• Title/Summary/Keyword: AOP.

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Removal of Total Organic Carbon and Micropollutants in Tertiary Treated Sewage by Medium Pressure UV/H2O2 (중압 자외선과 과산화수소 공정을 이용한 하수 3차 처리수중 총유기탄소와 미량오염물질 제거)

  • Lee, Jai-Yeop;Kim, Ilho
    • Journal of Korean Society on Water Environment
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    • v.36 no.4
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    • pp.314-321
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    • 2020
  • This study evaluated the applicability of UV-AOP process using medium-pressure UV lamp and H2O2 to remove TOC and emerging micropollutants in the effluent from a sewage treatment plant. The UV lamp with higher output(1.6~8.0 kW) showed slightly higher amount of power in removing TOC of 1 mg/L(0.09 kWh/mg/L~0.11 kWh/mg/L), however it was found that there was no significant difference for each cases. In addition, under the condition that the H2O2 concentration is sufficient, as the power consumption of the UV lamp increases, the unit TOC removal concentration per unit H2O2 decomposition concentration also increases, resulting in effective removal of TOC. The removal rate of 7 new trace contaminants, such as antibiotics by the UV-AOP tested, was at least 89.4%, and the ability to remove the emerging micro pollutants in the process was very effective. But, it was judged that it could not be excluded that the probablity of transforming to oxidated by-product in the case of a low TOC removal efficiency. Depending on the operating conditions of the UV and H2O2 processes, a higher BOD concentration is found in the treated water than in the influent, and it is necessary to review the UV power and proper injection conditions of H2O2 to maintain the BOD concentration increase below a certain level.

Superoxide Anion Radical: Principle and Application (슈퍼옥사이드 음이온 라디칼 화학과 응용)

  • Kwon, Bum Gun;Yoon, Jeyong
    • Applied Chemistry for Engineering
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    • v.20 no.6
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    • pp.593-602
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    • 2009
  • For a long time, there is much interest in the superoxide anion radical as one of reactive oxygen species (ROS) not only in the basic research field of chemistry and physics but also in the life science (or biotechnology). Recently, it is becoming ever more vital since the toxic property of nanomaterials as well as advanced oxidation processes (AOP) frequently employed for controlling pollutants are connected with the formation of superoxide anion radicals. Despite many researches on superoxide anion radical, the quantitative information of its presence and its detailed reaction mechanism in aqueous environments remains largely unclear, causing the controversy and confusion. In this review paper, we attempted to summarize the physicochemical property, mechanisms, and applications of superoxide anion radical. In addition, we briefly incorporated the important application of superoxide anion radical in AOP, nanomaterials, and life science (or biotechnology).

A Study on Applicability of Anti-Oppressive Practice to Foreign Workers in South Korea (한국 외국인근로자를 위한 반-억압 실천 (Anti-oppressive practice)의 적용가능성 연구)

  • Yang, Man Jae;Kim, Anna
    • 한국사회정책
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    • v.25 no.3
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    • pp.247-278
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    • 2018
  • Anti-oppressive practice (AOP) is a form of social work practice that has developed in the UK. In South Korea, Anti-oppressive social work has not been widely studied / explored unlike in other countries in the world. Its main principles, social justice and human rights, have become commonplace. AOP includes transformational practice because its orientation emphasizes social change through celebrating diverse identities and rejecting hierarchies of oppression and prestige. Recently, a growing body of literature on social work with foreign workers has resulted in an increased understanding of its population and its needs. It needs a theoretical and practical framework for foreign workers necessary to inform effective models of service delivery, reflecting cultural competence, and changing oppressive social structure. In this paper, we will introduce the main principles of AOP, analyse written texts reflected by foreign workers and social work practitioners' opinion, and suggest the implications on possibilities and constraints of applicability to foreign workers in South Korea.

A Systematic Review of Toxicological Studies to Identify the Association between Environmental Diseases and Environmental Factors (환경성질환과 환경유해인자의 연관성을 규명하기 위한 독성 연구 고찰)

  • Ka, Yujin;Ji, Kyunghee
    • Journal of Environmental Health Sciences
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    • v.47 no.6
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    • pp.505-512
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    • 2021
  • Background: The occurrence of environmental disease is known to be associated with chronic exposure to toxic chemicals, including waterborne contaminants, air/indoor pollutants, asbestos, ingredients in humidifier disinfectants, etc. Objectives: In this study, we reviewed toxicological studies related to environmental disease as defined by the Environmental Health Act in Korea and toxic chemicals. We also suggested a direction for future toxicological research necessary for the prevention and management of environmental disease. Methods: Trends in previous studies related to environmental disease were investigated through PubMed and Web of Science. A detailed review was provided on toxicological studies related to the humidifier disinfectants. We identified adverse outcome pathways (AOPs) that can be linked to the induction of environmental diseases, and proposed a chemical screening system that uses AOP, chemical toxicity big data, and deep learning models to select chemicals that induce environmental disease. Results: Research on chemical toxicity is increasing every year, but there is a limitation to revealing a clear causal relationship between exposure to chemicals and the occurrence of environmental disease. It is necessary to develop various exposure- and effect-biomarkers related to disease occurrence and to conduct toxicokinetic studies. A novel chemical screening system that uses AOP and chemical toxicity big data could be useful for selecting chemicals that cause environmental diseases. Conclusions: From a toxicological point of view, developing AOP related to environmental diseases and a deep learning-based chemical screening system will contribute to the prevention of environmental diseases in advance.

Improvement of Organic Substances Indicators by Linked Ultra Violet-Advanced Oxidation Process After Ozonation for Anaerobic Digested Wastewater (소화탈리액 대상 오존 전처리와 Ultra Violet-Advanced Oxidation Process 연계 처리를 통한 유기물질 지표 개선)

  • Jaiyeop Lee;Jesmin Akter;Ilho Kim
    • Journal of Korean Society of Water and Wastewater
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    • v.37 no.5
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    • pp.253-259
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    • 2023
  • Bioreactors are devices used by sewage treatment plants to process sewage and which produce active sludge, and sediments separated by solid-liquid are treated in anaerobic digestion tanks. In anaerobic digestion tanks, the volume of active sludge deposits is reduced and biogas is produced. After dehydrating the digestive sludge generated after anaerobic digestion, anaerobic digested wastewater, which features a high concentration of organic matters, is generated. In this study, the decomposition of organic carbon and nitrogen was studied by advanced oxidation process. Ozone-microbubble flotation process was used for oxidation pretreatment. During ozonation, the TOC decreased by 11.6%. After ozone treatment, the TOC decreased and the removal rate reached 80.4% as a result of the Ultra Violet-Advanced Oxidation Process (UV-AOP). The results with regard to organic substances before and after treatment differed depending on the organic carbon index, such as CODMn, CODCr, and TOC. Those indexes did not change significantly in ozone treatment, but decreased significantly after the UV-AOP process as the linkage treatment, and were removed by up to 39.1%, 15.2%, and 80.4%, respectively. It was confirmed that biodegradability was improved according to the ratio of CODMn to TOC. As for the nitrogen component, the ammonia nitrogen component showed a level of 3.2×102 mg/L or more, and the content was maintained at 80% even after treatment. Since most of the contaminants are removed from the treated water and its transparency is high, this water can be utilized as a resource that contains high concentrations of nitrogen.

Design of Systolic Multipliers in GF(2$^{m}$ ) Using an Irreducible All One Polynomial (기약 All One Polynomial을 이용한 유한체 GF(2$^{m}$ )상의 시스톨릭 곱셈기 설계)

  • Gwon, Sun Hak;Kim, Chang Hun;Hong, Chun Pyo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8C
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    • pp.1047-1054
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    • 2004
  • In this paper, we present two systolic arrays for computing multiplications in CF(2$\^$m/) generated by an irreducible all one polynomial (AOP). The proposed two systolic mays have parallel-in parallel-out structure. The first systolic multiplier has area complexity of O(㎡) and time complexity of O(1). In other words, the multiplier consists of m(m+1)/2 identical cells and produces multiplication results at a rate of one every 1 clock cycle, after an initial delay of m/2+1 cycles. Compared with the previously proposed related multiplier using AOP, our design has 12 percent reduced hardware complexity and 50 percent reduced computation delay time. The other systolic multiplier, designed for cryptographic applications, has area complexity of O(m) and time complexity of O(m), i.e., it is composed of m+1 identical cells and produces multiplication results at a rate of one every m/2+1 clock cycles. Compared with other linear systolic multipliers, we find that our design has at least 43 percent reduced hardware complexity, 83 percent reduced computation delay time, and has twice higher throughput rate Furthermore, since the proposed two architectures have a high regularity and modularity, they are well suited to VLSI implementations. Therefore, when the proposed architectures are used for GF(2$\^$m/) applications, one can achieve maximum throughput performance with least hardware requirements.

Design and Implementation of a BPEL Engine for Dynamic Function using Aspect-Oriented Programming (동적 기능 추가를 위하여 관점지향 프로그래밍 기법을 이용한 BPEL 엔진의 설계와 구현)

  • Kwak, Dong-Gyu;Choi, Jae-Young
    • Journal of KIISE:Computer Systems and Theory
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    • v.37 no.4
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    • pp.205-214
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    • 2010
  • BPEL is a standard workflow language, which interacts with Web Services and is used in various applications. But it is difficult to use BPEL for specific applications which require additional functions. In this paper, we present a system which can add new functions to BPEL based on an aspect-oriented programming (AOP) technique. In order to add new functions to BPEL, we define a JWX document format that can describe new functions to apply to BPEL. JWX is XML-oriented document that can code the corresponding Java program in order to dynamically add new functions to BPEL documents. It is possible for BPEL workflow to add new functions without modifying the existing programs using the AOP technique, which guarantees low degree of coupling between key and additional requirements. Additionally this systems weaves based on new functions of Java program and JWX document by expanding BPEL engine called B2J based on AOP and execute them. Therefore it is possible to develop a new BPEL engine with additional functions easily and with low cost. The new system can execute additional conditions that the current BPEL engine doesn’t provide. The new system using functions of BPEL supplied by B2J. The new system can be used to add a new rule engine, which isn't currently provided.

Advanced Treatment of Piggery Slurry Using Micro Ozone Bubble, UV, Ultra Sonic and Hydroxy Peroxide (미세기포화 오존과 자외선, 초음파, 과산화수소를 이용한 돈분뇨 슬러리 고도처리)

  • Jeong, K.H.;Kim, J.H.;Kwag, J.H.;Jeong, M.S.;Lee, K.H.
    • Journal of Animal Environmental Science
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    • v.15 no.3
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    • pp.209-216
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    • 2009
  • The aim of this study was to investigate the removal effects of the color, nutritive salts and other pollutants on piggery slurry by advanced oxidation process (AOP) system. The experimental AOP system was designed to treat 300 L of piggery slurry per hour. To enhance oxidizing power of the experimental APO system, a ultraviolet irradiation system and the ultrasonic system were attached to the AOP system. With 5 min ultrasonic treatment, COD, SS and T-N concentrations were changed from 210, 820, and 309 to 200, 760, and 262 mg/L, respectively. With 10 min ultrasonic treatment, SS and T-N concentrations tended to decrease but T-P concentration was not changed. With the treatment of both ozone and ultrasonic waves for 30 min, COD, SS, T-N and T-P decreased from 238, 900, 400, and 5 to 165, 540, 263, and 4 mg/L, respectively. With the treatment of both ozone and ultraviolet irradiation for 30 min, COD, SS, T-N and T-P decreased from 321, 340, 204, and 15 to 151, 140, 111, and 7 mg/L, respectively, and color was changed from 4,344 to 624.

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Removal Characteristics of Phenol at Advanced Oxidation Process with Ozone/Activated Carbon Impregnated Metals (오존/촉매 산화공정에서 금속담지 활성탄을 이용한 페놀의 분해 특성)

  • Choi, Jae Won;Yoon, Ji Young;Park, Jin Do;Lee, Hak Sung
    • Applied Chemistry for Engineering
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    • v.23 no.3
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    • pp.302-307
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    • 2012
  • Advanced oxidation processes (AOP) such as O3/activated carbon process and O3/catalysts process were used to compare the decomposition of phenol. Catalysts such as Pd/activated carbon (Pd/AC), Mn/activated carbon (Mn/AC), Co/activated carbon (Co/AC) and Fe/activated carbon (Fe/AC) were prepared by impregnation of Pd, Mn, Co and Fe into the activated carbon of pellet form, respectively. Based on an hour of reactions, the following descending order for the decomposition ratios of dissolved O3 to the 1.48 mg/L of saturated dissolved O3 was observed: Mn/AC (45%) > Pd/AC (42%) > Co/AC (33%) > AC (31%) > Fe/AC (27%). The removal efficiencies of phenol were also arranged in the descending order of AOP as follows: Mn/AC (89%) > Pd/AC (85%) > Co/AC (77%) > AC (76%) > Fe/AC (71%). The remaining ratios (C/Co) of TOC (total organic carbon) after an hour of experiments were arranged in the ascending order of AOP as follows : Pd/AC (0.29) < Mn/AC (0.36) < AC (0.40) < Co/AC (0.49) < Fe/AC (0.51). However, the catalytic effects in the Co/AC and the Fe/AC processes were little in comparison with O3/AC process. The maximum concentrations of intermediates such as hydroquinone and catechol formed from the decomposition of phenol were arranged in the ascending order of AOP as follows: Pd/AC < Fe/AC < Co/AC < AC < Mn/AC. In the case of Pd/AC process, these intermediates were almost disappeared after an one hour of reaction.