Effect of improvement of the dielectric barrier discharge (DBD) plasma system on the inactivation performance of bacteria were investigated. The improvement of plasma reactor was performed by combination with the basic plasma reactor and UV process or combination with the basic plasma reactor and circulation system which was equipped with gas-liquid mixer. Experimental results showed that tailing effect was appeared after the exponential decrease in basic plasma reactor. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of basic plasma process and UV process. The application of gas-liquid mixing device on the basic plasma reactor reduced inactivation time and led to complete sterilization. The effect existence of gas-liquid mixing device, voltage, air flow rate (1 ～ 5 L/min), water circulation rate (2.8 ～ 9.4 L/min) in gas—liquid mixing plasma, plasma voltage and UV power of gas—liquid mixing plasma+UV process were evaluated. The optimum air flow rate, water circulation rate, voltage of gas-liquid mixing system were 3 L/min, 3.5 L/min and 60 V, respectively. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of gas-liquid mixing plasma and UV process.

The aim of our research was to apply experimental design methodology in the optimization of N, N-Dimethyl- 4-nitrosoaniline (RNO, which is indictor of OH radical formation) degradation using gas mixing-circulation plasma process. The reaction was mathematically described as a function of four independent variables [voltage (X1), gas flow rate (X2), liquid flow rate (X3) and time (X4)] being modeled by the use of the central composite design (CCD). RNO removal efficiency was evaluated using a second-order polynomial multiple regression model. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) value of 0.9111, thus ensuring a satisfactory adjustment of the second-order polynomial multiple regression model with the experimental data. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and independent variables in a coded unit: RNO removal efficiency (%) = 77.71 + 10.04X1 + 10.72X2 + 1.78X3 + 17.66X4 + 5.91X1X2 + 3.64X2X3 - 8.72X2X4 - 7.80X1 2 - 6.49X2 2 – 5.67X4 2. Maximum RNO removal efficiency was predicted and experimentally validated. The optimum voltage, air flow rate, liquid flow rate and time were obtained for the highest desirability at 117.99 V, 4.88 L/min, 6.27 L/min and 24.65 min, respectively. Under optimal value of process parameters, high removal(> 97 %) was obtained for RNO.

This study carried out a laboratory scale plasma reactor about the characteristics of chemically oxidative species (․OH, H2O2 and O3) produced in dielectric barrier discharge plasma. It was studied the influence of various parameters such as gas type, 1st voltage, oxygen flow rate, electric conductivity and pH of solution for the generation of the oxidant. H2O2 and O3.) H2O2 and O3 was measured by direct assay using absorption spectrophotometry. OH radical was measured indirectly by measuring the degradation of the RNO (N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical). The experimental results showed that the effect of influent gases on RNO degradation was ranked in the following order: oxygen > air >> argon. The optimum 1st voltage for RNO degradation were 90 V. As the increased of 1st voltage, generated H2O2 and O3 concentration were increased. The intensity of the UV light emitted from oxygen-plasma discharge was lower than that of the sun light. The generated hydrogen peroxide concentration and ozone concentration was not high. Therefore it is suggested that the main mechanism of oxidation of the oxygen-plasma process is OH radical. The conductivity of the solution did not affected the generation of oxidative species. The higher pH, the lower H2O2 and O3 generation were observed. However, RNO degradation was not varied with the change of the solution pH.

Electrochemical degradation of phenol was evaluated at DSA (dimensionally stable anode), JP202 (Ru, 25%; Ir, 25%; other, 50%) electrode for being a treatment method in non-biodegradable organic compounds such as phenol. Experiments were conducted to examine the effects of applied current (1.0~4.0 A), electrolyte type (NaCl, KCl, Na2SO4, H2SO4) and concentration (0.5~3.0 g/L), initial phenol concentration (12.5~100.0 mg/L) on phenol degradation and UV254 absorbance as indirect indicator of by-product degraded phenol. It was found that phenol concentration decreased from around 50 mg/L to zero after 10 min of electrolysis with 2.5 g/L NaCl as supporting electrolyte at the current of 3.5 A. Although phenol could be completely electrochemical degraded by JP202 anode, the degradation of phenol COD was required oxidation time over 60 min due to the generation of by-products. UV254 absorbance can see the impact of as an indirect indicator of the creation and destruction of by-product. The initial removal rate of phenol is 5.63 times faster than the initial COD removal rate.

Decomposition of non-biodegradable contaminants such as phenol contained in water was investigated using a dielectric barrier discharge (DBD) plasma reactor in the aqueous solutions with continuous oxygen bubbling. Effects of various parameters on the removal of phenol in aqueous solution with high-voltage streamer discharge plasma are studied. In order to choose plasma gas, gas of three types (argon, air, oxygen) were investigated. After the selection of gas, effects of 1st voltage (80 ～220 V), oxygen flow rate (2 ～7 L/min), pH (3 ～11), and initial phenol concentration (12.5 ～100.0 mg/L) on phenol degradation and change of UV254 absorbance were investigated. Absorbance of UV254 can be used as an indirect indicator of phenol degradation and the generation and disappearance of the non-biodegradable organic compounds. Removal of phenol and COD were found to follow pseudo first-order kinetics. The removal rate constants for phenol and COD of phenol were 5.204 × 10-1 min-1 and 3.26 × 10-2 min-1, respectively.

Dielectric discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. For practical application of the plasma reactor, reactor that can handle large amounts of water are needed. Plasma research to date has focused on small-scale water treatment. This study was carried out basic study for scale-up of a single DBD (dielectric barrier discharge) plasma reactor. The degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) was used as a performance indicator of multi-plasma reactor. The experiments is divided into two parts: design parameters [effect of distance of single plasma module (1~14 cm), arrangement of ground electrode (single and multi), rector number (1~5) and power number (1~5)]; operation parameter [effect of applied voltage (60~220 V), air flow rate (1~5 L/min), electric conductivity of solution (1.4 μS/cm, deionized water)~18.8 mS/cm (addition of NaCl 10 g/L) and pH (5~9)]. Considering the electric stability of the plasma reactor, optimum spacing between the single plasma module was 2 cm. Multi discharge electrodes - single ground electrode array was selected. Combination of power 3-plasma module 5 was the optimal combination for maximum RNO degradation. The optimum 1st voltage and air flow rate for RNO degradation were 180 V and 4 L/min, respectively. The pH and conductivity of the solution was not influencing the RNO degradation.

A dielectric barrier discharge (DBD) plasma reactor was investigated for the inactivation of Ralstonia Solanacearum which causes bacterial wilt in aquiculture. The DBD plasma reactor of this study was divided into power supply unit, gas supply unit and plasma reactor. The plasma reactor consisted of a quartz dielectric tube, discharge electrode (inner) and ground electrode (outer). The experimental results showed that the optimum 1st voltage, 2nd voltage, air flow rate and pH were for 100 V (1st voltage), 15 kV (2nd voltage), 4 L/min, and pH 3, respectively. At a low 1st voltage, shoulder and tailing off phenomena was observed. The shoulder phenomenon was decreased as the increase of 1st voltage. R. Solanacearum disinfection in the lower air flow rate was showed shoulder and tailing off phenomenon because the active species generated less. Under optimum condition, shoulder and tailing off phenomenon was reduced. When the 2nd voltage was less than 7.5 kV, tailing off phenomenon was observed and this was not vanishes even though the increase of the disinfection time. The inactivation efficiency increased as the increase of air flow rate, however, the efficiency decreased when the air flow rate was above 4 L/min. R. Solanacearum disinfection at pH 3 showed somewhat higher than in pH 11. The pH effect of R. Solanacearum deactivation is less than the impact on other factor.

The application of disinfection models on the plasma process was investigated. Nine empirical models were used to find an optimum model. The variation of parameters in model according to the operating conditions (first voltage, second voltage, air flow rate, pH) were investigated in order to explain the disinfection model. In this experiment, the DBD (dielectric barrier discharge) plasma reactor was used to inactivate Ralstonia Solanacearum which cause wilt in tomato plantation. Optimum disinfection models were chosen among the nine models by the application of statistical SSE (sum of squared error), RMSE (root mean sum of squared error), r2 values on the experimental data using the GInaFiT software in Microsoft Excel. The optimum model was shown as Weibull+talil model followed by Log-linear+ Shoulder+Tail model. Two models were applied to the experimental data according to the variation of the operating conditions. In Weibull+talil model, Log10(No), Log10(Nres), δ and p values were examined. And in Log-linear+Shoulder+Tail model, the Log10(No), Log10(Nres), kmax, Sl values were calculated and examined.

Non-thermal plasma processing using a dielectric barrier discharge (DBD) has been investigated as an alternative method for the degradation of non-biodegradable organic compounds in wastewater. The active species such as OH radical, produced by the electrical discharge may play an important role in degrading organic compound in water. The degradation of N, N-Dimethyl-4-nitrosoaniline (RNO) was investigated as an indicator of the generation of OH radical. The DBD plasma reactor of this study consisted of a plasma reactor, recycling pump, power supply and reservoir. The effect of diameter of external reactor (15 ∼ 40 mm), width of ground electrode (2.5 ∼ 30 cm), shape (pipe, spring) and material (copper, stainless steel and titanium) of ground electrode, water circulation rate (3.1 ∼ 54.8 cm/s), air flow rate (0.5 ∼ 3.0 L/min) and ratio of packing material (0 ∼ 100 %) were evaluated. The experimental results showed that shape and materials of ground were not influenced the RNO degradation. Optimum diameter of external reactor, water circulation rate and air flow rate for RNO degradation were 30 mm, 25.4 cm/s and 4 L/min, respectively. Ground electrode length to get the maximum RNO degradation was 30 cm, which was same as reactor length. Filling up of glass beads decreased the RNO degradation. Among the experimented parameters, air flow rate was most important parameters which are influenced the decomposition of RNO.

A Dielectric barrier discharge (DBD) plasma is shown in the present investigation to be effective of phenol degradation in the aqueous solutions in batch reactor with continuous air bubbling. Removal of phenol and effects of various parameters on the removal efficiency in the aqueous solution with high-voltage streamer discharge plasma are studied. The effect of 1st voltage (80 ~ 220 V), air flow rate (3 ~ 7 L/min), pH (3 ~ 11), electric conductivity of solution (4.16 μS/cm, deionized water) ~ 16.57 mS/cm (addition of NaCl 10 g/L) and initial phenol concentration (2.5 ~ 20.0 mg/L) were investigated. The observed results showed that phenol degradation was higher in the basic solution than that of the acidic. The optimum values on the 1st voltage and air flow rate for phenol degradation were 140 V and 6 L/min, respectively. It was considered that absorbance variation of UV254 of phenol solution can be use as an indirect indicator of change of the non-biodegradable organic compounds within the treated phenol solution. Electric conductivity was not influenced the phenol degradation. To obtain the removal efficiency of phenol and COD of phenol over 97 % (initial phenol concentration, 10.0 mg/L), 80 min and 120 min were need, respectively. Phenol and COD degradation showed a pseudo-first order kinetics.

The influence of plasma discharge on the nutrient components (NO3-N, NH4-N, PO4-P, K, Ca, and Mg) and water quality [pH, ORP (oxidation-reduction potential) and electric conductivity] of hydroponic water were investigated. It was observed that the NH4-N, PO4-P, K, Ca, and Mg were kept at the constant concentrations for plasma discharging of 90 min. On the other hand, NO3-N concentration was increased with proceeding of the plasma discharge. The increase of NO3-N concentration was considered with the fact that nitric acid was created from nitrogen among supplying air for the insulation of inside of dielectric barrier. ORP and electric conductivity was increased with plasma discharging time. However, pH was decrease with what because of the generation of the nitric acid. When adjusting the hydroponic ingredients, pH and conductivity must to be considered because of the change of pH and conductivitiy with the discharging.

포도 대목 품종 육성 시, 주요 교배친으로 사용되는 대목 품종 29점 및 국내 자생 머루를 포함한 포도 속(Vitis) 야생 유전자원 13점 등 총 42점의 유전적 다양성을 분석하기 위하여 RAPD와 SSR 분석을 수행하였다. Random decamer 30 종을 분석하여 329개의 다형성 밴드(60.3%)를 얻었으며 primer 당 평균 다형성 밴드 수는 11.0개였다. SSR 마커 20종을 이용하여 분석한 결과 263개의 대립인자가 확인되었고, 마커

There is an increasing incidence in health problems related to environmental issues that originate from inadequate treatment of sewage. This has compelled scientists to engage in innovative technologies to achieve a effective disinfection process. Electrolysis has emerged as one of the more feasible alternatives to conventional disinfection process. The objectives of the present paper were to investigate the effect of chemical characteristics on oxidant formation and Escherichia coli (E. coli) disinfection in synthetic sewage effluents. The influence of parameters such as COD, SS, T-N and T-P were investigated using laboratory scale batch reactor. The results showed that the higher COD, T-N and T-P concentration, the lower N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) degradation and E. coli disinfection was observed. The order of effect of RNO degradation and E. coli disinfection was T-P > COD > T-N > SS. When 4 parameter of water quality were worked simultaneously, oxidants formation and disinfection was decreased with increase of the concentration of sewage. To increase of the disinfection performance, the increase of disinfection time or electric power was need.

This study investigated the application of experimental design methodology to optimization of conditions of air-plasma and oxygen-plasma oxidation of N, N-Dimethyl-4-nitrosoaniline (RNO). The reactions of RNO degradation were described as a function of the parameters of voltage (X1), gas flow rate (X2) and initial RNO concentration (X3) and modeled by the use of the central composite design. In pre-test, RNO degradation of the oxygen-plasma was higher than that of the air-plasma though low voltage and gas flow rate. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and test variables in a coded unit: RNO removal efficiency (%) = 86.06 + 5.00X1 + 14.19X2 - 8.08X3 + 3.63X1X2 - 7.66X2 2 (air-plasma); RNO removal efficiency (%) = 88.06 + 4.18X1 + 2.25X2 - 4.91X3 + 2.35X1X3 + 2.66X1 2 + 1.72X3 2 (oxygen-plasma). In analysis of the main effect, air flow rate and initial RNO concentration were most important factor on RNO degradation in air-plasma and oxygen-plasma, respectively. Optimized conditions under specified range were obtained for the highest desirability at voltage 152.37 V, 135.49 V voltage and 5.79 L/min, 2.82 L/min gas flow rate and 25.65 mg/L, 34.94 mg/L initial RNO concentration for air-plasma and oxygen-plasma, respectively.

The aim of this research was to evaluate the effect of combination of disinfection process (electrolysis, UV process) on Escherichia coli (E. coli) disinfection and oxidants (OH radical, ClO2, HOCl, H2O2 and O3) generation. The effect of electrolyte type (NaCl, KCl and Na2SO4) on the E. coli disinfection and oxidants generation were evaluated. The experimental results showed that performance of E. coli disinfection of electrolysis and UV single process was similar. Combination of electrolysis and UV process enhanced the E. coli disinfection and 4-carboxybenzaldehyde (4-CBA, indicator of the generation of OH radical) degradation. It is clearly showed synergy effect on disinfection and OH radical formation. However chlorine (ClO2, HOCl) and oxygen type (H2O2, O3) oxidants were decreased with the combination of two process. In electrolysis + UV complex process, electro-generated H2O2 and O3 were reacted with UV light of UV-C lamp and increased 4-CBA degradation(increase OH radical). Disinfection of electrolyte of chlorine type was higher than that of the sulfate type electrolyte due to the higher generation of OH radical and oxidants.

This study investigated the degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) by using dielectric barrier discharge (DBD) plasma. The DBD plasma reactor of this study consisted of a quartz dielectric tube, titanium discharge (inner) and ground (outer) electrode. The effect of shape (rod, spring and pipe) of ground electrode, diameter (9 ～ 30 mm) of ground electrode of spring shape and inside diameter (4 ～ 13 mm) of quartz tube, electrode diameter (1 ～ 4 mm), electrode materials (SUS, Ti, iron, Cu and W), height difference of discharge and ground electrode (1 ～ 15.5 cm) and gas flow rate (1 ～ 7 L/min) were evaluated. The experimental results showed that shape of ground electrode and materials of ground and discharge electrode were not influenced the RNO degradation. The thinner the diameter of discharge and ground electrode, the higher RNO degradation rate observed. The effect of height gap of discharge between ground electrode on RNO degradation was not high within the experimented value. Among the experimented parameters, inside diameter of quartz tube and gas flow rate were most important parameters which are influenced the decomposition of RNO. Optimum inside diameter of quartz tube and gas flow rate were 7 mm and 4 L/min, respectively.

The effect of the variation of aeration time on the microorganisms was investigated in sequencing batch reactor (SBRs). The cycling time in four SBRs was adjusted to 12 hours and then included different aerobic times as 1 hr, 2.5 hr, 4 hr and 5.5 hr, respectively. Four SBR systems have been operated and investigated for over 40 days. As the increase of aeration time, the consumption of glycogen within sludge at the 1st non-aeration time a little bit was increased and the production of glycogen at the aeration time was increased. Also, the produced PHB amounts and PHB production rate at the 1st non-aeration time were increased as the decrease of aeration time, which showed the activation of the phosphorus removal. The ratios of nitrifying microorganisms' number and GAOs to the total microorganisms' number in SBRs was decreased as the decrease of the aeration time, however, the PAOs ratio was almost constant irrespective of the variation of aeration time.

The effect of the variation of aeration time on the removal of organics, nitrogen and phosphorus using synthetic wastewater was investigated in sequencing batch reactors (SBRs) which included DNPAOs and DNGAOs. The cycling times in four SBRs were adjusted to 12 hours and then included different aerobic times as 1 hr, 2.5 hr, 4 hr and 5.5 hr, respectively. Four SBR systems have been operated and investigated for over 40 days. Average TOC removal efficiencies were about 71 % in all SBRs. The NH_4^+-N removal efficiency was increased as the increase of aeration time. After changing aeration time, the total nitrogen removal efficiencies of SBRs were shown as 35 %, 85 %, 75 % and 65 %, respectively. Higher phosphorus release and uptake were occurred as the decrease of the aeration time. After all, the overall phosphorus removal efficiency decreased and the deterioration of phosphorus removal was occurred when aeration time was over 4 hr. Denitrification in aerobic conditions was observed, which showed the presence of DNPAOs and DNGAOs. In batch experiments, PAOs were shown as the most important microorganisms for the phosphorus removal in this experiment, and the role of DNGAOs was higher than that of DNAPOs for the nitrogen removal.

The purpose of this study is to degradation of Rhodamine B (RhB, dye) and N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the electro-generation of OH radical) in solution using boron doped diamond (BDD) electrode. The effects of applied current (0.2~1.0 A), electrolyte type (NaCl, KCl, and Na2SO4) and electrolyte concentration (0.5~3.0 g/L), solution pH (3~11) and air flow rate (0~4 L/min) were evaluated. Experimental results showed that RhB and RNO removal tendencies appeared with the almost similar thing, except of current. Optimum current for RhB degradation was 0.6 A, however, RNO degradations was increased with increase of applied current. The RhB and RNO degradation of Cl type electrolyte were higher than that of the sulfate type. The RhB and RNO degradation were increased with increase of NaCl concentration and optimum NaCl dosage was 2.5 g/L. The RhB and RNO concentrations were not influenced by pH under pH 7. Optimum air flow rate for the oxidants generation and RhB and RNO degradation were 2 L/min. Initial removal rate of electrolysis process was expressed Langmuir - Hinshelwood equation, which is used to express the initial removal rate of UV/TiO2 process.

The experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV process were mathematically described as a function of parameters power (X1), NaCl dosage (X2), initial pH (X3) and disinfection time (X4) being modeled by use of the Box-Behnken technique. The application of RSM using the Box-Behnken technique yielded the following regression equation, which is an empirical relationship between the residual E. coli number and test variables in actual variables: Ln (CFU) = 23.57 - 0.87․power - 1.87․NaCl dosage - 2.13․pH - 2.84․time - 0.09․powe r․time - 0.07․NaCl dosage․pH + 0.14․pH․time + 0.03․power 2 + 0.47․NaCl dosage 2 + 0.20․pH 2 + 0.33․time 2 . The model predictions agreed well with the experimentally observed result (R 2 = 0.9987). Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the E. coli disinfection using canonical analysis was Ln 1.06 CFU (power, 15.40 W; NaCl dosage, 1.95 g/L, pH, 5.94 and time, 4.67 min). To confirm this optimum condition, the obtained number of the residual E. coli after three additional experiments were Ln 1.05, 1.10 and Ln 1.12. These values were within range of 0.62 (95% PI low)～1.50 (95% PI high), which indicated that conforming the reproducibility of the model.