-- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing.
    no popups, no spam
on this site
current topics
topic 2712

Turnkey system for cyanide removal from electroplating wastewater


RFQ: Dear everybody,

We are looking for a turnkey system for cyanide removal for electroplating wastewater. The initial cyanide concentration is about 100 mg/l and we want to get that down to less than 0.1 mg/l. Adding chlorine is not very effective for effluent with ferric and chromium ions. Would anybody know where I could find an effective system? Thank you for your help

Best Regards,

Ricky Chang
Hong Kong


A. 1. OZONE 2. ION EXCHANGE (especially if someone else does the regeneration)

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


A. Ricky,

If ferric and chromium ions exist in the wastewater, it is really hard to eliminate cyanide by oxidation process with chlorine, hypochlorite, even ozone. This is because the oxidation process should be carried out in basic solutions with pH>10.2, in which cyanide strongly tends to complex ferric and chromium ions. The complexed cyanide is hardly destroyed by regular oxidation processes.

Ion exchange technology is helpful to remove all the free cyanide and complexed cyanide ions in neutral wastewater. Of course the ion exchanger needs regularly regeneration and the discharged solution containing concentrated cyanides has to be destroyed using special process. It is very important to avoid ferric and chromium ion contamination of cyanide wastewater. Otherwise it is costly to treat it. Ling

Ling Hao
- Grand Rapids, Michigan


A. I run a plating company specializing in Chrome, Black Chrome, Nickel, Cadmium, Zinc, (Cyanide), Electroless Nickel, Copper (acid & cyanide), Gold, Silver. My cyanide consumption is approx. 200 kg per month and is mostly for Cadmium. Govt. regulation here demand very low levels of all contaminants.

I achieve low levels of all heavy metals by precipitation and plating out cells and cyanide destruction using electrolytic salt water chlorination.

Steve Baronas
- Perth, Western Australia


A. Re. cyanide residue, I suggest you might investigate the use of high intensity UV light to break down the cyanide as there probably would not be any interaction with the other heavy metals. Possibly you could concentrate the residue (without the cyanide)with a RO system and then evaporate to produce a solid, there may be a market for the dry residue hope these thoughts are of some use.

Geoff Casey
- Darwin, N.T. Australia

Readers: our advertisers make this site possible for technical information exchange & camaraderie; they will contact the inquirers privately regarding any commercial needs. Please appreciate that the site would drown in spam overnight if we posted offers to sell from people paying nothing.

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.