To Prof. Karki & Gautam

In the Guidebook on biogas development (ESCAP, 1980), in calculating the number of persons needed to provide human sewage to a digester, the following data (probably Chinese) is used :
1 adult can provide 200 gm (200 ml) night soil
800 ml urine and
1000 ml of flush water.
i.e. 2 litres per person of influent into the digester.

In your calculations used for your paper, you have an average of 285 visitors per day to the community latrine and based on 400 gm of faeces per person.

Q: is 400 gm an estimate or an experimental average ?
Q: what is the total estimated influent volume per day into the digester ? (i.e. including flush water, etc)

Comment:
I would suspect that a community-latrine as described in your paper would have more users to the urinals.
Q: was a survey conducted to find out how many visitors use the urinal or toilet ?

In Diagram 4, the flow chart from the biodigester indicates the use of the biogas and the sludge. There is no indication for the flow of the liquid portion of the digested slurry.

Q: what is the fate of this liquid  ?

regards
jacky foo
Unesco Microbial Reosurces Center
Dept of Biotechnology, Royal Inst of Technology, Stockholm