Humic Humic acidsacids

(HA)(HA)

Lenka TuhovčákováLenka Tuhovčáková& &

Marcela LagováMarcela Lagová

©©20052005

SummarySummary

Humic acidHumic acid PropertiesProperties StructureStructure PreparationPreparation Environmental Environmental

impactimpact

What are humic acids?What are humic acids? Unbelievable and Unbelievable and

amazing „chemical amazing „chemical stuff“!stuff“!

Natural organic Natural organic substances, situated substances, situated mainly in water, soil, mainly in water, soil, carbon and water carbon and water sediments.sediments.

Stuffs of the unique Stuffs of the unique properties and properties and structure, which were structure, which were not still exactly not still exactly described despite large described despite large experimentalsexperimentals..

Substances aren´t the Substances aren´t the chemical individuals, chemical individuals, they consist from the they consist from the mixture of compounds mixture of compounds

Division of humin stuffsDivision of humin stuffs

Humin stuff

Humic acidSalt of humic

acid

Humin acid Fulvin acidHemato-melanic

Acid

Lignin Humin Humic coal

CharacteristicsCharacteristics•dark brown to black in colordark brown to black in color

Issue from plant´s and animal´s decomposing Issue from plant´s and animal´s decomposing tissues.tissues.

Soluble in lyes, salts and organic solvents.Soluble in lyes, salts and organic solvents. Molecular weight, structure, quantity and Molecular weight, structure, quantity and

position functional groups depend on origin and position functional groups depend on origin and age of material.age of material.

IIs not soluble in water s not soluble in water Composed from: 40 – 60% carbon, 30 – Composed from: 40 – 60% carbon, 30 –

50% oxygen, 4 – 5 % hydrogen, 1 – 4% 50% oxygen, 4 – 5 % hydrogen, 1 – 4% nitrogen, 1- 2% sulphur and 0 – 0,3% nitrogen, 1- 2% sulphur and 0 – 0,3% phosphorusphosphorus

Important component of humic matters Important component of humic matters HA can bond hydrophobic and hydrophilic HA can bond hydrophobic and hydrophilic

stuffs.stuffs. Help to improve soil fertility, its physical Help to improve soil fertility, its physical

properties facilitate transport of nutrients.properties facilitate transport of nutrients. Min volume of HA is in sand, clay max Min volume of HA is in sand, clay max

volume is in brown carbon and lignit.volume is in brown carbon and lignit. Interesting: the highest volume of HA (over Interesting: the highest volume of HA (over

80%) is in peat.80%) is in peat.

Some hypotetical chemical formulas of Some hypotetical chemical formulas of humic acids describe position of characteristic humic acids describe position of characteristic functional groups. functional groups.

HHypotetical chemical ypotetical chemical structurestructure of humic acids of humic acids(Buffle´s model)(Buffle´s model)

Contains from aromatic and aliphatic Contains from aromatic and aliphatic structures, both extensively substituted structures, both extensively substituted with oxygen - containing functional groups. with oxygen - containing functional groups.

Hypothetical structure for humic acid, shown Hypothetical structure for humic acid, shown in figure, contains free and bound phenolic in figure, contains free and bound phenolic OH groups, quinone structures, nitrogen and OH groups, quinone structures, nitrogen and oxygen as bridge units and carboxylic groups oxygen as bridge units and carboxylic groups variously placed on aromatic rings.variously placed on aromatic rings.

Thought to be complex aromatic Thought to be complex aromatic macromolecules with amino acids, amino macromolecules with amino acids, amino sugars, peptides, aliphatic compounds sugars, peptides, aliphatic compounds involved in linkages between the aromatic involved in linkages between the aromatic groups.groups.

Preparation of HAPreparation of HA From lignit and From lignit and

oxihumolit. Higher oxihumolit. Higher yield of HA is from yield of HA is from oxihumolit.oxihumolit.

Yield must be deashed Yield must be deashed and repurified by and repurified by mixture of mixture of hydrochloric and hydrochloric and hydrofluoric acid.hydrofluoric acid.

The role of humic acid in the The role of humic acid in the environmentenvironment

Are essential but incompletely understood sorptive Are essential but incompletely understood sorptive and metal binding biopolymers in animals, plants, and metal binding biopolymers in animals, plants, soils and sediments. soils and sediments.

Continue to be intensively studied - their Continue to be intensively studied - their environmental importance.environmental importance.

HS have important physiological properties, many HS have important physiological properties, many of them are attributed to their sorptive properties. of them are attributed to their sorptive properties. 

Polyaromatic hydrocarbons, pesticides are Polyaromatic hydrocarbons, pesticides are adsorbed on HA surfaces.    adsorbed on HA surfaces.   

HA is therapeutic against uterine cancer in HA is therapeutic against uterine cancer in laboratory animals.laboratory animals.

Are usually found near lung tumors in coal Are usually found near lung tumors in coal miners and smokers.miners and smokers.

Our studies show that HA is a powerful Our studies show that HA is a powerful reductant and an excellent chelating agent.  reductant and an excellent chelating agent. 

The combination of these effects creates a The combination of these effects creates a chemical systems that can activate transition chemical systems that can activate transition metals.  Ferric iron is chelated and reduced to metals.  Ferric iron is chelated and reduced to ferrous iron. ferrous iron. 

Effects of work of ferrous iron in the H.A. matrix Effects of work of ferrous iron in the H.A. matrix is similar for copper and variety of transition is similar for copper and variety of transition metals.metals.

Used literatureUsed literature

InternetInternet Our lab diaryOur lab diary Diploma works: Diploma works: Renáta Superatová,Renáta Superatová, Květuše ChvátalováKvětuše Chvátalová Presentaitions of Presentaitions of

doc. Klučáková and doc. Klučáková and doc. Pekařdoc. Pekař

DictionaryDictionary humic acidshumic acids decomposing tissuesdecomposing tissues lyeslyes soil fertilitysoil fertility facilitatefacilitate clayclay peatpeat extensivelyextensively variouslyvariously involved ininvolved in yieldyield uterine canceruterine cancer ferric ironferric iron ferrous ironferrous iron varietyvariety

huminové kyselinyhuminové kyselinyrozkládající se tkáněrozkládající se tkánělouhlouhpůdní úrodnostpůdní úrodnostulehčitulehčitjíljílrašelinarašelinaznačněznačněrůzněrůznězapletený (do)zapletený (do)výtěžekvýtěžekrakovina dělohyrakovina dělohytrojmocné Fetrojmocné Fedvojmocné Fedvojmocné Fedruhdruh