동강유역의 포유동물상 및 어류 조사

김대원 ( Dae Won Kim ),김동석 ( Dong Seog Kim ) 대구가톨릭대학교 자연과학연구소 2003 자연과학연구논문집 Vol.1 No.2

멀티 플라즈마 반응기를 이용한 E. coli 소독

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경보건학회 2013 한국환경보건학회지 Vol.39 No.2

Objectives: For the practical application of the dielectric barrier discharge plasma reactor, a plasma reactor able to manage large volumes of water is needed. This study investigated the possibility of the practical application of a multi-plasma reactor which is a scaled-up version of a single plasma reactor. Methods: The multi-plasma reactor consists of several high-voltage transformers and plasma modules (discharge, ground electrodes and quartz dielectric tubes). The effects of water characteristics such as voltage (30-120 V), air flow rate (1-5 l/min), number of high-voltage transformers and plasma modules, and water quality on Escherichia coli (E. coli) disinfection and decrease of COD and $UV_{254}$ absorbance were investigated. Results: The experimental results showed that at a voltage of over 80 V, most of the E. coli were disinfected within 90 seconds. E. coli inactivation was not affected by the air flow rate. E. coli disinfection in the multiplasma process showed the traditional log-linear form of the disinfection curve. E. coli inactivation performance by transformer 3-Reactor 5 and transformer 3-Reactor 3 were similar. The disinfection performance of the UV process was affected by artificial sewage water. However, the plasma process was less affected by the artificial sewage within the standards for effluent water quality. Conclusions: Disinfection performance with several low voltages and plasma modules of three to five in number applied to the plasma process was higher than that concentrating a small amount of high voltage through a single plasma reactor. Removal of COD, $UV_{254}$ absorbance, and E. coli disinfection with the plasma process were better than with the UV process.

응집과 균질화가 팽화슬러지의 용존공기부상과 침전에 미치는 영향

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.1

The objective of this study is to examine the effect of the coagulation and homogenization in bulking sludge thickening of paper manufacturing plant using DAF(Dissolved Air Flotation) and gravitational sedimentation. The effects of parameters such as dosage of coagulant and homogenization time were examined. The results showed that DAF and sedimentation was affected aluminum sulfate and anion polymer coagulant differently. At the optimum dosage of aluminum sulfate, thickening efficiency of DAF and sedimentation process were increase 1.25 time and 2.02 time, respectively. At the optimum dosage of anion polymer coagulant, thickening efficiency of DAF process was increase 1.35 time, but thickening efficiency at sedimentation was 1.06 time. When anion polymer coagulant of 0.5 mg/l was added in DAF process, water content of sludge was decreased from 96.6% to 90.7% in dewatering process using Buchner funnel test device. After homogenization(20500 rpm, 10 min), Sauter mean diameter of sludge floc was decreased from 631 ${\mu}m$ to 427 ${\mu}m$, however increase of flotation efficiency by DAF was only 1.09 time.

스펀지에 고정한 광촉매를 이용한 안료의 탈색

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경보건학회 2005 한국환경보건학회지 Vol.31 No.5

The photocatalytic decolorization of Reactive Red 2B(RR2B) was studied using immobilized photocatalyst/UV System. Two pairs of 20 W UV-B and UV-C lamps were employed as the light source. Immobilization of $TiO_2$ was carried out using sponge (as the photocatalyst body) and silicone sealant(as the binder). The effects of parameters such as the thickness, pore size of sponge photocatalyst and attached material on the reactor bottom were investigated. The results showed that the optimum thickness of sponge photocatalyst was 1 cm. Decolorization of reactor which had the bottom coated $TiO_2$ was higher than that of reactor attached aluminum plate. Decolorization of photocatalyst with large pore size(mean pore size, 3.8 mm) was higher than that of the small(mean pore size, 1.75 mm). Initial decolorization of RR2B could be descrived using the Langmuir-Hinshelwood(L-H) model and gave constant values of $0.55mg/l{\cdot}min(k)\;and\;2.65{\times}10^{-2}l/mg(K)$, respectively.

수중 플라즈마 공정을 이용한 Rhodamine B 염료의 제거

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경보건학회 2011 한국환경보건학회지 Vol.37 No.3

Objectives: In this paper, a dielectric barrier discharge (DBD) plasma reactor was investigated for degrading the dye Rhodamine B (RhB) in aqueous solutions. Methods: The DBD plasma reactor system in this study consisted of a plasma component [titanium discharge (inner), ground (outer) electrode and quartz dielectric tube], power source, and gas supply. The effects of various parameters such as first voltage (input power), gas flow rate, second voltage (output power), conductivity and pH were investigated. Results: Experimental results showed that a 99% aqueous solution of 20 mg/l Rhodamine B is decolorized following an eleven minute plasma treatment. When comparing the performance of electrolysis and plasma treatment, the RhB degradation of the plasma process was higher that of the electrolysis. The optimum first voltage and air flow rate were 160 V (voltage of trans is 15 kV) and 3 l/min, respectively. With increased second voltage (4 kV to 15 kV), RhB degradation was increased. The higher the pH and the lower conductivity, the more Rhodamine B degradation was observed. Conclusions: OH radical generation of dielectric plasma process was identified by degradation of N, N-dimethyl-4-nitrosoaniline (RNO, indicator of OH radical generation). It was observed that the effect of UV light, which was generated as streamer discharge, on Rhodamine B degradation was not high. Rhodamine B removal was influenced by real second voltage regardless of initial first and second voltage. The effects of pH and conductivity were not high on the Rhodamine B degradation.

고급산화공정을 이용한 아세트아미노펜 분해 성능 비교

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경과학회 2022 한국환경과학회지 Vol.31 No.4

This study investigated the treatment of acetaminophen in municipal wastewater by conventional ozonation, ozone-based advanced oxidation, ozone/UV, and the electro-peroxone process. The ozone/UV process and electro-peroxone process of electric power consumption increased 1.25 and 2.04 times, respectively, compared to the ozone process. The pseudo-steady OH radical concentration was the greatest in the electro-peroxone process and lowest in the ozone process. The specific energy consumption for TOC decomposition of the ozone/UV process and electro-peroxone process were 22.8% and 15.5% of the ozone process, respectively. Results suggest that it is advantageous in terms of degradation performance and energy consumption to use a combination of processes in municipal wastewater treatment, rather than an ozone process alone. In combination with the ozone process, the electrolysis process was found to be more advantageous than the UV process.

영원일대(동강)의 수자원 조사

한진수 ( Jin Su Han ),김동석 ( Dong Seog Kim ) 대구가톨릭대학교 자연과학연구소 2003 자연과학연구논문집 Vol.1 No.2

UV, 전기분해 및 UV+전기분해 공정을 이용한 해수 중의 동물성 플랑크톤 제거

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경과학회 2021 한국환경과학회지 Vol.30 No.7

The International Maritime Organization (IMO) ballast water management agreement (International Convention for the Control and Management of Ship's Ballast Water and Sediments) came into force on September 8, 2017. This study evaluated the disinfection performance of electrolysis, UV treatment, and electrolysis + UV combined, to improve the treatment of zooplankton (size ≥ 50 ㎛), which is expected to strengthen the standards for biodegradation efficiency. Among the methods used, the disinfection time leading to 100% death was in the order: electrolysis > electrolysis + UV > UV process. For the same level of disinfection performance, the amount of electricity required for the electrolysis, UV, and electrolysis + UV processes were 1,300 W.s, 8,400 W.S, and 4,500 W.s, respectively. The combination of electrolysis + UV process for inactivation of zooplankton in ballast water did not show a synergic effect owing to the slow disinfection time and high power consumption.

전기-펜톤 반응을 이용한 해수 중의 염료 분해

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경과학회 2020 한국환경과학회지 Vol.29 No.4

To increase electrolysis performance, the applicability of seawater to the iron-fed electro-Fenton process was considered. Three kinds of graphite electrodes (activated carbon fiber-ACF, carbon felt, graphite) and dimensionally stable anode (DSA) electrode were used to select a cathode having excellent hydrogen peroxide generation and organic decomposition ability. The concentration of hydrogen peroxide produced by ACF was 11.2 mg/L and those of DSA, graphite, and carbon felt cathodes were 12.9 ~ 13.9 mg/L. In consideration of durability, the DSA electrode was selected as the cathode. The optimum current density was found to be 0.11 A/㎠, the optimal Fe²⁺ dose was 10 mg/L, and the optimal ratio of Fe²⁺ dose and hydrogen peroxide was determined to be 1:1. The optimum air supply for hydrogen peroxide production and Rhodamine B (RhB) degradation was determined to be 1 L/min. The electro-Fenton process of adding iron salt to the electrolysis reaction may be shown to be more advantageous for RhB degradation than when using iron electrode to produce hydrogen peroxide and iron ion, or electro-Fenton reaction with DSA electrode after generating iron ions using an iron electrode.

전기응집/부상 공정에서 반응표면분석법을 이용한 TiO₂ 수용액의 탁도 처리조건 최적화

김동석,박영식,Kim, Dong-Seog,Park, Young-Seek 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.6

The removal of turbidity from $TiO_2$ wastewater by an electrocoagulation/flotation process was studied in a batch reactor. The response surface methodology (RSM) was applied to evaluate the simple and combined effects of the three main independent parameters, current, NaCl dosage and initial pH of the $TiO_2$ solution on the turbidity removal efficiency, and to optimize the operating conditions of the treatment process. The reaction of electrocoagulation/flotation was modeled by use of the Box-Behnken method, which was used for the fitting of a 2nd order response surface model. The application of RSM yielded the following regression equation, which is an empirical relationship between the turbidity removal efficiency of $TiO_2$ wastewater and test variables in uncoded unit: Turbidity removal (%)=69.76+59.76Current+11.98NaCl+4.67pH+5.00Current${\times}$pH-160.11$Current^2-0.34pH^2$. The optimum current, NaCl dosage and pH of the $TiO_2$ solution to reach maximum removal rates were found to be 0.186 A, 0.161 g/l and 7.599, respectively. This study clearly showed that response surface methodology was one of the most suitable method to optimize the operating conditions for maximizing the turbidity removal. Graphical response surface and contour plots were used to locate the optimum point.