PHYTOEXTRACTION OF SELECTED HEAVY METALS BY Ipomoea aquatica AND Pteridium aquilinum FROM CONTAMINATED SOILS UNDER HUMID LOWLAND TROPICAL CLIMATIC CONDITIONS

Heavy metal toxicity from anthropogenic activities has become a human and environmental health concern and requires tailored management strategies. Therefore, an ecological survey and a greenhouse-based study were conducted to assess the phytoextraction potential of Ipomoea aquatica and Pteridium aquilinum as common plant macrophytes of Cd, Cu, Pb, and Zn from a human and surface environment health perspective. A gram of ground and sieved samples from whole plants (root, stem, and leaves) were weighed out in triplicate and digested aqua reqia. The concentrations of the four heavy metals in the digested plant samples were determined using atomic absorption spectrophotometer. The actual concentrations (mg kg-1) of the heavy metals of the soil I. aquatica was collected were Zn (448)>Pb(349)>Cu(197)>Cd(1.2) and in the plant samples Pb(12)>Cu(9)>Zn(2.2)>Cd(0.2). For P. aquilinum, concentrations for soil samples were Cu(1040)>Zn(193)>Pb(85)>Cd(10) and in plant samples Zn(195)>Pb(97)>Cu(43)>Cd(12). The results showed I. aquatica has a low potential for phytoextraction of heavy metals and lesser concern for human consumption. The role of the two plants from an environmental health perspective is that I. aquatica is not suitable for phytostablisation and P. aquilinum is more of an accumulator and has high potential. The two plant macrophytes’ high level of tolerance to soil contaminated with heavy metals has implications for revegetation, phytostabilisation, and phytoextraction, as management strategies for contaminated surface environments.