Phytoremediation Potential of Cyperus Alternifolius, Cyperus Dives and Canna Indica in Flamingo Farm Constructed Wetland, Naivasha Sub-County, Kenya
Oluoch, Josephat Otieno
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Contamination of fresh water sources with heavy metals found within the agricultural areas is largely contributed by amongst other factors, application of inorganic fertilizers and pesticides. Removal of heavy metals from the contaminated waters using conventional methods is cost prohibitive and more importantly less effective especially when concentration of heavy metals is low. As a result, use of alternative technologies such as phytoremediation is being promoted. Phytoremediation uses plants called phytoremediators and in order to achieve successful remediation of wastewater, proper selection of the phytoremediators is important. This study, therefore, aimed at evaluating phytoremediation potential of Cyperus alternifolius, Cypersu dives and Canna indica plants which grow in Finlays Flamingo Farm constructed wetland. The study was conducted between February 2014 and August 2014. The objectives were to determine bioconcentration and translocation factors of Arsenic, Cadmium and Lead metals in Cyperus alternifolius, Cyperus dives and Canna indica, and evaluate the phytoremediation potential of the study plants. Eighteen plants of each species were planted on the Gravel Bed Hydroponics and left to grow for four months. Six plants of each species and wastewater were then sampled at the end of the fifth, sixth and seventh months. Roots and shoots of each species were put together to form composite samples and analyzed for Arsenic, Cadmium and Lead metals using the Inductively Coupled Plasma Optical Emission. Wastewater samples were also analyzed for Arsenic, Cadmium and Lead metals using the American Public Health Association procedures. Data were presented in tables and graphs, and analyzed using Analysis of Variance and Tukey tests at p=0.05. The findings showed that biocentration factor values for Arsenic, Cadmium and Lead metal in the study plants were greater than one (ranging from 7 to 1208) while translocation factor values were less than one (ranging from 0.069 to 0.934). These results confirmed that the study plants were effective phytostabilizers of Arsenic, Cadmium and Lead metals and can be used for phytoremediation. However, for effective removal of these heavy metals from wastewater, harvesting of the study plants should include removal of their roots.