ABSTRACT
This chapter deals with the aerobic and anoxic transformations as they occur in a sewer network. These transformations are relevant in both the water phase and in the biofilm. The aerobic heterotrophic microbial processes dealing with the transformations of wastewater organic matter are in focus. The aerobic and anoxic oxidation of sulfide and their relation to the formation of sulfide under anaerobic conditions in the biofilm are also discussed. The anoxic transformations involving nitrate and nitrite as electron acceptors are likewise covered in this chapter. In this respect, it is important to realize that anoxic conditions in a sewer mainly occur artificially when nitrate is added for odor and sulfide control purposes.
