• 공업화학
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• 제28권2호
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• pp.153-157
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• 2017

Hydroxyethyl-cellulose (HEC) 함량별로 겔 타입 내부전해질을 제작하여 이온전도도와 내구성 측정 실험을 수행하였다. 이온전도도 측정결과 HEC 함량이 증가할수록 이온전도도가 감소하여 12% 함량의 겔 타입 내부전해질은 기준전극에 적용이 어려울 것으로 판단하였다. HEC 함량별 내구성 실험결과, HEC의 함량이 감소할수록 carrier density가 증가하여 다공성 막을 통해 유출되는 전해질(KCl)의 양이 증가하였다. 따라서 선박평형수 처리장치와 같이 장시간 사용하기 위해 겔 타입 내부전해질을 HEC 10%로 선정하였다. HEC 10%의 겔 타입 내부전해질을 이용하여 기준전극과 TRO (total residual oxidants) 센서를 제작하여 TRO 분리능 실험을 수행하였다. TRO 센서에 50 mV의 전위를 30 s 동안 동일하게 인가하여 전류변화를 비교한 결과 0.2~30 PSU 조건에서 0~15 mg/L의 TRO 농도가 분리됨을 확인하였다. 따라서 HEC를 이용한 겔 타입 내부전해질을 TRO 센서에 적용할 수 있으며, 이를 이용하여 담수뿐만 아니라 해수 조건에서 TRO를 측정할 수 있음을 확인하였다.

• 한국환경과학회지
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• 제28권5호
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• pp.495-502
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• 2019

This study was conducted to investigated the possibility of inactivating wilt germs (Fusarium oxysporum f. sp. radicis lycopersici) using Dielectric Barrier Discharge (DBD) plasma in a hydroponic system. Recirculating hydroponic cultivation system for inactivation was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic and DBD plasma reactor. Two experiments were conducted: batch and intermittent continuous process. The effect of plasma treatment on Total Residual Oxidants (TRO) concentration change, Fusarium inactivation and growth of lettuce were investigated. In the batch experiment, most of the Fusarium was inactivated at a TRO concentration of 0.15 mg/L or more at four-day intervals. There was no change in lettuce growth after two times of plasma treatment for one week. The intermittent continuous experiment consisted of 30-minute, 60-minute, and 90-minute plasma treatment in 2 day intervals and 30-minute treatment a one-day; most of the Fusarium was inactivated only by treatment for 30-minute every two days. However, if inactivation under $10^1CFU/mL$ is required, it will be necessary to treat for 60 minutes in 2 day intervals. The plasma treatment caused no damage to the lettuce, except the 30 min plasma treatment ay the one-day interval. It was considered that the residual TRO concentration was higher than that of the other treatments.

• 한국환경과학회지
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• 제25권5호
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• pp.737-744
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• 2016

For electrolysis process using an insoluble electrode, electrochemical performance was greatly affected by the manufacturing method and procedure, such as the firing temperature, pre-treatment, type of precursor solution, coating method, electrode material, etc. Components of the electrode therein is one of the most important factors in electrochemical reaction. To achieve such characteristics, a appropriate ratio of the electrode material should be carefully chosen. The aim of this research was to apply experimental design method in the optimization of electrode component for the maximum generation of oxidants in electrochemical oxidation process. Mixture design, especially expanded simplex lattice design, in DOME (design of mixture experiments) with Design Expert - commercial software - was used to analyze the data. Analysis of variance (ANOVA) showed a high coefficient of determination ($R^2$) value of 0.9470, thus ensuring a satisfactory adjustment of the $3^{rd}$ order special cubic 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 TRO generation concentration and independent variables(mol ratio of 3 electrode components) in a real unit: TRO generation concentration $(mg/L)=TRO\;conc.=98.25{\times}[Ir]+49.71{\times}[Sn]+95.29{\times}[Sb]-16.91{\times}[Ir]{\times}[Sn]-29.47{\times}[Ir]{\times}[Sb]-22.65{\times}[Sn]{\times}[Sb]+703.19{\times}[Ir]{\times}[Sn]{\times}[Sb]$. The optimized formulation of the 3 component electrode for an high TRO (total residual oxidants) generation was acquired at mol ratio of Ir 0.406, Sn 0.210, Sb 0.384 (desirability d value, 1).

• 한국환경과학회지
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• 제26권1호
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• pp.109-118
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• 2017

This study was conducted to investigate the effects of intermittent plasma and electrolysis treatments on lettuce (Lactuca sativa var. oak-leaf.), nutrient solution components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO{_4}^{3-}-P$, $K^+$, $Ca^{2+}$ and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH). The recirculating hydroponic cultivation system consisted of planting port, LED lamp, water reservoir and circulating pump. Nutrient solution was circulated in the following order: reservoir ${\rightarrow}$ filtration-plasma or filtration-electrolysis ${\rightarrow}$ planting port ${\rightarrow}$ reservoir. The results showed that nutrient solution components and environmental parameters were changed by plasma or electrolysis treatment. Lettuce growth was not affected by the intermittent plasma or electrolysis treatment with 30 minutes or 90 minutes, respectively. The roots of the lettuce was damaged by excessive plasma and electrolysis treatment. Electrolysis treatment had greater effect on than plasma treatment because of the accumulation of high levels of TRO (Total Residual Oxidants).

• 한국어병학회지
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• 제12권1호
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• pp.32-41
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• 1999

오존처리 해수중에 함유하는 잔류 옥시던트(TRO)가 양식 넙치의 생존, 혈액성상과 삼투질 농도, 산소소비 및 아가미 조직에 미치는 독성 영향을 조사하였다. TRO에 노출된 넙치의 48-hr 및 96-hr $LC_{50}$은 각각 26.4 와 22.3ppb이었고, 47ppb에서는 3시간 이내에 모두 치사하였으나 13ppb에서는 96시간 동안 폐사발생이 없었다. TRO 24~39ppb 농도범위에 노출된 넙치의 hematocrit, 헤모글로빈, 적혈구 수, 혈중 sodium과 chloride 이온 및 삼투압 농도는 TRO 농도가 높을수록 유의하게 증가하였고, 아가미 조직은 아가미 상피층이 모세혈관으로부터 박리되고, 괴사와 상피새포의 증생이 관찰되었다. 산소소비율은 TRO 농도가 높고, 노출이 계속될수록 감소하였다. 13ppb에서는 아가미 조직과 생리상태에 미치는 변화는 관찰되지 않았으나 혈당은 유의하게 증가하였다. 그러나 활성탄으로 TRO를 제거한 대조구에서는 오존의 독성 영향은 관찰되지 않았다. 잔류오존에 노출된 넙치는 삼투질 농도의 생리적 불균형 및 아가미 손상과 상피세포의 증생에 의한 산소섭취 부족이 치사를 유발하는 것으로 나타났다. 본 연구의 결과 해산어 양식장에서 오존을 사용할 경우에는 오존처리수중의 TRO는 제거하여야 하며, 비록 저농도라도 장기간 노출되면 양식어류의 생존과 생리상태에 미치는 영향은 현저할 것으로 평가되었다.

• 한국환경과학회지
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• 제23권6호
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• pp.1175-1182
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• 2014

In this study, we examined the effect of cathode from electrolysis reactor for treating ballast water. We are going to select a suitable cathode for seawater electrolysis after considering the effect on the generation of the oxidant of cathode and the electrode deposition materials adhering to the surface of cathode. Anode is Ru-Ti-Pd electrode and cathode are Ti, Pt, JP520 (Ni-Pt-Ce) electrodes. Using the cathode of the three types, experiments were conducted to examine the effects of TRO (total residual oxidants) generation concentration and RNO (N, N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical) degradation concentration (in 1, 35 psu), ohmic drop, FESEM(field emission scanning electron microscope) observation of cathode surface and EDX (energy dispersive X-ray spectroscopy) measurements of attached fouling material. The results showed that TRO generation concentration and RNO degradation concentration in according to each type of cathode are not different. The attached fouling materials were observed on the surface of Ti and the JP520 electrode by the observation of SEM after electrolysis for two hours, but it was not observed on the surface of Pt electrode. When considering the surface ohmic drop of cathode and the attached fouling materials, Pt electrode was judged as the excellent cathode.

• 한국어병학회지
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• 제12권1호
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• pp.42-48
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• 1999

해수중 잔류옥시던트(TRO) 농도를 0.1, 0.3 및 0.5 mg/liter로 조정하고 시간 경과에 따른 농도의 안정성을 관찰한 결과 0.1 mg/liter의 경우 측정 20분까지는 변화를 보이지 않았고, 0.3 및 0.5 mg/liter 에서는 1시간 경과시까지 안정하였다. 해수를 오존처리하여 해수중에 생성되는 TRO를 이용하여 해산어류 병원세균인 Edwardsiella tarda, Vibrio sp., Streptococcus sp., Staphylococcus sp.에 대한 살균효과를 실험한 결과 0.1 mg/liter에서 3분간의 처리로 99.9% 이상, 0.3~0.5 mg/liter에서는 30초에서 1분간의 반응시간으로 99.99% 이상이 살균되어졌다.