adsorption of heavy metals by salvinia biomass and agricultural residues

batch adsorption experiments were performed to study adsorption potential of agricultural residues viz. rice straw, wheat straw and salvinia plant biomass for removal of heavy metals such as cr, ni, and cd. plant materials were used in different combinations. heavy metal removal efficiency was more at low metal concentration (35 mg/l). salvinia biomass possessed higher efficiency for removing heavy metals such as cr, ni and cd followed by a combination where three materials (rice straw, wheat straw, salvinia biomass) were taken together in comparison to other combinations. the adsorption data fitted in langmuir and freundlich isotherm models.the present investigations revealed that agricultural residues such as rice straw and wheat straw along with salvinia biomass can serve as low-cost alternative for removal of heavy metals from wastewaters.