• 상하수도학회지
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• 제23권5호
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• pp.517-526
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• 2009

This research has been conducted to investigate the characteristics of hydraulic behavior within the PAC contactor, the rectangular shape sedimentation basin without inclined tube and the other one with inclined tube those are parts of demonstration plants(capacity : $2,000m^3/d$) in Korea Institute of Water and Environment. As results of tracer tests, the flow within PAC contactor was evaluated to divided into plug flow and dead space distinctly, and characteristics of dead space was close to that of CSTR(Complete/continuous Stirred Tank Reactor). Also, considering Reynolds number, Froude number, Morill, Modal, NCSTR Inex and plug flow/mixed flow fraction, in the case of the rectangular shape sedimentation basin without inclined tube, the characteristics of flow pattern was close to CSTR. On the other hand, in the case of the basin with inclined tube, the region of CSTR decreased precisely compared with the case of no-tube. Until now we have recognized that the inclined hydraulic structure just reduces the surface loading rate within a sedimentation basin. Actually besides, the inclined structure have an important effect on the hydraulic behavior within the basin.

• 한국축산시설환경학회지
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• 제5권3호
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• pp.189-196
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• 1999

Anaerobic digestion is a naturally occuring microbial process involving the decomposition of organic materials such as livestock manure. This study explores the effect of the operating conditions, HRT (Hydraulic Retention Time) and feeding frequency on treatment efficiency for digestion of pig slurry, which has been one of most difficult organic waste for proper treatment in livestock production industry in Korea at the present time. The pilot-scale CSTR of 5 m3 in volume was designed. manufactured, and operated at the temperature of 35$\pm$1$^{\circ}C$. The digester was designed to hydraulically stir for complete mixing and to supply heat from the water bath to maintain mesophilic temperature. The HRT of the digester for Test 1 and Test 2, and Test 3 was set for 17 days and 13 days respectively and pig slurry was fed once a day with 300$\ell$ each for Test 1 and Test 3, while twice with 150$\ell$each for Test 2. Test 2 showed better performance by increase of 4% in VS removal efficiency and 5% in biogas production rate. This is mainly attributed to smaller temperature drop by feeding frequently with half amount, which eventually led to lesser impact on anaerobic mocrobes in the digester. Test 2 maintained optimum pH 7.8 which uplifted the activaton of sulfur-reduction bacteria, alkalinity of around 4,000mg/$\ell$, VA of over 3,000mg/$\ell$ for whole period of experiment. Further research may require to provide the practical operation strategy of anaerobic treatment system for treatment of pig slurry.