IN THE EUROPEAN COMMUNITY, THE IMPLEMENTATION OF DIRECTIVE 91/271/EEC CONCERNING URBAN WASTE WATER TREATMENT HAS LED TO AN INCREASE IN THE QUANTITIES OF SEWAGE SLUDGE FROM WASTE WATER. ACCORDING TO THE LATEST AVAILABLE HARP DATA, SOME 800,000 TONNES OF SLUDGE WERE PRODUCED IN LOMBARDY IN 2017, OF WHICH 500,000 TONNES WERE PRODUCED FROM URBAN WASTE WATER. THESE ARE LARGE QUANTITIES THAT NEED TO BE DISPOSED OF AND/OR REUSED. THE PROBLEM OF SLUDGE TREATMENT AND DISPOSAL HAS BECOME INCREASINGLY IMPORTANT IN RECENT YEARS OF A SUSTAINABLE VISION OF THE MANAGEMENT AND TREATMENT OF WATER, AIR AND WASTE (PURIFICATION SLUDGE). CURRENTLY, THE MOST WIDELY USED SYSTEM FOR DISPOSAL Ê SPREADING ON AGRICULTURAL LAND CONSIDERING THEIR CONTENT OF ORGANIC SUBSTANCES AND MINERALS SUCH AS NITROGEN, PHOSPHORUS AND POTASSIUM. AGRONOMIC REUSE IS A GOOD SOLUTION TO THE PROBLEM OF DISPOSAL AND IS INTERESTING FOR