Preparation of Al-humates and their aluminum content and cation-exchange capacity

Open Access
Publisher Website
Google Scholar
Abstract
Five Al-humates were prepared from humic acid extracted from a volcanic ash soil and partially neutralized AlCl3 solution at different pHs. The Al content of the Al-humate increased and its CEC decreased with increasing pH of Al-humate preparation from 3.8 to 5.8. The average number of positive charges on the Al combined with humic acid was estimated to be 2.86 to 0.40. It was inferred that Al ions with a positive charge of 1.0 to 0.5 or smaller block the cation exchange sites of humic acid.