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

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.

Removal of humic substances by chitosan

2004 ◽  
Vol 4 (5-6) ◽  
pp. 121-129 ◽  
Author(s):  
C. Vogelsang ◽  
D.O. Andersen ◽  
A. Hey ◽  
T. Håkonsen ◽  
T.G. Jantsch ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Humic Substances ◽  
Surface Waters ◽  
Laboratory Tests ◽  
Uv Absorbance ◽  
Raw Water ◽  
Triggering Mechanism ◽  
Particle Content ◽  
Reduced Dose ◽  
Maximum Removal

Results from laboratory tests, conducted to study different aspects regarding the removal of humic substances by the environmentally friendly cationic biopolymer chitosan, are presented. Chitosan was shown to be an efficient remover of the high molecular weight humic substances, significantly reducing the colour and UV absorbance in typical humus-rich Norwegian surface waters with low particle content. By adding small amounts of Fe3+ together with a reduced dose of chitosan, it was possible to significantly improve the removal of the medium molecular weight humic substances. The highest charged (low Fa) chitosans were the most efficient coagulants, indicating that charge neutralisation was the triggering mechanism for the coagulation. Surface charge measurements of coagulated raw water gave strong indications in the same direction. However, net positive surface potentials of flocs after neutralisation indicated that excess chitosan participated in the build-up of flocs, suggesting that bridging or electrostatic patch flocculation could be important mechanisms during flocculation. However, the molecular weight of chitosan had no significant influence on the maximum removal of the humic substances.

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

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

Identifying Sources of Sulfate Aerosols Reaching Whiteface Mountain, NY

1985 ◽  
Vol 43 ◽  
pp. 98-101
Author(s):  
James S. Webber
Keyword(s):  
Trace Metals ◽  
Acid Deposition ◽  
Surface Waters ◽  
Dry Deposition ◽  
Coal Combustion ◽  
Public Awareness ◽  
Sulfate Aerosols ◽  
Wet And Dry Deposition ◽  
Whiteface Mountain ◽  
Toxic Trace Metals

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.

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