Bacterial Alginate Role in Aerobic Granular Bio‐particles Formation and Settleability Improvement

Abstract

To understand the greatly enhanced settleability of aerobic granular bio‐particles, bacterial alginate, one component of extracellular polysaccharides, was extracted both from aerobic granular bio‐particles and the seed activated sludge. Their guluronate to mannuronate radio, reaction with Ca²⁺, and the gel formation property were investigated and compared by the FT‐Raman spectroscopy and atomic force microscopy. The larger amount of guluronate rich alginate (310±16 mg g⁻¹) in the bio‐particles inclines to integrate into strong gel, which becomes the structural polymer and promotes the bio‐particles formation. By enlarging the particle size, increasing the density and hydrophobicity, bacterial alginate tremendously improves the granular bi‐particles' setteability.

Keywords:

• Bio‐particles
• aerobic granules
• bacterial alginate
• settleability
• biological wastewater treatment

Acknowledgments

This work was supported by the China National Foundation for Natural Science No. 30570339. Authors would like to thank Professor Avner Adin (Israel) for his helpful suggestions.