how to estimate H2S emissions from wastewater treatment plants.

[Socrate]

Is there a formulae for estimating the released H2S from wastewater treatment plant based on BOD/COD.
I've 1000 m3/d plant at 500 mg/L BOD using MBR technology for treatment and would like to estimate the released H2S at 12 air changes per hour to give to odor control unit designer/ supplier.

appreciate your valued responses.
Socrate

 

[bimr]

No, there is not.

There should not be any hydrogen sulfide emissions from the typical wastewater treatment plant.

Hydrogen sulfide emissions are typically associated with sewerage collection and lift stations. The amount of emissions is highly variable depending on the sewage, length of sewers, climate, time of day, etc.. The best estimate would be from an actual sample.

You may estimate also from an EPA report:

EPA Report

 

[ashtree]

An MBR might have an anaerobic zone for sludge stabilisation and to foster P removal. If this is not properly mixed and sludge was allowed to settle and "ferment" it might allow the formation of H2S which would be released into the air. However this is difficult to calculate and would be best to sample from the plant itself under real operating conditions. There are too many variables.

Many MBR plants do not have an anaerobic zone and even if they do may not be operated in the way i describe above.

In allowing for the 12 air changes and hour does this include the air coming from the MBR aerations system or only from some form of forced ventilation.


Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[Socrate]

Thanks Ashtree
Thanks bimr

I think there must be some (at least rough estimation), otherwise how designers could primary size deodorization units for a new wastewater treatment plant.
bimr is right that most of the H2S is coming from the head works, but the question is how much is. it 10 ppm or 100 ppm? in my opinion (but needs verification) it may largely depend on the amount of sulfur in in-fluent and the BOD removal efficiency?

thanks

 

[bimr]

I researched this topic and recommend you review the attached paper. Table 11 has asaumed hydrogen sulfide concentrations.

WWTP EIS

VOC Emissions WWTP

 

[Socrate]

Thanks bimr
This is very useful

I've seen the figure 100 ppmV couple of times, but couldn't figure how they reach it.
in your document, however, it assumes that maximum total sulfide is < 0.5 mg/L in influent. (this agrees with my estimation above), now the question is
can we say that approx. 0.5 mg/L total sulphide would result in approx. 100 ppmV emissions?!!

 

[bimr]

Believe that it what the report is stating.