Comparative Analysis of Humic and Fulvic Acids Extraction and Characterization From Different Organic Sources

Abstract

There is a scarcity of information on the chemical and spectral properties of humic substances obtained from various organic sources. For this purpose, a laboratory experiment was carried out to extract humic and fulvic acids from vermicompost, compost, farmyard manure, and sheep manure. Humic and fulvic acids have the following chemical properties: electrical conductivity (E.C), pH, organic carbon, total nitrogen, total acidity, the level of humiliation and aroma activity of humic substances (E 4 /E 6 ratio), and spectral characterization methods using spectroscopic methods such as UV-Vis and Fourier transform infrared spectra (FTIR). The results showed that the highest value of pH was 3.25 for humic acid extracted from sheep manure. The highest EC was 6.68 dSm -1 of fulvic acid extracted from sheep manure. The C/N ratio of humic was less than fulvic acid extracted from all organic sources. In comparison to humic acid, fulvic acid had a higher total acidity. Also, Fulvic acid contained more functional groups than humic acid extracted from all organic sources, including carboxyl and phenolic-OH groups. According to the results, humic acid has lower E 4 /E 6 ratio values than fulvic acid. Analysis of UV-Vis spectra revealed that humic substances contained aromatic components. According to Fourier transform infrared spectra, humic and fulvic acids contain aliphatic CH, hydroxyl, and carboxyl groups with varying values depending on the organic sources.