Small scale waste water treatment plant design needed.

[varma]

I am working for firm which constructs sewage treatment plants in
India ( Govt. funded ).
Now we would like to design a very small STP for about 20 households
( say an apartment ).
Please educate me on this. Any information on this is appreciated.

Thanking you,
Varma.

[none]

Dear Varma,

What are your constraints?

Land area? Energy supplies? Required effluent treatment? Cost?
Maintenance requirements?

Your choices would certainly run to the following:

* Septic tank
* Reed bed
* RBCs
* Package activated sludge
* Extended aeration is common
* SBRs and membrane bioreactors have also been seen

Roughly speaking, effluent quality gets better as you go down the list;
but so too do costs and complexity.

For activated sludge systems you could look at either the ATV or BS/ISO
standards.

www.ciria.co.uk/acatalog/pr72.pdf
http://www.epa.gov/owm/mtb/package_plant.pdf
http://www.standardsdirect.org/standards/standards4/StandardsCatalogue24_view_5158.html
http://products.ihs.com/cis/Doc.aspx?AuthCode=&DocNum=252510
http://www.dwa.de/dwa/shop/shop_english.nsf/Produktanzeige?openform&produktid=P-CBUR-7DDGMT&navindex=110201
http://www.dwa.de/dwa/shop/shop_english.nsf/Produktliste?openform&sprache=English&kategorie=2&navindex=110200

For reed beds try

http://www.cat.org.uk/information/catinfo.tmpl?command=search&db=catinfo.db&eqSKUdatarq=InfoSheet_SmallScaleSewage
http://www.reedbeduk.co.uk/info.htm

should give you a starting point. You may need to join-up some of these
links: I imagaine that they will be broken up in most newsreaders.

After you have done outline design (making sure that the thing is big
enough to do the job) then you will n eed to move on to detail design
(making sure it is strong enough to last, and well-enmgineered enough to
ensure that it doesn't leak & that flows can get where they want.)

For detail design you should ensure that you have appropriate mechanical &
civil engineers.

Regards,

Jeremy