Fluorescence fingerprint of fulvic and humic acids from varied origins as viewed by single-scan and excitation/emission matrix techniques

Sierra, Maria Marta de Souza; Giovanela, Marcelo; Parlanti, E.; Soriano-Sierra, Eduardo Juan

doi:10.1016/j.chemosphere.2004.09.038

Cited by 266 publications

(160 citation statements)

References 35 publications

Supporting

Mentioning

135

Contrasting

Unclassified

Order By: Relevance

“…30,47 EEM spectrum (Figure 2c) shows a maximum fluorescence intensity in λ exc /λ emi 250/425 nm and in λ exc /λ emi 340/430 nm, which correspond to fulvic and humic acids, respectively, according to the literature. 25,48,49 It stands out that maximum fluorescence intensity in λ exc /λ emi 250/425 nm attributed to fulvic acids have a greater intensity. Therefore, it can be verified that AHS extracted from the Preto River waters have the characteristics of a recently degraded organic matter due to a predominance of aliphatic compounds in their structure, as seen from the spectra.…”

Section: Fluorescence Spectramentioning

confidence: 99%

See 1 more Smart Citation

Solar radiation effect on the complexation capacity of aquatic humic substances with metals

Melo

Toffoli

Moreira

et al. 2012

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Este estudo teve como principal objetivo avaliar o efeito da radiação solar sobre a capacidade de complexação das substâncias húmicas aquáticas (AHS) com as espécies metálicas Al 3+ , Cr 3+ , CrO 42-e Ni 2+ . Microcosmos foram montados com AHS extraídas do Rio Preto com concentração de 5,0 mg L -1 de carbono orgânico dissolvido e diferentes concentrações de metais, sendo expostos à radiação solar in situ. As constantes de estabilidade condicional foram de 2,0 × 10 -2 , 1,1 × 10 -5 e 2,6 × 10 -2 para os complexos AHS-Cr 3+ , AHS-Ni 2+ e AHS-CrO 4 2-, respectivamente. Os resultados mostraram que a radiação solar foi responsável por um decréscimo na capacidade de complexação de 15-26% para AHS-Al 3+ , 15-72% para AHS-Cr 3+ , 12-18% para AHS-CrO 4 2-e de 13-42% para AHS-Ni 2+ . Conclui-se que a radiação solar altera a disponibilidade de metais previamente complexados às AHS, tornando-os disponíveis no corpo aquático.This study had as main objective to assess the effect of solar radiation on the capacity of the aquatic humic substances (AHS) to complex Al 3+ , Cr 3+ , CrO 4 2-and Ni 2+ . Microcosms were prepared with AHS from Preto River containing 5.0 mg L -1 of dissolved organic carbon and different concentrations of metal species, being exposed to solar radiation, in situ. Conditional stability constants obtained for the AHS-Cr 3+ , AHS-Ni 2+ and AHS-CrO 4 2-complexes were 2.0 × 10 -2 , 1.1 × 10 -5 and 2.6 × 10 -2 , respectively. The results showed that solar radiation is responsible for decreasing capacity complexation in 15-26% for AHS-Al 3+ , 15-72% for AHS-Cr 3+ , 12-18% for AHS-CrO 4 2-and 13-42% for AHS-Ni 2+ . We can conclude that solar radiation alters metals' availability previously complexed to AHS, making them available in the aquatic body.Keywords: aquatic humic substances, metal complexation, solar radiation, fluorescence IntroductionAquatic humic substances (AHS) have been intensively studied because they play an essential role in biogeochemical processes. 1,2 They can participate in the complexation reactions with metal ions thereby influencing the transport and availability of them in the environment, 2-4 may suffer interactions with organic compounds and thus, reduce or increase its toxicity to the biota, 4,5 can act in redox 6 and photochemical reactions. 7 Aquatic HS are products of the decomposition of vegetal and animal remains from microbiological transformations. They are normally dark colored organic macromolecules with a high molecular weight, a complex structure consisting of aromatic and aliphatic compounds, which have a large number of functional groups containing oxygen, e.g., carboxylates (-COOH), phenolics (aromatics-OH), alcoholics (-OH), quinones (aromatics=O), among others. 1,2 Depending on the water solubility, AHS can be operationally separated into three fractions: fulvic acids that are soluble in all pH range, humic acids that are soluble in alkaline pH and insoluble in acid pH, and humin that is insoluble in all pH range. It is worth noting that the AHS comprise about 40-60% ...

show abstract

Section: Fluorescence Spectramentioning

confidence: 99%

“…[20][21][22] Among them molecular fluorescence has been one of the techniques used in many works to characterize AHS, [23][24][25][26] as well as studies of complexation with metal ions. [27][28][29] The fluorescence has advantages over others, such as nuclear magnetic resonance (NMR) which is also widely used in AHS studies.…”

Section: Introductionmentioning

confidence: 99%

Solar radiation effect on the complexation capacity of aquatic humic substances with metals

Melo

Toffoli

Moreira

et al. 2012

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…1) were built using the FLWinlab software (Perkin Elmer). Correspondence of the main noticeable peaks (Table 1) was established in these maps based on data collected from the literature (Alberts and Takacs 2004;Burdige et al 2004;Saadi et al 2006;Sierra et al 2005).…”

Section: Soil Properties and Experimental Proceduresmentioning

confidence: 99%

Steam treatment of surface soil: how does it affect water-soluble organic matter, C mineralization, and bacterial community composition?

et al. 2010

View full text Add to dashboard Cite

“…Humic substances (HS) are known to perform many useful functions in soil and are considered to be one of the fundamental factors determining practically all properties and transformations occurring within it (Stevenson 1994;Tan 2003;Ghabbour and Davies 2005). Most published studies of HS show wide range of benefits including a growth of beneficial soil microbes, improvements in soil structure including water retention capacity as well as a soil porosity, aeration, compaction, and adhesion (Piccolo et al 1993;Nardi et al 2016;Ouni et al 2014;Ciarkowska et al 2017).…”

Section: Introductionmentioning

confidence: 99%

“…From a chemical point of view, humic substances can be described generally as a concentration of aromatic and aliphatic rings, aliphatic chains, bridges, and numerous functional groups. Among the most important functional groups of humus compounds are carboxyl, hydroxyl, phenolic, methoxy, and carbonyl groups (Stevenson 1994;Chen et al 2002;Tipping 2002;Tan 2003).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the possibilities of using humic acids obtained from lignite in the production of commercial fertilizers

Huculak-Mączka

Hoffmann

2018

J Soils Sediments

View full text Add to dashboard Cite

Purpose Technological progress and high market demand contributed to a significant interest in the production of fertilizers based on humic acids. The aim of this study was to evaluate the possibilities of using humic acids obtained from lignite in the production of new commercial products. For this purpose, it is necessary to determine the quality standard requirements for such material. Properties of humic acids depend on source of origin as well as method of its extraction. Materials and methods The humic acids were extracted from polish deposit of lignite-Sieniawa Lubuska by alkaline extraction using for this purpose six kinds of extractants: 0.1 M NaOH and 0.25 M NaOH, 0.1 M KOH and 0.25 M KOH, and 0.1 M Na 4 P 2 O 7 and 0.25 M Na 4 P 2 O 7 . The humic samples were used in solid powder form and characterized by UV-Vis spectroscopy, 13 C NMR spectroscopy, fluorescence spectroscopy, and thermal analysis. Results and discussion The determining factor influencing a degree of humic acids extraction from lignite and their structure is type of extractant. The largest efficiency of extraction (about 50%) was obtained with the use of NaOH solutions. All examined humic acids were generally characterized by simple and heterogeneous molecularly structure with low molecular weight and low aromatic polycondensation. Therefore, it can be concluded that humic acids extracted with NaOH and KOH solutions are less condensed than those extracted with Na 4 P 2 O 7 solutions. It can suggest that humic acids obtained from lignite using solutions of Na 4 P 2 O 7 are characterized by a low transformation degree and greater amount of carboxyl groups. Conclusions Low rank coal can be successfully used in agriculture as a rich source of humic acids. Reagent used in their extraction, apart from high efficiency should have a neutral impact on their structure. Studies on the physicochemical properties of humic acids can be helpful in predicting behaviors of such fertilizer components in the environment and in inventing new products taking the principles of sustainable development into consideration.

show abstract

Fluorescence fingerprint of fulvic and humic acids from varied origins as viewed by single-scan and excitation/emission matrix techniques

Cited by 266 publications

References 35 publications

Solar radiation effect on the complexation capacity of aquatic humic substances with metals

Solar radiation effect on the complexation capacity of aquatic humic substances with metals

Steam treatment of surface soil: how does it affect water-soluble organic matter, C mineralization, and bacterial community composition?

Evaluation of the possibilities of using humic acids obtained from lignite in the production of commercial fertilizers

Contact Info

Product

Resources

About