Abstract
To evaluate the role of biofilms in improving microbial quality in rainwater tanks, the cell number of Pseudomonas aeruginosa was investigated after inoculation in pilot and full-scale rainwater tanks with different surface-to-volume (S/V) ratios. In pilot-scale experiments, the total number of inoculated cells sampled from the tank water, bottom and walls decreased. After 4 and 5 d, 99% of the inoculated cells were removed from the water in pilot tanks 2 and 1, respectively. Cell death due to low-nutrient conditions contributed to the observed cell number decline. The high removal rate in pilot tank 2 was because of the high S/V ratio. Further, the high removal rate of planktonic P. aeruginosa in full-scale experiment was confirmed in the tanks with high S/V ratios. Our observations indicated that biofilms play a significant role in improving the quality of stored rainwater.
Acknowledgement
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No.0415-20110098).