DEVELOPMENT OF AN INNOVATIVE SOIL-WASHING TECHNOLOGY BASED ON THE USE OF CHOLIC ACID-DERIVATIVES AS POLLUTANT-MOBILIZING AGENTS: IMPACT OF THE ADDITIVES ON SOIL DECONTAMINATION AND THE AEROBIC BIOREMEDIATION OF THE RESULTING WASTEWATERS

The opportunity to use deoxycholic acid (DA), bovine bile (BB), and the residue resulting from DA extraction from BB (BBR) as nontoxic and biodegradable pollutant-mobilizing agents in the washing of (chloro)aromatic-contaminated soils was studied. They were applied in parallel to Triton X 100 and evaluated for their ability to mobilize pollutants from a contminated soil and to influence the aerobic treatment of the resulting effluents. The soil was suspended at 15% (w/v) in water or in water with 1.0% (w/v) DA, BB, BBR or TX in batch reactors shaken at 120 rpm for 24 h. The resulting effluents were treated in shaken batch reactors at 20°C for 56 days. The biogenic agents enhanced by 227÷441% the pollutant mobilizing capability of water by also sustaining the effluent aerobic bioremediation. TX enhanced the same process by about 536% but increased the soil toxicity and adversely affected the biotreatability of the resulting effluent.