Determination of the solubility products of nitrilotriacetic acid, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid

Karhu, Jouni; Harju, Leo; Ivaska, Ari

doi:10.1016/s0003-2670(98)00657-6

Cited by 20 publications

(18 citation statements)

References 4 publications

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“…Nakamoto et al found that the crystalline structure of the macroscopically neutral DTPA has the four terminal carboxyl groups as well as the central nitrogen atom protonated . Lowering the pH further, to less than 1, leads to the formation of positively charged species, and eventually all sites will be protonated, giving rise to a cationic surfactant with a charge of +3 …”

Section: Resultsmentioning

confidence: 99%

Anomalies in Solution Behavior of an Alkyl Aminopolycarboxylic Chelating Surfactant

et al. 2013

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The solution behavior of a DTPA (diethylenetriamine pentaacetic acid)-based chelating surfactant, 4-C12-DTPA, has been studied by tensiometry and NMR diffusometry. In the absence of metal ions, the eight donor atoms in the headgroup are titrating, and the charge of the headgroup can thus be tuned by altering the pH. 4-C12-DTPA changes from cationic at very low pH, over a number of zwitterionic species as the pH is increased, and eventually becomes anionic at high pH. Around the isoelectric point, the chelating surfactant precipitated. The solution properties, studied above the solubility gap, were found strongly pH dependent. When increasing the amount of negative charges in the headgroup, by increasing the pH, the adsorption efficiency was reduced and the cmc was increased. An optimum in surface tension reduction was found at pH 5, due to a proper balance between protonated and dissociated groups. Anomalies between surface tension measurements and NMR diffusometry in determination of cmc revealed a more complex relation between surface tension, surface coverage, and cmc than usually considered, which is not in line with the common interpretation of the Gibbs adsorption equation. At some of the investigated pH levels, measurements of bulk pH could confirm the location of cmc, due to the increased protonation of micelles compared to monomers in solution. The adsorption of monomers to the air-water interface showed unusually slow time dependence, evident from decreasing surface tension for several hours. This is explained by rearrangements of the large head groups to reduce the headgroup area and increase the packing parameter.

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Section: Resultsmentioning

confidence: 99%

Anomalies in Solution Behavior of an Alkyl Aminopolycarboxylic Chelating Surfactant

et al. 2013

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“…Esse comportamento não foi observado para as coletas, visto que a concentração de Pb decresceu ao longo destas, exceto para o NTA. Segundo Karhu et al (1999), o NTA apresenta menor solubilidade (log S = 16,36) quando comparado a outros quelantes sintéticos, como EDTA (log S = 24,6) e DTPA (log S = 30,43). Ao contrário dos demais quelantes, o NTA mostrou elevação na taxa de lixiviação do metal da primeira até a décima e da primeira até a décima primeira coleta, respectivamente para as doses de 10 e 20 mmol kg -1 (Figura 3).…”

Section: Resultados E Discussão Experimento I: Dessorção De Pb Promovunclassified

Dessorção e lixiviação de chumbo em espodossolo tratado com agentes quelantes

Freitas

Nascimento

Biondi

et al. 2009

Rev. Bras. Ciênc. Solo

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A baixa degradabilidade no solo de quelantes sintéticos usados para induzir a fitoextração pode significar elevado risco ambiental pela lixiviação de metais pesados. Agentes quelantes naturais, mais rapidamente degradados no solo, podem ser uma alternativa para os quelantes sintéticos. Este trabalho objetivou avaliar a capacidade de três agentes quelantes sintéticos e dois quelantes naturais de cadeia alifática na dessorção de Pb de um Espodossolo contaminado pela deposição de escórias resultantes da reciclagem de baterias automotivas. A lixiviação de Pb promovida pelos quelantes foi também estudada. O trabalho compreendeu dois experimentos: (1) dessorção de Pb utilizando as concentrações de 0, 2, 5, 10, 20 e 30 mmol kg-1 dos ácidos cítrico e oxálico e dos quelantes sintéticos EDTA, DTPA e NTA; (2) lixiviação realizada em colunas de PVC com concentrações de 0, 10 e 20 mmol kg-1 de ácido cítrico, ácido oxálico, EDTA e NTA. O uso do EDTA promoveu elevada dessorção e lixiviação de Pb, não sendo recomendado para programa de fitoextração na área em estudo. A elevada dessorção de Pb, aliada à baixa lixiviação promovida pelo NTA, qualifica o quelante para indução da fitoextração de Pb no solo. Os quelantes naturais não apresentaram riscos para a lixiviação de Pb nas concentrações estudadas, mas parecem pouco promissores para a fitoextração do elemento, devido à baixa dessorção.

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“…Therefore, these phases cannot be solubility-controlling phases for EDTA in natural systems. For instance, the solubility of H 4 EDTA(s) is ~10 -2 mol•dm -3 at pH 1, whereas it increases to ~1 mol•dm -3 at pH 4 (Karhu et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…The solid phases for EDTA include solid EDTA acid (Karhu et al, 1999) H 2 EDTA and M (+II) H 2 EDTA (Fiorucci et al, 2002), where M(+I) and M(+II) denote alkali and alkali earth metal ions, respectively. There are also EDTA basic salts with alkali and alkali earth metals such as M (+II) M (+I) 2 EDTA and M (+II) 2 EDTA (Vorob'ev et al, 1970), and EDTA salts with transition metal ions such as Ag 2 EDTA (e.g., Saran et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Experimental determination of solubilities of di-calcium ethylenediaminetetraacetic acid hydrate [Ca2C10H12N2O8·7H2O(s)] in NaCl and MgCl2 solutions to high ionic strengths and its Pitzer model: Applications to geological disposal of nuclear waste and other low temperature environments

2017

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Determination of the solubility products of nitrilotriacetic acid, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid

Cited by 20 publications

References 4 publications

Anomalies in Solution Behavior of an Alkyl Aminopolycarboxylic Chelating Surfactant

Anomalies in Solution Behavior of an Alkyl Aminopolycarboxylic Chelating Surfactant

Dessorção e lixiviação de chumbo em espodossolo tratado com agentes quelantes

Experimental determination of solubilities of di-calcium ethylenediaminetetraacetic acid hydrate [Ca2C10H12N2O8·7H2O(s)] in NaCl and MgCl2 solutions to high ionic strengths and its Pitzer model: Applications to geological disposal of nuclear waste and other low temperature environments

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