Assessment of Phyto-Remediation Quotient of Cultivated Waterleaf Talinum Triangulare on Soil Contaminated With Sodium Arsenate Pesticide

The potential of Waterleaf Talinum triangulare to abstract and consequently remediate As from As-pesticide contaminated soil was investigated by pot experiment and the concentration of As in the plant and soil was determined through mass plasma atomic emission spectroscopy (MP-AES). The composite soil in two separate groups of pots was spiked with 50 mg/kg and 70 mg/kg disodium arsenate pesticide and stands of Waterleaf were grown on them over a 9 weeks growth period. The plant parts (leave and root) and soil after harvesting were pretreated, acid digested and subjected to MP-AES analysis. The results depicted that As concentrations in the plant parts differ at all the treatment levels over the graded period of growth for frequency of harvest and time of harvest and exceeded the maximum permissible limit established by FAO/WHO, and makes the plant unfit for human and animal consumption. The experimental results revealed a statistically significant difference (p<0.05) in the bioaccumulation of As over the graded period of growth at all the treatment levels. The Bio-accumulation factor (BAF) and Bio-concentration factor (BCF) were generally greater than unity (BAF > 1 and BCF > 1) in all treatment levels at the time of harvest which indicates that Waterleaf is suitable for phytoextraction and phytostabilization. However, BAF < 1 and BCF < 1 were observed in the 3^rd week and 9^th week in the frequency of harvest. Furthermore, Translocation factor (TF <1 and TF > 1) were observed for frequency of harvest and time of harvest, implying that the plant can serve as a bad and good accumulator of As in contaminated soil for phytoremediation if the plant is frequently harvested or allowed to fallow. TF > 1 means that the vegetable will be suitable as a good phytoextractor.  It can, therefore, be concluded that Waterleaf can be used for commercial and environmental friendly phytoremediation technology (Green technology) to clean up As polluted sites and environmental monitoring.

Keywords: BAF, BCF, Contamination, Phytoextraction and phytostabilization, TF