The influences of different organic fractions in refuse on the sorption and bioavailability of dibutyl phthalate

Abstract

The structure and composition of the organic matter in landfilled refuse might have an influence on the migration and transformation of dibutyl phthalate (DBP). Humic acid (HA) and humin (HU) were separated from aged-refuse to determine the influences of different organic fractions in the refuse on the sorption and bioavailability of DBP. The sorption kinetics and isotherms for the sorption of DBP to HA, HU, and whole refuse were determined. The results showed that the sorption constants (K) and nonlinearities decreased in the order HU > whole refuse > HA. The HA had lower K values than did the other refuse fractions, and it retarded the biodegradation of DBP over a short degradation period (48 h). Increasing the amount of HA present caused the amount of DBP that was biodegraded to decrease significantly, 81.3% of the DBP sorbed to HA being degraded in the original experiments after 48 h but 21.8% of the DBP being degraded when three times as much HA was used. Similar results were not observed when the amount of HU used was changed. These findings suggest that HA plays an important role in the biodegradation of DBP adsorbed by refuse.