The Dispersion of Extra-Polysaccharide and Protein of Activated Sludge in Sodium Pyrophosphate Solution

The dispersion of extra-polysaccharide and protein of sludge in sodium pyrophosphate solution (pH=7.0) was studied under the conditions of low mixing speed. The results showed that as the mixing speed were set at 150 and 350 rpm/min, the dispersion of polysaccharide and protein in sodium pyrophosphate solution was mainly controlled by chemical process, and the dispersion efficiency of protein was greater than polysaccharide. It was analyzed that the different affinity of protein and polysaccharide to bivalent Ca²⁺ was the main factor resulting in their different dispersion characteristic in sodium pyrophosphate solution.