ORGANIC WASTE WATER SEDIMENT TREATMENT PROCESS Russian patent published in 2003 - IPC

FIELD: waste water treatment. SUBSTANCE: crude organic sediment is mixed with excess activated sludge at ratio between 1:1 and 1:3. resulting mix is subjected to multiple cavitation treatment for 9-12 h, number of cavitation cycles being 3 to 10 and cavitation number 0.01 to 0.05, accompanied by aerobic stabilization and ejection aeration. To above-named mix, 1/3 volume of over-sludge water is added, the total is compacted, and lower compacted part constituting 1/3 volume of treated mix is discharged. Product can be used as organomineral fertilizer owing to transfer of biogenic substances from sludge water into solid phase of treated mix, whereas heavy metal salts are brought into safe natural state without use of additional reagents. Fertilizer is appropriate for enrichment of depleted soils and land reclamation. EFFECT: enhanced economical efficiency of process. 2 tbl, 3 ex