Substances which no longer perform satisfactorily (e.g. contaminated acid, contaminated solvents, exhausted tempering salts, etc.)

Tens of thousands of tons of feed containing the contaminated acids were then delivered to poultry farms in several German states, with a heavy concentration in Lower Saxony.

Adsorption tests were also successfully completed with three types of heavily contaminated acid effluents: a multi-element synthetic solution and effluents produced during sewage sludge and soil decontamination.