Nitrate removal from synthetic groundwater by tetradesmus obliquus algae culture

Ion exchange, reverse osmosis, electrodialysis and denitrification are known methods used for nitrate removal from ground water. In this study, nitrate removal by algae culture was investigated as a new alternative treatment method to the others which have several disadvantages; high operating costs, waste disposal difficulties, and necessity of secondary treatment and additional chemicals. In this thesis; it was aimed to eliminate nitrate, which is an important pollution parameter in groundwater, by Tetradesmus obliquus and to determine the optimum conditions affecting nitrate removal. A bioreactor was designed with its chambers seperated by a nylon membrane. This membrane bioreactor and a photobioreactor were used together for the experiments to investigate the effect of Tetradesmus obliquus species in nitrate removal under different conditions, such as: different light, different temperature, different pH values and different air flow rate. Obtained data showed that under the 28 °C temperature, 24 hours light time, pH 8, and 0,5 L/min air flow rate conditions, the nitrate concentration was reduced from 170 mg NO3-/L to 32 mg NO3-/L in 10 days with a removal efficiency of 81%. With this thesis study, it was determined that algae cultures could be used for removal of nitrate from groundwater and required no additional treatment methods for its own elimination.