Does anyone have information regarding the treatment of copper sulphate plating solutions for organic contamination. We do this approximately once a year on all solutions and have been using the following method:- 0.5-1.5gm/litre of Potassium Permanganate depending on level of organics Agitate for 2 hours 0.5 ml/litre of 35% Hydrogen Peroxide Agitate for 1 hour Heat to 60 C (140F) Add 2gm/litre of activated carbon Continue with heat and agitation for 2 hours Allow to settle and filter pump to storage tank as soon as possible to prevent organics leaching back into solution from carbon. Conversion factors ( g/l x 0.134 = 0z/US gal) & (1 litre = 0.264 US Gals) This method is very effective at removing the organics but I would like to know more about how this works. My concern is the level of Manganese left in the solution after treatment. We recently tried using peroxide only and carbon but this did not reduce the organics sufficiently. We are told there is a finite number of times where permanganate can be used before the bath has to be replaced. Is this method likely to cause a build up of manganese and is there any alternative? Many thanks for any information Paul Gould Teknacron Circuits Ltd