Water and Wastewater.com Help Forums

Sheepdog

YaBB Newbies

Offline

I love Water and
Wastewater.com

Posts: 6

Company or Organization: Spectrm Plating Company

Cyanide testing
May 30^th, 2012, 5:05am

I work for a somewhat small electronic plating company as their wastewater treatment tech...
I have had many a discussion with our lab manager, but we can't seem to come to a conclussive agreemnt in regards to what we need to use to consistently check for cyanide.
The current test we use is a visual color check post reagent addition, but because of the quality of the water pre-treatment and on occasion post-treatment, it is hard to determine the color change, if any, to indicate cyanide presence. Which then becomes more of a problem. The kit came with a color wheel, but neither of us know how to use it properly as she lost any form of instruction well before my employment here.
We were given another test as a sample, but it is not exactly consistent as I have had it, a few times now, show me no cyanide pretreatment, but significant cyanide (0.4+) post treatment.

Are there any recommendations out there for accurate and consistent cyanide tests we can consider?
Thank you.

Back to top

IP Logged

H2O_Tech Junior Member Offline Water and Wastewater.com is the best! Posts: 86	Re: Cyanide testing Reply #1 - May 30^th, 2012, 10:20am Sheepdog, drop me an e-mail with the test kit info that you use (brand, model, range...anything you can tell me). Hach has what sounds like a similar kit (Model CYN-3). rsedlace@hach.com Don't know if I can help, but I'll give it a shot. Cynanide is/can be tricky to analyze. Roger
Back to top	IP Logged

BWater

YaBB Newbies

Offline

Life is Good!

Posts: 16

Company or Organization: Town Water and Sewer Dept

Re: Cyanide testing
Reply #2 - May 31^st, 2012, 10:15am

You would probably be better off with a spectrophotometer. I'm not sure, but they make a "kit" type one for cyanide. Using a color wheel is often very subjective at low concentrations and won't give you the ability to color-correct for background color if that is an issue for you. Are you testing for total cyanide or free cyanide? I am accustomed to performing a distillation with colorimetric analysis. SM 9010 and 9014, I believe. This is time and space intensive, but produces good results. What is your treatment process? Are you using chlorine?

Back to top

IP Logged

Sheepdog

YaBB Newbies

Offline

I love Water and
Wastewater.com

Posts: 6

Company or Organization: Spectrm Plating Company

Re: Cyanide testing
Reply #3 - May 31^st, 2012, 10:57am

We treat for free cyanide.
Our waste batches, are a large mixture of our dragouts, old baths, and etc.
Our cyanide destruction procedure is:
Raise pH to 11-12 via Caustic, not ORP
Add NaOCl to bring ORP to +200 - +300, allow 45min for mix
Decrease pH to ~7 via Sulfuric, ensure ORP to remain positive
Test for cyanide, present = repeat, not present = continue to metal treatment

I have been making inquiries around here in regards to a spectrophotometer, though I would not know where to begin in regards to their quality and what company(ies) to go with

Back to top

IP Logged

BWater

YaBB Newbies

Offline

Life is Good!

Posts: 16

Company or Organization: Town Water and Sewer Dept

Re: Cyanide testing
Reply #4 - Jun 1^st, 2012, 1:30pm

Then you don't have to worry about distillation apparatus. Maybe something like the DR 2700™ Portable Spectrophotometer from Hach would suit your needs. I've never used it, but it was along the lines I was thinking of if you don't require a full-scale spec for multiple applications. I would keep asking around and talk to them about it, I've had good luck talking to their technical team in the past.

Back to top

IP Logged

Sheepdog YaBB Newbies Offline I love Water and Wastewater.com Posts: 6 Company or Organization: Spectrm Plating Company	Re: Cyanide testing Reply #5 - Jun 8^th, 2012, 10:13am Thank you greatly I have been looking into the DR850, for its portability
Back to top	IP Logged

boffin YaBB Newbies Offline Posts: 15 Warrnambool Gender: Company or Organization: Water Treatment	Re: Cyanide testing Reply #6 - Jul 12^th, 2012, 7:56pm if you can spend a little bit more get the DR890 is has way more tests and you will find it a better investment in the long run. I have one and i have tried many other brands and none of them compare to the HACH.
Back to top	Give a man a fish and he will eat for a day. Teach a man to fish and he will sit in a boat and drink beer for the rest of his life. IP Logged

Dedalus Full Member Offline Science is a business of empiricism. Posts: 238 NY Gender: Company or Organization: Dedalus Environmental	Re: Cyanide testing Reply #7 - Jul 16^th, 2012, 10:18am You have to do the distillation regardless of whether you use complex cyanides in your process - if your permit regulates total cyanide. Traces of iron, nickel, etc. have a way of getting into the cyanide baths, and you're not going to chlorinate either away, not easily.
Back to top	IP Logged