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-----Etching effluent regeneration
we deal with a large amounts of chemical waste in anodizing plant. combination of both acidic and alkaline waste make a difficulty in the waste treatment plant.
In etching bath could you please suggest an economical technique to regenerate caustic soda ⇦liquid caustic soda in bulk on
Amazon [affil link]
and eliminate it from waste effluent.
environmental engineer - Cairo, Egypt
December 3, 2009
December 7, 2009
Dina
If you are using a commercial etch, it is likely to contain sodium gluconate which helps keep the aluminum from dropping out in solution. If you dump one of these baths to your waste treatment, you could expect difficulties in precipitating other metals.
Most anodizing shops I am familiar with have an acidic waste stream. You could try making your own etch, omitting the gluconate, and making frequent decants and using the decant for other neutralizations in your waste treatment.
There are ion exchange units available that should work, although it may not be economically viable.
- Colorado Springs, Colorado
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