LAUSR

ABSTRACT An effective method to remove cadmium (Cd) from scallop by-product enzymatic hydrolysate (SBEH) was developed, and the Cd bonding sites were studied. Cation-exchange resin, anion-exchange resin, activated charcoal, and zeolite were tested. The result showed that strong acid polystyrene cation-exchange resin was the most suitable sorption material for the removal of Cd. The optimal conditions were as follows: SBEH concentration at 17.07 mg/mL, pH value at 4.92, and adsorption time with 11.73 min, while 4 g resin was added in 50 mL solution at 30°C. The experimentally measured removal rate was 95.38% under these conditions. The Cd element has an intense bonding pattern with macromolecules, and more than half of the Cd element exists as positively charged ion in the SBEH. The cation-exchange resin removed Cd by dumping the macromolecules associated with the Cd element. Infrared (IR) spectra suggested that the sulfate ester groups and carboxyl groups in the macromolecules were binding sites of the Cd element in SBEH. These results provide a useful method for Cd removal from SBEH that potentially can be used for industrial processing.