• Title/Summary/Keyword: Acid.Alkaline treatment

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Fouling and cleaning of a tubular ultrafiltration ceramic membrane

  • Siddiqui, Farrukh Arsalan;Field, Robert W.
    • Membrane and Water Treatment
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    • v.7 no.5
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    • pp.433-449
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    • 2016
  • The successful application of cleaning protocols is vital for optimized filtration processes. A series of experiments with an ultrafiltration ceramic tubular membrane were carried out for the foulants dextran and carboxymethyl cellulose. Firstly, the impact on fouling of concentration changes was investigated with the increase in resistance being used as the key parameter. In the second phase, removal of reversible fouling was also investigated by employing intermittent rinsing consisting of a cold water rinse followed by a hot one. A comparative analysis for both foulants is reported. Across a range of concentrations and for both foulants, the reduction in resistance due to rinsing was found to depend upon concentration (C); it changed as $C^n$ where n was found to be 0.3. A plausible semi-theoretical explanation is given. Thirdly, for both foulants, the application of a combination of strong alkaline solutions with oxidizing agent (mainly sodium hypochlorite) followed by acid was found to be appropriate for cleaning of the ceramic membrane. The effect of increased temperature for cleaning agents followed by a warm water rinse contributed positively to the cleaning capability.

Fouling and cleaning of reverse osmosis membrane applied to membrane bioreactor effluent treating textile wastewater

  • Srisukphun, Thirdpong;Chiemchaisri, Chart;Chiemchaisri, Wilai;Thanuttamavong, Monthon
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.45-51
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    • 2016
  • Membrane bioreactor (MBR) and reverse osmosis (RO) membrane system was applied to the treatment and reclamation of textile wastewater in Thailand. An experiment was carried out to determine the fouling behavior and effect of anti-scalant and biocide addition to flux decline and its recovery through chemical cleaning. The RO unit was operated for one month after which the fouled membranes were cleaned by sequential chemical cleaning method. RO flux was found rapidly declined during initial period and only slightly decreased further in long-term operation. The main foulants were organic compounds and thus sequential cleaning using alkaline solution followed by acid solution was found to be the most effective method. The provision of anti-scalant and biocide in feed-water could not prevent deposition of foulant on the membrane surface but helped improving the membrane cleaning efficiencies.

Hepatoprotective activity of Indigofera aspalathoides extract against CCl4-induced liver damage

  • Gupta, M.;Mazumder, U.K.;Haldar, P.K.;Manikandan, L.;Senthilkumar, G.P.;Kander, C.C.
    • Advances in Traditional Medicine
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    • v.4 no.2
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    • pp.100-103
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    • 2004
  • The plant Indigofera aspalathoides are used by a large number of tribes in India for the treatment of various hepatic disorder. The methanol extract of Indigofera aspalathoides (MEIA) was evaluated for its effect on carbontetrachloride $(CCl_{4})$ induced liver damage. Biochemical parameters such as serum glutamine oxaloacetate trasaminase (SGOT), serum glutamine pyruvate transaminase (SGPT), serum alkaline phosphatase (ALP), total serum protein (TP), thiobarbituric acid reactive substances (TBRS) and glutathione content of the liver were estimated to assess liver function and metabolism. Biochemical observations suggest that methanol extract of Indigofera aspalathoides (MEIA) significantly restored the liver function and metabolism towards normal condition in $CCl_{4}$-induced hepatic damage.

Synthesis and Surface Modification of Magnesium Hydroxide by Hydrothermal Method (수열법에 의한 수산화 마그네슘의 합성과 표면개질)

  • Lee, Hae-Young;Kang, Kuk-Hyoun;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.1
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    • pp.149-158
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    • 2012
  • Magnesium hydroxide[$Mg(OH)_2$] was prepared by hydrothermal method using oleic acid as surface modifier. $Mg(OH)_2$ particles exhibit flake morphology with micrometer in size and the surface modification starts from the reaction of $C_{17}H_{33}COO^-$ group, derived from oleic acid molecule in alkaline environments. It is found that hydrothermal treatment conditions such as pH, temperature and reaction time are important for the control of the morphology and properties of surface modified magnesium hydroxide. The obtained magnesium hydroxide groups were characterized by FE-SEM, XRD, FT-IR, TGA. The dispersion in organic solution was determined by sedimentation test and compared with the result of raw $Mg(OH)_2$.

Cloning and Characterization of a Multidomain GH10 Xylanase from Paenibacillus sp. DG-22

  • Lee, Sun Hwa;Lee, Yong-Eok
    • Journal of Microbiology and Biotechnology
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    • v.24 no.11
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    • pp.1525-1535
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    • 2014
  • The xynC gene, which encodes high molecular weight xylanase from Paenibacillus sp. DG-22, was cloned and expressed in Escherichia coli, and its nucleotide sequence was determined. The xynC gene comprised a 4,419bp open reading frame encoding 1,472 amino acid residues, including a 27 amino acid signal sequence. Sequence analysis indicated that XynC is a multidomain enzyme composed of two family 4_9 carbohydrate-binding modules (CBMs), a catalytic domain of family 10 glycosyl hydrolases, a family 9 CBM, and three S-layer homologous domains. Recombinant XynC was purified to homogeneity by heat treatment, followed by Avicel affinity chromatography. SDS-PAGE and zymogram analysis of the purified enzyme identified three active truncated xylanase species. Protein sequencing of these truncated proteins showed that all had identical N-terminal sequences. In the protein characterization, recombinant XynC exhibited optimal activity at pH 6.5 and $65^{\circ}C$ and remained stable at neutral to alkaline pH (pH 6.0-10.0). The xylanase activity of recombinant XynC was strongly inhibited by 1 mM $Cu^{2+}$ and $Hg^{2+}$, whereas it was noticeably enhanced by 10 mM dithiothreitol. The enzyme exhibited strong activity towards xylans, including beechwood xylan and arabinoxylan, whereas it showed no cellulase activity. The hydrolyzed product patterns of birchwood xylan and xylooligosaccharides by thin-layer chromatography confirmed XynC as an endoxylanase.

Spermatogenic index and hormonal profile in the rats received chromatographic fractions of ethanol extract of Crotalaria juncea L. seeds

  • Malashetty, Vijaykumar B.;Patil, Saraswati B.
    • Advances in Traditional Medicine
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    • v.6 no.2
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    • pp.86-95
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    • 2006
  • The ethanol extract of the Crotalaria juncea seeds, which showed promising antispermatogenic and antiandrogenic activities in albino mice, was taken up further for the isolation of the active fractions present in it. Two fractions that were obtained from thin layer chromatography were subjected for testing to know their antispermatogenic and antiandrogenic activities. After preliminary trials the fraction I showed maximum antifertility activity at the dose level of 200 mg/kg body weight when administered orally to the rats for 50 days. The fraction I was found to affect spermatogenesis as well as the endocrine functions of the testis as indicated by gravimetric, histopathological and biochemical changes. Further this fraction has caused degenerative changes in the seminiferous tubules and Leydig cells of the testis. The accessory reproductive organs like epididymis, seminal vesicles, vas deferens, prostrate, Cowper's gland and Levator Ani muscle showed significant malfunction. Cauda epididymal sperm count and sperm motility were reduced significantly. The treatment has also resulted in increase in the cholesterol level and alkaline phosphatase activity, and decrease in protein, glycogen, sialic acid contents and acid phosphatase activity in testis. It is noteworthy that RIA studies have shown significant reduction in serum FSH, LH and testosterone. Scanning electron microscopic observations revealed abnormalities in sperm structure.

Gastroprotective effect of cirsilineol against hydrochloric acid/ethanol-induced gastric ulcer in rats

  • Gong, Guojin;Zhao, Rigetu;Zhu, Yuhui;Yu, Jinfeng;Wei, Bin;Xu, Yan;Cui, Zhaoxun;Liang, Guoying
    • The Korean Journal of Physiology and Pharmacology
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    • v.25 no.5
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    • pp.403-411
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    • 2021
  • This study was designed to evaluate the gastroprotective activity of cirsilineol in hydrochloric acid (HCl)/ethanol-induced gastric ulcer model. Cirsilineol was administered at the doses of 20 and 40 mg/kg in HCl/ethanol-induced rats. The gastroprotective ability was verified by determining the ulcer score, total acidity, hemoglobin, inflammatory cytokines, lipid peroxides, and enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT) in gastric tissue and serum biochemical analysis. The results showed a favorable increase in the hemoglobin level, antioxidant enzymes (SOD and CAT), restored electrochemical balance (carbon dioxide & anion gap) while a noticeable decrease in ulcer index, total acidity, lipid peroxides, inflammatory cytokines (interleukin-1 beta [IL-1β], IL-6, and tumor necrosis factor alpha) in rats treated with the cirsilineol. The serum biochemical analysis on liver markers (alkaline phosphatases, alanine aminotransferase, and aspartate aminotransferase), kidney markers (urea, creatinine, albumin, globulin, total protein), and lipid profile (triglyceride, high-density lipoprotein, total cholesterol) were attenuated by cirsilineol treatment in rats. Histopathology showed enhanced gastric protection and preserved the integrity of gastric mucosa upon cirsilineol administration. These results ultimately suggest that cirsilineol has gastroprotective effects that prevent the development of gastric ulcer.

Characterization of Neutral Invertase from Fast Growing Pea (Pisum sativum L.) Seedlings after Gibberellic Acid (GA) Treatment (GA 처리 후 급 성장하는 완두콩(Pisum sativum L.) 발아체로부터 분리된 중성 invertase의 특성)

  • Kim, Donggiun
    • Journal of Life Science
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    • v.25 no.9
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    • pp.1021-1026
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    • 2015
  • Invertase (β-D-fructosfuranosidase, EC 3.2.1.26) catalyzes the hydrolysis of sucrose into D-glucose and D-fructose. Three biochemical subgroups of invertases have been investigated in plants: vacuolar (soluble acid), cytoplasmic (soluble alkaline), and cell wall-bound (insoluble acid) invertases. An isoform of neutral invertase was purified from pea seedlings (Pisum sativum L.) and treated with gibberellic acid (GA) by sequential procedures consisting of ammonium sulfate precipitation, ion-exchange chromatography, absorption chromatography, and reactive green-19 affinity chromatography. The results of the overall insoluble invertase purification were a 430-fold increase. The purified neutral invertase was not glycosylated and had an optimum pH between neutral and alkaline (pH 6.8-7.5). It was inhibited by Tris, as well as by heavy metals, such as Hg2+ and Cu2+. Typical Michaelis–Menten kinetics were observed when the activity of the purified invertase was measured, with sucrose concentrations up to 100 mM. The Km and Vmax values were 12.95 mM and 2.98 U/min, respectively. The molecular mass was around 20 kDa. The sucrose-cleaving enzyme activity of this enzyme is similar to that of sucrose synthase and fructosyltransferase, but its biochemical characteristics are different from those of sucrose synthase and fructosyltransferase. Based on this biochemical characterization and existing knowledge, neutral INV is an invertase isoform in plants.

Biochemicl Caracterization of Entomocidal Parasporal Crystals of Bacillus thuringiensis Strains (Bacillus thuringiensis 결정성독소의 생화학적 특성)

  • Lee, Yeong-Geun;Gang, Seok-Gwon;Kim, Sang-Hyeon
    • Journal of Sericultural and Entomological Science
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    • v.31 no.1
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    • pp.37-44
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    • 1989
  • The parasporal crystals of Bacillus thuringinsis subspecies kurstaki, dendrolimus, finitimus, aizawai and israelensis were compared by polyacrylamide electrophoresis, amino acid composition and immunological analysis. In the subspecies of kurstaki, dendrolimus, finitimus and aizawai, the molecular weights of main subusnits of crystal solubilized by alkaline solution were 1.3${\times}$105 and 6.5${\times}$104 while those of subsp. israelensis were 4${\times}$104 and 1,4${\times}$104. The degradation of lepidopteran toxic subspecies crystals by silkworm midgut protease showed 6.0-6.4${\times}$104 molecular weight and the pattern of degradation of subsp. israelensis crystals was similar to that of alkaline solution treatment. In the amino acid composition, aspartic acid in subsp. israelensis and glutiamic acid in the other four subspecies were the most abundant. The immunological characteristics of the crystals revealed that the antibody produced against the alkali-solubilized crystal protein of subsp. israelensis reacted with only its antigen, but the crystal antigens from the other four lepidopteran toxic subspecies did cross-react with each other as well as with their own homologous antisera.

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The Effect of NaOH treatment-Citric acid neutralization of Korean Standard Operating Procedure (SOP) on Physicochemical Compositions of Domestic Swine Excrement for the Connection to Thermophilic Aerobic Oxidation (TAO) (구제역 긴급행동지침(SOP)상의 화학처리방법으로 처리된 양돈분뇨의 고온호기산화공정 적용 연구)

  • Kim, Ha-Je;Kim, Soo-Ryang;Hong, In-Gi;Jeon, Sang-Jun;Kim, Cho-Rong;Jung, Gwang-Hwa;Han, Ho;Kim, Dong-Kyun;Lee, Myung-Gyu
    • Journal of Animal Environmental Science
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    • v.19 no.2
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    • pp.81-88
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    • 2013
  • We planned to study how the chemical disposal designed by SOP can affect on physicochemical compositions of the livestock excrement. According to Livestock Manure Management Scheme, we experimented in two steps; the first step, NaOH treatment-Citric acid neutralization, and then the second procedure, Thermophilic Aerobic Oxidation (TAO) system. Physicochemical compositions of the 3-days-old samples after NaOH treatment were pH 10.31, EC 24.54 mS/cm, SCOD 3,022 mg/L, T-N 4,315 mg/L, $NH{_4}^+-N$ 1,960 mg/L, and not detected E. coli.. And those of one-day-old samples after citric acid neutralization were pH 7.36, EC 32.89 mS/cm, $SCOD_{Mn}$ 12,733 mg/L, T-N 4,787 mg/L, $NH{_4}^+-N$ 2,450 mg/L, and E. coli. not detected. In contrast, the physicochemical compositions of the treatment plots after the second treatment with TAO system (72hr) were pH 9.42 EC 24.21 mS/cm, $SCOD_{Mn}$ 3,660 mg/L, T-N 3,616 mg/L, $NH{_4}^+-N$ 1,190 mg/L, and no detection of E. coli.