Treatment Capacity of Vetiver Grass of A Mixture of Laboratory and Domestic Wastewaters

In this study, laboratory wastewater containing organic matters, heavy metals and aromatic compounds, was treated by vetiver grass (Vetiveria zizanioides) as a phytoremediation. Sewage effluent as a source of nutrient supply for plant growth was first fed to two wetland systems: mini horizontal subsurface flow (HSSF) and floating raft (FR) wetlands. Next, laboratory wastewater was added gradually to mix with sewage. Nominal hydraulic retention time in both wetlands is 12 hours. Performance of the wetlands were monitored.Vetiver presented reasonable removal efficiencies of about 59-62%, 63.5-68.6%, and 53.0-58.3% for BOD, TN, and TP removal respectively. Vetiver also showed impressive efficiencies in heavy metals removals of 92.4-99.2, 85.1-95.8, 91.8-96.2, and 91.5-96.7% for Cr+6 (in K2Cr2O7), Mn (MnSO4), Fe (FeSO4), and Cu (CuSO4), respectively. For aromatic compounds, the wetland is responsible for 91.5-96.8 and 96.0-100% of correspondingly phenol and benzene removal efficiencies. Microorganism behaviour was investigated along with the wetland performances