Evaluation of remediation process with soapberry derived saponin for removal of heavy metals from contaminated soils in Hai-Pu, Taiwan

摘要

The use of a biodegradable natural plant-based surfactant extracted from soapberry is proposed for the remediation of Ni,Cr and Mn from industrial soil site in Hai-Pu,Taiwan.Batch experiments were performed under variation of fundamental factors(saponin concentration,pH,and incubation time) for metal remediation.Removal of Ni and Mn were increased with increasing saponin concentration(0.015-0.150 g/L),whereas the removal of Cr was increased upto 0.075 g/L saponin.The Ni,Cr and Mn were removed significantly(p ≤ 0.05) at near to the neutral and slightly acidic(pH 5 to 8) conditions.Removal efficiency of Ni(99%) from the soil was found to be greater than that of Cr(73%) or Mn(25%) in the presence of saponin at a concentration of 0.150 g/L at pH 5.The removal percentage increased with incubation time where the removal of Ni was faster than that of Cr and Mn.The result indicates the feasibility of eco-friendly removal of heavy metal(Ni,Cr and Mn) from industrial soil by soil washing process in presence of plant derived saponin.