Characterization and flocculation mechanism of high efficiency microbial flocculant TJ-F1 from Proteus mirabilis.
The characterization and the flocculation mechanism of microbial flocculant TJ-F1 with high flocculating activity, produced by Proteus mirabilis from a mixed activated sludge, was investigated. Mainly consisting of protein and acid polysaccharide, TJ-F1 owns a molecular weight of 1.2 x 10(5)Da, which brings strong van der Waals forces and ample binding-sites. It contains carboxyl, hydroxyl, amino groups and hydrogen bonds preferred for the flocculation process. The key parameters influencing the flocculation behavior were investigated by analyzing both the Zeta potentials of the flocculation systems and the flocculating efficiencies of TJ-F1. An alkaline condition promotes its flocculating efficiency. CaCl(2) aids TJ-F1 by effectively decreasing the absolute value of Zeta potential. Appropriate dose of TJ-F1 is crucial to the flocculating efficiency. During the precipitating process, the growing flocs sweep the small flocs and the suspended particles to form big flocs, which also contribute to the excellent flocculating efficiency of TJ-F1.
State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment of Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Zhiqiang
Z
Zhang
Siqing
S
Xia
Jianfu
J
Zhao
Jiao
J
Zhang
D000538:Aluminum Silicates / Q000737:chemistry; D002122:Calcium Chloride / Q000494:pharmacology; D000077215:Clay; D005427:Flocculation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007616:Kaolin / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D011513:Proteus mirabilis / Q000737:chemistry* / Q000187:drug effects; D013997:Time Factors
D000538:Aluminum Silicates; D011135:Polysaccharides, Bacterial; D007616:Kaolin; D002122:Calcium Chloride; D000077215:Clay