• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.50-56
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• 2000

In this study, sewage were treated with operating Two-step Aeration System and conventional activated sludge process together in a condition. At the same HRT 8hr of Two-step Aeration System and Activated Sludge Process, BOD treatment efficiency of 1st sedimentation basin effluent 36.9% by Two-step Aeration system was 12.3% higher than 24.65 by Activated Sludge Process and the COD treatment efficiency 39.8% by two-step Aeration System was 11.6.3% higher than 28.2% by Activated Sludge Process. BOD and COD treatment efficiencies of 2nd sedimentation basin effluent were 88.1% and 85.6% Two-step Aeration System and were 83.8% and 82.3% Activated Sludge Process. In the first treatment, as BOD was relatively removed a lot, F/M ratio 0.17, $0.21{\cdot}BOD/kg{\cdot}MLSS.d$ was maintained by Activated Sludge Process. Therefore it was proved that organic matter treatment efficiency by Two-step Aeration System os Higher than by Activated Sludge Process in a aeration time 8hr. $NH_4^{+}-N$ treatment efficiencies were 55.5% by Two-step Aeration System and 39.75 by Activated sludge Process. $NO_3^{-}-N$ concentration in 2nd. sedimentation basin effluent were 3.33% by Two-step Aeration System and 2.36% by Activated Sludge Process. From this result, Two-step Aeration System was proved more advantageous treatment process for nitrification than Activated Sludge Process. The fluctuation range of BOD, COD and SS concentration in 2nd sedimentation basin effluent $16~33mg/{\ell}$, $15~23mg/{\ell}$ and $14~22mg/{\ell}$ by Two-step Aeration System was smaller than $16~57mg/{\ell}$, $15~25mg/{\ell}$ by Activated sludge Process. Overall the fluctuation range in 2nd sediment basin effluent by was smaller than by Activated Sludge Process. As a result, it is possible for this Two-step Aeration with no facility investment and a little of operation condition change in a conventional sewage treatment plant to get stability and nitrification of treatment water quality.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.83-92
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• 1990

Adapting two step aeration system to a waste water treatment of W-paper manufactory as Full-Scale Plants, we drew a following conclusion from its practical working. 1. Because BOD removal efficiency was 20% in A-Stage, 90% in B-Stage and total removal efficiency was 97%. It worked treatment plant well and was suitable for effluent water standard as well. Because COD removal efficiency was 42% in A-stage, 71% in B-stage and the total removal efficiency was 94% COD control was possible in effluent water quality. 2. Treatment efficiency according to a load capacity was average 20% in 1.401 BOD kg/m3/d load of A-Stage and average 90% in 0.273 BOD kg/$\textrm {m}^3$ / d load of B-Stage. 3. Treatment efficiency according to a ratio of F/M was 2.657--5.024 kg BOD/kg MLSS/d in A-Stage and BOD removal efficiency was 16-261 in the same stage. The ratio of F/M was 0.068-0.094 kg BOD /kg MLSS/d and BOD removal efficiency ratio was 85-94%. Therefore treatment efficiency could be kept stably and volume of aeration tank could be reduced wholly. 4. Treatment efficiency according to MLSS appeared BOD 20%. COD 42%, in A-Stage and removal efficiency appeared BOD 90%, COD 71% in B-Stage. They were suitable for plan condition. 5. Because of working of complemented treatment plant by AB-Process. 20,000,000 Won a month was saved than the ordinary working cost. Therefore, it was assumed that invested cost could be recollected in 19 months or so consequently.

• Journal of Life Science
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• v.19 no.3
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• pp.349-355
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• 2009

Metabolic fingerprinting of microbial communities was investigated with Biolog GN2 plates using samples of biofilm and aeration tanks from an RABC (rotating activated Bacillus contactor) system - an advanced wastewater treatment system for the food wastewater of pig slaughterhouses. Aerobic and anaerobic results revealed the following four aspects. First, simple matching and pairs t-test of daily variation showed more defined qualitative and quantitative relatedness of active microbial communities than that of mere optical densities. Second, metabolic potentials were higher in biofilm than in aeration tanks (p<0.01), meaning higher activity of biofilm. Third, two aeration tanks showed the highest similarity (78%) and similar metabolic power (p=0.287). However, actively used carbon sources were different among samples, signifying change of active communities at each wastewater treatment step. Finally, aerobic and anaerobic metabolic fingerprinting patterns were different for the same samples representing activities of microaerophilic and/or anaerobic communities. These results suggest that daily variation and anaerobic incubation would help in the comparison of metabolic fingerprintings.

• Journal of Plant Biotechnology
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• v.5 no.1
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• pp.1-6
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• 2003

The adventitious root of Panax ginseng C.A. Meyer is regarded as an efficient alternative to cell culture or hairy root culture for biomass production due to its fast growth and stable metabolite production. To determine optimal culture conditions for the bioreactor culture of ginseng roots, experiments have been conducted on physical and chemical factors such as bioreactor type, dissolved oxygen, gas supply, aeration, medium type, macro- and micro-elements, medium supplement during culture period, sucrose concentration, osmotic agents, medium pH and light. Elicitation is a key step to increase ginsenoside accumulation in the adventitious roots but biomass growth is severely inhibited by elicitor treatment. To obtain high ginsenoside content with avoiding biomass decrease, we applied two-stage bioreactor culture system. Ginseng adventitious roots were cultured for 40 days to maximize biomass increase followed by elicitation for 7 days to enhance ginsenoside accumulation. We also experimented on types and concentrations of jasmonate to determine optimal elicitation methods. In this paper, we discussed several factors affecting the root propagation and ginsenoside accumulation. Based on the results obtained from previous experiments we have established large-scale bioreactor system (1 ton-10 ton) for the efficient production of ginseng adventitious roots and bioactive compounds including ginsenoside. Still, experiments are on going in our laboratory to determine other bioactive compounds having effects on diet, high blood pressure, DPPH elimination and increasing memories.