Ozonization to Upgrade Waste-Derived Soluble Lignin-Like Substances to Higher Value Products

摘要

Soluble biobased lignin-like polymeric substances (SBO) isolated from the alkaline hydrolysates of composted biowastes are promising chemical auxiliaries for multiple uses. They have good surfactant properties. Their black color spoils their performance in detergency and dyeing. Ozonization of SBO is reported now to yield bleached biosurfactants with improved performance. The work was performed, with SBO obtained from composted gardening residues, alone or mixed with kitchen wastes. They were dissolved in water at 3.3% concentration. Oxygen containing 4 mol/mol % ozone was flown at 60 L h~(-1) for 48 h through the SBO solution. The crude ozonized products in ca. 80% yield were filtered through different molecular cut off membranes and characterized for chemical features, molecular weight, and surface tension in water. The ozonized fractions with 200–500 kDa molecular weights accounted for 12–29% of the total ozonized fractions’s organic matter. They lowered water surface tension to 48–52 mN m~(-1). The lower molecular weight ozonized fractions had no surfactant activity, but their molecular features suggest other potentially valuable uses.