Correlation of humic substances chemical properties and their thermo-oxidative degradation kinetics

Kučerík, Jiří; Kislinger, J.; Majzlík, Petr; Pekař, Miloslav

doi:10.1007/s10973-009-0310-2

Cited by 5 publications

(6 citation statements)

References 32 publications

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“…This behavior is caused by a typical chelate effect due to that metal ions are complexed by more than one active binding site of humic acid [21,35]. The chelate effect observed in cation adsorption by humic acid confirms the stabilization of the supramolecular aggregates of humic acid by mordant action with metal ions [4,36].…”

Section: Calorimetric Titrationmentioning

confidence: 67%

“…HA infrared spectrum, Fig. 2, displays typical peaks characteristic of HA, such as: (i) a strong and very broad band at 3500-3000 cm −1 assigned to OH stretching of alcohol, phenol, and carboxylic groups; (ii) bands at 2922 and 2851 cm −1 are related to CH stretching of sp 3 carbon; (iii) broad bands between 1720 and 1650 cm −1 assigned to C=O of amides, ketones, ester, and carboxylic acid groups; (iv) other broad bands at 1600-1500 cm −1 assigned to COO − symmetric stretching frequencies and assigned to C=C aromatic groups; (v) the broad bands between 1400 and 1300 cm −1 , attributed to OH deformation and COO − antisymmetric stretching which are characteristic for HA molecules; (vi) broad bands between 1290 and 1100 cm −1 attributed to aromatic C and to C-O stretching frequencies of phenol and aliphatic groups, and also assigned to OH deformation of -COOH; and (v) peaks between 1120 and 1000 cm −1 attributed to C-O of polysaccharides [21]. The main absorbance bands and corresponding assignments obtained for HA are listed in Table 2 and all peaks are in agreement with the literature [1,6,15,16,[18][19][20][21].…”

Section: Characterizationmentioning

confidence: 99%

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Buffer capacity of humic acid: Thermodynamic approach

Pertusatti

Prado

2007

Journal of Colloid and Interface Science

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Section: Calorimetric Titrationmentioning

confidence: 67%

Section: Characterizationmentioning

confidence: 99%

Buffer capacity of humic acid: Thermodynamic approach

Pertusatti

Prado

2007

Journal of Colloid and Interface Science

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“…It has been applied to study transformation in clay minerals (Plante et al 2009) as well as thermal degradation processes in soil organic matter (SOM) including pyrolysis (Leinweber et al 1992) and thermal combustion (Dell'Abate et al 2000Provenzano et al 2000;Kucerik et al 2009;Siewert 2004). The most widely used thermoanalytical techniques include thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).…”

Section: Introductionmentioning

confidence: 99%

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Schaumann

Mouvenchery

2011

J Soils Sediments

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Purpose This exploratory study evaluates the potential of nanothermal analysis (nTA) coupled with atomic force microscopy (AFM) of soil samples for understanding physicochemical processes in soil and for linking the nanospatial and microspatial distribution of thermal characteristics with the macroscopic properties of soil samples. Materials and methods Soil and reference samples were investigated by differential scanning calorimetry and AFMnTA. nTA was conducted on 16 points of each AFM image in two subsequent heating cycles (55-120°C and 55-300°C, respectively). Thermograms were subdivided into characteristic types and their spatial distribution was compared between sample replicates and materials. Results and discussion Thermogram types consisted of partly structured expansion and compression phases, suggesting material-specific thermal profiles. The distribution of thermogram types reflected sample-dependent nanoscale and microscale heterogeneity. Indications for water molecule bridge transitions were found by nTA in peat and soil. Organic materials generally revealed strong expansion and irreversible compression phases, latter probably due to the collapse of pore and aggregate structures. In contrast to charcoal and manure, peat shows strong expansion below 120°C and compression only above 120°C. Conclusions All investigated samples are heterogeneous on the nanoscale and microscale with respect to thermal behaviour. AFM-nTA allows distinguishing numerous different materials on nanometre and micrometre scales in soil samples. The material-dependent characteristics will help in understanding and learning more about the nanoscale distribution of different materials and properties. Related to the macroscopic thermal behaviour, this will allow studying links between the properties of biogeochemical interfaces and the processes governed by them.

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“…However, in the temperature range considered, evaporation or sublimation of organic compounds may also have occurred. [69] Fluctuation of the DTA curve for the ~m1 stage does not allow for a clear indication of the thermal effect of the observed processes. However, it is supposed that little change in the endo direction is caused by the dehydration or dehydroxylation of the sample, which has been primally overlapped by the exo-peak from decomposition of HC compounds.…”

Section: Thermal Analysis Resultsmentioning

confidence: 98%

Ultrasound‐Assisted Synthesis of Humic‐Silica Composites by the Isolation of Humic Substances from Peat and Lignite

Nieweś,

Biegun,

Marecka

et al. 2024

ChemPlusChem

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The aim of the presented study was to evaluate an integrated, direct procedure for the synthesis of humic‐silica composites (HSiC) by the isolation of humic substances (HS) from peat and lignite by the use of sodium silicate solution as an extractant. The obtained materials, because of the presence of humic functional groups, may potentially be used for removing contaminants from aqueous solutions. The quantitative assessment was based on experiments designed according to the Box‐Behnken plan. The statistical analysis of the results allowed to determine the optimal conditions of the process tested, for which the isolation efficiency of humic substances (HS) was greater than 50% for both raw materials. This made it possible to synthesize humic silica composites with a high content of HS, which have been qualitatively evaluated. This step was focused on the analysis of the humic structure using elemental analysis, spectroscopic methods, and differential thermal analysis coupled with thermogravimetry. On the basis of them, the presence of structures characteristic for HS in the HSiC tested was observed. Moreover, the results of the thermal analysis pointed to the higher thermal stability of the synthesized compounds, compared to the HS isolated with the use of a traditional extractant.

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Correlation of humic substances chemical properties and their thermo-oxidative degradation kinetics

Cited by 5 publications

References 32 publications

Buffer capacity of humic acid: Thermodynamic approach

Buffer capacity of humic acid: Thermodynamic approach

Potential of AFM–nanothermal analysis to study the microscale thermal characteristics in soils and natural organic matter (NOM)

Ultrasound‐Assisted Synthesis of Humic‐Silica Composites by the Isolation of Humic Substances from Peat and Lignite

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