Comparative assessment of phytoremediation feasibility of water caltrop (Trapa natans L.) and water hyacinth (Eichhornia crassipes Solms.) using pulp and paper mill effluent

Abstract

Experiments for the comparative assessment of phytoremediation feasibility of water caltrop (Trapa natans L.) and water hyacinth (Eichhornia crassipes Solms.) using paper mill effluent were carried out for 60 days. The results revealed that the pulp and paper mill effluent was varied in characteristics and highly loaded with TDS, EC, BOD5, COD, TKN, PO4 3- , Na+ , K+ , Ca2+, Mg2+, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, SPC and MPN. It was observed that and both the plant species T. natansand E. crassipes significantly (P<0.05/P<0.01/P<0.001) reduced the contents of TDS, EC, BOD, COD, TKN, PO4 3- , Na+ , K+ , Ca2+, Mg2+, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, SPC and MPN of pulp and paper mill effluent after phytoremediation experiments. Albeit, the maximum removal of these parameters were obtained at 60 days of the phytoremediation experiments but the removal rate of these parameters were gradually increased from 15 days to 45 days and it was decreased at 60 days. The most contents of Cd, Cu, Fe, Mn and Zn was translocated in the leaves of T. natans and E. crassipes during the phytoremediation experiments whereas, the least contents of Cr, Ni and Pb was translocated in the leaves of T. natans and E. crassipes. Among both the macrophytic species (i.e. T. natans and E. crassipes) used for the phytoremediation, E. crassipes was found to be more effective for the removal of different parameters of pulp and paper mill effluent in comparison to T. natans. Therefore, T. natans and E. crassipes can be used effectively to reduce the pollution load of pulp and paper mill effluent.