Influencing factors of immobilized bacteria particles for improving denitrification efficiency

The aim of this study was to investigate the factors which influence the denitrification performance of immobilized denitrifying bacteria. Single variable control method was used and it was found that the immobilized denitrifying bacteria particles had the best denitrification performance under these conditions: bacteria addition proportion in the immobilized particles was 15% and with a particle size of 3–4 mm, immobilized particles adding amount was 20%, and using glucose as external carbon sources with carbon–nitrogen ratios of 3.0–3.5 and hydraulic residence time over 6 h under the temperature of 25°C–30°C. This study suggested that a better denitrification effect could be achieved by extending the hydraulic retention time when other environmental factors are difficult to control. The information obtained in this study may help to put the microbial immobilized technology a step forward in wastewater treatment application.