Treatment of waste effluents from processing has become an important issue in good laboratory practice. There is a wide variety of waste treatment systems. As a result the treatment of used chemistry differs from that for chromogenic colour negative processing. Waste volumes differ between laboratories and local legislation is changing fast.
Many authorities prohibit disposal of used chemistry to the sewer.
It is usually unacceptable for economic and environmental reasons to dispose of used tank solutions as waste water. This has led to many developments aimed at minimising waste . Tank solutions now use lower concentrations of chemistry and lower replenishment rates. Fixer desilvering which used to be justified solely on the value of the silver collected now also has the additional justification of lowering the levels of silver in waste to avoid punitive pollution charges and fines. Other processing solutions can easily be collected, neutralised and treated by a specialised contractor.