Abstract: Three kinds of oligotrophic bacteria screened were used as strains to prepare microcapsules by exogenous emulsification method. The results showed that the particle size of the microcapsule was concentrated between 105 μm and 240 μm. After microencapsulation, the biologics significantly improved the acid and alkaline resistance and stability, and the TOC degradation rate reached 61.21% in 7 days, which could be safely and effectively used in the field of advanced treatment of the water supply system.

Key words: oligotrophic bacteria, slightly polluted water, microcapsules, total organic carbon（TOC）