Re: [SEW] Photo Processing (COD)

[dlr@mindspring.com]

Will:
    The wastes from the silver recovery unit are usually precipitated with
Sulfide or Chloride.  Check those levels and then re-run your COD for
interferences, and then drop me a note off list.  In answer to your
questions, yes, those levels are not unusual depending upon the recovery
system.  In the photoprocessing unit, there is often a variety of organics
and sulfides, sulfates, and some nitrates.  Generally they won't bother your
process, but the silver might.  It might be a good idea to check on the
silver levels as well.
Dave Russell

----- Original Message -----
From: Will Howard <Will_Howard@p2pays.org>
To: <sewer-list@lists.cc.utexas.edu>; <p2tech@great-lakes.net>
Sent: Thursday, July 08, 1999 9:30 AM
Subject: [SEW] Photo Processing (COD)


> Recently we received a call from a local POTW, requesting
> data/information on photo processing effluent.  Sampling showed high
levels
> of cod (40,000mg/l) being discharged from the silver recovery unit.  POTW
is
> concerned about these high levels.  Vendor data shows typical COD
> concentrations of 200-2000mg/l - total effluent.  Has anyone conducted
> sampling or seen data with similar high numbers?  Suggestions are welcome.
> Thanks in advance
>
>
> Will Howard
>
> 919-715-6527
>