Bacterial leaching process and composition

Patent · Tue Jun 08 04:00:00 UTC 1993

OSTI ID:6191511

Tyagi, R D; Jain, D K; Couillard, D

A process for removing heavy metals and substantially destroying indicator bacteria present in municipal sludges is described, which comprises: (a) lowering, under aerobic conditions, the pH of a municipal sludge from about 7 to 8 to about 2.0 to 2.5 by adding to said sludge 10% by volume of an inoculum containing a mixture of microorganisms comprising Thiobacillus thiooxidans ATCC 55127 and Thiobacillus thioparus ATCC 55128 with 1 to 3 g per liter of sulphur, and incubating for a period of at least 40 hours where the heavy metals originally present in said sludge have been substantially solubilized and the concentration of the indicator bacteria have been lowered to a non-toxic level; and (b) recovering the metals from the low pH treated sludge of step (a). A mixture of microorganisms comprising 50 [plus minus] 5% of a biologically pure culture of Thiobacillus thiooxidans ATCC 55127 and 50 [plus minus] 5% of a biologically pure culture of Thiobacillus thioparus ATCC 55128 is used.

• Assignee: Inst. National de la Recherche Scientifique, Ste-Foy, Quebec (Canada)
• Patent Number(s): A; US 5217615
• Application Number: PPN: US 7-659723
• OSTI ID: 6191511
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROBIC CONDITIONS
BACILLUS
BACTERIA
BIODEGRADATION
BIOLOGICAL INDICATORS
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
CHEMICAL REACTIONS
CLEANING
DECOMPOSITION
DECONTAMINATION
DISSOLUTION
ELEMENTS
LEACHING
MANAGEMENT
MATERIALS
MATERIALS RECOVERY
METALS
MICROORGANISMS
MUNICIPAL WASTES
PH VALUE
PROCESSING
SEPARATION PROCESSES
SEWAGE
SEWAGE SLUDGE
SLUDGES
SULFUR-OXIDIZING BACTERIA
THIOBACILLUS OXIDANS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES