iron, copper, zinc, cadmium, and lead with a various anion component were used as growth inhibitors in the study. The criterion for the selection of compounds was a high level of their dissociation in water solutions. Data presented in this work experimentally confirm the capability of using probiotic strains in ecosystems of biological origin. A comparison of two strains of Bacillus subtilis showed a high level of resistance to xenobiotic elements with strain differences in the studied microorganism. The B. subtilis 534 strain revealed a higher level of resistance to compounds with a direct correlation between the inhibitory characteristics of the elements and the level of element sorption from the nutrient substrate.

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