Treatment of materials, namely, treatment of waste water, water, gasses and airstreams by means of filters, filtering units and activated carbon; treatment of materials, namely, decolouration being treatment of water, filtration and purification of waste water, water, gasses and airstreams, and also the absorption of impurities from waste water, water, gasses and airstreams; rental of installations and apparatuses for the treatment of waste water, water, gasses and airstreams, namely, install...