Comparison of two methods for characterising biodegradable COD of wastewater
- Received Date: 15/12/2008
- Accepted Date: 05/11/2008
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Key words:
- BOD /
- short-term BOD measurement /
- long-term BOD measurement
Abstract: For the wastewater in a certain wastewater treatment plant in Chongqing, its respiration rate under seeded sludge condition was measured by the self-developed respirometer and the end of this shortterm BOD test was defined as the time when endogenous respiration restarted; besiedes, BI-2000 electrolytic respirometer was utilized to test BOD under unseeded sludge condition and this longterm BOD test is theoretically ended with organism mineralized. The comparation between the results of the two experiment methods show that, the BCOD obtained by the two methods is quite different and the short-term BOD measurement result was only 40%～60% of the long-term BOD measurement result. The concentration of heterotrophic microorganisms, XH(0), of the raw wastewater was tested through the batch respirometry. The result showed that the ratio of the sum of XH(0) and BCODst to BCODlt was between 0.88～1.02 with an average of 0.94, indicating that the sum was closed to BCODlt.
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