Determination of Humic Acid Content in Sapropel

The agricultural industry, in particular crop farming, is in need of using biological plant and soil protection products, as well as mineral fertilizers. A number of problems associated with soil contamination with substances of chemical nature that are part of mineral fertilizers can be solved through the use of biofertilizers based on humic acids (HA). HA can also be used as plant growth stimulants, restorers of disturbed soils and sorbents of toxic pollutants. One of the promising sources for obtaining HA is sapropel obtained during the reclamation of reservoirs. The study was conducted in order to determine the concentration of humic acids in sapropel harvested in the water bodies of the Republic of Mari El (RME) and to identify the method that assumes the best yield of HA. The object of the study were sapropel samples of various water bodies of the RME. Humic acids were isolated by two methods: the method of alkaline extraction and the method of aqueous extraction. According to the results of the study, significant differences in humic acid concentrations in sapropel samples were noted. It was found that sapropel of the Lake Vodoozerskoye deposit is characterized by the highest content of humic acids. It was also determined that the sapropel of this deposit is the leader in the amount of HA, regardless of the extraction method