Fig. 3From: Antibacterial and antioxidant properties of humic substances from composted agricultural biomassesHPSEC chromatograms of humic substances (HS) extracted from artichoke (CYN), coffee grounds (COF), and pepper (PEP) composted residues, before and after addition of acetic acid (AcOH) to adjust sample pH from 7 to 3.5Back to article page