• 제목/요약/키워드: pH agent

검색결과 1,342건 처리시간 0.031초

Using response surface methodology and Box-Behnken design in the study of affecting factors on the dairy wastewater treatment by MEUF

  • Khosroyar, Susan;Arastehnodeh, Ali
    • Membrane and Water Treatment
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    • 제9권5호
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    • pp.335-342
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    • 2018
  • Micelle-Enhanced Ultrafiltration (MEUF) is a membrane separation processes that improving ultrafiltration process with the formation of micelles of the surface active agents. Surface active agents are widely used to improve membrane processes due to the ability to trap organic compounds and metals in the treatment of industrial waste water. In this study, surface active agents are used to improve micelle-enhanced ultrafiltration (MEUF) to reduce chemical oxygen demand (COD), total dissolved solid (TDS), turbidity and clogging the membrane in dairy wastewater treatment. Three important operational factors (anionic surface active agent concentration, pressure and pH) and these interactions were investigated by using response surface methodology (RSM) and Box-Behnken design. Results show that due to the concentration polarization layer and increase the number of Micelles; the anionic surface active agent concentration has a negative effect on the flux and has a positive effect on the elimination of contamination indices. pH, and the pressure have the greatest effect on flux. On the other hand, it could be stated that these percentages of separation are in the percentages range of Nano-filtration (NF). While MEUF process has higher flux than NF process. The results have been achieved at lower pressure while NF process needs high pressure, thus making MEUF is the replacement for the NF process.

침투성 알칼리성부여제 도포에 의한 중성화된 콘크리트의 알칼리성 회복성능에 관한 실험적 연구 (An Experimental Study on the Alkali-Recovery Performance of Impregnating Alkalization Agent for Deteriorated Concrete by Carbonation)

  • 김무한;강석표;유재강;권영진
    • 콘크리트학회논문집
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    • 제13권1호
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    • pp.9-15
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    • 2001
  • 콘크리트 구조물의 성능저하는 여러 성능저하 요인들의 상호작용에 의해 발생한다. 특히 중성화는 시간의 경과에 따라 증가하는 대표적인 성능저하기구로 알려져 있다. 최근 들어 중성화 메카니즘에 관한 기초적인 연구와 더불어 중성화로 성능저하된 구조물의 내구성 증진을 위한 공법 및 기술개발이 활발히 진행중이다. 이에 본 논문에서는 기존에 제안되고 있는 중성화 단계에 따른 보수공법을 바탕으로 중성화된 콘크리트에 침투성 알칼리성부여제를 도포함에 따른 알칼리성 회복성상과 표면피복재의 종류에 따른 알칼리성 유지성능을 정량적으로 비교.분석하였다. 본 실험결과 알칼리성부여제를 토포함에 의해 촉진중성화에 의해 pH가 저하된 콘크리트의 알칼리성 회복성능을 확인 할 수 있었으며, 알칼리성부여제 도포후 표면피복재에 따라 콘크리트의 알칼리성 유지성능은 큰 차이를 나타내는 것으로 나타났다.

복합탈묵제의 ONP 탈묵 적성 (Deinking efficiency of ONP with enzyme blended deinking agent)

  • 윤경동;박헌신;엄태진
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 춘계학술발표논문집
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    • pp.167-173
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    • 2006
  • Deinking is a series of unit operations designed to detach ink from cellulose fibers and separate the dispersed ink from the pulp slurry. Deinking chemicals are process aids that enable expensive mill equipment used in these unit operations to operate more efficiently - often much more efficiently. We propose the blended deinking agent with cellulolutic enzymes and synthetic collector in deinking pulp of conventional alkaline method. The deinking efficiency of old news print in alkaline pH was enhanced with enzyme treatments. The brightness of deinked pulp was increased with less residual ink particles and yield of enzymatic deinked pulp was improved compared to the deinked pulp of conventional alkaline method. Enzymes in biomass were use to Chemical Deinking for reduce environment pollution through surfactant and improve surfactants. examining into compatibility Enzymes and surfactants, these new materials are studied efficiency of deinking efficiency.

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Gadolinium Complex of 1,4,7,10-Tetraazacyclododecane-1,4,7-trisacetic acid (DO3A) Conjugate of [(p-aniline benzothiazole)methyl]pyridine as a Tumor-Targeting MRI Contrast Agent

  • Nam, Ki Soo;Jung, Ki-Hye;Chang, Yongmin;Kim, Tae-Jeong
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3654-3658
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    • 2013
  • The synthesis of a DO3A conjugate of [(p-aniline benzothiazole)methyl]pyridine ($L^2H_3$) and its gadolinium complex of the type [$Gd(L^2)(H_2O)$] ($GdL^2$) is described. The $R_1$ relaxivity ($=4.50mM^{-1}sec^{-1}$) and kinetic inertness of $GdL^2$ compares well with those of structurally analogous Dotarem$^{(R)}$ ($R_1=3.70mM^{-1}sec^{-1}$), a typical extracellular (ECF) MRI contrast agent (CA). Yet, by comparison with Dotarem$^{(R)}$, $GdL^2$ exhibits non-covalent interactions with human serum albumin (HSA) as evidenced by the ${\varepsilon}^*$ titration curve along with in vivo MR signal enhancement in both aorta and heart. Liver-specific nature of $GdL^2$ is also observed as excretion is made through gallbladder. Most notably, $GdL^2$ further demonstrates specificity toward the MDA-MB-231 breast cancer.

생쥐 골수세포에서 아드리아마이신의 소핵생성에 미치는 N-마세틸시스테인의 억제효과 (Suppressive Effect of N-Acetylcysteine on the Adriamycin-Induced Micronuclei Formation in Mouse Bone-marrow Cells)

  • 손수정;허인회;최성규;허문영
    • 약학회지
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    • 제37권3호
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    • pp.278-285
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    • 1993
  • The anticlastogenic effect of N-acetylcysteine was tested in vivo in mouse bone-marrow micronucleus assay. The frequencies of micronuclei induced by adriamycin (5 mg/kg i.p.) in bonemarrow cells were decreased by the oral administration of N-acetylcysteine at 12 h before adriamycin injection. The observed suppressing effect was not a reflection of a delay in the formation of micronuclei by the cytotoxic effect of N-acetylcysteine. The anticlastogenic effects of SH compound including N-acetylcysteine, cysteine, cystine, S-carboxy methylcysteine and glutathione were also investigated by the multiple pretreatment. Each SH compound was administered orally every day for 5 days and adriamycin (5 mg/kg i.p.) was injected at 24h after the last dose of test compound. N-acetylcysteine and glutathione showed significantly the suppressive effect at dose of 10 and 25 mg/kg for N-acetylcysteine and at the dose of 25 mg/kg for glutathione. Our study suggests that N-acetylcysteine is capable of protecting the chromosomal damages in the normal cells during cancer chemotherapy by adriamycin, and may act as an anticlastogen against induction of micronuclei by superoxide generating agent such as adriamycin.

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Investigation on the Factors Determining the Size Distribution of Gold Nanoparticles in the Citrate Reduction Method

  • Kang, Ae-Yeon;Park, Dae-Keun;Lee, Cho-Yeon;Yun, Wan-Soo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.554-554
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    • 2012
  • Controlling the size distribution of gold nanoparticles (NPs) is of great importance due to the fact that their properties are strongly dependent upon the size distribution as well as the size itself. In the citrate reduction method for gold NP synthesis, the citrate works as (1) a reducing agent, (2) a surfactant, and also (3) a weak base: it raises the pH of the whole reaction mixture. Here, we have extensively studied the all three roles of the citrate, by adding other reagents separately (NaBH4, CTAB, and NaOH) for the independent control of the three roles of the citrate. Among the roles of the citrate, that as a weak base was found to be the most critical parameter affecting the size distribution of gold NPs and the size distribution became much more improved with the increase of the solution pH, while adding a supplementary surfactant or reducing agent resulted in the formation of less homogeneous NPs.

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수용성 약물인 세파클러를 함유하는 젤라틴 마이크로캅셀의 제조 및 약물 방출특성 (Preparation of Cefaclor-Containing Gelatin Microcapsules and Their Drug Release Characteristics)

  • 조성완;박종화;박준상;장정수;최영욱
    • 약학회지
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    • 제41권1호
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    • pp.30-37
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    • 1997
  • In order to formulate a controlled release system for oral drug delivery, the microcapsules were prepared in w/o emulsion containing cefaclor as a water-soluble model drug by th e method of interfacial polycondensation. Gelatin wis selected as a suitable polymer for interfacial polycondensation. Gelatin solution containing drug was emulsified in an organic phase under mechanical stirring. After emulsification, terephthaloyl chloride was added as cross linking agent, followed by mechanical stirring, washing and drying. Physical characteristics of microcapsules were investigated by optical microscopy, scanning electron microscopy and particle size analysis. Mean particle sizes of gelatin microcapsules were, in the range, of about 20~50 ${\mu}$m. The microcapsules were in good apperance with spherical shapes before washing, but were destroyed partially after washing and drying, even though some microcapsules were still maintained in their shapes. Contents of cefaclor in the microcapsules were calculated by UV spectrophotometry after 3 days extraction with pH 4 carbonate buffer solution. The effects of cross linking time. pH. concentration of cross-linking agent, and temperature on drug release kinetics have been discussed extensively.

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암모늄이온의 현장 분석 방법 개발에 관한 기초 연구 (Feasibility Study of On-site Analysis on Ammonium ion)

  • 정용준
    • 한국습지학회지
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    • 제16권2호
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    • pp.275-280
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    • 2014
  • 수중 암모니아성 질소는 각종 수질오염을 일으키는 물질로서 관리대상이다. 인도페놀법을 변형한 발색대 길이 측정으로 암모니아성 질소를 분석하기 위한 기초 실험을 수행하였다. 1-naphthol을 발색제로 사용한 암모니아성 질소 분석에서 최대 흡광도는 720nm 부근의 파장대에서 관찰되었고, 적정 주입양은 $0.5-1.5m{\ell}$였다. 발색 반응은 신속히 진행되어 20분이 경과하여 전체 최고 흡광도의 80%으로 나타내었고, 발색 시약을 조제하는 과정에서 NaOH 농도는 1.5-2.5M 농도로 설정하였으며, 초기 pH는 영향을 미치지 않았다. 또한, $25^{\circ}C$의 온도에서는 발색대의 길이에 미치는 영향이 미미한 것으로 나타났다.

Chemical cleaning of fouled polyethersulphone membranes during ultrafiltration of palm oil mill effluent

  • Said, Muhammad;Mohammad, Abdul Wahab;Nor, Mohd Tusirin Mohd;Abdullah, Siti Rozaimah Sheikh;Hasan, Hassimi Abu
    • Membrane and Water Treatment
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    • 제5권3호
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    • pp.207-219
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    • 2014
  • Fouling is one of the critical factors associated with the application of membrane technology in treating palm oil mill effluent (POME), due to the presence of high concentration of solid organic matter, oil, and grease. In order to overcome this, chemical cleaning is needed to enhance the effectiveness of membranes for filtration. The potential use of sodium hydroxide (NaOH), sodium chloride (NaCl), hydrochloric acid (HCl), ethylenediaminetetraacetic acid (EDTA), and ultrapure water (UPW) as cleaning agents have been investigated in this study. It was found that sodium hydroxide is the most powerful cleaning agent, the optimum conditions that apply are as follows: 3% for the concentration of NaOH, $45^{\circ}C$ for temperature solution, 5 bar operating pressure, and solution pH 11.64. Overall, flux recovery reached 99.5%. SEM images demonstrated that the membrane surface after cleaning demonstrated similar performance to fresh membranes. This is indicative of the fact that NaOH solution is capable of removing almost all of the foulants from PES membranes.

Anti-Ulcer Activity of Newly Synthesized Acylquinoline Derivatives

  • Cheon, Hyae-Gyeong;Kim, Hyun-Jung;Mo, Hye-Kyoung;Shin, En-Joo;Lee, Yeon-Hee
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.137-142
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    • 1999
  • Anti-ulcer activity of newly synthesized acylquinoline derivatives was investigated. For the in vitro screening, the effects of compounds on gastric $H^{+}/K^{+}$ ATPase isolated from hog and rabbit were examined. Among them, AU-090, AU-091, AU-254, AU-413 and AU-466 exhibited good in vitro activity on both enzymes. To correlate the in vitro activity with in vivo action, the effects of the compounds on the basal gastric acid secretion were studied. Some derivatives showed considerable anti-secretory activities, and AU-413 was selected for further studies. AU-413 protected gastric damage induced by either ethanol or NaOH dose dependently when given orally. $ED_{50}$ values of 12 mg/kg, p.o. (ethanol) and 41 mg/kg, p.o. (NaOH) were obtained. In addition, histamine-stimulated gastric secretion was reduced upon AU-413 administration. Taken together, newly synthesized acylquinoline derivatives, especially AU-413, is worthy of further investigation to be developed as an anti-ulcer agent.

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