Thank you, Joe, for your enlightened response. I reckon, there will be then few cases of truly aerobic composting systems.

And, in case, anaerobic process creeps in, we can use adsorption, absorption or scrubbing, thermal oxidation and biological treatment for the removal of VOCs and other gases, in the emissions.

F H Mughal

Note by moderator: this post is the answer to a post by Elisabeth von Muench on 7 April (see on page 2 of this thread above):

+++++++++++

About URLs, unfortunately, most of them are copyright protected by the publishers, so they are not open access. The abstract can be consulted in the webpage of the journal, as I have indicated. One of them is open access (I have added the URL*).

About the Wikipedia sentence ( en.wikipedia.org/wiki/Composting_toilet#Components ):

a ventilation unit to ensure that the degradation process in the toilet is predominantly aerobic and to vent odorous gases, such as hydrogen sulfide and ammonia (some methane may also be present but is not odorous)

, it is right, but I would also add a family of not so well-known gases, which have some importance, being detected in any composting process:

N2O: a powerful GHG (298 times more impact per unit mass of CO2).
VOCs: a large family of organic volatile compounds which are just being identified, some of them with hazardous characteristics.

Regards,
Toni

* This one is open access:
Detection, Composition and Treatment of Volatile Organic Compounds from waste treatment plants. Font, X., Artola, A., Sánchez, A. Sensors. 11, 4, 4043-4059 (2011).
www.mdpi.com/1424-8220/11/4/4043

See also the book chapter that I mentioned here on "Greenhouse Gas from Organic Waste Composting: Emissions and Measurement":
forum.susana.org/forum/categories/70-com...nd-measurement#14585

Dear Toni,

I have now worded the information about odorous gases from composting toilets like this:

en.wikipedia.org/wiki/Composting_toilet#Odorous_gases

Odorous gases
The following gases might be emitted from the composting processes which take place in composting toilets: hydrogen sulfide (H2S), ammonia, nitrous oxide (N2O) and volatile organic compounds (VOCs).[4] These gases can potentially lead to odour nuisance. Some methane may also be present but it is not odorous.

Reference 4 is your publication from 2011 entitled "Detection, Composition and Treatment of Volatile Organic Compounds from Waste Treatment Plants" which could be used to back this up, right?

By the way, if you are an odor expert, could you provide some comments on this odor research project by Duke University?:
forum.susana.org/forum/categories/105-pr...colorado-boulder-usa

I would be curious to hear your thoughts about that project (in that other thread).

They also ran an odor survey, see here:
forum.susana.org/forum/categories/105-pr...iversities-in-the-us

Regards,
Elisabeth