APPARATUS FOR NITRIFICATION, DENITRIFICATION AND/OR PHOSPHATE-ELIMINATION OF SEWAGE WATER, AND CLEARING BASINS THEREFOR; PACKED BEDS FOR WATER PURIFICATION, TOWER PACKINGS FOR AIR AND GAS PURIFICATION, SPRAYING NOZZLES, BIOLOGICAL FILTERS AND REACTORS FOR GAS AND AIR PURIFICATION, GAS SCRUBBERS, AIRSCOOPS, AERATION DISKS, AERATION TANKS, AERATION PIPES, IMMERSION PERCOLATING FILTER FOR WATER PURIFICATION, MIST COLLECTORS, FILLER AND SPACING MATERIALS FOR DISTRIBUTION OF GASES AND LIQUIDS, BED...