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...