• Title, Summary, Keyword: HAA

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Effects of EBCT and Water Temperature on HAA Removal using BAC Process (BAC 공정에서 EBCT와 수온에 따른 HAA 제거 특성)

  • Son, Hee-Jong;Yoo, Soo-Jeon;Yoo, Pyung-Jong;Jung, Chul-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.12
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    • pp.1255-1261
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    • 2008
  • In this study, The effects of three different biological activated carbon (BAC) materials (each coal, coconut and wood based activated carbons), empty bed contact time (EBCT) and water temperature on the removal of haloacetic acid (HAA) 5 species in BAC filters were investigated. Experiments were conducted at three water temperatures (5, 10 and 20$^{\circ}C$) and four EBCTs (5, 10, 15 and 20 min). The results indicated that coal based BAC retained more attached bacterial biomass on the surface of the activated carbon than the other BAC, increasing EBCT or increasing water temperature increased the HAA 5 species removal in BAC columns. To achieve an HAA removal efficiency 50% or higher in a BAC filter, the authors suggest 10 min EBCT or longer for 5$^{\circ}C$ waters and 5 min EBCT for waters at 10$^{\circ}C$ or higher. The kinetic analysis suggested a first-order reaction model for HAA 5 species removal at various water temperatures (5, 10 and 20$^{\circ}C$). The pseudo-first-order reaction rate constants and half-lives were also calculated for HAA removal at 5, 10 and 20$^{\circ}C$. The pseudo-first-order reaction rate constants and half-lives were also calculated for HAA 5 species removal at 5$\sim$ 20$^{\circ}C$. The half-lives of HAA 5 species ranging from 0.75 to 18.58 min could be used to assist water utilities in designing and operating BAC filters for HAA removal.

Hardware Abstraction Architecture for Low Cost Flash Memories in Wireless Sensor Nodes (무선 센서 노드상의 저가형 플래시 메모리를 위한 하드웨어 추상화 구조)

  • Kim, Chang-Hoon;Kwon, Young-Jik
    • Journal of the Korea Industrial Information Systems Research
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    • v.14 no.2
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    • pp.72-80
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    • 2009
  • In this parer, we propose a hardware abstraction architecture(HAA) for low cost flash memories that can be applicable to wireless sensor nodes. The proposed HAA consists of three layers. The three layers are 1) HHL(Hardware Interlace Layer), HAL(Hardware Adaption Layer), and HPL(Hardware Presentation Layer), where HIL provides a platform independent interlace to applications of upper layers, HAL performs hardware resource management, program status control, and generation of logical instructions as main core of the HAA, and HPL initializes hardware and communicates data between MCU and flash memory. We implemented our HAA on AT45DB flash memory, and the HAA used 4,384 bytes program memory and 195 bytes data memory respectively. Since the proposed HAA is composed of well defined three layers and shows a low utilization of memory, it can provides a high efficiency in terms of flexibility, scalability, and re-usability, and thus the HAA is well suited for wireless sensor nodes.

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Tryptophan Metabolite 3-Hydroxyanthranilic Acid Augments TRAIL-Induced Apoptosis in Activated T Cells (트립토판 대사체 3-hydroxyanthranilic acid의 TRAIL-유도 활성 T 세포 사멸 효과)

  • Seo, Su-Kil
    • Journal of Life Science
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    • v.21 no.2
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    • pp.316-321
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    • 2011
  • Generation of tryptophan-derived metabolites by indoleamine 2,3-dioxygenase (IDO) is a potent immunoregulatory mechanism in T cell responses. However, the mechanism remains unclear. We showed that 3-hydroxyanthranilic acid (3-HAA), the most potent metabolite, selectively induced apoptosis in activated T cells, but not in resting T cells. This was not associated with cell cycle arrest. We found that TRAIL expression was selectively induced in activated T cells by treatment of 3-HAA. Blockade of the TRAIL: DR4/DR5 pathway significantly inhibited 3-HAA-mediated T cell death. Our data suggest that TRAIL-induced apoptosis is involved in the mechanism of 3-HAA-mediated T cell death.

Oxidation of Acridine by Laccase of Pycnoporus cinnabarinus SCH-3 (주걱송편버섯(Pycnoporus cinnabarinus SCH-3)의 Laccase에 의한 Acridine 산화)

  • Lee, Hyoun-Su;Han, Man-Deuk;Yoon, Kyung-Ha
    • Korean Journal of Microbiology
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    • v.44 no.2
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    • pp.110-115
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    • 2008
  • Acridine was not a substrate for fungal laccase but it was oxidized to acridone in the culture medium of P. cinnabarinus SCH-3. During the cultivation of P. cinnabarinus SCH-3, Laccase was the predominant extracellular phenoloxidase, and 3-hydroxyanthranilic acid (3-HAA) was produced in the early culture. Cinnabarinic acid (CA) was observed to accumulate in the culture medium. When P. cinnabarinus was grown in the culture medium containing acridine, acridine was oxidized to acridone. But when the laccase purified from the culture medium of P. cinnabarinus directly reacted with acridine in sodium tartrate buffer (pH 3.0), The oxidation of acridine did not happen. In contrast, when 3-HAA was added to the buffer that was mixed with laccase and acridine, the acridine was oxidized to acridone. While in vitro studies, the CA was formed from 3-HAA in the presence of purified laccase. The results suggest that the acridine should be oxidized to the acridone through the mediation of 3-HAA by the laccase in the culture medium of P. cinnabarinus SCH-3.

Preparation and Properties of $N^1,N^1,N^4,N^4$-Tetrakis(hydroxyethyl)cyclohexanetrans-1,4-dicarboxamide as a Crosslinker of Polyester Powder Coatings (폴리에스터계 분체도료용 경화제 $N^1,N^1,N^4,N^4$-Tetrakis(hydroxethyl) cyclohexane-trans-1,4-dicarboxamide의 제조 및 특성)

  • Jung, Hong-Ryun;Heo, Joon;Lee, Wan-Jin;Kim, Hyung Jin;Lim, Hyung Soo
    • Applied Chemistry for Engineering
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    • v.20 no.2
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    • pp.195-200
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    • 2009
  • To develop a crosslinker for the polyester powder coatings, $N^1,N^1,N^4,N^4$-tetrakis(hydroxyethyl)cyclohexane-1,4-dicarboxamide (Cy-${\beta}-HAA$), incorporated with a cyclohexane ring within the main chain of commercial ${\beta}-hydroxyalkylamide$ (${\beta}-HAA$), was prepared from the amidation of dimethyl trans-1,4-cyclohexanedicarboxylate and diethanolamine in the presence of $NaOCH_3$, The structure of $Cy-{\beta}-HAA$ was confirmed by its NMR, FT-IR and ESI-MS spectra. $Cy-{\beta}-HAA$ was thermally more stable than ${\beta}-HAA$. When $Cy-{\beta}-HAA$ was used as a crosslinker for the polyester powder coatings, it provided the smooth coating surface and reduced the formation of pinholes in the coating surface with comparison with ${\beta}-HAA$.

A Study on the Variation of HAA Precursors by Ozonation of Phenol (페놀의 오존 산화시 관찰된 HAA 전구물질 변화에 관한 연구)

  • Oh, Byung Soo;Kim, Kyoung Suk;Kang, Joon-Wun
    • Journal of Korean Society on Water Environment
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    • v.21 no.2
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    • pp.153-157
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    • 2005
  • The purpose of this study was to find out the effect of oxidation by-products for the formation of haloacetic acid (HAA) during ozonation. The phenol was used as a model precursor of HAA, and its oxidation by-products, such as hydroquinone, catechol, glyoxal, glyoxylic acid and oxalic acid were investigated to find out how much HAA formation potential (HAAFP) they have. As the result, among the phenol and its oxidation by-products, the highest reactivity with chlorine was found from the phenol, showing the highest HAAFP. Even though the tested by-products had a lower HAAFP than phenol, it was confirmed that all of them can act as the precursor of HAA. From the ozonation of phenol-containing water, it was found that the efficiency of ozone in controlling of HAAs can be reduced due to the oxidation by-products. In addition, the ozonation of HAAFP was performed under the both pH conditions (acid and base), and the result indicates that OH radical play a important role to decrease HAAFP.

Predictive Model Selection of Disinfection by-products (DBPs) in D Water Treatment Plant (D 정수장 소독부산물 예측모델 선정)

  • Kim, Sung-Joon;Lee, Hyeong-Won;Hwang, Jeong-Seok;Won, Chan-Hee
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.460-467
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    • 2010
  • For D-WTP's sedimentation basin and distribution reservoir, and water tap the predictive models proposed tentatively herein included the models for estimating TTHM concentration in precipitated water, for treated water and for tap water, and the estimated correlation formula between treated water's TTHM concentration and tap water. As for TTHM-concentration predictive model in sedimentation water, the coefficient of determination is 0.866 for best-fitted short-term $DOC{\times}UV_{254}$ based Model (TTHM). As for $HAA_5$-concentration predictive model in sedimentation water, the coefficient of determination is 0.947 for the suitable $UV_{254}$-based model ($HAA_5$). In case of the predictive model in treated water, the coefficient of determination is 0.980 for best-fitted $DOC{\times}UV_{254}$ based model (TTHM) using coagulated waters, while the coefficient of determination is 0.983 for best-fitted $DOC{\times}UV_{254}$ based model ($HAA_5$) using coagulated waters, which described the $HAA_5$ concentration well. However, the predictive model for tap water could not be compatible with the one for treated water, only except for possibility inducing correlation formula for prediction, [i.e., the correlation formula between TTHM concentration and tap water was verified as TTHM (tap water) = $1.162{\times}TTHM$ (treated water), while $HAA_5$ (tap water) = $0.965{\times}HAA_5$ (treated water).] The correlation analysis between DOC and $KMnO_4$ consumption by process resulted in higher relationship with filtrated water, showing that its regression is $DOC=0.669{\times}KMnO_4$ consumption - 0.166 with 0.689 of determination coefficient. By substituting it to the existing DOC-based model ($HAA_5$) for treated water, the consequential model formula was made as follows; $HAA_5=8.35(KMnO_4\;consumption{\times}0.669-0.166)^{0.701}(Cl_2)^{0.577}t^{0.150}0.9216^{(pH-7.5)}1.022^{(Temp-20^{\circ}C)}$

Evaluation of Filter-Adsorber(F/A) Process for Removal of Disinfection By-products(DBPs) (소독부산물 제어를 위한 실공정 F/A 운영에 관한 고찰)

  • Kim, Seong-Su;Lee, Kyung-Hyuk;Lim, Jae-Lim;Chae, Seon-Ha;Kang, Byeong-Soo;Moon, Pil-Joong;Ahn, Hyo-Won
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1035-1042
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    • 2005
  • Granular Activated Carbon(GAC) is widely used in drinking water treatment. At S and B Water Treatment Plant, GAC is used in place of granular media in conventional rapid filters(GAC Filter-Adsorber) for removal of Disinfection By-products(DBPs). The primary focus of this study is on the performance of existing filter-adsorber, and their operation. It was found that F/A process removed turbidity as effective as sand system. The ratio of Hydrophobic DOM (HPO) and hydrophilic DOM (HPI) fraction in the raw water at S and B WTP was similar. Filter Adsorber presented earlier DOC breakthrough and steady state condition which was contributed by biodegradation during operation period. The removal efficiency of DBPs were used to evaluate the filter performance. The DBPs concentration of F/A treated water was below treatment goal level (THM < $80\;{\mu}g/L$, HAA < $60{\mu}g/L$). The removal efficiency of THM decreased rapidly during operation period. However, HAA were removed steadily regardless of the influent concentration of HAA. These results indicate that the removal of THM depend upon the adsorption mechanism while the removal of HAA depend upon biodegradation as well as adsorption. The decrease of adsorption capacity and characteristic value of GAC may be attributed to the effect of high organic loading, residual free chlorine, coagulants, manganese oxidants and frequently backwashing. This study has confirmed that Filter adsorber process can be considered as effective alternatives for the removal of DBPs, especially HAA.

HAAs Formation by Chlorine Dose and Reaction Time and The Removal Effect of Precursors by The Advanced Oxidation Processes (염소주입량과 반응시간에 따른 HAAs 생성과 고도산화처리에 의한 전구물질 제거 영향)

  • Kim, Kyoung-Suk;Oh, Byung-Soo;Ju, Seul;Kang, Joon-Wun
    • Journal of Korean Society on Water Environment
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    • v.20 no.2
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    • pp.145-150
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    • 2004
  • This study investigated the effect of chlorine dose and chlorine reaction time for the formation of haloacetic acids (HAAs). According to the results, HAA formation was highly affected by chlorine dose and chlorine reaction time. HAA formation reached a plateau value at 30 mg/L of chlorine dose and 24 hr of chlorine reaction time. For the speciation of formed HAAs in the test water, the concentration of brominated-HAAs was significantly lower than that of chlorinated-HAAs because of low level of bromide ion concentration in the test water. It also investigated the removal efficiency of HAA precursors by several unit processes, such as ozone alone, UV alone, and combined ozone/UV system. Of them, ozone/UV system was proved as the best process to control the HAAs formation. The increase of the brominated-HAAs was observed during ozonation with and without UV irradiation showing the slight increase of total HAA concentrations.