IMAZETHAPYR ADSORPTION TO SEWAGE SLUDGES AND SEWAGE-SLUDGE HUMIC ACIDS

Sewage sludges exhibit linear adsorption isotherms and different adsor ption capacity for imazethapyr. Humic acids show nonlinear, L-shaped i sotherms, and adsorb imazethapyr in amounts that are greater than thos e of the correspondent sludge, and depend on their chemical properties . FT-IR fluorescence and ESR spectroscopic data indicate that humic ac ids interact with imazethapyr to different extent, according to their chemical properties, through binding mechanisms that include ionic and charge-transfer bonds, also involving fluorescent groups.