Preliminary study on removal of cadmium in aqueous solution by shrimp shell activated by phosphate buffer

Adhesion protein in shrimp shell is found with relatively higher content of acidic amino acid residues，which is conducive to remove heavy metals in the aqueous solution for shrimp shells through cation exchange. Decalcified shrimp shell and activated by phosphate buffer can produce a kind of shrimp shell material that can remove cadmium ion from dilute aqueous solution. Taking Cd2+ removal rate as index，single-factor test combined with orthogonal test were used to optimize the shrimp shell activation condition. The optimum conditions were obtained as follows: phosphate buffer pH of 7.5，concentration of 0.15 mol/L，ratio of liquid to solid of 20∶1，activation time of 120 min. And the Cd2+ removal rate was 95.25（ ±0.57）% when the phosphate buffer activation shrimp shell dosage was 100 mg/80 mL in Cd2+ aqueous solution.