Assessment of PCB-contaminated soil pretreatment remediation by hydroxypropyl-β-cyclodextrin (HP-β-CD)

Abstract

The present study thoroughly evaluated the effect of hydroxypropyl-β-cyclodextrin (HP-β-CD) on eluting of Aroclor1242 (one kind of PCBs (polychlorinated biphenyls)) from contaminated soil. The factors that might affect eluting efficiency including HP-β-CD concentration, contact time, eluting cycles, temperature, pH, salt content, humic acid, and ultrasonic were all tested to evaluate the PCBs eluting efficiency by HP-β-CD. Results indicated that Aroclor1242 can be eluted effectively from soil by HP-β-CD solution, 81% of Aroclor1242 was eluted from soil by 50 g/L of HP-β-CD solution after three cycles eluting, and the eluting efficiency was improved by increasing temperature and with ultrasonic. Furthermore, it was shown that the humic acid and extreme acidic/alkaline condition both decreased the eluting efficiency. In addition, column eluting experiment was conducted to simulate the practical HP-β-CD eluting of Aroclor1242 from contaminated soil, 18% of the PCBs was eluted from the soil column by 10 g/L of HP-β-CD. Overall, the results indicated the high extract power of HP-β-CD toward PCBs polluted soil and potential use of HP-β-CD for in situ remediation of PCBs contaminated soils.

Keywords

• hydroxypropyl-β-cyclodextrin
• polychlorinated biphenyls
• contaminated soil
• eluting