Hello Benedek

As you no my starting point today is Switzerland and I guess we have several references that fits your question. For the small community plant what we have build as compact treatment is based on the following Process Technologies:

SBR, MBBR (and IFAS), MBR and now also Aerobic Granules.

So you see already quite a few solutions, which solution to choose where again will be depending on in fluent water quality and the effluent demand.

Thanks for that, Kim - very-very useful. It is easy to guess from your answer which process solution to pick as a function of the project boundary sets and design criteria; any less obvious engineering problems?

Regarding the solutions, would you be happy to share some of the attributes of such compact WWTPs and info on the communities they serve?; perhaps, only the most interesting cases?

Compact systems encourage compact implementations, resulting in problems with maintenance and upgrading. Specifics are MBRs fitted in garage-style buildings.

Benedikt

I am out office for a couple of days when I am back I will share some  cases with you

My work was mainly in rural Africa. But you could look at the systems designed by Ken Stedman.

https://hydro-int.com/en/products/hydro-microscreen-0