Khanitta Somtrakoon, Waraporn Chouychai, and Hung Lee

DOI: 10.14456/sjst-psu.2018.83

pp. 725 - 731

Abstract

The ability of butterfly pea (Clitoria ternatea) and yam bean (Pachyrhizus erosus) to stimulate the removal of
anthracene and pyrene from contaminated soil was investigated. Of the two plants, only butterfly pea enhanced the removal of
anthracene and pyrene from soil on day 30. The initial concentrations in soil of anthracene and pyrene were 86.3 and 74.1 mg/kg,
respectively, while their remaining concentrations were 20.1 and 27.1 mg/kg on day 30. In comparison, the respective
concentrations in unplanted soil on day 30 were 67.6 and 68.2 mg/kg. Anthracene and pyrene were completely removed from soil
planted with butterfly pea and yam bean on day 75. In comparison, 17.8 and 18.2 mg/kg of anthracene and pyrene, respectively,
remained in unplanted soil on day 75. Neither anthracene nor pyrene accumulated in any of the plant tissues examined during the
study, so the mechanism for enhanced anthracene and pyrene removal was the stimulation by these plants of competent
indigenous microorganisms to degrade the PAH compounds.