Formation and Chromium Removal Mechanism of Protein-polysaccharide-Cr(III) Complexes

In this study, sodium alginate (SA) and bovine serum albumin (BSA) were utilized to mimic polysaccharides and proteins during the leather tanning wastewater treatment. This research examined the characteristics and stability of various complexes formed by the interaction of polysaccharides, proteins, and Cr(III). It was discovered that the molecular weights of the SA-BSA-Cr(III) complexes were considerably lower than those of the separate ligands, suggesting that the complexes predominantly arise from intramolecular coordination. A shift in the isoelectric points of the complexes towards a neutral pH enhanced neutralization precipitation and flocculation sedimentation processes. However, the maximum chromium removal efficiency achieved was only 85.62%. Introducing ultrasonic pretreatment in combination with a reflocculation agent increased the chromium removal efficiency of the complexes to over 98%, with the process remaining unaffected by pH variations. The findings of this investigation offer a theoretical and practical foundation for the enhanced removal of chromium in non-neutral environments.