BIOLOGICAL NUTRIENT REMOVAL: MERGING ENGINEERING INNOVATION AND SCIENCE

Engineering innovations have led to new process configurations and designs for biological phosphorus and nitrogen removal. Comprehensive process models have been developed and applied to quantify and predict process performance. Engineering efforts have been responsible for the integration the processes into wastewater plant facility design, and to determine necessary site-specific information needed to carry out process designs. On the science side, valuable information has been gained about the microbial ecology in biological nutrient removal processes and the biochemical mechanisms involved. Specific microbial populations have been identified that are responsible for key biological reactions in BNR or BPR systems. Perhaps even more important has been the development of molecular biology tools that are now used to identify or characterize bacteria, and to follow specific populations in mixed microbial systems such as activated sludge or biofilm processes. This paper reviews significant process designs developed in the area of biological nutrient removal, identifys key fundamental issues related to the processes, and illustrates how scientific results have aided engineering applications and process modifications to further advance the capabilities of biological nutrient removal processes.