Biosorption of Crystal Violet from Water on Leaf Biomass of Calotropis procera

The biosorption of a triphenylmethane dye, crystal violet from water on leaf biomass of Calotropis procera, a member of the family Asclepiadaceae, was studied. The effect of contact time, initial dye concentration and adsorbent dose were investigated. The biomass showed good removal efficiency for crystal violet from water. The adsorbent removed 80.48 % of crystal violet from aqueous solution at a dye concentration of 20 mg L ^{- 1} (about 50 μ M) in 60 min. The adsorption data fitted well into Langmuir adsorption isotherm showing monolayer coverage of the adsorbent surface. The Langmuir parameters, q_o and K_L were calculated to be 4.14 mg g ^{- 1} and 0.1139 L mg ^{- 1}, respectively. The kinetic data showed that the biosorption of crystal violet on the biomass obeys Lagergren first order rate expression. The rate of biosorption was rapid in the initial 5 min and then decreased gradually and attained equilibrium in 60 min. The rate constant came out to be 0.0322 min ^-1.