11 WASTE WATER TREATING EQUIPMENT-NAMELY, FILTERING EQUIPMENT, FLOTATION SYSTEMS, PRECIPITATORS, ABSORBERS, ADSORBERS, CISTERNS, SEDIMENTATION TANKS, DEHYDRATORS; DEODORIZING EQUIPMENT-NAMELY, CATALYTIC FURNACES AND ACTIVATED CARBON FURNACES, SCRUBBERS AND DRY TYPE CATALYTIC DESULPHURIZING AND DENITRATING APPARATUS, AND INDUSTRIAL AND RESIDENTIAL INCINERATORS