Highly Efficient Heavy-Metal-Ion Removal from Shellfish Processing Liquid with Low Protein and Polysaccharide Loss by Hybrid Mesoporous Silica Diol-APDC-SBA15

Heavy metal ions in shellfish products are harmful to human health, and their removal with low nutrient loss remains challenging. Herein, a new type of mesoporous silica (SBA15), modified internally with ammonium pyrrolidine dithiocarbamate (APDC) and externally with alkyl-diol groups, which was named as Diol-APDC-SBA15, was successfully developed and characterized by powder X-ray diffraction patterns, nitrogen adsorption, and Fourier transform infrared spectroscopy. The solutions with lead, chromium, cadmium, and copper were used to investigate the adsorption capacity of Diol-APDC-SBA15. Diol-APDC-SBA15 was adopted to remove heavy metals from cooking liquids of clams ( Ruditapes philippinarum ), hydrolysate liquids of oysters ( Ostrea gigas Thunberg ), and polysaccharide solution from the cooking liquid of R. philippinarum . The efficiencies of removing heavy metal ions and the loss rates of proteins and polysaccharides were examined. The results showed that the adsorption capacities of Diol-APDC-SBA15 for Pb, Cr, Cd, and Cu in standard heavy-metal solutions were 161.4, 166.1, 29.6, and 60.2 mg g −1 , respectively. The removal efficiency of Diol-APDC-SBA15 for Pb in the three shellfish processing liquids ranged from 60.5% to 99.6%. The Cr removal efficiency was above 99.9% in the oyster hydrolysate liquid. Meanwhile, the percentages of polysaccharide loss were 5.5% and 3.7% in the cooking liquid of clam and polysaccharide solution, respectively, and the protein loss was 1.2% in the oyster hydrolysate liquid. Therefore, the Diol-APDC-SBA15 material exhibits a great potential application in the removal of heavy metals from shellfish processing liquids with low losses of proteins and polysaccharides.