Perennial Plants in the Phytoremediation of Lead-contaminated Soils

In this experiment, three local perennial plant species, Alternanthera philoxeroides, Sanvitalia procumbens and Portulaca grandiflora, were examined for their ability to uptake lead from lead contaminated soils (75 mg kg-1). Lead concentration in soil under all treatments decreased between 30-80% (62.61-23.18 mg kg -1) when compared to the control (75 mg kg -1). In all treatments, lead accumulation in the plants was higher on day 45 than what was found on days 55 and 65. Among these three species, A. philoxeroides showed a greater potential for lead accumulation than P. granaiflora and. S. procumbens. On day 45, A. philoxeroides showed significant differences in lead accumulation (29.99%) compared to that from P. granaiflora (13.03%) and S. procumbens (16.44%). Even though the amount of lead extracted by these three plants was small, the results showed that A. philoxeroides had the ability to extract an approximately 1.3-1.8 times greater amount than P. grandiflora and S. procumbens. Phytoremediation technology is environmentally friendly and cost-effective; A. philoxeroides may be a practicable alternative for protecting the soil in Thailand from leaching lead.