METHOD OF PRODUCTION OF ORGANOMINERAL FERTILIZER FROM WASTE WATER SEDIMENTS Russian patent published in 1999 - IPC

FIELD: ecology; utilization of waste water sediments formed at municipal aeration stations. SUBSTANCE: method consists in treatment of sediments with acid washing solution, neutralizing with alkaline reagent; waste water sediments are first dried, ground and are subjected to magnetic separation; nonmagnetic fraction is subjected to treatment with acid washing solution by counter-flow; sediment is washed with water; washing water is used for preparation of acid washing solution; used acid washing solution is alkalified by any known method and at pH equal to 1.5 to 1.8, sediment of humates of heavy metals which is treated with ammonia solution to pH equal to 10.5 to 11.0; ammonia humate solution thus obtained is used for neutralization of waster water sediments after washing with water ; then fertilizer is dried and heavy metals are separated from used acid washing solution; regenerated solution is used for treatment of sediments. Acid washing solution is mixture of four parts of sulfuric acid at pH equal to 0.0 to 0.25 and one part of sulfuric acid solution used for steel pickling. EFFECT: reduced consumption of acid for treatment of sediments at high degree of cleaning from ions of heavy metals; possibility of closed waste-free treatment of waste water and extraction of heavy metals together with regeneration of washing solution. 2 cl, 2 dwg, 5 tbl