Adsorptive properties of modified peanut shell to heavy metal Cr( VI)

In order to solve the problem of high cost and low efficiency to remove the heavy metals such as chromium in wastewater,adsorption with low cost and simple operation has been explored,whose core technology is the selection of excellent adsorbent. Screening of low cost adsorbent is the hot point in the study of removing Cr( VI). Crops stem which was rich in cellulose becomes an important source of lowcost adsorbent. A great effort has been carried out on the modified peanut shell for their property to absorb Cr( VI). The effects of pH value,initial concentrate ration of Cr( VI),contact time,temperature and modified peanut shell dosage on adsorption had been investigated. The results indicated that modified peanut shell had good adsorption to Cr( VI). Under the condition of 50 ℃,10 g /L modified peanut shell,50 mg /L Cr( VI) solution,the initial pH = 1 and contact time 140 min,the adsorption rate of Cr( VI) is up to 99.6%. The Langmuir and Freundlich adsorption models were used to represent the experimental data and equilibrium data fitted well to Freundlich and Langmuir isotherm mode. Pseudo-second-order model was found to explain the kinetics of Cr( VI) adsorption most effectively. Through analysis and experiments,the modified peanut shell for the adsorption of Cr( VI) in wastewater is feasible and effective.