Nitrification Enhancement through pH Control with Rotating Biological Contractors

摘要

The need to achieve compliance with ammonia-nitrogen discharge limitations and the current emphasis on energy conservation have resulted in the utilization of RBC (Rotating Biological Contractors) technology for the nitrification of secondary wastewater effluents. The objectives of this research were to: Establish the relative rates of nitrification for domestic wastewater treatment within an acclimated RBC fixed film system as a function of pH. Observe and characterize the relative changes in the RBC biofilm as a function of pH. Evaluate the efficacy of chemical addition to improve nitrification within an RBC fixed film system through the maintenance of an optimum pH. Evaluate alternative alkaline chemicals for pH controlled nitrification for the RBC. Develop design criteria, as appropriate, for pH controlled nitrification for the RBC. This research examined the short and long-term effect of pH upon the nitrification of wastewater within RBC fixed film systems. In the long-term, the rate of nitrification within an RBC fixed film system was dependent upon pH. The rate of nitrification increased with increasing pH up to a maximum at pH 8.5. Approximately five weeks of operation were required to clearly observe these differences. The response of a nitrifying RBC system to short-term changes in pH was relatively constant from pH 7.0 to pH 8.5, the adverse effect of pH becomes more pronounced.