Dear Mr. Pawan, 
I just draw a simple module for the FSTP of Mr. Mayor if he has the interest than we can work for the detail design of it, I will provide the details information when I get the survey data from Mr. Mayor,.

Thank you sir, 

Dear Fahim
The sequence of technologies shown appears to be good. What is HRT in AF and PGF and what is the expected values of different parameters of final effluent. 
Thanks
Pawan

Dear Mr. Mayor, 

I have reed your post and the replies according to that i draw a simple module for the FSTP which you design, kindly see the attachedment and let me know to help you more in this case if you want,.


Thank you

Hi ! Elisabeth,

Thanks for taking interest in FSTP design.
As regards your queries, the Master Plan does not specify provision of Facultative Primary Lagoon. Secondly the source of faecal sludge is Septic Tanks which in reality are Leaching Pits----bottomless one compartment u/g structures with no baffles.

With regards,

Mayor Kumar

Dear all,
 
As regards the design of Faecal Sludge Treatment Plant that we have proposed here, has following treatment
process Flow Diagram:-
 
Drying Beds >>> Settler>>>Anaerobic Filter>>>PlantedGravel Filter>>>Polishing Ponds 
 
Bio solids retained on top of the SDB would be drawn and kept in the Storage for using as soil conditioning agent.
 
Somehow our client is convinced that existing system already installed in the other District having following
treatment process  should be adopted:-
 
Facultative [Primary ]Lagoon>>>Aerobic lagoon>>>Storage of treated effluent.
 
I am not at all comfortable having  an aerobic lagoon installed with an electro-mechanical aerating
equipment. Could you please throw light on necessity of using aerobic lagoon for faecal sludge treatment.
 
Secondly to bring down the concentration of Helminth eggs in the treated effluent, is it must to include a
disinfection agent like Liquid Chlorine . Idea is to recycle this  treated
effluent for flushing and irrigation purpose.
 
Is my approach correct?
 
Regards,
 
Mayor Kumar 
Water Supply & SanitationSpecialist
Project Team Leader
DED Consultants
 

Hi Mayor,
Thank you for sharing your experiences with the design of a typical faecal sludge treatment plant. Did the said master plan stipulate facultative primary lagoon for the supernatant after dewatering or for the faecal sludge itself? A lagoon before dewatering would seem a bit strange to me unless the faecal sludge is very watery? Where is the faecal sludge from; is it from septic tanks?

Please clarify your question and then I hope more people will be able to comment and assist in this thread.

And did you see this interesting report by EAWAG?: 
Evaluation of Faecal Sludge Treatment Plants in South-Asia and sub-Saharan Africa: Scoping Study Report
I haven't read it in detail yet. Did any of the FSTPs that were analysed in this report use aerobic lagoons?

(for anyone unfamiliar with those lagoons, I recommend this Wikipedia article for a quick little overview:  en.wikipedia.org/wiki/Waste_stabilization_pond )

Regards,
Elisabeth

 Dear all,

We as detailed Engineering Design consultants are involved in designing FSTP in East Asian tropical country where the client has got distracted by the earlier design given in the Master plan which advocates the use of facultative primary lagoon followed by aerobic lagoon for the treatment of faecal sludge.

While as learnt from my Indian experience where the climate is similar with the only difference that in this part of the world, the rainy season is longer i.e. up to 05 months in a year. there are a number of FSTP which are working satisfactorily using
[1] screening & grit chamber,
[2]Stabilisation reactor( for anaerobic digestion of sludge),
[3]Sludge Drying Beds [ for dewatering the sludge) ,
[4] Integrated Anaerobic baffle reactor with filter chambers( for secondary treatment) ,
[5] Planted Gravel Filter & Activated carbon filter ( Tertiary treatment ),
[6] UV radiation( for killing of pathogens and Helminth eggs) and lastly
[7] Co-composting Unit /Sludge pasteurization Unit.

With some  small variation here in there , a number of FSTPS have come up in India and are  working satisfactorily and generating bio solids which can be used as soil conditioner and treated effluent which is being used for irrigation purpose.

Please share your experience in case you have used aerobic lagoon .
With regards,

Mayor Kumar
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