Remediation of DDTs-Contaminated Sediments through Retrievable Activated Carbon Fiber Felt

摘要

Addition of adsorbent to the sediments has become an effective way for in situ treatment of persistent organic pollutants (POPs) contaminated sediments in recent years. However, once the adsorbents are added to the sediments, they are difficult to be retrieved, and potential risks of POPs are still existed. In this study, we proposed a new method that used activated carbon fiber felt (ACFF) to remediate POPs-contaminated sediments with the advantage of retrievability. As an example of POPs remediation, three sediments were spiked with p,p′-dichlordiphenyltrichloroethanes (DDT), o,p′-DDT, p,p′-dichlorodiphenyldichloroethylene, and p,p′-dichlorodiphenyldichloroethane, and were allowed to age for 7, 28, or 100 days before viscose-based ACFF was added to the spiked aqueous slurry in batch experiments. The effects of ACFF on DDTs removal efficiency in these sediments were examined. It was found that ACFF could efficiently remove DDTs released from the sediments. The DDTs removal efficiency of ACFF was influenced by the initial spiking concentrations, hydrophobicity of DDTs, aging times of the contaminated sediments, and organic carbon contents of the sediments. Moreover, the removal efficiency of ACFF was enhanced by increasing the amount of ACFF, as well as by sequential replacement of ACFF. The use of retrievable ACFF could potentially be an effective method for in situ remediation of sediments contaminated with POPs.