Long Term Effects of Cadmium on Anammox Process


Uzunhasanoğlu A. E. , Kalkan Aktan Ç. , Bakırcı K. , Mertoğlu B.

2nd International Conference of Civil and Environmental Engineering (ICOCEE 2017), Nevşehir, Turkey, 8 - 10 May 2017

Abstract

The role and importance of the Anammox process in the nitrogen cycle has been recently discovered and it is no longer just a process applied in the laboratory but more than 100 full scale treatment plants were currently put into operation in the world. Our previous studies have shown that, variability in the inhibition levels are not only due to operating parameters, but also due to the different microbial species involved in the process. For example, the threshold value of inhibition in nitrification process is different if the dominant species is Nitrosomonas, but also another value if it is Nitrosospira. Therefore, all details of the Anammox process needs to be investigated and the sensitivity and resistance levels against the toxic species should be determined for the bacteria. In recent years, studies on the impact of toxic heavy metals frequently found industrial wastewaters on Anammox types began to take place in the literature. In these studies, levels of inhibition for the same heavy metal are very different from each other and this in turn can cause confusion over the operators of the treatment plant.In this study, lab-scale Anammox was operated using a continuous sequencing batch reactor (SBR) and the effect of Cd on Anammox activity was evaluated. This study showed that prolonged exposure to Cd at 0.2 mg/L levels did not have a significant effect on the nitrogen removal. The response of higher exposure levels will be presented at the full paper.
The role and importance of the Anammox process in the nitrogen cycle has been recently discovered and it is no longer just a process applied in the laboratory but more than 100 full scale treatment plants were currently put into operation in the world. Our previous studies have shown that, variability in the inhibition levels are not only due to operating parameters, but also due to the different microbial species involved in the process. For example, the threshold value of inhibition in nitrification process is different if the dominant species is Nitrosomonas, but also another value if it is Nitrosospira. Therefore, all details of the Anammox process needs to be investigated and the sensitivity and resistance levels against the toxic species should be determined for the bacteria. In recent years, studies on the impact of toxic heavy metals frequently found industrial wastewaters on Anammox types began to take place in the literature. In these studies, levels of inhibition for the same heavy metal are very different from each other and this in turn can cause confusion over the operators of the treatment plant.In this study, lab-scale Anammox was operated using a continuous sequencing batch reactor (SBR) and the effect of Cd on Anammox activity was evaluated. This study showed that prolonged exposure to Cd at 0.2 mg/L levels did not have a significant effect on the nitrogen removal. The response of higher exposure levels will be presented at the full paper.