Specific UV Absorbance of Aldrich Humic Acid:  Changes during Transport in Aquifer Sediment

2002 ◽  
Vol 36 (4) ◽  
pp. 608-616 ◽  
Author(s):  
William P. Johnson ◽  
Gaobin Bao ◽  
Wynn W. John
Keyword(s):  
Humic Acid ◽  
Uv Absorbance ◽  
Specific Uv Absorbance

Dissolved organic matter from agricultural fields in the irrigation period

2005 ◽  
Vol 52 (12) ◽  
pp. 233-241 ◽  
Author(s):  
S. Shim ◽  
B. Kim ◽  
Y. Hosoi ◽  
T. Masuda
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Paddy Fields ◽  
Agricultural Fields ◽  
Uv Absorbance ◽  
Crop Fields ◽  
Irrigation Period ◽  
Doc Concentration ◽  
Specific Uv Absorbance ◽  
Hydrophobic Fraction

The aim of this study was to quantify and characterize the dissolved organic carbon (DOC) of paddy fields and crop fields in Tottori, Japan. Dissolved organic carbon (DOC) and ultraviolet (UV) absorbance was measured for the filtrated water of each samples. DOC concentration and SUVA (specific UV absorbance) of biodegradation analysis samples were determined around 50 days after the incubation. In the Fukui paddy fields, DOC concentration varied seasonally from 1.1 to 10.1mg.Cl−1, showing higher concentration in heavy runoff of non-agriculture period in April. However, DOC concentration variation did not always correspond to rainfall. The Obadake paddy fields also showed a similar pattern with Fukui paddy fields. The daily DOC discharge per area in Fukui (up), Fukui (down), Obadake (south), Obadake (north) paddy fields influent from paddy fields were 0.02, 0.0161, 0.0135 and 0.0027kg.a−1.day−1, respectively. These differences resulted from differences in agricultural types and customs of farmers according to paddy fields and fields. Also, SUVA (an indirect means to evaluate humic substances (hydrophobic fraction)) of the studied influent waters from paddy fields were generally lower than the influent waters from crop fields. The non-biodegradable DOC accounted for 50.2–98%, 46.8–85.5% of the total DOC in the paddy fields and crop fields.

scholarly journals Prediction of DOM removal of low specific UV absorbance surface waters using HPSEC combined with peak fitting

2012 ◽  
Vol 24 (7) ◽  
pp. 1174-1180 ◽  
Author(s):  
Linan Xing ◽  
Rolando Fabris ◽  
Christopher W.K. Chow ◽  
John van Leeuwen ◽  
Mary Drikas ◽  
...  
Keyword(s):  
Surface Waters ◽  
Uv Absorbance ◽  
Peak Fitting ◽  
Specific Uv Absorbance

Comparison of Titanium Dioxides Prepared from Different Materials and its Photocatalytic Evaluation

2013 ◽  
Vol 749 ◽  
pp. 77-81
Author(s):  
Dong Seok Rhee ◽  
Young Do Kim ◽  
Se Gu Son
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Titanium Dioxide ◽  
Humic Acid ◽  
Room Temperature ◽  
Uv Absorbance ◽  
Higher Temperature ◽  
Titanium Dioxides

Titanium dioxides were synthesized from two different titanium salts, which contained chlorine and sulfur respectively. Titanium dioxide prepared from TiCi4 and had a particle size of ca. 20nm and its phase transition from anatase to rutile stated at 500°C. Titanium dioxide from TiOSO4 had a particle size of ca. 50nm and retained its anatase and sperit structure until 700°C by calcination. For the photocatalytic evaluation of these titanium dioxides, photocatlytic oxidation of organic model pollutant, humic acid, have been conducted. UV absorbance decrease by titanium dioxides prepared from both from TiCi4 and TiOSO4 at room temperature showed very similar results, compared to titanium dioxide prepared from TiCi4 at higher temperature.

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
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

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.

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