Acide humique — Wikipédia
Les acides humiques sont des polymères à haut poids moléculaire, chargés négativement, de couleur noire à brun foncé, résultant d'un processus de condensation oxydative des composés phénoliques et liés à des acides aminés, des peptides et des polysaccharides.
Humic substance - Wikipedia
By definition, humic acid (HA) is soluble in water at neutral and alkaline pH, but insoluble at acidic pH < 2. Fulvic acid (FA) is soluble in water at any pH. Humin is not soluble in water at any pH. This definition of humic substances is largely operational.
Acide humique : définition et explications - AquaPortail
Les acides humiques sont des composés organiques des sols solubles dans une solution alcaline et insolubles dans une solution acide. Ils contribuent à sa qualité physico-chimique et sont des précurseurs de combustibles fossiles.
Humic acid | Soil, Fertilizer, Organic | Britannica
humic acid, one of two classes of natural acidic organic polymer that can be extracted from humus found in soil, sediment, or aquatic environments.
Humic acids: Structural properties and multiple ...
May 1, 2016 · Humic acids (HAs) are macromolecules that comprise humic substances (HS), which are organic matter distributed in terrestrial soil, natural water, and sediment. HAs differ from the other HS fractions (fulvic acid and humins) in that they are soluble in alkaline media, partially soluble in water, and insoluble in acidic media.
Humic acids are complex molecules that exist naturally in soils, peats, oceans and fresh waters. The one source of humic acids are the sedimentation layers referred to as Leonardite. These layers were originally deep in the earth’s crust, but over many years have been exhumed to near-surface location.
Humic Acid - an overview | ScienceDirect Topics
Humic acid and fulvic acid represent up to 80% of the TOC – dissolved organics – of natural waters. Humic substances are weak acidic electrolytes with carboxylic- and phenolic-OH groups with a micelle-like structure and with a molecular weight …