• Journal of Environmental Science International
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• v.12 no.12
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• pp.1309-1313
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• 2003

This study was carried out to obtain the optimal ammonia removal efficiency using pyroligenous liquid for the economical and environment-friendly odor removal at a petty livestock farmhouse. The ammonia removal efficiencies were evaluated due to changing dilution rates(${\times}$10, ${\times}$20, ${\times}$30, ${\times}$50 and ${\times}$100 times) and different spray amounts(10$m\ell$ and 20$m\ell$) of pyroligenous liquid. The wet scrubber device was used to remove odor in closed-type livestock farmhouse. According to dilution rate of the pyroligenous liquid, the optimum rate was 20 times and the removal efficiency increased by decreasing dilution rates. In the case of spray amounts with the optimum dilution, the amount was 20 me and the removal efficiency increased by increasing spray amount. Also, the removal efficiency by using wet deodorizing device was 83.0-97.0％ with 20 times diluted liquid.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.76-85
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• 2008

Biological nutrient removal (BNR) sludge was added to a sequencing batch reactor (SBR) in the addition ratios of 0%, 20%, 40%, 50% while observing the variation of nutrient removal characteristics and microorganism groups. When the BNR sludge was added in a ratio over 40%, the characteristics of EBPR (enhanced biological phosphorus removal) was shown at the 27 days. However, a distinct BNR was not shown when the addition ratio of BNR sludge was lower than 40%. The organic removal efficiency were shown as 90% in all SBRs irrespective of the addition ratio of BNR sludge. At the 27 days, the phosphorus removal efficiencies were shown as 40%, 55%, 77% and 69%, respectively, according to the addition ratio of BNR sludge. Overall, efficient nitrification and phosphorus removal was shown when the added BNR sludge ratio was over 40%.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.112-118
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• 2000

In case ESO(evolutionary structural optimization) which is one of topology optimization methods, the element removal ratio is fixed throughout topology optimization by 1 or 2%. As a result it has no flexibility for various types of structures and thus the rate of convergence might not be efficient. Thus various element removal methods were developed in order to improve the efficiency of ESO. In this paper, various element removal methods for ESO are compared with each other for a bracket and a short cantilever. In addition, a new improved bi-directional element removal method is suggested in order to obtain much better optimized topology. From the comparative results of the examples, it is verified that all of the developed various element removal methods are very effective, and the suggested element removal method is the most effective.

• Journal of environmental and Sanitary engineering
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• v.13 no.2
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• pp.57-65
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• 1998

In this research, Effect of C/N ratio on nutrient removal in intermittently aerated activated sludge system(IAASS) was investigated with dormitary, building and swine wastewater. Three types (2-stage, 4-stage, modified) of IAASS were operated. Time interval of aeration/nonaeration in IAASS was 1hr/1hr. In treatment of Dormitary wastewater(BOD/T-N ratio : 4.4), Building wastewater (BOD/T-N ratio : 3.14) and swine wastewater(BOD/T-N ratio : 3.84), Nitrogen removal efficiency of 80, 70 and 90.4% was achieved, respectively. Nitrogen removal in IAASS was a great influenced on influent C/N ratio, efficient nitrogen removal was achieved at BOD/T-N ratio over 4. In IAASS operation, $\Delta $BOD mg/L/$\Delta $ nitrogen mg/L ratio was about 4-6. Simultaneous removal of organic, nitrogen and phosphorus in IAASS can achieved. And influent organic was efficiently utilized in denitrification. IAASS could be one of the best alternative process for the retrofit of conventional activated sludge system for the removal of nutrients.

• Carbon letters
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• v.11 no.2
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• pp.112-116
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• 2010

The objective of this study was to evaluate the possibility of simultaneous removal of ammonium, nitrate and phosphorus in water using the zeocarbon. In this study, the surface of zeocarbon was modified by acid because of difficulty in application of water treatment. After surface modification, the strength was enhanced about 62% higher than that of original one. The removal efficiency of ammonium and nitrate using the modified zeocarbon was about 47% and 32%, respectively and were higher than that of zeocarbon. In batch type experiment on the simultaneous removal of ammonium, nitrate and phosphorus, the presence of phosphorus did not have influence on nitrogen removal efficiency. Concomitantly, removal efficiency of phosphorus was obtained was about 35%. This indicates that the surface modified zeocarbon can be applied for simultaneous removal of nitrogen and phosphorus. Consequently, our results could be used as basic data to design of one-stage nitrogen/phosphorus simultaneous removal system.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.39-48
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• 1997

The study was conducted to know the possibility that the removal efficiency of organic and suspended solids(SS) could be increased by suppling of sea water and the optimum amount of sea water to be supplied treat bleaching waste water by lime coagulation settlement at pulp mill process. When the lime dosage was increased, the removal efficiency of COD and SS in the waste water was increased based on the removal efficiency of COD and SS. The lime dosage and removal efficiency was increased proportionally with the lime concentration of 4,000 mg/l, but the increase of removal efficiency was presented slightly above the 4,000mg/l. It was evaluated that the removal efficiencies of COD and SS could be increased and the requirement of lime dosage could be decreased by the sea water supplement. The removal efficiency of SS was most increased when the sea water supplement was 10% or more in the waste water. The removal efficiencies of COD was the best at 4% sea water excepting the dilution efficiency by sea water supplement.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.1
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• pp.19-25
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• 1989

Effect of removal time of mulched polyethylene film on the chlorine content of toP soil and on the chlorine absorption by burley tobacco Plants was investigated under the field condition in 1986 and 1987. Treatment consisted of 4 removal times (from 30 to 75 days after transplanting with IS days interval) and control (no removal). The chlorine content of top Boll at 15 days after removal of mulched polyethylene film(MPF) lowered temporarily, and the decrement of chlorine content of top soil was closely related to the sum of rainfalls after removal of MPF. The chlorine was accumulated much in upper leaves when the MPF being removed early, while the chlorine was accumulated much in lower loaves when the MPF being removed late, relatively. However, the removal of MPF had no effect on the chlorine content of whole leaf. The yield decreased with removal of MPF during growing period.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.361-366
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• 2002

Several effects on Pb$^{2+}$ removal by crab shell from aqueous solution were investigated. As the increase of initial Pb$^{2+}$ concentration and decrease of initial crab shell concentration, the time required to reach an equilibrium state and the residual Pb$^{2+}$ concentration increased. In our experimental ranges, the optimum initial Pb$^{2+}$ concentration and crab shell concentration were below 103 mg/$\ell$ and over 0.5 mg/$\ell$, respectively. Also, in order to investigate the mechanism of Pb$^{2+}$ removal by crab shell in aqueous solution, the crab shell was compared with chitosan and chitin on aspects of Pb$^{2+}$ removal capacity and Pb$^{2+}$ removal rate. The Pb$^{2+}$ removal by crab shell was greater than that by chitin and chitosan. The role of chitin was not so great in Pb$^{2+}$ removal by crab shell. The Pb$^{2+}$ removal by chitosan was not exactly correlated to the molecular weight of chitosan. weight of chitosan.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.54-60
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• 2011

To evaluate the feasibility of electrodialysis for copper removal from industrial wastewater, the effect of operating parameters on the removal of copper was experimentally estimated. The limiting current density (LCD) linearly increased with the copper concentration and the flow rate. The time when the copper concentration of diluate reaches to 3 mg/L was linearly proportional to initial concentration of diluate, and the concentration of concentrate did not affect the removal rate. Increase in the flow rate gave a positive effect on the removal rate and became insignificant at flow rates greater than 2.4 L/min. The removal rate increased with the applied voltage. From the operation of the electrodialysis module used in this research, the flow rate of 2.4 L/min and the voltage corresponding to the 80~90% of LCD were found be the optimum operating condition for the copper removal from highly concentrated copper solutions.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.59-64
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• 2001

The effect of major operating parameters in spray drying sorber(=SDS) for automatic control for the simultaneous removal of acidic and organic gaseous pollutants from solid waste incinerator was performed. The field experiment was carried out in pilot scale test for the quantification of major operating parameters of hydrophilic and the hydrophobic pollutants. The removal efficiencies of $SO_2$and HCI in the 5wt% slurry condition were being increased with the increase of the stoichiometric ration which is the molecular ratio of lime to the pollutant concentration, and with the decrease of inflow flue gas temperature in the pilot SDS reactor. The removal efficiency along the height of spray drying sorber was closely related to the temperature profile, and more than 90% of total removal efficiency was achieved in an absorption region. For the removal of acidic gas the optimum operating condition considering the economics and a stable operation is the 5wt% of slurry concentration, 1.2 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. For the organic gases of benzene and toluene the removal efficiencies were 20-60% which is much lower than that of acidic gas. The best removal efficiency was obtained at 1.5 of stoichiometric ratio and 25$0^{\circ}C$ of inflow flue gas temperature. The organic\`s removal efficiency along the height of spray drying sorber was quite different from that of acidic gas, that is, more than 60% of the total removal efficiency for benzene and 90% of the total removal for toluene were achieved in the dried adsorption region, which was formed at the lower or exit part of the reactor.