Humus Acids in the Digested Sludge and Their Properties.

Area of Science:

• Environmental Chemistry
• Soil Science
• Biogeochemistry

Background:

• Digested sludge from wastewater treatment plants contains valuable humic substances.
• Understanding the composition and properties of these humic acids is crucial for their effective utilization.

Purpose of the Study:

• To extract and characterize fulvic acids, alpha humic acids, and hymatomelanic acids from digested sludge.
• To investigate the interactions between these acids and micropollutants.
• To assess the potential applications of humic acids from wastewater treatment.

Main Methods:

• Extraction of humic substances from digested sludge.
• Elemental composition analysis.
• Infrared (IR) and UV-VIS spectroscopy for characterization and interaction studies.
• Quantitative analysis of acid content.

Main Results:

• Fulvic acids exhibited moderate maturity, while humic acids were well-developed.
• Strong correlations were observed between acid type, micropollution, and spectral characteristics.
• Digested sludge contains significant amounts of FA (5.07–5.30 g/kg), αHA (59.22–74.72 g/kg), and HMA (20.31–43.66 g/kg).

Conclusions:

• Wastewater treatment sludge is a viable source of humic acids.
• These humic acids have broad applications in agriculture, environmental protection, and medicine.
• Infrared absorption analysis is an effective method for characterizing these compounds.