2009.4-2010.3 Yearbook of NILIM
Research Summary
Water Quality Control Department
| Reference Number | Y090205 |
| Title | Research on Control of Odor released from Wastewater pumped from Underground Pit to Sewers |
| Start-End Date | 2008.4-2010.3 |
| Division | Wastewater System Division |
| Author | Head, Yosuke MATSUMIYA Researcher, Wataru FUKATANI |
| Summary | In the downtown of Japanese big cities, lots of buildings with underground floors are in place. In order to carry wastewater from the underground floor to public sewers, pumps are used because underground floors are below the level of cleanout leading to public sewer. In some pits, wastewater remains for many hours because entering wastewater amount is so small that pumps do not operate regularly. This causes anaerobic reaction of wastewater in the pits. When the pumps start operating, corroded wastewater is discharged to public sewers releasing H2S gas. The odorous gas comes up to the busy streets nearby through gully pots in combined sewer system or openings of manhole or cleanout covers in separate and combined system. Lots of citizen complaints are coming to sewer operators for this problem. Our research tries to facilitate the enforcement of odor control law to solve the problem. The owners of buildings with underground pits are subjected to the law. Enforcing odor control law is the job of environmental affairs section in municipalities while the detection of problematic pits is made possible by sewer operators through the H2S gas detectors placed in cleanouts. The problem has been neglected due to sectionalism and evasiveness. Parameters of odor control enforcement in this problem are H2S concentration in wastewater or sensory dilution-to-threshold measurement for wastewater. Our research focuses on the relationship between these enforcing parameters in wastewater and commonly measured H2S gas concentration in cleanouts. The result is expected to be used for the smooth communication between sewer operators and environmental affairs section so that enforcement is duly conducted. |