نتایج جستجو برای: humic acids has

تعداد نتایج: 2820344  

Journal: :تحقیقات نظام سلامت 0
قربان عسگری عضو هیأت علمی، گروه بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان، ایران. عبدالمطلب صید محمدی عضو هیأت علمی، گروه بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی همدان، همدان، ایران افشین ابراهیمی استادیار، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران.

background: the use of alternative disinfectants and the control of natural organic material are two approaches that are typically applied in water treatment utilities to reduce the formation of chlorinated disinfection by-products in recent years. catalytic ozonation as a new technology is used to promote the efficiency of the single ozonation processes. the purpose of this study was to invest...

2012
Eric A. Calhoun

Radiocarbon dating of Late deposits has shown that erosion of old organic materials and their redeposition in younger sediments ages that are too old. Also, the humid climate and leaching pedogenic environment of much of Tasmania translocation humic acids down profile through porous sediments. The humic acids may then be perched by impermeable clay or may be adsorbed/ absorbed by older clay and...

2011
N. GHOSH A. K. BANIK

A comparison is drawn between fungal humic acid produced by Aspergillus niger X1 and soil humic acid regarding elementary and functional groups analysis. Elementary and functional groups analysis show that unhydrolyzed fungal humic acid contained more H and N per unit weight, more alcoholic OH but lower CO2H and phenolic OH groups than unhydrolyzed soil humic acids. The C and N content of 6(N) ...

2012
C. SAIZ - JIMENEZ J. W. DE LEEUW

Three vermicomposts derived from animal manures exposed to the action of the earthworms Eisenia foetida or Lumbricus rubellus were investigated to determine the nature of the humic acid fraction in relation to the potential fertility of the vermicomposts. The isolated humic acid fractions were analysed by pyrolysis-gas chromatography-mass spectrometry. The greater part of the humic acids consis...

Journal: :Journal of environmental quality 2010
Marta Fuentes Roberto Baigorri Francisco J González-Vila Gustavo González-Gaitano José M García-Mina

Flash pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS) was used to study the structural transformations of humic fractions formed as a result of composting processes of diverse organic materials (solid wastes of wineries, solid olive-mill wastes, domestic wastes, ovine manures plus straw, and mixtures of animal manures). Sodium hydroxide-extracted total humic-like extracts (THE; humic p...

2017
Gersende Berthier Sen Dou Torren Peakman Eric Lichtfouse Gersende BERTHIER Sen DOU Torren PEAKMAN Eric LICHTFOUSE Louisa Paulin

Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to bring some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mas...

2013
Maris Klavins Oskars Purmalis Valery Rodinov

Studies of the properties of soil organic matter are essential for understanding the humification reactions and soil diagenesis processes. The aim of this study is to analyse properties of peat and peat humic acids as well as factors influencing their variability. Humic acids isolated from an ombrotrophic bog peat profile were used as study objects. Relations among peat age, decomposition and h...

Journal: :Journal of the Fuel Society of Japan 1954

Journal: :Environmental letters 1971
D F Martin R H Pierce

Humic acids are generally defined operationally as those decomposir tion products of plants and animals that comprise the base-soluble, 2 acidand alcohol-insoluble fractions of the soil. These materials are of interest because of their geological significance, possible nutritive properties, involvement of biological processes, and the challenge 3 afforded by their chemical and structural comple...

Journal: :Chemosphere 2003
I J Fahimi F Keppler H F Schöler

The mechanism of formation of chloroacetates, which are important toxic environmental substances, has been controversial. Whereas the anthropogenic production has been well established, a natural formation has also been suggested. In this study the natural formation of chloroacetic acids from soil, as well as from humic material which is present in soil and from phenolic model substances has be...

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