Investigation of the intereactions between humic substances and a cationic detergent

Visible spectrophotometric measurements were used to study binding of cetltrimethylammonium to humic molecules. Detergent molecules appeared to bind to ionized carboxyl and phenolic groups. Complete neutralization of negative charges caused quantitative precipitation of humic substances at low ionic strength. Detergent amounts higher than the stoichiometric ratio caused salting in of precipitate. The influence of organic carbon concentration, ionic strength and pH of the solution on the complex composition at minimum solubility was investigated.