Effects of conductivity in wastewater for the anaerobic ammonium oxidation (Anammox) process

The traditional biological processes for removal of ammonium contaminants from industrial wastewaters were based on nitrification and denitrification, but higher operating costs and a larger land demand were required for these processes. In order to solve these problems, the Anammox process was presented by Mulder in the 90s. But there are many restrictions for this process, such as nitrite concentration, conductivity and so on. In this study, the effect of conductivity for Anammox process was discussed. The biological activity of the Anammox like bacteria in different conductivity was measured and the result shows that the highest biological activity was obtained in 1000 μS/cm and the biological activity decreased with increasing the conductivity. In order to confirm the effect of conductivity for ammonia removal rate in Anammox process operation, a series of continuous experiments were performed. The results show the highest ammonia removal and growth rate of the Anammox like sludge was obtained in 1250 μS/cm and it was reduced very significantly in growth rate when the conductivity was higher than 2500 μS/cm. In summary, the conductivity in wastewater is an important factor for the operation of the Anammox process.