Stefan Trethan wrote:
>
> You can buy small commercial stations now that use ion exchangers for
> treatment of rinsing water.
>
Traditionally, people precipitate the copper in large tanks and after
the solids settle, it should be below about 5ppm and ready to dump. ion
exchanges are only required when precipitation fails , for example,
rinse waters containing chelators, which keep metal ions soluble.
Are you sure the discharge limit in Europe is 0.5mg ?, That level is
lower than what is considered safe to drink. Heck , some natural water
supplies are higher than 0.5mg.