Hi, I'm thinking of trying the Mordan?age process on my photographic prints (based on etch/bleach process), and I would like advice on how to dispose of the solution afterwards. It'll be made up of 10g copper (II) chloride, 50ml glacial acetic acid, 105ml 12% hydrogen peroxide, made up to 1 litre with de-ionised water. Would I need to add something to it to make it less harmful, or is there a dilution value with water that would make it safe to go down the drain. (I'm in UK if it makes any difference) Thanks