Treatment potential of Typha latifolia in removal of heavy metals from wastewater using constructed wetlands

The objective of the study was to evaluate the phytoremediation potential of the aquatic macrophyte Typha latifolia for removal of cadmium, chromium and lead from synthetic wastewaters in constructed wetlands (CW). Four laboratory scale CW units were set up, each containing granite and soil. Typha latifolia was planted in the 1st unit then intercropped with Vetiveria zizanioides, Phragmites australis and Cyperus latifolius in the 2nd, 3rd and 4th unit respectively. The units were treated to wastewaters of different metal concentrations and metal combinations. Wastewater was sampled at different retention periods. Results showed substantial reduction in metal concentrations. Metals were removed in the order Cr>Cd>Pb with maximum removal efficiencies being 96.36±0.52%, 95.70±1.26% and 80.59±3.58% for Cd, Cr and Pb respectively in the typha only units. The percentage removal of the metals increased with increase in retention time. This study recommends application of Typha latifolia in treatment of industrial and mine wastewaters