HAZARDOUS CHEMICALS ARE THE MAJOR CAUSE OF SOIL CONTAMINATION IN THE ENVIRONMENT. TO PREVENT THE LEACHING OF POLLUTANTS IN SOILS, DIFFERENT STABILIZATION AND CONTAINMENT TECHNIQUES HAVE BEEN DEVELOPED IN RECENT YEARS.
ORGANOPHILIC BENTONITES, DUE TO THEIR LARGE SURFACE AREAS, NEGATIVE CHARGES ON THEIR PARTICLES, AND HIGH ADSORPTION CHARACTERISTICS HAVE MANY APPLICATIONS FOR REMEDIATION OF CONTAMINATED SITES. THE ABOVE CHARACTERISTICS OF MODIFIED BENTONITES HAVE ENABLED THEM TO ADSORB CONTAMINANTS FROM SOLUTIONS OR TO STABILIZE THEM IN SOILS.
THIS STUDY FOCUSES ON INTERLAYER CHANGES OF BENTONITE CLAYS DUE TO THE ADSORPTION OF HYDROCARBONS (I.E, CRUDE OIL, MTBE, BTEX COMPOUNDS AND GASOLINE). FREE SWELL TESTS AND X-RAY DIFFRACTION ANALYSIS WERE CONDUCTED ON THE CLAYS. THE FREE SWELL TEST RESULTS SHOWED THAT MODIFIED BENTONITES EFFECTIVELY INTERCALATED CRUDE OIL INTO THEIR PARTICLES AND ADSORB THEM, HENCE PRESENTING 410 % VOLUME INCREASE WHEN EXPOSED TO THIS COMPOUND.
RESULTS OF X-RAY DIFFRACTION ANALYSIS FOR MODIFIED BENTONITE SAMPLES INDICATED A 63.15% INTERLAYER INCREASE AFTER THEIR EXPOSURE TO THE CRUDE OIL WHILE THAT OF ORDINARY BENTONITES WAS RELATIVELY INSIGNIFICANT (0.50%). SIMILAR OBSERVATIONS WERE NOTED FOR OTHER HYDROCARBONIC COMPOUNDS, DENOTING THE ORGANOPHILIC PROPERTIES OF MODIFIED BENTONITES.