Humic acid-like matter isolated from green urban wastes. Part I: structure and surfactant properties

A humic acid-like substance (cHAL2) isolated from urban green wastes before composting is 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. The former substance was found to contain more aliphatic and O-alkyl C atoms relatively to aromatic, phenol and carboxyl C atoms, and to yield higher critical micellar concentration in water than the latter substance. The results point out that biomass wastes may be an interesting source of biosurfactants with diversified properties depending on the nature of waste and of its treatment process.