• Title/Summary/Keyword: removal efficiency

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Photocatalytic Oxidation of Free Cyanide Using UV LED (자외선 LED를 이용한 자유 시안의 광촉매 산화)

  • Kim, Seong Hee;Seol, Jeong Woo;Lee, Woo Chun;Lee, Sang-Woo;Kim, Soon-Oh
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.1
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    • pp.34-44
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    • 2015
  • This study was initiated to remove free cyanide from wastewater using the process of photocatalytic oxidation. UV lamp has been extensively used as a light source in conventional photocatalytic oxidation, but numerous drawbacks of UV lamp have been raised so far. Thus, this study focused on evaluating the applicability of UV LED as an alternative light source to overcome the drawbacks of UV lamp. Furthermore, the effects of diverse operational parameters on the performance of process were investigated. The results demonstrated the applicability of UV LED as a substitute of UV lamp. Also, the results show that the performance of process was improved by the increase in the number of UV LEDs used. To acquire economic feasibility as well as high efficacy, however, it is required to determine the optimum number of UV LED prior to practical implementation of the process. Among the three types of photocatalysts (anatase, rutile, and Degussa P25) tested, the Degussa P25 showed the greatest performance, and it was proven that the process was not improved as much as the Degussa P25 through simple mixing of anatase and rutile without any pretreatment. In addition, the removal efficiency of free cyanide appeared to be increased with the decrease in the particle size of $TiO_2$ photocatalyst. Besides, the process was enhanced with injection of oxygen which is considered as a major electron acceptor in the photocatalytic oxidation.

Study on Growth Characteristics of Sargassum fulvellum in the Integrated Multi-trophic Aquaculture (IMTA) System

  • Kim, Young-Dae;Park, Mi-Seon;Min, Byung-Hwa;Jeong, Seong-Jae;Kim, Hyung-Chul;Yoo, Hyun-Il;Lee, Won-Chan;Choi, Jae-Suk
    • Journal of Environmental Science International
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    • v.23 no.10
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    • pp.1703-1718
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    • 2014
  • An eco-friendly integrated multi-trophic aquaculture (IMTA) farming technique was developed with the goal of resolving eutrophication by excess feed and feces as fish-farming by-products. A variety of seaweed species were tried to remove inorganic nutrients produced by fish farming. However, there have been few trials to use Sargassum fulvellum in an IMTA system, a species with a relatively wide distribution across regions with various habitat conditions, great nutrient removal efficiency and importance for human food source and industrial purposes. In this regard, our study tried to examine feasibility of using S. fulvellum in an IMTA system by analyzing growth characteristics of the species in an IMTA system comprising of rockfish (Sebastes shlegeli), sea cucumber (Stichopus japonocus) and the tried S. fulvellum (October 2011 - November 2012). We also monitored environment conditions around the system including current speed, water temperature and inorganic nutrient level as they may affect growth of S. fulvellum. S. fulvellum in the IMTA system, which were $15.72{\pm}5.67mm$ long at the start of the experiment in October 2011, grew to a maximum of $1093{\pm}271.13mm$ by May 2012. In September, seaweed growth was reduced to a minimum of $280{\pm}70.43mm$ in length. Then, S. fulvellum began to grow again reaching $325{\pm}196.19mm$ by November 2012. Wet weight of the seaweed was $4.01{\pm}1.89g$ at the start of the experiment and reached a maximum of $109.26{\pm}34.23g$ in May. The weight gradually declined to a low of $15.12{\pm}8.40g$ in September 2012. Weight began to increase once more, rising to $39.27{\pm}21.69g$ by November. During the experiment, the average velocity at the surface and the bottom was 6.5 cm/s and 3.4 cm/s, respectively. The water temperature ranged $5.0-23.5^{\circ}C$, which was considered suitable for growing S. fulvellum. Results of the study indicated no significant differences in inorganic nutrients between pre- and post-IMTA installation. It was thus concluded that S. fulvellum can be a suitable seaweed species to be used in an IMTA system.

Effect of Garlic with Different Processing on Lipid Metabolism in 1% Cholesterol Fed Rats (처리조건을 달리한 마늘 첨가식이가 1% 콜레스테롤 급여 흰쥐의 지질대사에 미치는 영향)

  • Kang, Min-Jung;Lee, Soo-Jung;Shin, Jung-Hye;Kang, Shin-Kwon;Kim, Jeong-Gyun;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.2
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    • pp.162-169
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    • 2008
  • This study was designed to investigate the effect on treatments of garlic and the improvement of lipids in dietary-induced hyperlipidemic rats. Rats were administrated 1% cholesterol to induce hyperlipidemia and were fed diets containing fresh garlic powder (FGP), steamed garlic powder (SGP) and black garlic powder (BGP) by 3% (w/w) for 4 weeks. Body weight gain and food efficiency was not significantly different between control and garlic powder fed groups. Liver weight was significantly higher in control and SGP fed groups. Blood glucose was decreased in FGP and BGP fed groups than control group. The concentration of total lipid was significantly decreased in BGP group. Total cholesterol and triglyceride of serum were significantly lower in garlic powder fed groups than control group. HDL-cholesterol was significantly higher, LDL-, and VLDL-cholesterol were significantly lower in the garlic powder fed groups than the control group. Activities of serum GOT was lower in SGP fed group than control group. Total hepatic lipid and cholesterol concentration were conspicuously decreased by garlic powder fed groups. TBARS concentration of liver was significant different for the added garlic powder administration. Antioxidant activity of liver tended to increase in garlic powder fed groups compared with control group. In this result, we suggest the preventive effect of black garlic against the atherosclerotic process and the improvement of hyperlipidemia through the removal of cholesterol.

Adsorption Characteristics Evaluation of Natural Zeolite for Heavy-metal Contaminated Material Remediation (중금속 오염물질 정화를 위한 천연제올라이트의 흡착특성)

  • Shin, Eun-Chul;Park, Jeong-Jun;Jeong, Cheol-Gyu;Kim, Sung-Hwan
    • Journal of the Korean Geosynthetics Society
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    • v.13 no.2
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    • pp.59-67
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    • 2014
  • The amount of the contaminants that can be adsorbed on the drain was evaluated for the effective remediation of the contaminated soil, and the contaminants adsorptivity of the drain was evaluated by comparing the isothermal adsorption model after carrying out the contaminants adsorption test of the reactants coated on the surface of the drain. The reactant used in the experiment is a natural zeolite, and the contaminants are copper, lead and cadmium. The results that Freundlich and Langmuir adsorption isotherm model are compared to the adsorption amount according to the change of the initial concentration by the contaminants. As a result of the component analysis, because Si, Al and O are contained approximately 28%, 11% and 48%, respectively, it is identified that the material coated on the surface of the drain is the component of the zeolite which is the reactant for the adsorption of the heavy-metal (Cu, Pb, Cd) contaminants. The heavy-metal adsorption kinetic of the zeolite which is the reactant was decreased in order of lead, copper and cadmium. The important factor of the performance evaluation of the adsorbent is the reaction rate, and if zeolite is used as the reactant in the relationship between the maximum amount of adsorption and reaction rate, it can be utilized as the design factor that determine the removal order of the complex heavy-metal. In other words, because the maximum adsorption quantity of lead is smaller compared to copper but the reaction rate is relatively fast, it can be primarily removed, and copper can be removed after removing the lead. It was analyzed that Cadmium can be finally removed after that other heavy-metal is removed.

Removal of Chlorinated Organic Compounds in Flue Gas by Activated Carbon Injection in a Semi-Drying Reactor (반건식 반응기에서의 활성탄 혼합주입에 의한 소각로 배가스중의 유기 염소계 화합물의 제거 공정 연구)

  • Choo, Changupp;Whang, Jaedong;Lee, Joyoung;Cho, Chulhoon;Shin, Byungchul
    • Clean Technology
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    • v.6 no.2
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    • pp.121-127
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    • 2000
  • There are several kinds of hazardous materials in incinerator flue gas, such as particulate matter, acid gas, heavy metal, dioxin, etc. The activated carbon adsorption is considered as one of the methods removing dioxin from flue gas. Without any additional equipment and facilities, the activated carbon was mixed with lime and sprayed in the semi-drying reactor of an incinerator and filtered in the bag filter, and its efficiency of removing hazardous organic material was investigated. 1,2-dichlorobenzene (o-DCB) was used as a precursor material of dioxin and the effects of the activated carbon amount, the operating temperature of the reactor, and the atomizer r.p.m were measured and analyzed. Experimental results showed that the optimum outlet temperature of the reactor was $145^{\circ}C$ considering the performance of the bag filter, and the adsorption performance improved with the increase of the atomizer r.p.m. Also the performance of removing o-DCB in the bag filter is higher than of the semi-drying reactor.

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Studies on the Artificial Cultivation of Pleurotus cystidiosus O.K.Miller, the Abalone Mushroom (전복느타리버섯(Pleurotus cystidiosus O.K.Miller)의 인공재배에 관한 연구)

  • Jang, Kab-Yeul;Jhune, Chang-Sung;Shin, Chul-Woo;Park, Jung-Sik;Oh, Se-Jong;Choi, Sun-Gyu;Sung, Jae-Mo
    • The Korean Journal of Mycology
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    • v.31 no.3
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    • pp.200-205
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    • 2003
  • The study was carried out on the artificial cultivation of the abalone mushroom, Pleurotus cystidiosus O.K.Miller. The pine sawdust substrates with 20% rise bran were good for mycelial growth and high quantity of P. cystidiosus in the bottle cultivation. Moreover, the proper volume for bottle cultivation was 850 ml and the removal of spawn and surface layer of the medium before pin-heading was more efficient. The yields of P. cystidiosus were higher in sawdust substrates added calcium carbonate than those not added calcium carbonate. The volume of 3 kg polypropylene bag is good for yield and biological efficiency in bag cultivation of P. cystidiosus. Cotton wastes were proper substrates for bag cultivation. In the effect of different cultivation temperature, $28{\pm}2^{\circ}C$ cultivation temperature was good for for primordial formation after inoculation.

Application of the Hybrid Constructed Wetland for a Reuse of the Effluent from Bio-industrial Wastewater Treatment Plant (바이오산업폐수처리수의 재이용을 위한 hybrid 인공습지 시스템의 적용가능성 연구)

  • Shin, Jae-Suk;Kim, Sung-Chul;Cho, Kwang-Ju;Choi, Choong-Ho;Choi, In-Wook;Park, Jeong-Ja;Park, Goo-Hyeon
    • Journal of Wetlands Research
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    • v.11 no.1
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    • pp.115-121
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    • 2009
  • The hybrid constructed wetland(HCW) as tertiary treatment process of a bio industrial wastewater treatment plant was employed to estimate applications for the reuse of final effluent. Raw wastewater was sequently treated through chemical and biological treatment processes and the biologically treated water was flowed into the HCW. The HCW system was composed of two constructed wetlands connected in series; The one is the aerobic constructed wetland with natural air draft system whose driving force for air supply was the difference between the temperature of the air inside the wetland and the ambient air, and the other is the anaerobic/anoxic constructed wetland. Average influent concentrations of BOD, SS, T-N and T-P in the HCW were 53mg/L, 48mg/L, 34mg/L and 3mg/L, respectively. After being treated at HCW, final effluent concentrations of BOD, SS, T-N and T-P were 2.3mg/L, 1.2mg/L, 7.95mg/L and 0.83mg/L, respectively. Referring to a reuse standard for a sewage wastewater, final effluent could sufficiently be reuse as landscaping, washing or agriculture water. HCW system with the aerobic/anaerobic combined constructed wetland could be achieved a high removal efficiency because each constructed wetland was functionalized to be removed efficiently organics, nitrogen and phosphorus. HCW system could be estimated to be successful application as tertiary treatment process of a various industrial and municipal wastewater.

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Filter Media Specifications for Low Impact Development: A Review of Current Guidelines and Applications (LID 시설 여재에 관한 기술지침 및 적용에 관한 고찰)

  • Guerra, Heidi B.;Kim, Lee-Hyung;Kim, Youngchul
    • Journal of Wetlands Research
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    • v.21 no.4
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    • pp.321-333
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    • 2019
  • A primary aspect of low impact development (LID) design that affects performance efficiency, maintenance frequency, and lifespan of the facility is the type of filter media as well as the arrangement or media profile. Several LID guidelines providing media specifications are currently available and numerous studies have been published presenting the effectiveness of these systems. While some results are similar and consistent, some of them still varies and only a few focuses on the effect of filter media type and arrangement on system performance. This creates a certain level of uncertainty when it comes to filter media selection and design. In this review, a synthesis of filter media specifications from several LID design guidelines are presented and relevant results from different laboratory and field studies are highlighted. The LID systems are first classified as infiltration or non-infiltration structures, and vegetated or non-vegetated structures. Typical profiles of the media according to classification are shown including the different layers, materials, and depth. In addition, results from previous studies regarding the effect of filter media characteristics on hydraulic and hydrologic functions as well as pollutant removal are compared. Other considerations such as organic media leaching, clogging, media washing, and handling during construction were also briefly discussed. This review aims to provide a general guideline that can contribute to proper media selection and design for structural LIDs. In addition, it also identifies opportunities for future research.

Characterization of Natural Zeolite and Study of Adsorption Properties of Heavy Metal Ions for Development of Zeolite Mine (제올라이트 광산개발을 위한 천연 제올라이트의 특성 분석 및 중금속 이온 흡착 특성 연구)

  • Kim, Hu Sik;Kim, Young Hun;Baek, Ki Tae;Lim, Woo Taik
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.4
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    • pp.299-308
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    • 2015
  • The six natural zeolites collected in Pohang area, Kyungsangbuk-do, Korea, were characterized by XRD, XRF, DTA, TGA, and CEC analysis. The primary species of these zeolite are modenite, albite, and quarts in Kuryongpo-A (Ku-A), Kuryongpo-B (Ku-B), Kuryongpo-C (Ku-C), Donghae-A (Dh-A), Donghae-B (Dh-B), and Donghae-C (Dh-C) samples. The XRF analysis showed that the six zeolites contain Si, Al, Na, K, Mg, Ca, and Fe. Cation exchange capacity of Kuryongpo-C (Ku-C) zeolite was the highest compared to other zeolites. The capabilities of removing heavy metal ions such as $Pb^{2+}$, $Cd^{2+}$ and $Cu^{2+}$ were compared. The effect of reaction time in removing heavy metal ions was studied. The experimental results showed that the efficiency of removal was low for $Pb^{2+}$, $Cd^{2+}$ and $Cu^{2+}$ ions. These may be caused by the low content of zeolite in the six natural zeolites. This indicates that the adsorption capacity roughly tends to depend on the zeoite contents, ie., the grade of zeolite ore.

Deduction of affecting factors for selecting the way of going into the main building of an apartment complex when constructing an underground parking lot. (지하주차장 공사시 주동진입방법 선정 영향요인 도출)

  • Song, Nak-Hyun;Whang, Kyoung-Jin;Lee, Chan-Sik
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.995-998
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    • 2007
  • The number of households old over as much as 20 years is expected to get increased rapidly more than 1,000,000(1 million). As a measure to this fact remodeling is being revitalized over the country. parking lots expansion actually takes up a great deal of weight among the requirement for remodeling. When constructing a parking lot for enlargement, the way of going into the main building determines such construction features as selection of Retaining Wall Method, installation of an elevator, parking measure of capacity, etc. This study derived the affecting factors for selecting the way of going into the main building when constructing an underground parking lot. In a research way, we examined the features on each method of going into the main building in an apartment complex through an in-depth interview with some experts after investigating the method of enlarging an underground parking lot and going into the main building. After that, we derived the affecting factors for selecting the way of going into the main building. The affecting factors include constructability, convenience, economic efficiency as a high level as well as existence and nonexistence of basement and removal, safety of current building, parking measure of capacity, amenity, inhabitant traffic line, construction expenses and construction duration as a low one. This study will be applied as a reference for selecting the way of going into the main building when constructing an underground parking lot especially targetted on an old apartment house.

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