HUMIC ACID-LIKE MATTER ISOLATED FROM GREEN URBAN WASTES. PART I: STRUCTURE AND SURFACTANT PROPERTIES

Abstract

A humic acid-like substance (cHAL2) isolated from urban green wastes before composting was compared to a humic acid-like substance (cHAL) isolated from a mix of urban organic humid waste fraction and green residues composted for 15 days. cHAL2 was found to contain more aliphatic and O-alkyl C atoms relative to aromatic, phenol, and carboxyl C atoms, and to yield higher critical micellar concentration (cmc = 0.97 g L-1) and surface tension at the cmc (cmc = 37.8 mN/min water than cHAL (cmc = 0.40 g L-1; cmc = 36.1 mN/m). The results point out that biomass wastes may be an interesting source of biosurfactants with diversified properties that depend on the nature of waste and on its process of treatment.

Keywords

• Urban refuse
• Compost
• Biosurfactants
• Humic acids
• Biomass