Speciation Modelling of the CO2-H2O-Alkanolamine System for Single Amines and Their Blends

2019 ◽  
Author(s):  
Klaus-Joachim Jens ◽  
John A. Svendsen ◽  
Ida Bernhardsen ◽  
Zulkifli Idris ◽  
M. H. Wathsala N. Jinadasa ◽  
...  
Keyword(s):  
Speciation Modelling

scholarly journals Use of speciation modelling of heavy metals in Los Patos lagoon, Argentina, to improve waterbody management

2018 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Dario Andrinolo ◽  
Andres Porta ◽  
Santiago Elisio ◽  
Esteban Colman Lerner ◽  
Leonardo Cano ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Patos Lagoon ◽  
Speciation Modelling

Summer–winter transitions in Antarctic ponds: III. Chemical changes

2011 ◽  
Vol 24 (2) ◽  
pp. 121-130 ◽  
Author(s):  
Jenny Webster-Brown ◽  
Ian Hawes ◽  
Karl Safi ◽  
Brian Sorrell ◽  
Nathaniel Wilson
Keyword(s):  
Trace Elements ◽  
Water Column ◽  
Ice Shelf ◽  
Toxic Trace Elements ◽  
Mineral Phases ◽  
Show Evidence ◽  
Speciation Modelling ◽  
Geochemical Speciation ◽  
Inorganic Solutes ◽  
High Concentrations

AbstractObservations were made of water column chemistry in four Na-Cl dominated ponds on the McMurdo Ice Shelf from the end of January to early April in 2008. During that time the ponds went from ice-free to predominantly frozen, with only a small volume of residual hypoxic, saline liquid trapped at the base of each pond. Changes in the concentrations of inorganic solutes with time distinguished Na, Cl, Mg, K, SO4, As, U and Mn as ions and trace elements that behave mainly conservatively during freezing, from those which are affected by biological processes (removing HCO3) and the precipitation of mineral phases such as calcite (removing Ca and more HCO3). Dissolved Fe, Mo, Cu and Zn also show evidence of precipitation from the water column during freezing; geochemical speciation modelling predicts the formation of stable insoluble mineral phases such as Fe oxides and oxyhydroxides while conditions are oxic, and Fe-, Cu-, Mo- and Zn-sulphide minerals in the presence of H2S. Consequently, under winter conditions, residual liquid beneath the ice in such ponds is anticipated to be an anoxic Na-Cl brine with the capacity to develop high concentrations of toxic trace elements such as As and U.

Thermodynamic models applied to CO2 absorption modelling

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tohid N. Borhani ◽  
Seyed A. Nabavi ◽  
Dawid P. Hanak ◽  
Vasilije Manovic
Keyword(s):  
Carbon Capture ◽  
Vital Role ◽  
Modelling And Simulation ◽  
Co2 Absorption ◽  
Thermodynamic Models ◽  
Gas Streams ◽  
Speciation Modelling ◽  
Emission Reduction Target ◽  
And Storage ◽  
Modelling Methods

AbstractCarbon capture, utilisation, and storage (CCUS) is considered as the least cost-intensive option towards achieving the emission reduction target by 2050. One of the important technologies to remove CO2 from different gas streams is solvent-based CO2 capture. Modelling and simulation of solvent-based CO2 capture processes have been attracting a lot of attention in recent years. Thermodynamic models play a vital role in these modelling and simulation studies. Hence, this study critically reviews the thermodynamic models applied in the modelling of solvent-based CO2 capture systems over the past years, to provide a guideline for the selection of the optimum models for future studies. These models have wide applications in two main areas: equilibrium modelling [vapour-liquid equilibrium (VLE) (physical) and speciation equilibrium (chemical)], and calculation of some thermodynamic properties. VLE and speciation modelling methods are classified rigorously. VLE modelling methods are classified as homogeneous, heterogeneous, and empirical, and speciation modelling methods are classified as iterative (which could be stoichiometric and non-stoichiometric) and non-iterative. Thermodynamic models are categorised into three key families: activity-coefficient based, equation of state based, and quantum mechanical based. Theory and concepts of different thermodynamic models are presented. Some selected studies that used each family of thermodynamic models are reviewed.

scholarly journals Integration of complete elemental mass-balanced stoichiometry and aqueous-phase chemistry for bioprocess modelling of liquid and solid waste treatment systems − Part 2: Bioprocess stoichiometry

Water SA ◽  
2021 ◽  
Vol 47 (3 July) ◽  
Author(s):  
CJ Brouckaert ◽  
GA Ekama ◽  
BM Brouckaert ◽  
DS Ikumi
Keyword(s):  
Aqueous Phase ◽  
Waste Treatment ◽  
Model Development ◽  
Oxygen Demand ◽  
Weak Acid ◽  
Aqueous Environment ◽  
Base System ◽  
Speciation Modelling ◽  
Phase Chemistry ◽  
And Control

Bioprocesses interact with the aqueous environment in which they take place. Integrated bioprocess and three-phase (aqueous−gas−solid) multiple strong and weak acid/base system models are currently being developed for a range of wastewater treatment applications including anaerobic digestion, biological sulphate reduction, autotrophic denitrification, biological desulphurization and plant-wide water and resource recovery facilities. In order to model, measure and control such integrated systems, a thorough understanding of the interactions between the bioprocesses and aqueous phase multiple strong and weak acid/bases are required.  In the first of this series of five papers, the generalized procedure for deriving bioprocess stoichiometric equations was explained. This second paper presents the stoichiometric equations for the major biological processes and shows how their structure can be analysed to provide insight into how bioprocesses interact with the aqueous environment. Such insight is essential for confident, effective and reliable use of model development protocols and algorithms. It shows that the composite parameters, total oxygen demand (TOD, electron donating capacity) and alkalinity (proton accepting capacity), are conserved in bioprocess stoichiometry and their changes in the aqueous phase can be calculated from the bioprocess components. In the third paper, the measurement of the organics composition is presented. The link between the modelling and measurement frameworks of the aqueous phase, which uses the composite parameter alkalinity, is described in the fourth paper. Aqueous ionic speciation modelling is described in detail in the fifth.

Modelling the speciation pattern of metals in Ondo coastal water with geochemical model – PHREEQCI

2012 ◽  
Vol 7 (3) ◽  
Author(s):  
Foluso O. Agunbiade ◽  
Bamidele I. Olu-Owolabi ◽  
Kayode O. Adebowale
Keyword(s):  
Coastal Water ◽  
Toxic Metals ◽  
Quality Parameters ◽  
Geochemical Model ◽  
Free Ion ◽  
Speciation Modelling ◽  
High Alkalinity ◽  
Ondo State ◽  
Fe Hydroxide ◽  
Ion Species

The speciation pattern of ten metals was studied in the coastal water of Ondo State, Nigeria using geochemical modelling software (PHREEQCI). The metals classified as macronutrients – Na, Ca, K, Mg; micronutrients – Fe, Cu, Mn, Zn; toxic metals – Cd, Pb were evaluated along with other general water quality parameters from ten sampling sites. The results served as input data for the modelling. The outcomes of the water speciation modelling revealed that the macronutrient metals exist as free ions which aid the reduction of free ion species of toxic metals. The micronutrients exist as neutral or complex salts which are less toxic according to free ion activity model theory. The self purification capacity of the coastal water was aided by the abundant formation of Fe-hydroxide precipitates; high alkalinity; pH; salinity of the coastal water which are responsible for the reduction of free ion specie of Pb and its ecotoxicity but increased the concentration of toxic Cd chloride species. Therefore, the prevailing biogeochemistry of the coast enhances demobilization of the metal contaminants and favours the reduction of their toxicity except Cd.

scholarly journals Volatile metal emissions from volcanic degassing and lava–seawater interactions at Kīlauea Volcano, Hawai’i

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Emily Mason ◽  
Penny E. Wieser ◽  
Emma J. Liu ◽  
Marie Edmonds ◽  
Evgenia Ilyinskaya ◽  
...  
Keyword(s):  
Late Stage ◽  
Gas Mixtures ◽  
Kilauea Volcano ◽  
Metals And Metalloids ◽  
Natural Sources ◽  
Volcanic Degassing ◽  
Direct Measurements ◽  
Kīlauea Volcano ◽  
Speciation Modelling ◽  
Hcl Gas

AbstractVolcanoes represent one of the largest natural sources of metals to the Earth’s surface. Emissions of these metals can have important impacts on the biosphere as pollutants or nutrients. Here we use ground- and drone-based direct measurements to compare the gas and particulate chemistry of the magmatic and lava–seawater interaction (laze) plumes from the 2018 eruption of Kīlauea, Hawai’i. We find that the magmatic plume contains abundant volatile metals and metalloids whereas the laze plume is further enriched in copper and seawater components, like chlorine, with volatile metals also elevated above seawater concentrations. Speciation modelling of magmatic gas mixtures highlights the importance of the S2− ligand in highly volatile metal/metalloid degassing at the magmatic vent. In contrast, volatile metal enrichments in the laze plume can be explained by affinity for chloride complexation during late-stage degassing of distal lavas, which is potentially facilitated by the HCl gas formed as seawater boils.

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