Nitrate Removal from Wastewater Using Different Carbon Sources

Kavitha Ramachandran, Vijayan N

Abstract: Nutrient loading in water bodies has known to cause eutrophication and nutrient leaching. These are identified as a major global environmental issue, contributing to health hazards and various environmental threats. There are many sources of nitrogen and phosphorus which have been increased largely over the years. Instead of controlling the source, the main processes involved is the reduction of nitrate produced, which can be done by various physiological and biological methods. But the most efficient method identified is microbial denitrification, where the reactive nitrate is sequentially reduced to non-reactive nitrogen in the presence of facultative aerobic bacteria. It requires a major carbon source and many studies have been done to identify the most efficient external carbon source that can be used. This study mainly deals with comparing the efficiency of simple carbon sources (wood chips, paddy straw and newspaper) for denitrification. All the three sources are easily available indigenously. The study is done in synthetic wastewater with an initial NO3-N of 50 mg/L inoculated with Pseudomonas aeruginosa in packed bed reactors of 5 L capacity as batch flow. The study has identified newspaper as the most efficient among the three.

Keywords: Batch flow reactor, Denitrification, Efficiency, External carbon source, Microbes, Nitrate reducing bacteria, Synthetic wastewater