Effect of Cyclic Phytoremediation with Different Wetland Plants on Municipal Wastewater

Phytoremediation is a promising cleanup technology for contaminated soils, groundwater, and wastewater that is both low-tech and low-cost. The objective of this study was to investigate the ameliorative effect of phytoremediation on municipal wastewater (MWW). For this purpose, a phytoremediation garden was established using different aquatic plants species [Pistia stratiotes, Eichhornia crassipess, Hydrocotyle umbellatta, Lemna minor, Tyhpa latifolia, and Scirpus acutus] in seven earthen pond systems (P1-P7) for the cyclic treatment of MWW. The physico-chemical analysis of MWW was carried out before and after the cyclic phytoremediation. Results showed that pH, EC and turbidity of MWW were reduced by 5.5%, 33.7%, and 93.1%, respectively after treatment (from P1 to P7). Treatment system also reduced total dissolved solids (TDS) by 35.2%, Cl by 61%, HCO3 by 29.2%, hardness by 45.7%, Ca by 32.3% and Mg by 55.9%. Nitrate concentration was reduced by 77.6% but SO4 was enhanced slightly. An ameliorative combined effect of wetland plants namely L. minor, T. latifolia, and S. acutus on MWW was noticed. Sequential phytoremediation with a mixture of plants was more effective than that relying only on a single plant species.