scholarly journals Isolation and purification treatments change the metal-binding properties of humic acids: effect of HF/HCl treatment

2017 ◽  
Vol 14 (7) ◽  
pp. 417 ◽  
Author(s):  
Wander G. Botero ◽  
Michael Pineau ◽  
Noémie Janot ◽  
Rute F. Domingos ◽  
José Mariano ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Organic Matter ◽  
Humic Acids ◽  
Metal Binding ◽  
Sample Treatment ◽  
Isolation And Purification ◽  
Binding Characteristics ◽  
Carboxylic Groups ◽  
Order Of Magnitude ◽  
Donnan Model

Environmental contextStudying the mechanism of binding between metals and natural organic matter is fundamental to understanding the transport and availability of these contaminants in the environment. The influence of sample treatment on the purification of organic matter showed significant differences in the interaction with metals. The results will contribute to improved modelling of metal binding to organic matter in soils, thereby providing a basis for a more realistic risk assessment. AbstractWe studied the changes in metal binding characteristics of extracted humic acids induced by HF/HCl treatment followed by dialysis, i.e. the last step of the International Humic Substances Society (IHSS) extraction protocol. We performed metal binding experiments with both the alkaline-extracted material (AE) and the fully purified (FP) humic acid using the electrochemical stripping technique (AGNES) and modelled the results using the NICA-Donnan model. The results showed an increase of free Zn, Cd and Pb concentrations of ~1 order of magnitude for the AE compared with the FP. These differences may be mostly explained by the different carbon content (51.3 % FP and 36.5 % AE) associated with an AE/FP carboxyl ratio of 0.5. Simulations using the NICA-Donnan model showed that halving the amount of carboxylic groups (Qmax,1) for the FP reduced this difference to 0.25 log units for Cd and Zn and to 0.15 log unit for Pb. There is a clear need for further research on the differences between purified v. less-disturbed natural organic material, which will contribute to improved modelling of metal binding to organic matter in soils, hence providing a basis for a more realistic risk assessment.

scholarly journals 14C Tephrochronology With Different Fractions of Paleosol Humic Matter at Procida Island, Italy

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 664-671 ◽  
Author(s):  
Marisa Alessio ◽  
Lucia Allegri ◽  
Carlo Azzi ◽  
Gilberto Calderoni ◽  
Cesarina Cortesi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Acids ◽  
Age Differences ◽  
Humic Matter ◽  
Photosynthetic Pathway ◽  
Common Pattern ◽  
Complete Decomposition ◽  
Age Variation ◽  
Order Of Magnitude

14C apparent ages along with δ13C values for three different fractions of humic matter (HM) isolated from a suite of four paleosols (PAs) interbedded within tephra are reported. The dated HM fractions were: 1) HA, the easily released humic acids; 2) HAtot, the bulk of humic acids; 3) RES, the insoluble HM. The 14C sequence dated from 13,000–25,000 BP, in agreement with stratigraphy and previous data. Age differences up to 2540±430 were statistically significant among fractions; their order of magnitude being independent from C content and depth. All the PAs showed a common pattern of among-fraction age variation, 14C aging trending from RES to HAtot through HA. As the HM fractions exhibited quite comparable δ13C values (δ13C = −25.4±0.2), it is inferred that the primitive organic matter (OM) input to PAs was dominantly supplied by vegetation of C-3 photosynthetic pathway which underwent complete decomposition during diagenesis.

scholarly journals Metal Binding and Sources of Humic Substances in Recent Sediments from the Cananéia-Iguape Estuarine-Lagoon Complex (South-Eastern Brazil)

2021 ◽  
Vol 11 (18) ◽  
pp. 8466
Author(s):  
Christian Millo ◽  
Carlo Bravo ◽  
Stefano Covelli ◽  
Elena Pavoni ◽  
Elisa Petranich ◽  
...  
Keyword(s):  
Organic Matter ◽  
Trace Metals ◽  
Humic Substances ◽  
Humic Acids ◽  
Metal Binding ◽  
Binding Capacity ◽  
Stable Carbon Isotope ◽  
Fulvic Acids ◽  
Freshwater Environment ◽  
Estuarine Lagoon

The Cananéia-Iguape estuarine–lagoon complex (São Paulo state, Brazil) is a natural laboratory to study metal binding by humic substances (HS) in subtropical settings. This transitional environment is evolving into a freshwater environment due to water input from the Ribeira River, funneled through the Valo Grande Canal (Iguape). Past mining activities in the Ribeira River basin and maritime traffic are suspected to be potential sources of trace metals in the system. In this study, the trace metal contents of Free Humic Acids (FHA), Bound Humic Acids (BHA), and Fulvic Acids (FA) extracted from sedimentary organic matter were investigated. Moreover, the sources of HS were traced using their stable carbon isotope compositions and C/N ratios. The results suggested a mixed marine–terrestrial source of FHA, BHA, and FA. Copper and Cr were the most abundant trace metals bound to HS. On average, Cu showed concentrations of 176, 115, and 37.9 μg g−1 in FHA, BHA, and FA, respectively, whereas Cr showed average concentrations of 47.4, 86.3, and 43.9 μg g−1 in FHA, BHA, and FA, respectively. Marine FHA showed the highest binding capacity for trace metals, whereas terrestrial FA derived from the decay of mangrove organic matter showed the lowest binding capacity.

scholarly journals Characterization of wastewater from landfills - amount and type of humic substances extracted from leachate

2019 ◽  
Vol 80 ◽  
pp. 03002
Author(s):  
Maria Elisabete Silva ◽  
Marlene Santos ◽  
Isabel Brás
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Functional Groups ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Organic Fertilizers ◽  
Structural Composition ◽  
Carboxylic Groups ◽  
Humification Degree

This study aimed to characterize the humic substances (HS) extracted from landfills wastewater – leachates, with different ages of exploration. To reach the objective it was applied spectroscopy techniques, UV-Vis and FTIR spectra, as well as the ratio between the absorbance analysed. First, the HS were extracted, then fractionated in fulvic acids (FA) and humic acids (HA) and it was evaluated the phytotoxicity. HS content in the leachates were higher than the typical values found in the natural aquatic humic sources. It has been identified that the leachate HS, HA and FA aromatic fractions increased with the increase of the landfilling age, suggesting that the degree of humification increased with the landfilling age. All the HS showed a high aromaticity and humification degree. The HS extracts irrespective of their source presents similar structural composition. The functional groups found are in agreement with the literature: phenols, alcohols, carboxylic groups, aliphatic structures, among others. It was found that HA are mainly organic matter with a higher aromatic degree than FA. The HS and HA showed absence of phytotoxicity, testing by germination index, suggesting that may be used to produce liquid organic fertilizers.

scholarly journals THE COMPARISON OF THE STRUCTURE OF HUMIC ACIDS FROM SOIL AMENDED WITH DIFFERENT SOURCES OF ORGANIC MATTER

2016 ◽  
Vol 48 (1) ◽  
pp. 57 ◽  
Author(s):  
Jolanta Kwiatkowska-Malina
Keyword(s):  
Organic Matter ◽  
Humic Acids ◽  
Soil Amendment ◽  
Soil Constituent ◽  
Lower Oxygen ◽  
Carboxylic Groups ◽  
Essential Problem ◽  
Different Sources ◽  
Content Of Oxygen

<p>Soil organic matter (SOM) is an essential soil constituent. The deficiency of SOM is an essential problem in many regions in Poland. Diversity of organic matter and the environment create varying structures and compositions, and thus differences in properties of humic substances (HS) especially humic acids (HAs). It was found that soil amendment with organic matter resulted in improving of soil and HAs properties compared with non-treatment ones. The results obtained provided the following evidences. With respect to HAs: an increasing content of carboxylic groups in HAs from amended soils; a major content of aromatic ring systems; higher carbon, nitrogen, hydrogen, and sulphur and lower oxygen contents comparing to the control; the addition of straw caused an increase of carbon content in HAs particles and, consequently a decrease of the C:H ratio; higher content of oxygen functional groups compared with non-treated ones. Organic matter from straw is more resistant to fast decomposition as compared to compost and it shows higher long-term sorption capacity. Therefore, straw may be an equivalent to natural sources of SOM in terms of agriculture and ecosystems protection.</p><p> </p><p>W zależności od rodzaju egzogennej materii organicznej (obornik, kompost, słoma) wprowadzonej do gleb wyekstrahowane kwasy huminowe charakteryzowały się różnymi właściwościami. Stwierdzono, że w kwasach huminowych wystąpił wzrost zawartości grup karboksylowych i fenolowych, większy udział struktur aromatycznych. W kwasach huminowych z gleb nawożonych stwierdzono większą zawartość węgla, wodoru, azotu i siarki oraz niższą zawartość tlenu w porównaniu do kwasów huminowych z gleb bez dodatku egzogennej materii organicznej. Dodatek słomy spowodował wzrost zawartości węgla w składzie pierwiastkowym kwasów huminowych a w konsekwencji zmniejszenie stosunku C:H. Materia organiczna ze słomy jest bardziej odporna na szybki rozkład w porównaniu z kompostem.</p>

Structural Characterization of Soil Organic Matter and Humic Acids in Particle-Size Fractions of an Agricultural Soil

2002 ◽  
Vol 66 (1) ◽  
pp. 129 ◽  
Author(s):  
Benny Chefetz ◽  
Jorge Tarchitzky ◽  
Ashish P. Deshmukh ◽  
Patrick G. Hatcher ◽  
Yona Chen
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Acids ◽  
Structural Characterization ◽  
Agricultural Soil ◽  
Size Fractions ◽  
Particle Size Fractions

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

Relating Ion Binding by Fulvic and Humic Acids to Chemical Composition and Molecular Size. 2. Metal Binding

2001 ◽  
Vol 35 (12) ◽  
pp. 2512-2517 ◽  
Author(s):  
Iso Christl ◽  
Chris J. Milne ◽  
David G. Kinniburgh ◽  
Ruben Kretzschmar
Keyword(s):  
Chemical Composition ◽  
Humic Acids ◽  
Metal Binding ◽  
Molecular Size ◽  
Ion Binding

THE EXTRACTION OF ORGANIC MATTER FROM SELECTED SOILS AND PARTICLE SIZE FRACTIONS WITH 0.5 M NaOH AND 0.1 M Na4P2O7 SOLUTIONS

1989 ◽  
Vol 69 (2) ◽  
pp. 253-262 ◽  
Author(s):  
M. SCHNITZER ◽  
P. SCHUPPLI
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acids ◽  
Nmr Spectra ◽  
Attractive Alternative ◽  
Particle Size Fractions ◽  
Molecular Weights ◽  
Naoh Solution ◽  
C Nmr ◽  
Medium Silt

Organic matter (OM) in the Bainsville and Melfort soils, and in coarse clay and medium silt fractions separated from these soils, was extracted under N2 with 0.5 M NaOH and unadjusted 0.1 M Na4P2O7 solutions. pH ranges of the soils and fractions in contact for 24 h with 0.5 M NaOH and 0.1 M Na4P2O7 solutions extended from 12.2 to 12.6 and 9.0 to 9.4, respectively. Slightly greater proportions of the soil-carbon were extracted by 0.5 M NaOH than by 0.1 M Na4P2O7 solution. The differences, however, did not appear to be significant and may vary from soil to soil. The efficiency of extraction and the characteristics of the extracted materials were assessed on humic acids (HAs), which were isolated from the extracts. From the Bainsville soil and fractions, 0.1 M Na4P2O7 solution extracted more high-molecular weight and more deeply colored HAs than did 0.5 M NaOH solution. But HAs extracted from the Melfort soil and fractions had similar molecular weights and colours. 13C NMR spectra showed that HAs extracted by 0.1 M Na4P2O7 solution tended to be more aromatic than HAs extracted by 0.5 M NaOH solution. Well defined solid-state 13C NMR spectra of HAs, containing up to 69.0% ash, could be recorded. Unadjusted 0.1 M Na4P2O7 solution under N2 was found to be an attractive alternative to 0.5 M NaOH solution as an extractant for soil OM. Key words: Humic acids, E4:E6 ratios, IR spectra, 13C NMR spectra, aromaticity

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