ISOLATION OF NOVEL AEROBIC DENITRIFIER AND OPTIMIZATION OF PROCESS PARAMETERS FOR BIOLOGICAL DENITRIFICATION USING RSM

摘要

The study was aimed to isolate and characterize a high efficiency novel denitrifier bacterium for reducing nitrate in wastewater and the optimization of the process parameters for biological denitrification. One of the bacteria among four chosen for study displayed maximum of 98% reduction of nitrate. The strain was identified as Enterobacter sp. NCCP-29 by biochemical tests and further identified based on similarity of PCR-16S rRNA using universal primers. The parameter (pH, temperature, agitation speed, C:N ratio) which affect the denitrification were screened using one factor at a time approach. The pH, temperature and C:N ratio exhibited significant affect on the denitrification using Enterobacter sp. NCCP-29. The levels of these parameters were optimized using a central composite design (CCD). The denitrification of 98% was achieved at optimized conditions (pH 6.5, temperature 30°C and C: N ratio of 3:1). The second order model was generated and found to have good fit with R2 value of 0.93.The investigation revealed the ability of Enterobacter sp. NCCP-29 to remove nitrate under aerobic conditions.