Research on mechanisms and effects of microbial agent applied in scaling control of circulating cooling water

Scaling control is vital for the safe operation of circulating cooling water system. Biological treatment involves the addition of microbial agent; it employs the metabolism of functional strains, and it is a novel, efficient and environmentally friendly method used to control scaling. In this study, microbial agent (including Nitrosomonas, Nitrospira, Bacillus cereus, Bacillus subtilis and Pseudomonas) were selected to investigate their anti-scaling mechanisms and the effects of employing biological methods. The anti-scaling efficiency of the microbial agent was found to be approximately 55.34-61.29%. The anti-scaling mechanisms of the functional strains included (a) acid production and solubilisation, (b) acid production and dissolution, (c) CaCO3 lattice distortion and (d) biosorption of scaling ions. Our study provides a deeper understanding of the anti-scaling mechanisms of functional strains and will assist in the advanced development and application of microbial agent in scaling control.