There are many products that ...

There are many products that counter the smell. The anaerobic conditions can be mitigated with a few of the comments below. Jean Marius is the highest qualified person in the European theatre using microbial odor and pathogenic control.  The one system I am already familiar with is the biogenerator/biodigester. Eros Kaw has vast knowledge in this area.  I work all biodegrading problems using the microbial species called Archaea. It reduces all of the compounds into their elemental form. This way it will eliminate the odor the first hour it enters the oxygenating tank. No pathogens and no toxic materials. Just clean mineralized water to do with as you wish.