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.

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.

scholarly journals Cadmium and Lead Removal from Aqueous Solution by Grape Stalk Wastes: Modeling of a Fixed-Bed Column

2010 ◽  
Vol 55 (9) ◽  
pp. 3548-3554 ◽  
Author(s):  
Nuria Miralles ◽  
César Valderrama ◽  
Ignasi Casas ◽  
María Martínez ◽  
Antonio Florido
Keyword(s):  
Aqueous Solution ◽  
Fixed Bed ◽  
Lead Removal ◽  
Fixed Bed Column ◽  
Cadmium And Lead

Adsorption of cadmium and lead from aqueous solution using modified biochar: A review

2021 ◽  
pp. 106502
Author(s):  
Tianqi Liu ◽  
Yelly Lawluvy ◽  
Yang Shi ◽  
Joshua O. Ighalo ◽  
Yide He ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Modified Biochar ◽  
Cadmium And Lead

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.

scholarly journals Biosorption of cadmium and lead from aqueous solution by fresh water alga Anabaena sphaerica biomass

2013 ◽  
Vol 4 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Azza M. Abdel -Aty ◽  
Nabila S. Ammar ◽  
Hany H. Abdel Ghafar ◽  
Rizka K. Ali
Keyword(s):  
Aqueous Solution ◽  
Fresh Water ◽  
Cadmium And Lead ◽  
Fresh Water Alga
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