Wastewater Treatment Application

[Tom Hill]

I am looking for information regarding the treatment of H2S or other undesirable dissolved gases which are entrained in a yet to be constructed 6 mile long wastewater pipeline. Due to the up and down elevation profile, there will likely be combination air and vacuum valves installed at 8 relative high points to prevent column separation or vapor lock. Can the exhaust gases from these air & vacuum valves be processed through some type of ozonator, without having to process the entire pipelines fluid stream? If so, what is the flow coefficient, K-factor or other quantitative resistance inherent in the ozonator that relates the pressure drop to the flowrate going through the ozonator. The pipelines air & vacuum valves are likely to be sized at 3" for air ingress and 1" for air exhaust with a smaller size orifice for passing the exhaust air and entrained gases. Is this a feasable application for ozone processing?
Tom Hill, P.E.

[jimcox]

Years ago prior to my employment, the sulfuric acid destroyed a force main. We have since added a 'highpoint' with air release. We are currently using charcoal for air treatment at a single highpoint. We are also involved in a study using ferrous chloride for odor control at a lift-station upstream, which is claimed to increase the life of the charcoal.

[ELVISKY]

I am looking for information regarding the treatment of H2S or other undesirable dissolved gases which are entrained in a yet to be constructed 6 mile long wastewater pipeline. Due to the up and down elevation profile, there will likely be combination air and vacuum valves installed at 8 relative high points to prevent column separation or vapor lock. Can the exhaust gases from these air & vacuum valves be processed through some type of ozonator, without having to process the entire pipelines fluid stream? If so, what is the flow coefficient, K-factor or other quantitative resistance inherent in the ozonator that relates the pressure drop to the flowrate going through the ozonator. The pipelines air & vacuum valves are likely to be sized at 3" for air ingress and 1" for air exhaust with a smaller size orifice for passing the exhaust air and entrained gases. Is this a feasable application for ozone processing?
Tom Hill, P.E.

TOM-I ASSUME YOU MEAN TO PASS THE GASSES FROM THE A & V VALVES THRU AN OZONE DESTRUCTOR. There should be no ozone in these gas streams but you didn't list the waste stream strength. There have been some good articles written on pure oxygen injection forodor control which may give you insight. Hope this is of some help. I know there is a limited amount of info on
the use of ozone for wastewater disinfection.

[mackay]

I think an alcaline wet scrubber would work for this aplication. The purged gas doesn't go through an ozonator, but rather through a packed tower with circulating water with dissolved NaOH. The hydrogen sulfide is absorbed by the caustic solution. Ozone can be applied in the basin of the tower to preserve the capacity of the solution to absorb H2S.