EFFECT OF RECYCLE RATIO AND HYDRAULIC RETENTION TIME ON DENITRIFICATION-NITRIFICATION PROCESS

In this study, the elimination of nitrogen compounds from is based on nitrifiication and denitrification. Ammonium released from the mineralization of nitrogen-containing organic compounds is oxidized first to nitrite/nitrate in nitrification process. During denitrification, nitrate is reduced to dinitrogen. The parameters effect this process are pH, temperature, electron donor/accepter ratio, hydraulic retention time nitrate-recycling rate etc. In this study, sequential batch denitrification-nitrification reactor was operated for testing different nitrate recycling ratio (100-700%). The batch reactor was fed with Kahramanmaraş urban wastewater during 80d at constant temperature of 25±0.5°C. The reactor performance was determined by color, ammonium (NH4+), nitrate (NO-3), nitrite (NO-2), inorganic carbon (IC), total organic carbon (TOC) parameters. According to our results, 100% recycling time was found optimum. Nitrate and ammonium removals were over 99%.