Anoxic transformations of wastewater in sewer networks

摘要

Anoxic processes can effectively control odour and corrosion in sewer networks. However, the absence of fundamental knowledge on anoxic transformation in sewer limits the engineering application for control measures in sewers. This paper focuses on a basic understanding of anoxic transformations in sewers in terms of process kinetics. A bench scale experimental setup was applied to study the fate of nitrate in both bulk water and biofilm. Experiments conducted show that nitrite builds up. The nitrate reduction in biofilm can be defined as a two-stage reaction. The denitrification rate in the bulk water was determined to 2.1 g N (m~3 h)~(-1). The specific denitrification surface rate in sewer biofilms was found to be 0.15 g N (m~2h)~(-1).