A study on Kinetics modeling and isotherms for removal of Cr (VI) from aqueous solution by modified Cyperus rotundus Weed biomass

Chromium, found in many industrial effluents, is one of most important heavy metal with health and environmental risks. Therefore, the aim of this study is to survey the effect of Cr (VI) removal by using Cyperus rotundus Weed biomass. This empirical study was done in lab scale. The variation of pH, dose of adsorbent, contact time, and concentration of chromium were investigated. The adsorption data was explained by adsorption isotherms and kenitics.The residual concentration was analyzed by spectrophotometer in maximum wavelength of 540 nm. It was determined that the pH value of 3, contact time of 60 min, adsorbent dosage of 4 g/L and Cr (VI) concentration of 10 mg/L were the optimum conditions for adsorbents. The most Cr (VI) removal efficiency of 99% was obtained for Cystoseira indica biomass in optimum conditions. The equilibrium data is best fitted on Langmuir isotherm and the adsorption kinetic model follows pseudo-second model. The maximum capacity of adsorption was 10.12 mg/g. The results revealed that by using Bio-absorption the removal of Cr+6 can be done quickly and effectively.