Experimental study on removing Cr(VI) from simulated wastewater by dynamic absorption with peanut shells

The treatment of simulated wastewater,which had a concentration of Cr(Ⅵ) of 20 mg/L,with peanut shells was studied through dynamic absorption experiments under different conditions.The results show that the removal rate of Cr(Ⅵ) reached 99.08% when the diameter was 1.6 to 2.5 mm,the adsorbent dosage of peanut shells was 5.0 g,the optimum condition was pH=1.0,and the flow rate was 3.0 mL·min-1.The concentration of Cr(Ⅵ) was 0.184 mg/L after adsorption,meeting the Integrated Wastewater Discharge Standard(GB8978-1996).The model fitting is explained in the paper.The Thomas model can well reflect the characteristics of the adsorption process,and the saturated adsorption capacity of peanut shells was 9.4 mg/g.It can be seen from the dynamic adsorption breakthrough curve that the penetrative point and the failure point were reached at 219 min and 1312 min,respectively.