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FW: Heavy metals in activated sludge

See comment by TVA researcher below.

Steve Hillenbrand
Industrial Waste Reduction Engineer
Synterprise Group, Division of Tennessee Valley Authority
(423) 632-8489; (423) 632-3616 (fax)
TVA IWR HomePage  www.tva.gov/orgs/iwr/iwrhome.htm

> Once metals are in sludge you can chemically stabilize them by lime
> treatment. However, the resulting product would be unsuitable for
> plant production without dilution because of the high pH.  After
> dilution and soil incorporation, there would still be the possibility
> of the metals becoming available for plant uptake.  
> The best solution is to keep the metals out of the sludge and failing
> that to base application rates on acceptable levels of metals (either
> with or without any chemical stabilization).
> Richard Strickland, TVA
> ----------
> From: 	Joe Pringle[SMTP:joepringle@compuserve.com]
> Sent: 	Wednesday, March 11, 1998 3:01 PM
> Cc: 	Sangeetha
> Subject: 	Heavy metals in activated sludge
> Question from Exnora International in India:
> We have taken up composting of vegetable wastes from the Koyambe-
> du  market  in  Madras, Asias's largest  vegetable  market.   The 
> Chennai  Metro  Water  Supply and Sewerage Board  has  agreed  to 
> compost  the waste by using the activated sludge from the  sewage  
> treatment  plant in Koyambedu. But one important issue  would  be 
> `How  do  you remove heavy metals in the sludge?'  We  have  been 
> writing to several people enquiring about this. Any ideas?
> please CC any responses to Exnora International at: 
> exnora@giasmd01.vsnl.net.in   
> or   exnorain@md2.vsnl.net.in