SUMMARY (Cont) SOLUTION
Conventional Sewage treatment processes significantly reduce the amount of pathogens and BOD in sewage, but do not eliminate them completely. Certain virus, in particular, may be somewhat resistant to the sewage disinfection processes. (A virus is an extremely small pathogenic organism that can only be seen with electron microscopes). To decrease the amount of Nitrogen and Phosphorus in sewage, usually some form of advanced sewage treatment must be applied.