Factors increasing efficiency of deammonification process for nitrogen removal from mainstream wastewater.

Abstract: In recent years, the use of Anammox process for wastewater treatment has been thoroughly investigated. Currently, a major challenge is to use this process for the mainstream. The aim of this study is to find factors increasing efficiency of the deammonification process for nitrogen removal from mainstream wastewater in conditions of low ammonia concentration and low temperatures. Two types of lab-scale batch tests were done and obtained results were analysed separately. In the first lab-scale batch test suspended sludge was used and series of OUR tests were carried out. Inhibitors used during experiments were: FNA, FA, NaClO3, fresh UASB effluent and formic acid. The best results, after all tests obtained for using the free nitrous acid as an inhibitor. Results shows that NOB bacterial activity was inhibited, while AOB activity was still high. The second type of lab-scale batch test was used to check interactions between factors which have impact for the NOB suppression. Selected factors were: pH, DO and TAN and these factors were used to plan a series of experiments with MODDE application. After series of 34 experiments, results showed that this method is not effective for low concentrations of TAN and another, more efficient strategy is needed. New strategy should reduce the NOB activity or increase the activity of Anammox. It is difficult to find a good strategy to carry out this process because many factors are affecting it. Using the results, it is necessary to conduct further research, which will give indications to use the deammonification process for mainstream wastewater and will let to achieve good results.