No registration, no passwords; no pop-up ads -- just aloha, fun, & authoritative answers.
As an eBay Partner & Amazon Affiliate we receive compensation for qualifying purchases.
Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub  Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Selection of filter cloth for filter press for wastewater treatment sludge




Is there any literature available for the selection of cloth materials used in plate & frame filter presses? How can I determine the best fabric mesh size for an application?

Rick Alexander
engravers - Gaffney, South Carolina
1999


Vendors of the filter cloth may have a few selections, but the last time I replaced some, there was only one choice for the filtering of sludges from a metal finishing operation.

The particles tend to blind up the mesh rapidly, but if you have some bleed-through, you can add a few parts/million of polymer to help lower suspended solids after filtration.

tom pullizzi monitor   tom pullizi signature
Tom Pullizzi
Falls Township, Pennsylvania
1999




Multiple threads were merged: please forgive repetition, chronology errors, or disrespect towards other postings [they weren't on the same page] :-)



We have started running a filter press on our pH adjusted wastewater, containing mostly Ni. At pH about 10.5-11.0, we form a decent amount of precipitate, which sort of goes through the filter-press cloth instead of staying on it. Is there a particular cloth weight/density or whatever measure is commonly applied here, that works well on hydroxides, or would it be advisable to use a filter aid, flocculent or some other technique to prevent the breakthrough? Thanks

berl stein berl sig
"PlaterB" Berl Stein
NiCoForm, Inc.
supporting advertiser
Rochester, New York
nicoform
1996


I think you need to generate a larger particle size. The filter press cloth is probably quite coarse and most unflocculated metal hydroxides are pretty fine. You should be able to see the flocs form as the flocculating agent mixes in. Just don't overdose as it will turn the sludge into a slimy mess. Almost any industrial chemical supplier can provide the flocculating agent, probably an anionic agent will work best. Do a jar test first (waste sample in beaker [adv: beakers on eBay or Amazon], very small amount of agent added per manufacturer's dosing rates, mix and voila! flocculated sludge). Jar tests are good for evaluating different types/manufacturers. You may even get enough in the samples to do the whole job!  

bill vins
Bill Vins
microwave & cable assemblies - Mesa (what a place-a), Arizona
1996



1996

In regards to the nickel hydroxide precipitate, I would definitely use a filter aid such as diatomaceous earth to precoat the cloth. This should prevent leak through of the precipitate.

Rocky C. Costello, P.E.


(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"