How does one neutralize methane in a lift station?

Answer 1

It all depends on what you mean by neutralize. Methane is a gas given off when organic material decays with little of no oxygen present. It is an odorless flamable gas. Usually there are other gases formed at the same time (such as hydrogen sulfide) that has a bad smell. There is not much that can be done about it except vent it to the atomosphere to prevent explosions. In large treatment plants, it is collected and burned as a fuel but this is not practical in a lift station.

Anaerobic decay can be stopped by adding an oxidident such as chlorine. This kills the bacteria and stops decay until the chlorine combines into stable compounds. Then the decay will resume.

One way to prevent or minimize methane in the design process, is to dispatch the wastewater as quickly as possible. The longer it sits, in the tank, the more the decay and the more methane is produced. This can be accomplished by pumping more often. States usually regulate the storage and pumping requirements which may interfere with a good solution. They are less concerned with odor than they are making the station big enough to handle large periodic loads... which may increase the time the wastwater sits during times of low flows.

One simple improvement might be to pump the tank down at night (when the flow drops off) whether it has reached the "pumps on " level or not.. so it doesn't sit all night while the population is sleeping.