Method to detoxify sewage sludge

Details Method to detoxify sewage sludge Method to detoxify sewage sludge

1990-10-31

1991-09-24

Hruskoci, Peter

Liquid purification or separation

Processes

Making an insoluble substance or accreting suspended...

210724, 210758, 210759, 210901, 210912, 210913, C02F 1114

Patent

active

050511912

ABSTRACT:
A method to detoxify municipal sewage sludge containing heavy metals comprises the steps of mixing sewage sludge, at least one catalytic oxidant such as a ferric salt, at least one regenerative oxidant and an acid to form a reacting slurry having a solids fraction and a liquid fraction and, after a suitable retention time, separating the solids fraction from the liquid fraction. The reacting slurry is maintained during its retention time at a pH range between approximately 1.0 to 2.0 and at an oxidation reduction potential of, at least, +400 milivolts. The heavy metals originally absorbed into the solids fraction of the sewage sludge solubilize into the liquid fraction of the reacting slurry. Thereafter, the reacting slurry is discharged into a conventional solids/liquid separating device so that the metal-laden liquid fraction becomes separated from the solids fraction which is now substantially bar ren of heavy metals. The solids fraction is neutralized to a pH prescribed by EPA regulations so that it can be safely applied to agricultural land as a detoxified fertilizer and soil conditioner.

REFERENCES:
patent: 1511418 (1925-10-01), Maclachlan
patent: 4108771 (1978-08-01), Weiss
patent: 4221661 (1980-09-01), Shimizu et al.
patent: 4256630 (1981-03-01), Fremont
patent: 4277342 (1981-07-01), Hayes et al.
patent: 4370233 (1983-01-01), Hayes et al.
patent: 4377486 (1983-03-01), Barrick et al.
patent: 4717484 (1988-01-01), Kauffer
patent: 4765908 (1988-08-01), Monick et al.
patent: 4765911 (1988-08-01), Rasmussen
patent: 4814091 (1989-03-01), Napier et al.
patent: 5009793 (1991-04-01), Muller

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