Chemically disinfected sewage sludge-containing materials
US5423992A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1991 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | May 20, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F11/004
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A chemically disinfected sewage sludge-containing material comprising (1) an aqueous slurry of sewage sludge-containing material having a solids content in the range of about 10 to 30 wt. %; and (2) a chemical disinfectant comprising a water soluble silicate of sodium in the amount of 5 to 20 wt. % (basis dry wt. of said sewage sludge). In one embodiment, a pumpable chemically disinfected sewage sludge-containing material was produced by the steps of (1) dewatering sewage sludge to produce an aqueous slurry having a solids content of about 10 to 30 wt. %; (2) shearing the dewatered sewage sludge from (1) at a temperature in the range of about ambient to 230.degree. F. and at a shear rate of at least 30 per second for a period in the range of about 0.5 to 180 minutes; and (3) mixing the following materials together at a temperature in the range of about ambient to 230.degree. F. to produce a pumpable aqueous slurry having a solids content in the range of about 30 to 65 wt. % and a pH of at least about 11: (a) about 0.5 to 7 parts by wt. of sheared dewatered sewage sludge from (2); (b) about 5 to 20 wt. % of a silicate of sodium (basis total dry weight of sewage sludge); and (c) abou…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.