6533b7d4fe1ef96bd1263557
RESEARCH PRODUCT
Pyrolysis of humic acids from digested and composted sewage sludge
Kari HänninenV. MiikkiJ. HyötyläinenJuha Knuutinensubject
chemistry.chemical_classificationEnvironmental EngineeringChromatographyHealth Toxicology and MutagenesisPublic Health Environmental and Occupational HealthGeneral MedicineGeneral ChemistryBiodegradationMass spectrometryPollutionchemistry.chemical_compoundWaste treatmentchemistryEnvironmental ChemistryHumic acidComposition (visual arts)DerivatizationPyrolysisSludgedescription
Humic acids (HAs) were extracted from four digested sewage sludge samples composted for four months, one, two and four years. HAs were pyrolyzed at three different temperatures applying both conventional and in situ methylation (ISM) pyrolysis. The pyrolysates were analyzed using gas chromatography-mass spectrometry (GC/MS). Derivatization (ISM) and pyrolysis temperature had dramatic effects on the composition and relative amounts of the pyrolysates. Among the derivatized HA fragments aliphatic compounds prevailed under all the pyrolysis conditions tested. Aromatic substances consisting mainly of guaiacyl-type compounds were detected in higher abundances only at elevated temperatures. Without ISM the contribution of aromatic structures to the total pyrogram was considerably greater than that of the aliphatics. Increase of the pyrolysis temperature from 450 degrees C to 600 degrees C had smaller effect on the proportions and composition of the compounds studied than increase from 350 degrees C to 450 degrees C.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2000-07-20 | Chemosphere |