Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23658-23665 ◽  
Author(s):  
A. Nebbioso ◽  
A. Piccolo ◽  
M. Lamshöft ◽  
M. Spiteller

Humeomics encompasses step-wise chemical fractionation and instrumental determination to fully characterize the heterogeneous molecular composition of natural organic matter.


1991 ◽  
Vol 42 (6) ◽  
pp. 675 ◽  
Author(s):  
GM Day ◽  
R Beckett ◽  
BT Hart ◽  
ID McKelvie

The natural organic matter (NOM) from three streams (Redwater Creek, Slip Creek, Myrtle Creek) and one small lake (the Inkpot) in Victoria, Australia, was fractionated by a simplified version of Leenheer's method in which the NOM is separated into two fractions-hydrophobic acid (HFo-A) compounds and total hydrophilic (HE-T) compounds-on the basis of association with XAD-8 resin. Subsequently, the HFo-A fraction was further separated into humic acid and fulvic acid fractions. One sample (Redwater Creek) was also separated into six different fractions by the full Leenheer scheme. Considerable variation was found in the ratio of humic substances (or the HFo-A fraction) to nonhumic substances (or the HFi-T fraction) between the four samples, with ratios ranging from a high of 77:23% for the Inkpot to a low of 20:80% for Slip Creek. Samples with higher NOM concentrations had higher percentages of humic substances. The major differences in the proportions of humic to nonhumic compounds observed for Slip Creek (20:80%) and Myrtle Creek (52:48%) support the hypothesis that the residence time of the water in the catchment (or, more specifically, the contact time between this water and the sediments, soil, vegetation and microbial community) may control the concentration and nature of aquatic NOM. Within the HFo-A, or humic fraction, the ratio of fulvic acids to humic acids was fairly constant for each of the four water samples investigated, being dominated (>80%) by fulvic acids.


2012 ◽  
Vol 518-523 ◽  
pp. 201-204
Author(s):  
Yue Jin Zhang ◽  
Juan Wang

The five surface soil samples were collected in along zhonghuan road of Jiaxing city. According to different solubility in acid and alkali solution, the soil organic matters were divided into different kinds of components such as fulvic acid, humic acid and Humin. Both humic acid and minerals were extracted by sequence and the images were displayed in assistance of scanning electron microscope. Different extraction time and extraction conditions were optimized and the methods were established in the last. Correlations between organic matter content, pH value and contents of HA were fitted and a linear relationship was found between OM and HA. On the help of SEM, different structure of HA and minerals were found that images of HA were columnar and that of mineral were Massive. It is just the reason that why the OM has great sorption ability than the minerals.


2013 ◽  
Vol 807-809 ◽  
pp. 486-489
Author(s):  
Tong Zhou Liu ◽  
Pin Hua Rao

An investigation on the effects of humic acid (representing NOM) on TCE (a typical organic contaminant) removal by Fe0in batch settings was carried out. Inhibitory effects of humic acid on Fe0towards TCE removal were observed. At early stage of the experiments, humic acid might partition with TCE, and the adsorption or deposition of humic acid onto Fe0surface would further facilitated TCE immobilization. Once the reduction reactive sites on Fe0surfaces were covered by accumulated humic acid and the partition of TCE to humic acid became saturated, TCE removal in Fe0was observed retarded.


2000 ◽  
Vol 88 (2) ◽  
Author(s):  
D. Rößler ◽  
K. Franke ◽  
R. Süß ◽  
E. Becker ◽  
H. Kupsch

A natural moor soil humic acid (HA) was labeled with Tc-99m via reduction of pertechnetate with stannous chloride. The humic acid species obtained were characterized by thin layer chromatography (TLC), gel permeation chromatography (GPC), sequential chromatographic analysis (SCA), paper electrophoresis and micropore filtration. Labeling was found to take place in all ranges of molecular weight. Due to the complex humic acid composition and the formation of hydroxo species the labeling yields strongly depend on the separation conditions, ranging from 42% to 80%. The pH-dependent distribution of mobile and immobile species was determined by SCA for HTcO


2005 ◽  
Vol 34 (3) ◽  
pp. 842-853 ◽  
Author(s):  
Rossane C. DeLapp ◽  
Eugene J. LeBoeuf ◽  
Jie Chen ◽  
Baohua Gu

2003 ◽  
Vol 60 (1) ◽  
pp. 167-173 ◽  
Author(s):  
Clístenes Williams Araújo do Nascimento ◽  
Renildes Lúcio Ferreira Fontes ◽  
Adilson César Fortes Dias Melicio

The knowledge of the chemical forms of copper in soils and the relationships of these forms with soil copper availability are important for predicting the copper behavior in the soil-plant system. The present work studies the influence of liming on the available contents of copper as well as on the forms of copper fractions in six types of Oxisols. Soil samples, with and without liming, received copper at rates of 0.0, 20.0 and 40.0 mg dm-3 and remained incubated for 30 days. Then, available copper was extracted with Mehlich-1, Mehlich-3, DTPA and EDTA solutions, and analyzed by atomic absorption spectrophotometry. Additionally, soil samples were extracted in a sequential procedure to determine Cu in fractions of soil, as follows: exchangeable-Cu fraction, organic matter-Cu fraction, Mn oxide-Cu fraction, amorphous Fe oxide-Cu fraction, crystalline Fe oxide-Cu fraction, residual-Cu fraction, and the total Cu content in the soil. Soil samples to which Cu was added presented higher Cu retention in the organic matter fraction with a small percentage retained in the exchangeable-Cu fraction. Liming resulted in a decrease of Cu in the exchangeable and organic matter fractions and an increase in the Fe and Mn oxide fractions and in the residual fraction. Without liming, the organic matter fraction presented the highest contribution to Cu content found in the soil extracts obtained with all extractors, except EDTA. For treatments with liming, Cu contents in the organic matter fraction were better correlated to Cu contents in extracts obtained with DTPA and Mehlich-3.


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