نتایج جستجو برای: natural organic matter

تعداد نتایج: 851631  

2016
Michael Lawson David A. Polya Adrian J. Boyce Charlotte Bryant Christopher J. Ballentine

Biogeochemical processes that utilize dissolved organic carbon are widely thought to be responsible for the liberation of arsenic from sediments to shallow groundwater in south and southeast Asia. The accumulation of this known carcinogen to hazardously high concentrations has occurred in the primary source of drinking water in large parts of densely populated countries in this region. Both sur...

1998

Organic matter isolated from the Florida Everglades caused a dramatic increase in mercury release (up to 35 μM total dissolved mercury) from cinnabar (HgS), a solid with limited solubility. Hydrophobic (a mixture of both humic and fulvic) acids dissolved more mercury than hydrophilic acids and other nonacid fractions of dissolved organic matter (DOM). Cinnabar dissolution by isolated organic ma...

Journal: :Ecology 2010
Nina Caraco James E Bauer Jonathan J Cole Steven Petsch Peter Raymond

Recent studies indicate that highly aged material is a major component of organic matter transported by most rivers. However, few studies have used natural 14C to trace the potential entry of this aged material into modern river food webs. Here we use natural abundance 14C, 13C, and deuterium (2H) to trace the contribution of aged and contemporary organic matter to an important group of consume...

Journal: :به زراعی کشاورزی 0
اعظم رضوی نسب مربی، دانشگاه پیام نور میبد، میبد حسین شیرانی استادیار، گروه علوم خاک، دانشکده کشاورزی، دانشگاه ولی عصر (عج) رفسنجان، رفسنجان احمد تاج آبادی پور دانشیار، گروه علوم خاک، دانشکده کشاورزی، دانشگاه ولی عصر (عج) رفسنجان، رفسنجان حسین دشتی استادیار، زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه ولی عصر (عج) رفسنجان، رفسنجان

to study the effect of salinity and organic matter on chemical composition and root morphology of pistachio cv. badami, budded on seedling root stocks, a greenhouse experiment was conducted as a factorial based on a completely randomized design with three replications. treatments consisted of four salinity (zero, 800, 1600 and 2400 mg nacl kg-1 soil) and three organic matter (zero, two and four...

Journal: :Environmental Health Perspectives 1989
Y Soma M Soma

Chemical reactions of organic compounds including pesticides at the interlayer and exterior surfaces of clay minerals and with soil organic matter are reviewed. Representative reactions under moderate conditions possibly occurring in natural soils are described. Attempts have been made to clarify the importance of the chemical nature of molecules, their structures and their functional groups, a...

2015

In the stratosphere, the ozone (O3) plays a role of natural and beneficial screen in relation to the harmful effects of ultraviolet (UV) for the organic matter (= good ozone). In the troposphere, O3 is a pollutant that is produced during the atmospheric photo-oxidation of ozone precursors: Volatile Organic Compounds (VOCs) and nitrogen oxides (NOx) mainly emitted by anthropogenic activities (= ...

Journal: :بوم شناسی کشاورزی 0
علی اصغر محمد آبادی پرویز رضوانی مقدم جبار فلاحی زینت برومند رضازاده

in order to study the effect of different organic fertilizers on quantitative and qualitative characteristics of fenugreek forage, an experiment was conducted based on completely randomized block design with six treatments and three replications at agricultural research station, college of agriculture, ferdowsi university of mashhad, iran, during 2006. the experimental treatments were four orga...

Journal: :Environmental geochemistry and health 2016
T Lescure J Moreau C Charles T Ben Ali Saanda H Thouin N Pillas P Bauda I Lamy F Battaglia-Brunet

The global AsIII-oxidizing activity of microorganisms in eight surface soils from polluted sites was quantified with and without addition of organic substrates. The organic substances provided differed by their nature: either yeast extract, commonly used in microbiological culture media, or a synthetic mixture of defined organic matters (SMOM) presenting some common features with natural soil o...

2017
MARTIN ANDERSSON

Andersson, M. 2017. Extent and limitations of functional redundancy among bacterial communities towards dissolved organic matter. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1578. 41 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0112-9. One of the key processes in the carbon cycle on our planet is the degradation of dissolve...

2009
Slavica Matijević Grozdan Kušpilić Mira Morović Branka Grbec Danijela boGner Sanda SKejić Jere veža

Physical and chemical characteristics of the water column and sediments at sea bass/sea bream farm located on the middle Adriatic island of Brač were investigated during the 2001-2006 period. Measurements and samplings were performed at stations inside the farm area and at reference station, approximately 1 km distant from the farm. Investigated parameters in the water column were temperature, ...

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