This manual presents theoretical and process design criteria for the implementation of nitrogen control technology in municipal wastewater treatment facilities. Design concepts are emphasized through examination of data from full-scale and pilot installations. Design data are included on biological nitrification and denitrification, breakpoint chlorination, ion exchange, and air stripping. One chapter presents the concepts involved in assembling various unit processes into rational treatment trains and presents actual case examples of specific treatment systems that incorporate nitrogen control processes. (Author/BB)