Chemical and biological studies on environmental humic acids

Abstract

Abstract Forty humic acid samples were extracted from various types of soils, including aquatic sediments. To estimate the degree of humification, absorbance coefficients for 1% humic acid solutions at 600 nm () and ΔlogK values were measured. Mean values for decreased in the order: Andisol (A)>Oxisol (O), Mollisol (M), Vertisol (V)>Histosol (H)>Entisol (E), sediment (s), Inceptisol (I). Mean values for ΔlogK increased in the order: A I, E, O, H>M, V>A. A linear correlation was found to ...