Title:
SEWAGE TREATMENT METHOD
Document Type and Number:
Japanese Patent JP2015112512
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a sewage treatment method that can effectively prevent odors of hydrogen sulfide and methyl mercaptan generated from sludge produced during sewage treatment processes.SOLUTION: A sewage treatment method comprises the processes of: settling and separating primary sedimentation sludge from sewage in a primary sedimentation tank 12; biologically treating the sewage after the separation of the primary sedimentation sludge to separate surplus sludge; concentrating the primary sedimentation sludge and concentrating the surplus sludge; mixing the concentrated primary sedimentation sludge and surplus sludge; and dewatering the mixed concentrated primary sedimentation sludge and surplus sludge. In a step before the process of concentrating the primary sedimentation sludge and the surplus sludge, a polyvalent metal salt is added to the sewage, or the primary sedimentation sludge and/or the surplus sludge, and then a nitrite and sodium pyrithione are added.
Inventors:
TAZAKI TAKEHIRO
Application Number:
JP2013254708A
Publication Date:
June 22, 2015
Filing Date:
December 10, 2013
Export Citation:
Assignee:
MUSHUGEN IND CO LTD
International Classes:
C02F11/00; C02F1/00; C02F1/50; C02F1/52; C02F11/14
Domestic Patent References:
| JP2004216252A | 2004-08-05 | |||
| JP2002028696A | 2002-01-29 | |||
| JP2010110666A | 2010-05-20 | |||
| JP2002361300A | 2002-12-17 | |||
| JPH07204691A | 1995-08-08 |
Foreign References:
| US20090000752A1 | 2009-01-01 |
Attorney, Agent or Firm:
Hiroyuki Okuda
Noriyuki Okuda
Noriyuki Okuda
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