Sulfide dissolved in wastewater is a potential source of hydrogen sulfide. Hydrogen sulfide is an odorous substance that causes civil complaints and is a dangerous substance that threatens the corrosion of structures and the safety and health of workers. The removal efficiencies of the chemical oxidant and the coagulants were compared to evaluate the removal of dissolved sulfide. Since the effectiveness may vary depending on the characteristics of the wastewater, water was used as a control, and 5 mg/L of dissolved sulfide was dissolved in water and sewage wastewater. When oxidant was used, the results showed a high sulfide removal rate in sewage wastewater than water, and the removal efficiency was enhanced with increasing oxidant concentration. Sulfide removal efficiencies after one hour after injecting oxidants H2O2, NaOCl, NaClO2 to sewage wastewater were 70%, 90%, and 100%, respectively. After the oxidants were administered four times, the removal was 90%, 100%, and 100%, respectively. In the case of sulfide removal with the oxidizing agent, the removal efficiency was NaClO2, NaOCl, H2O2 (highest - lowest). NaClO2 showed 100% removal efficiency within 10 minutes under all conditions (A condition, B condition), making it the most sewage effective agent in this study. In the case of the coagulants, 100% of the sulfides dissolved in water were removed in the first 10 minutes under all conditions. In sewage wastewater, FeCl2 and FeSO4 also showed 100% removal efficiency under all conditions after one hour, and FeCl3 showed 90% and 99% removal rates under A and B conditions, respectively. That is, the monovalent iron coagulants (FeCl2, FeSO4) were found to be somewhat more effective in the removal of sulfides in sewage wastewater than the divalent iron (FeCl3) coagulants. When the sulfides were removed with coagulants, FeCl2 had the highest removal efficiency followed by FeSO4 and FeCl3. Moreover, it was found that NaClO2 has the best reaction efficiency at the minimum reaction time and the reaction concentration.

망간은 수중에서 대체적으로 불용성이나, 지하나 지표에서 여러 가지 반응으로 인해 수중으로 용존되어 유입된다. 용존된 망간은 먹는 물에서 0.1 mg/L 이상일 경우 불쾌한 금속냄새가 나며, 0.02 mg/L 이상에서는 박테리아에 의한 이취미가 발생할 수 있다. 또한, 망간산화물이 급배수관에 피복되어 통수능을 감소시킨다. 최근 강화된 국내 먹는 물 수질 기준치는 0.05 mg/L이다. 이러한 망간 문제를 해결할 수처리 공정 연구가 필요하다. 본 연구에서는 과망간산칼륨(KMnO4)과 차아염소산 나트륨(NaOCl)을 이용하여 망간을 산화물로 변화시키고, 이를 한외여과막으로 제거한 후의 망간제거효율을 연구하였다. 특히, 두 산화제를 복합으로 사용할 때의 효과를 분석하고 실제 적용 가능성을 타진하였다.

The odorants from wastewater sludge treated with four different chemical oxidants, i. e., potassium ferrate, sodium hypochlorite, sodium permanganate, and calcium nitrate, were analyzed. The release of odorants from the treated sludge was not completely eliminated, only retarded, possibly due to the low one time doseof oxidants. In a comparison of the concentration profiles of methyl mercaptan and dimethyl sulfide, calcium nitrate was the best of the four different oxidants at reducing their emission. For methyl mercaptan, calcium nitrate gave the best result, while for dimethyl sulfide, potassium permanganate was found to be the best oxidant. From this study, it was found that the oxidation-reduction potential (ORP) would be an easy and inexpensive parameter for the monitoring of the release of offensive odors.

Background : Native oak tree species dominated the deciduous forests of South Korea. The acorns of them represent the main food source for wildlife species as well as human being, and they have 28 species. We analyzed and compared to the antioxidants including total phenolics and functional nutrients components among the acorns of nine kinds of oak trees (Quercus acutissima, Q. aliena, Q. mongolica, Q. variabilis, Q. serrata, Q, palustris, Q. rubra, Q. glauca, and Q. acuta). Methods and Results : Acorns were collected from each tree species, which were grown in a seed orchard. Contents of both total phenolic content (TPC) in acorns of Q. serrata were higher than others. Interestingly, Q. serrata contained the highest amount of water soluble tannins and the lowest levels of water insoluble tannins among 9 oak species, resulting that acorns of Q. serrata had the lowest proportion of insoluble tannins. Among 9 oak species tested, Q. aliena acorns contained the highest levels of total flavonoids content (TFC). Conclusion : Our result showed that nutritional composition of acorns was significantly different between oak species, indicating that tastes or nutritional values might be different as well among major oak species in Korea.

연구에서는 수염에 대한 면도력을 향상시킬 수 있는 화장료 제형 개발을 위하여 대면용 화장료에서 사용 가능한 우레아 및 여러 항산화제의 수염 강도 약화 효과를 연구하였다. 실제 모발 강도 약화 효과는 우레아 농도 에 의존적인 성향을 보였으며, 모발 면적 증가율 역시 농도에 의존적인 것으로 나타나 우레아 농도에 따라 모발 의 수화 정도가 달라지며 이것이 강도 약화에 영향을 주는 것을 확인할 수 있었다. 항산화제는 종류에 따라 소량 으로도 뛰어난 강도 감소 효과를 보이며, 이는 모발에 다량 존재하는 시스틴 결합을 환원시키기 때문으로 해석된 다. 마지막으로 대면용으로서의 적합성 판단을 위해 우레아 및 항산화제의 in vitro 안전성 테스트를 진행하였다. 안전성 테스트 결과 우레아는 대면용으로 사용하기 적합한 정도로 나타났으며, 항산화제 중에서는 글루타치온이 적합한 것으로 나타났다. 위 결과들을 통해 피부 자극이 적고 모발 강도 약화 효과가 뛰어나 면도용 제품에 적용 하기 적합한 원료는 우레아 및 글루타치온임을 알 수 있었다.

Livestock wastewater has high potential as one of energy resources because this wastewater is including high organic matter. Therefore the studies attempting to bio-gasification and bio-electricity generation using livestock wastewater is being tried. The pre-treatment system used in this study was the purpose to control the ammonia nitrogen in conjunction with the system and the microbial fuel cell. Because ammonia nitrogen is to inhibit the electricity generation efficiency of microbial fuel cell. These studies were to ascertain the effect of oxidants on the nitrogen removal in the pre-treatment system using catalyst and microbubbles to treat the ammonia nitrogen. The three kinds of oxidant such as air, oxygen (O2), and hydrogen peroxide (H2O2) were used to know the ammonia and nitrate nitrogen removal. This system was operated with four kinds of conditions. First method is O2 gas with 100 mL/min with 1ml of 30% H2O2 was supplied to the wastewater. A second method, the O2, with 400 and 1,000 mL/min was supplied through the flow meter before livestock wastewater was flow in the reactor. The last method, air was supplied 800 mL/min. The nitrate removal had no significant difference all conditions except the air supply. On the other hand, the ammonia and nitrate nitrogen removal when oxygen was supplied with 1000 mL O2/min was higher than that of the other conditions. The removal rate when air was supplied 800 mL/min was similar to the value in the supplied with 400 ml O2/min. This result showed that oxidant was important factor to improve the ammonia nitrogen removal rate.

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.

The aim of this research was to evaluate the performance of insoluble electrode for the purpose of degradation of Rhodamine B (RhB) and oxidants generation [N,N-Dimethyl-4-nitrosoaniline (RNO, indicator of OH radical), O3, H2O2, free Cl, ClO2)]. Methods: Four kinds of electrodes were used for comparison: DSA (dimensional stable anode; Pt and JP202 electrode), Pb and boron doping diamond (BDD) electrode. The effect of applied current (0.5～2.5 A), electrolyte type (NaCl, KCl and Na2SO4) and electrolyte concentration (0.5～3.5 g/L) on the RNO degradation were evaluated. Experimental results showed that the order of RhB removal efficiency lie in: JP202 > Pb > BDD ≒> Pt. However, when concerned the electric power on maintaining current of 1 A during electrolysis reaction, the order of RhB removal efficiency was changed: JP202 > Pt ≒ Pb > BDD. The total generated oxidants (H2O2, O3, free Cl, ClO2) concentration of 4 electrodes was Pt (6.04 mg/W) > JP202 (4.81 mg/W) > Pb (3.61 mg/W) > BDD (1.54 mg/W), respectively. JP202 electrode was the best electrode among 4 electrodes from the point of view of performance and energy consumption. Regardless of the type of electrode, RNO removal of NaCl and KCl (chlorine type electrolyte) were higher than that of the Na2SO4 (sulfuric type electrolyte) RNO removal. Except BDD electrode, RhB degradation and creation tendency of oxidants such as H2O2, O3, free Cl and ClO2, found that do not match. RNO degradation tendency were considered a simple way to decide the method which is simple it will be able to determinate the electrode where the organic matter decomposition performance is superior. As the added NaCl concentration was increases, the of hydrogen peroxide and ozone concentration increases, and this was thought to increase the quantity of OH radical.

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.

The purpose of this study is to investigate electro-generation of free Cl, ClO2, H2O2 and O3 and degradation of Rhodamine B in solution using Ru-Sn-Sb electrode. Electrolysis was performed in one-compartment reactor using a dimensionally stable anode(DSA) of Ru-Sn-Sb/Ti as the working electrode. The effect of applied current (0.5-3 A), electrolyte type (NaCl, KCl, HCl, Na2SO4 and H2SO4) and concentration (0.5-2.5 g/L), air flow rate (0-3 L/min) and solution pH (3-11) was evaluated. Experimental results showed that concentration of 4 oxidants was increased with increase of applied current, however optimum current for RhB degradation was 2 A. The generated oxidant concentration and RhB degradation of the of Cl type-electrolyte was higher than that of the sulfate type. The oxidant concentration was increased with increase of NaCl concentration and optimum NaCl dosage for RhB degradation was 1.75 g/L. Optimum air flow rate for the oxidants generation and RhB degradation was 2 L/min. ClO2 and H2O2 generation was decreased with the increase of pH, whereas free Cl and O3 was not affected by pH. RhB degradation was increase with the pH decrease.

Fabrication and oxidants production of 3 or 4 components metal oxide electrode, which is known to be so effective to destruct non-biodegradable organics in wastewater, were studied. Five electrode materials (Ru as main component and Pt, Sn, Sb and Gd as minor components) were used for the 3 or 4 components electrode. The metal oxide electrode was prepared by coating the electrode material on the surface of the titanium mesh and then thermal oxidation at 500℃ for 1 h. The removed RhB per 2 min and unit W of 3 components electrode was in the order: Ru:Sn:Sb=9:1:1 > Ru:Pt:Gd=5:5:1 > Ru:Sn=9:1 > Ru:Sn:Gd=9:1:1 > Ru:Sb:Gd=9:1:1. Although RhB decolorization of Ru:Sn:Sb:Gd electrode was the highest among the 4 components electrode, the RhB decolorization and oxidants formation of the Ru:Sn:Sb=9:1:1 electrode was higher than that of the 3 and 4 components electrode. Electrogenerated oxidants (free Cl and ClO2) of chlorine type in 3 and 4 components electrode were higher than other oxidants such as H2O2 and O3. It was assumed that electrode with high RhB decolorization showed high oxidant generation and COD removal efficiency. OH radical which is electrogenerated by the direct electrolysis was not generated the entire 3 and 4 components electrode, therefore main mechanism of RhB degradation by metal oxide electrode based Ru was considered indirect electrolysis using electrogenerated oxidants.

Fabrication and oxidants formation of 1 and 2 component metal oxide electrode, which is known to be so effective to destruct non-biodegradable organics in wastewater, were studied. Five electrode materials (Ru, Pt, Sn, Sb and Gd) were used for the 1 and 2 component electrode. The metal oxide electrode was prepared by coating the electrode material on the surface of the titanium mesh and then thermal oxidation at 500℃ for 1 h. The removed RhB per 2 min and unit W for one component electrode decreased in the following sequences: Ru/Ti > Sb/Ti > Pt/Ti > Gd/Ti > Sn/Ti. The concentration of oxidants generated in 1 and 2 component electrodes was in the order of: ClO2 > free Cl > H2O2 > O3. OH radical was not generated from in entire one and two component electrodes. RhB degradation rate and generated oxidants of the Ru-Sn=9:1 electrode was higher than that of the two component electrode. The exact relationship between the removal of RhB and the generated oxidants concentration was not obvious. However, it was assumed that electrode with high RhB decolorization had high oxidant concentration.