EVALUATION OF DETOXIFYING ABILITY OF ORGANOMINERAL COMPLEXES BASED ON HUMIC ACIDS AND Al30-PILLARED MONTMORILLONITE IN RELATION TO OIL IN WATER

Abstract

The detoxifying ability of humic-clay complexes obtained by sorption of humic acids of two types of peat on the original and modified forms of montmorillonite with respect to oil in water has been studied. The differences found in the values of the adsorption parameters of humic acids on clay minerals are due to the structural features of humic acids, as well as the textural properties of montmorillonite forms. Due to the layered-columnar structure and the presence of slit-like meso- and micropores, Al30-pillared montmorillonite is a more effective matrix for obtaining humic-clay complexes: the maximum adsorption reaches 73 mg/g. Humic acids immobilized on the mineral surface act on the ecotoxicant as a natural sorbent and slow down the migration of petroleum hydrocarbons. Humic-clay complexes do not have an inhibitory effect on the growth of the test object - duckweed small. Detoxification of oil in water using a humic-clay complex based on Al30-pillared montmorillonite is higher than that based on the original montmorillonite. The detoxification coefficient of the humic-clay complex based on Al30-pillared montmorillonite reaches 80%; at the same time, the toxic effect of oil in water decreases from 65% to 13%. The resulting humic-clay complexes act as stabilizers of the oil-water emulsion. They are capable of being spontaneously sorbed at the oil-water interface with the formation of a structural-mechanical barrier around oil droplets, which transfer oil into the water column with further intensive decomposition by microorganisms - oil destructors - due to the large contact surface. Oil is not released from mineral "capsules" and does not form a surface film, which allows the use of humic-clay complexes in the in situ purification process.