Printech Archive, February, 1998
Re: Treatment of Wastewater for Reuse; Flexo Printer


New Message Reply About this list Date view Thread view Subject view Author view

From: Wayne Pferdehirt (pferdehi@epd.engr.wisc.edu)
Date: Thu Feb 05 1998 - 07:02:55 CST


Start with the water handling system. Look for dead legs where sludge
can collect. These areas will breed bacteria. For the entire
process, think sanitary. Can you hard pipe to holding tanks ? Shops
that use the floor drains to convey wastewater will never maintain
sanitary conditions.

What about worker habits ? Do they smoke or eat in the shop ? Do
they spit into open trenches ? Eliminate these sources of
contamination and you will be able to bring bio growth under control.

In terms of treatment, a small UV/ozone system should help. Biocides
may be used but there may be restrictions if the paper can come in
contact with food. UV/ozone is nice because it does not generate
chlorinated by-products. Its downside is that there is little
long-term protection provided to the treated wastewater. That's why
maintaining sanitary conditions is important.


>
> Would appreciate any suggestions that might help a flexographic
> printer that UW is assisting decrease wastewater:
>
> BACKGROUND:
> The company is a flexographic printer, manufacturing primarily
> printed kraft paper bags (grocery sacks, take-out bags, etc.) All
> inks used are water-based. The company is not connected to a
> municipal sewer system. Only sanitary wastes are discharged to the
> on-site septic system; other wastewater must be trucked to a municipal
> wastewater treatment plant, at considerable expense.
>
> There is considerable wastewater from cleanup of the paste makeup and
> cooking operations, and from ink cleanup. Presently, wastewater is
> pretreated through precipitation and vacuum drum to remove solids, and
> effluent is trucked to wastewater treatment plant.
>
> THE CHALLENGE:
> The company would like to increase its reuse of wastewater. They
> tried in the past, but said that remaining bacteria in the wastewater
> caused problems with paste makeup. Said the bacteria caused the paste
> to break down and lose strength.
>
> Any experience and suggestions from P2Tech users that might help
> identify improvements that would help company to successfully treat
> wastewater to enable reuse for paste makeup?
>
>


New Message Reply About this list Date view Thread view Subject view Author view
 
PNEAC
Disclaimer / Copyright Info
Email the PNEAC Webmaster