Effect of charcoal particles on concentration of Cd~(2+) and Cr~(3+) in aqueous solution

Objective: To study the effect of different charcoal particle sizes,amounts and contact time on the concentrations of Cd2 + and Cr3 + in aqueous solution.Methods: Different simulation tests were employed and conducted in 7 days.Results: The concentrations of Cd2 + and Cr3 + decreased with decreasing charcoal particle sizes between 0.25 mm and 0.15 mm,while the concentrations of Cd2 + and Cr3 + decreased with increasing charcoal particle sizes between 0.25 mm and 0.85 mm.Only when the particle sizes were less than 0.25 mm,it was obvious that the smaller the particle sizes were,the better adsorption effect appeared.The concentrations of Cd2 + and Cr3 + were significantly lower than the control group when the charcoal amount was 20 g.L-1.And as the amount of the charcoal particles increased,the concentrations of Cd2 + and Cr3 + remaining in the aqueous solution became lower and lower slightly.Cr3 + concentration decreased in 4 kinds of Cr3 + aqueous solutions with time increasing from the 1st day to the 4th day when the charcoal particle amount was 40 g.L-1.After 4 days,the increasing trend of Cr3 + concentration decreased.Conclusion: Optimizing the experimental factors,such as particle size,amount and contact time of the charcoal used,the heavy mental ions in aqueous solution can be effectively adsorbed.