Kūdras humusvielas: to sastāvs un tā veidošanos ietekmējošie faktori
Date
2015
Authors
Purmalis, Oskars
Journal Title
Journal ISSN
Volume Title
Publisher
Latvijas Universitāte
Abstract
Promocijas darbā pētītas no trīs atšķirīgas ģenēzes Latvijas purvu profiliem izdalītas kūdras humusvielas (HV) ar atšķirīgu humifikācijas pakāpi, vecumu, izcelsmi, salīdzinājumam izmantojot HV, kuras izdalītas no citām vidēm, kā arī references un rūpnieciski ražotus humusvielu paraugus. Tika veikta kompleksa HV īpašību un to makromolekulārās struktūras izpēte, lai novērtētu to izmaiņas humifikācijas gaitā. HV īpašību noteikšanai tika izmantotas tādas spektrālās analīzes metodes kā fluorescences, Furjē transformācijas infrasarkanās gaismas spektrometrija, kodolmagnētiskās rezonanses un UV spektrometrija, kā arī tika analizēts elementsastāvs, funkcionālo grupu saturs, termogravimetriskie parametri u. c. humusvielu īpašības. Rezultāti liecina par strukturālajām izmaiņām HV makromolekulārajos kompleksos humifikācijas gaitā, kas ietekmē to īpašības, līdz ar to arī uzvedību vidē un kompleksveidošanās īpašības, tai skaitā arī ar ar vidi piesārņojošām vielām. Purvos HV veidošanās procesos un to struktūras izveidē būtiska loma ir kūdru veidojošajai veģetācijai, tās sastāvam, materiāla mikrobiālajai degradācijai un to metabolītu klātbūtnei, kā arī tādiem organiskā materiāla transformācijas procesiem kā humificēšanās un pārogļošanās. Šo degradācijas, sintēzes un enzimātisko reakciju norises vienlaicīgums rada priekšnoteikumus relatīvi alifātiskas izcelsmes materiāla transformācijai, tam kļūstot aromātiskākam ar oglekļa un slāpekļa daudzuma palielināšanos.
Atslēgvārdi: kūdra, humusvielas, humifikācija, oglekļa aprite, spektrometriskās metodes, makromolekulu kompleksi.
In doctoral thesis humic substances (HS) isolated from three different ombrothrophic bog profiles in Latvia with different degree of humification, age, origin, botanical composition are studied. HS which were isolated from different environments including industrially produced and reference ones are compared with peat HS. Multi-parameter characterization of macromolecular properties of peat HS were performed in order to analyze structural changes and properties of HS during decay and humification processes. Characterization of HS was used by various methods including fluorescence spectroscopy, FTIR, NMR and UV spectrometry as well as analysis of the elemental composition, functional group content, hydrophobicity, thermogravimetric parameters and others. The results show the structural changes of macromolecular properties of HS during humification affecting their properties, behavior in the environment as well as complexing properties in contact with environmental pollutants. Formation of HS in bogs is greatly influenced by botanical composition of peat; also important is the presence of microbial biota and their metabolites with such transformation processes of organic matter as humification and coalification. Degradation of organic material, enzymatic reactions and synthesis of refractory compounds are ongoing simultaneously. Results have proven that relatively aliphatic material during transformation become aromatic with increasing amount of carbon and carboxylic acidity. Keywords: peat, humic substances, humification, transformation of organic carbon
In doctoral thesis humic substances (HS) isolated from three different ombrothrophic bog profiles in Latvia with different degree of humification, age, origin, botanical composition are studied. HS which were isolated from different environments including industrially produced and reference ones are compared with peat HS. Multi-parameter characterization of macromolecular properties of peat HS were performed in order to analyze structural changes and properties of HS during decay and humification processes. Characterization of HS was used by various methods including fluorescence spectroscopy, FTIR, NMR and UV spectrometry as well as analysis of the elemental composition, functional group content, hydrophobicity, thermogravimetric parameters and others. The results show the structural changes of macromolecular properties of HS during humification affecting their properties, behavior in the environment as well as complexing properties in contact with environmental pollutants. Formation of HS in bogs is greatly influenced by botanical composition of peat; also important is the presence of microbial biota and their metabolites with such transformation processes of organic matter as humification and coalification. Degradation of organic material, enzymatic reactions and synthesis of refractory compounds are ongoing simultaneously. Results have proven that relatively aliphatic material during transformation become aromatic with increasing amount of carbon and carboxylic acidity. Keywords: peat, humic substances, humification, transformation of organic carbon
Description
Elektroniskā versija nesatur pielikumus
Keywords
Vides zinātne , Vides aizsardzība