Chemical Speciation of Hg(II) with Environmental Inorganic Ligands

2004 ◽  
Vol 57 (10) ◽  
pp. 993 ◽  
Author(s):  
Kipton J. Powell ◽  
Paul L. Brown ◽  
Robert H. Byrne ◽  
Tamas Gajda ◽  
Glenn Hefter ◽  
...  
Keyword(s):  
Organic Matter ◽  
Complex Formation ◽  
Numerical Modelling ◽  
Thermodynamic Data ◽  
Natural Waters ◽  
Chemical Speciation ◽  
Interaction Coefficients ◽  
Low Concentrations ◽  
The Common ◽  
Inorganic Ligands

Abstract Complex formation between Hg(ii) and the common environmental ligands Cl−, OH−, CO32−, SO42−, and PO43− can have profound effects on Hg(ii) speciation in natural waters with low concentrations of organic matter. Hg(ii) is labile, so its distribution among these inorganic ligands can be estimated by numerical modelling if reliable values for the relevant stability constants are available. A summary of critically reviewed constants and related thermodynamic data is presented. Recommended values of log10βp,q,r° and the associated reaction enthalpies, ΔrHm°, valid at Im = 0 mol kg−1 and 25°C, along with the equations and specific ion interaction coefficients required to calculate log10βp,q,r values at higher ionic strengths and other temperatures are also presented. Under typical environmental conditions Hg(ii) speciation is dominated by the reactions Hg2+ + 2Cl− ↔ HgCl2(aq) (log10β2° = 14.00 ± 0.07), Hg2+ + Cl− + H2O ↔ Hg(OH)Cl(aq) + H+ (log10β° = 4.27 ± 0.35), and Hg2+ + 2H2O ↔ Hg(OH)2(aq) + 2H+ (log10*β2° = −5.98 ± 0.06).

scholarly journals Chemical speciation of environmentally significant metals with inorganic ligands Part 2: The Cu2+-OH-, Cl-, CO32-, SO42-, and PO43- systems (IUPAC Technical Report)

2007 ◽  
Vol 79 (5) ◽  
pp. 895-950 ◽  
Author(s):  
Kipton J. Powell ◽  
Paul L. Brown ◽  
Robert H. Byrne ◽  
Tamás Gajda ◽  
Glenn Hefter ◽  
...  
Keyword(s):  
Natural Waters ◽  
Chemical Speciation ◽  
Formation Constants ◽  
Water Systems ◽  
Interaction Coefficients ◽  
Low Concentrations ◽  
Technical Report ◽  
The Common ◽  
A Minor ◽  
Inorganic Ligands

Complex formation between CuII and the common environmental ligands Cl-, OH-, CO32-, SO42-, and PO43- can have a significant effect on CuII speciation in natural waters with low concentrations of organic matter. Copper(II) complexes are labile, so the CuII distribution amongst these inorganic ligands can be estimated by numerical modeling if reliable values for the relevant stability (formation) constants are available. This paper provides a critical review of such constants and related thermodynamic data. It recommends values of log10βp,q,r° valid at Im = 0 mol kg-1 and 25 °C (298.15 K), along with the equations and specific ion interaction coefficients required to calculate log10βp,q,r values at higher ionic strengths. Some values for reaction enthalpies, ΔrHm, are also reported where available. In weakly acidic fresh water systems, in the absence of organic ligands, CuII speciation is dominated by the species Cu2+(aq), with CuSO4(aq) as a minor species. In seawater, it is dominated by CuCO3(aq), with Cu(OH)+, Cu2+(aq), CuCl+, Cu(CO3)OH-, Cu(OH)2(aq), and Cu(CO3)22- as minor species. In weakly acidic saline systems, it is dominated by Cu2+(aq) and CuCl+, with CuSO4(aq) and CuCl2(aq) as minor species.

Chemical speciation of environmentally significant heavy metals with inorganic ligands. Part 1: The Hg2+– Cl–, OH–, CO32–, SO42–, and PO43– aqueous systems (IUPAC Technical Report)

2005 ◽  
Vol 77 (4) ◽  
pp. 739-800 ◽  
Author(s):  
Kipton J. Powell ◽  
Paul L. Brown ◽  
Robert H. Byrne ◽  
Tamás Gajda ◽  
Glenn Hefter ◽  
...  
Keyword(s):  
Natural Waters ◽  
Chemical Speciation ◽  
Equilibrium Constants ◽  
Critical Evaluation ◽  
Interaction Theory ◽  
Interaction Coefficients ◽  
Weighted Linear Regression ◽  
Technical Report ◽  
The Common ◽  
Inorganic Ligands

This document presents a critical evaluation of the equilibrium constants and reaction enthalpies for the complex formation reactions between aqueous Hg(II) and the common environmental inorganic ligands Cl–, OH–, CO32–, SO42–, and PO43–. The analysis used data from the IUPAC Stability Constants database, SC-Database, focusing particularly on values for 25 °C and perchlorate media. Specific ion interaction theory (SIT) was applied to reliable data available for the ionic strength range Ic < 3.0 mol dm–3. Recommended values of log10βp,q,r° and the associated reaction enthalpies, ∆rHm°, valid at Im = 0 mol kg–1 and 25 °C, were obtained by weighted linear regression using the SIT equations. Also reported are the equations and specific ion interaction coefficients required to calculate log10βp,q,r° values at higher ionic strengths and other temperatures. A similar analysis is reported for the reactions of H+ with CO32– and PO43–. Diagrams are presented to show the calculated distribution of Hg(II) amongst these inorganic ligands in model natural waters. Under typical environmental conditions, Hg(II) speciation is dominated by the formation of HgCl2(aq), Hg(OH)Cl(aq), and Hg(OH)2(aq).

scholarly journals Chemical speciation of organic matter in natural waters. Interaction of nucleotide 5’ mono-, di- and triphosphates with major components of seawater

2004 ◽  
Vol 16 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Francesco Crea ◽  
Concetta De Stefano ◽  
Antonio Gianguzza ◽  
Daniela Piazzese ◽  
Silvio Sammartano
Keyword(s):  
Organic Matter ◽  
Natural Waters ◽  
Chemical Speciation

Toxicity of Heavy Metals to the Marine Diatom Ditylum Brightwellii (West) Grunow: Correlation between Toxicity and Metal Speciation

1980 ◽  
Vol 60 (1) ◽  
pp. 227-242 ◽  
Author(s):  
G. S. Canterford ◽  
D. R. Canterford
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters ◽  
Chelating Agents ◽  
Sea Water ◽  
Metal Speciation ◽  
Marine Diatom ◽  
Dissolved Organic Compounds ◽  
Inorganic Ligands

The possibility of dissolved organic compounds acting as complexing or chelating agents in natural waters has received considerable attention in the last two to three decades. Stumm & Morgan (1970) have expressed doubts about the existence of humicmetal ion complexes in natural waters. Strickland (1972) has also stated that although the addition of chelating agents to sea water often improved the growth of phytoplankton, there was little evidence that the function of dissolved organic matter in oceans and lakes was to complex metals so as to increase or decrease their availability to phytoplankton. Strickland argued that even if all dissolved organic carbon were present as a compound of strong complexing ability it would not be able to compete for most metals with inorganic ligands such as chloride, sulphate and hydroxide. However, there is an increasing amount of data indicating that metals in natural waters may exist in chelated forms with dissolved organic matter (see, for example, Davey, Morgan & Erickson, 1973; Chau & Lum-Shue-Chan, 1974).

scholarly journals Chemical Speciation and Bioavailability of Iron in Natural Waters - Linkage of Forest, River and Sea in View of Dynamics of Iron and Organic Matter

2016 ◽  
Vol 39 (6) ◽  
pp. 197-210 ◽  
Author(s):  
Masafumi NATSUIKE ◽  
Tetsuro KIKUCHI ◽  
Ying Ping LEE ◽  
Hiroaki ITO ◽  
Manabu FUJII ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Waters ◽  
Chemical Speciation

Chemical speciation of environmentally significant metals with inorganic ligands. Part 5: The Zn2+ + OH–, Cl–, CO32–, SO42–, and PO43– systems (IUPAC Technical Report)

2013 ◽  
Vol 85 (12) ◽  
pp. 2249-2311 ◽  
Author(s):  
Kipton J. Powell ◽  
Paul L. Brown ◽  
Robert H. Byrne ◽  
Tamás Gajda ◽  
Glenn Hefter ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Formation Constants ◽  
Water Systems ◽  
Organic Ligands ◽  
Interaction Theory ◽  
Interaction Coefficients ◽  
Weakly Alkaline ◽  
Specific Ion Interaction Theory ◽  
Technical Report ◽  
Inorganic Ligands

The numerical modeling of ZnII speciation amongst the environmental inorganic ligands Cl&ndash;, OH&ndash;, CO32&ndash;, SO42&ndash;, and PO43&ndash; requires reliable values for the relevant stability (formation) constants. This paper compiles and provides a critical review of these constants and related thermodynamic data. It recommends values of log10&beta;p,q,r&deg; valid at Im = 0 mol&middot;kg&ndash;1 and 25 &deg;C (298.15 K), and reports the empirical reaction ion interaction coefficients, ∆&epsilon;, required to calculate log10&beta;p,q,r values at higher ionic strengths using the Br&oslash;nsted&ndash;Guggenheim&ndash;Scatchard specific ion interaction theory (SIT). Values for the corresponding reaction enthalpies, ∆rH, are reported where available. There is scope for additional high-quality measurements for the Zn2+ + H+ + CO32&ndash; system and for the Zn2+ + OH&ndash; and Zn2+ + SO42&ndash; systems at I &gt; 0. In acidic and weakly alkaline fresh water systems (pH &lt; 8), in the absence of organic ligands (e.g., humic substances), ZnII speciation is dominated by Zn2+(aq). In this respect, ZnII contrasts with CuII and PbII (the subjects of earlier reviews in this series) for which carbonato- and hydroxido- complex formation become important at pH &gt; 7. The speciation of ZnII is dominated by ZnCO3(aq) only at pH &gt; 8.4. In seawater systems, the speciation at pH = 8.2 is dominated by Zn2+(aq) with ZnCl+, Zn(Cl)2(aq), ZnCO3(aq), and ZnSO4(aq) as minor species. This behaviour contrasts with that for CuII and PbII for which at the pH of seawater in equilibrium with the atmosphere at 25 &deg;C (log10 {[H+]/c&deg;} &asymp; 8.2) the MCO3(aq) complex dominates over the MCln(2&ndash;n)+ species. The lower stability of the different complexes of ZnII compared with those of CuII, PbII, and CdII is also illustrated by the percentage of uncomplexed M2+ in seawater, which is ca. 55, 3, 2, and 3.3 % of [MII]T, respectively.

scholarly journals Chemical speciation of environmentally significant metals with inorganic ligands. Part 3: The Pb2+ + OH–, Cl–, CO32–, SO42–, and PO43– systems (IUPAC Technical Report)

2009 ◽  
Vol 81 (12) ◽  
pp. 2425-2476 ◽  
Author(s):  
Kipton J. Powell ◽  
Paul L. Brown ◽  
Robert H. Byrne ◽  
Tamás Gajda ◽  
Glenn Hefter ◽  
...  
Keyword(s):  
Stability Constant ◽  
Natural Waters ◽  
Formation Constants ◽  
Alkaline Solutions ◽  
Weakly Alkaline ◽  
Low Concentrations ◽  
The Stability ◽  
Empirical Coefficients ◽  
A Minor ◽  
Inorganic Ligands

Complex formation between PbII and the common environmental inorganic ligands, Cl–, OH–, CO32–, SO42–, and PO43–, can be significant in natural waters with low concentrations of organic matter. Numerical modeling of the speciation of PbII amongst these inorganic ligands requires reliable values for the relevant stability (formation) constants. This paper provides a critical review of such constants and related thermodynamic data. It recommends values of log10 βp,q,r° valid at Im = 0 mol kg–1 and 25 °C (298.15 K), along with the equations and empirical coefficients required to calculate log10βp,q,r values at higher ionic strengths using the Brønsted–Guggenheim–Scatchard specific ion interaction theory (SIT). Some values for reaction enthalpies, ΔrH, are also reported. In weakly acidic fresh water systems (–log10 {[H+]/c°} &lt; 6), the speciation of PbII is similar to that of CuII. In the absence of organic ligands, PbII speciation is dominated by Pb2+(aq), with PbSO4(aq) as a minor species. In weakly alkaline solutions, 8.0 &lt; –log10 {[H+]/c°} &lt; 9.0, the speciation is dominated by the carbonato species PbCO3(aq) and Pb(CO3)22–. In weakly acidic saline systems (–log10 {[H+]/c°} &lt; 6), the speciation is dominated by PbCln(2–n)+ complexes, (n = 0–3), with Pb2+(aq) as a minor species. In this medium (and in seawater), the speciation contrasts with that of CuII because of the higher stability of the Pb2+-chlorido- complexes. In seawater at –log10 {[H+]/c°} = 8.2, the calculated speciation is less well defined, although it is clearly dominated by the uncharged species PbCO3(aq) (41 % of [Pb]T) with a significant contribution (16 %) from Pb(CO3)Cl– and minor contributions (5–10 %) from PbCln(2–n)+, (n = 0–3) and Pb(CO3)22–. The uncertainty in calculations of PbII speciation in seawater arises from (a) the large uncertainty in the stability constant for the apparently dominant species PbCO3(aq), (b) the reliance on statistical predictions for stability constants of the ternary species Pb(CO3)Cl– and Pb(CO3)OH–, and (c) the uncertainty in the stability constant for PbCl42–, the available value being considered "indicative" only. There is scope for additional detailed high-quality measurements in the Pb2+ + CO32– + Cl– system.

scholarly journals Estimation of WHAM7 constants for GaIII, InIII, SbIII and BiIII from linear free energy relationships, and speciation calculations for natural waters

2020 ◽  
Vol 17 (2) ◽  
pp. 140 ◽  
Author(s):  
Edward Tipping ◽  
Montserrat Filella
Keyword(s):  
Organic Matter ◽  
Metal Binding ◽  
Metal Ion ◽  
Natural Waters ◽  
Chemical Speciation ◽  
Equilibrium Constants ◽  
Model Parameters ◽  
Binding Model ◽  
Critical Elements ◽  
Linear Free Energy

Environmental contextNatural organic matter exerts a powerful control on chemical conditions in waters and soils, affecting pH and influencing the biological availability, transport and retention of metals. Modelling can help to predict these effects, but for many metals, model parameters are missing. We report parameters for four technology-critical elements in a chemical speciation model, and consider the chemistries of the elements in natural waters. AbstractWe compiled the equilibrium constants for the interactions of the technology-critical elements (TCEs) GaIII, InIII, SbIII and BiIII with ammonia, fluoride, hydroxyl and ligands with oxygen atoms. We then combined them with predictive equations to estimate parameters for Humic Ion-Binding Model VII, which permits the calculation of metal binding by natural organic matter (fulvic acid, FA, and humic acid, HA). Derived values of the Model VII parameter quantifying the interaction of metal ions with carboxyl-type groups (log KMA) were among the highest estimated so far, as were the values for the parameter (ΔLK2) that quantifies the tendency of the metal ion to interact with softer ligand atoms (N and S). The Windermere Humic Aqueous Model, version 7 (WHAM7), which incorporates Model VII, was then used to estimate the chemical speciation of each TCE element.

Photocatalytic Effect of Fe(III) on Oxidation of Two-Carbon Substrates Related to Natural Waters

1994 ◽  
Vol 59 (5) ◽  
pp. 1066-1076 ◽  
Author(s):  
Šárka Klementová ◽  
Dana M. Wagnerová
Keyword(s):  
Mathematical Model ◽  
Natural Waters ◽  
Substrate Oxidation ◽  
Quantum Yields ◽  
Ferric Ions ◽  
Photochemical Reduction ◽  
Photocatalytic Effect ◽  
Carbon Substrates ◽  
Glyoxalic Acid ◽  
The Common

The influence of ferric ions on photoinitiated reaction of dioxygen with two carbon organic acids, aldehydes and alcohols related to natural waters was demonstrated. Photocatalytic effect of ferric ions, i.e. photochemical reduction of Fe(III) as the catalyst generating step, has been found to be the common principal of these reactions. The overall quantum yields of the reactions are in the range from 0.3 to 1.2. A mathematical model designed for the mechanism of cyclic generation of catalyst in the singlet substrate oxidation by O2 was applied to the system glyoxalic acid + Fe(III); a fair agreement between the simulated and experimental kinetic curves was obtained. The experimental rate constant is 4.4 .10-4 s -1.

scholarly journals Photochemical effects on the interaction of enzymes and dissolved organic matter in natural waters

2003 ◽  
Vol 48 (5) ◽  
pp. 1818-1824 ◽  
Author(s):  
Norman M. Scully ◽  
Lars J. Tranvik ◽  
William J. Cooper
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters
Sign in / Sign up

Export Citation Format

Share Document