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Article
Adsorption Study for Chromium (VI) on Iraqi Bentonite
دراسة امتزاز الكروم السداسي على طين البنتونايت العراقي

Authors: Sara Badrie Jassim سارة بدري جاسم --- Khulood A. Al-Sa’adie خلود عبد صالح السعدي
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2010 Volume: 7 Issue: عدد خاص بمؤتمر العلمي النسوي 1 Pages: 745-756
Publisher: Baghdad University جامعة بغداد

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Abstract

The subject of this research involves studying adsorption to remove hexavalent chromium Cr(VI) from aqueous solutions.Adsorption process on bentonite clay as adsorbent was used in the Cr(VI) concentration range (10-100) ppm at different temperatures (298, 303, 308 and 313)K, for different periods of time.The adsorption isotherms were obtained by obeying Langmuir and Freundlich adsorption isotherm with R2 (0.9921-0.9060) and (0.994-0.9998), respectively.The thermodynamic parameters were calculated by using the adsorption process at four different temperatures the values of H, G and S was [(+6.582  +6.547) kJ.mol-1, (-284.560  -343.070) kJ.mol-1 and (+0.977  +1.117) kJ.K-1.mol-1] respectively. This data indicates the spontaneous sorption process. The kinetic study of adsorption process was studied depending on three kinetic equations:1-Lagergren equation2-Morris-Weber equation3-Reichenberg equation

يتضمن موضوع البحث دراسة امتزاز الكروم السداسي لازالته من المحاليل المائية. عملية الامتزاز على طين البنتونايت (كمادة مازة) لازلة تراكيز مختلفة من الكروم السداسي تراوحت بين (10-1000) ملغم/لتر بمدى من درجات الحرارة (298-313) كلفن وعند الازمان المختلفة.تم الحصول على ايزوثرمات الامتزاز بتطبيق معادلتي لنكماير وفرندلش بنسبة خطية (R2=0.9921-0.9060) و (R2=0.994-0.9998) على التوالي.تم حساب القيم الثرموديناميكية باربع درجات حرارية وكانت قيم الانثالبي محصورة بين (6.547+ ـــ 6.582+) كيلوجول.مول-1 وقيم الطاقة الحرة لكبس بين (284.56- ـــ 343.07-) كيلوجول مول-1 وقيم الانتروبي بين (977+ ـــ 1117)جول.مول-1. بينت القيم تلقائية عملية الامتزاز.تمت دراسة حركيات الامتزاز اعتماداً على ثلاث معادلات حركية هي 1- معادلة لنكماير 2- معادلة موريس-ويبر 3- معادلة ريجمبرغ.

Keywords

Study --- Adsorption --- Chromium --- Bentonite.


Article
Removal of hexavalent chromium metal ions from aqueous solutions by adsorption using a novel organoclay

Author: Mohammed Jasim M.Hassan
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2016 Volume: 27 Issue: 3 Pages: 36-42
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

A new method for the preparation of organoclay named porcelain-organoclay using Iraqi’s porcelain in the presence of hexadecyltrimethyl ammonium bromide as organic surfactant, for the first time is described. The method involves mixing kaolin with hexadecyltrimethylammonium (HDTMA) .Different techniques such as infrared spectroscopy, and x-ray diffraction were employed for the characterization of chemical structure of the prepared organoclay. Isotherm study of Cr (VI) on the surface of the prepared organoclay was evaluated by applying Langmuir, Freundlich and Temkin equations. The optimum conditions for the adsorption were: pH=1, temperature 15°C, stirring speed, 120 rpm, contact time, 60 min; adsorbent weight 0.1g, concentration of adsorbent, 50 ppm and total volume, 25mL. Under the optimum conditions, removal percentage of 99% for the adsorption of chromium ion (VI) was achieved. Isothermal adsorption of chromium ions from porcelain-organoclay surface was agreed with Langmuir isotherm rather than Temkin and Freundlich. The developed method was applied for the separation of mixture of Cr(VI) and Cr(III) using porcelain-organoclay surfaces and removal of chromate from different water samples i.e., tap water and river water (Tigris river) that collected from different areas of Baghdad. Good recoveries were obtained ranged from 95 to 99% and RSDs were <1.7%.

يتضمن البحث تحضير طين عضوي جديد, وقد أعد للمرة الأولى باستخدام البورسلين العراقي بوجود سداسي ديسايل بروميد الأمونيوم مادة عضوية مطورة. درست التركيبة الكيميائية للطين العضوي المحضر من خلال تقنيات مختلفة مثل مطياف الأشعة تحت الحمراء وحيود الأشعة السينية . دُرس امتزاز الكروم (VI) على سطح للطين العضوي المحضر عن طريق تطبيق معادلات لانكماير وفروندلش وتمكن ودرست الظروف المثلى لعملية الامتزاز. كانت الظروف المثلى للامتزاز-الدالة الهيدروجينية = 1، ودرجة الحرارة 15 °م ، و سرعة رج 120 دورة في الدقيقة، وقت التماس 60 دقيقة،ووزن السطح الماز0.1غم وتركيز المادة الممتزةة 50 جزء في المليون وإجمالي حجم 25مل. واعطت النتائج في ظل الظروف المثلى معدل إزالة 99٪ لامتزاز الكروم السداسي. وقد بينت الدراسة ان امتزاز أيونات الكروم على سطح البورسلين العضوي ينطبق مع ايزوثرم لانكمير ولاينطبق على ايزوثيرمي فروندلش وتمكن. طبقت هذة الطريقة لفصل خليط من الكروم السداسي والكروم الثلاثي باستخدام سطح للطين العضوي ,وكذلك تم تطبيق الطريقة في إزالة الكروم السداسي من عينات ماء الحنفية ومياه النهر (نهر دجلة) والتي تم جمعها من مناطق مختلفة من بغداد. وتراوحت نسبة الازالة بين 95 -99٪ باسترداد نسبي مئوي ٪ 1.7 .


Article
CHROMIUM INHIBITS IN VITRO VIABILITY AND STEROIDOGENIC IN RAM LEYDIG CELLS

Author: Mohanad A. Al-Bayati
Journal: Basrah Journal of Veterinary Research. مجلة البصرة للابحاث البيطرية ISSN: Print:18138497 E; 24108456 Year: 2017 Volume: 16 Issue: 2 Pages: 1-25
Publisher: Basrah University جامعة البصرة

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Abstract

One of an ecological hazardous agent Chromium; Cr (VI), The present experimentin vitro design to examine the mechanism of Leydig cell functions of Cr (VI) in ramtestis, Cr (VI) treated groups demising cell growth behavior of exponential phase wasupset of feeding time to Leydig cell in a dose-dependent manner, and inducedmitochondria-dependent ATP depletion and subsequently apoptosis. Cr (VI) effectmay be attributed, at least in part to DNA fragmentation increase DNA tail numberand tail length of COMET as compared with control group. Furthermore, theproperties of cell-specific regulation of cell membrane integrity had reduced anddeterminant cell concentration drop an.d reflected on the testosterone concentrationwere decreased as concentration-dependent manner, In conclusion, our results displaythe Cr (VI) is cytotoxic and impairs both viability and steroidogenic functions ofLeydig cells in ram testis via actually different pathway direct affecting of viabilityand indirect on steroidogenic activity, succeeding in testicular performance. However,the definite modes of action of harmfulness are not evidently unknown and must berechecked and studied in a different aspect

Keywords

Chromium --- Leydig cell --- DNA.


Article
Strength, hardness, corrosion evaluation and computer-aided designing of cobalt–-chromium molybdenum maxillary major connectors. (Part I)

Authors: Nadira A Hatim نادرة حاتم --- Ahmed A Al–Ali احمد العلي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 1 Pages: 24-29
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Rigidity is one of the main criteria for the major connector. This study was conducted to determine the effect of width and thickness on the rigidity of single palatal strap major connector using two cobalt–chromium molybdenum (Co–Cr–Mo) alloys, Remanium and Biosil cast by two different techniques, electrical induction–melting, and gas–oxygen torch melting on the transverse strength of maxillary major connectors.Materials and methods: Forty–eight specimens for transverse strength, twenty–four specimens for hardness, and twenty–four specimens for corrosion were prepared, examined by x–ray then tested by engineering test equipment, hardness tester, and sensitive electronic balance respectively. Ion release into saliva was tested by Atomic Absorption Spectrophotometer and chemical methods.Results: There was a statistically significant effect of each of the products, casting techniques, width (4&8)mm and thickness (0.4&0.6)mm on the transverse strength of Co–Cr–Mo single palatal strap major connector and statistically significant effect of each of products and casting techniques on hardness of Co–Cr–Mo alloy, but results of corrosion and ion release tests were insignificant.Conclusions: The major connector made from Remanium cast by induction technique produces stronger and harder specimens. The effect of thickness is more significant than the width, and there was no significant change in weight after 760 hours immersion in saliva.


Article
Evaluation of macrohardness of recast-ed Cobalt–chromium alloy

Author: Ahmed A Al–Ali
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 1 Pages: 111-117
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To study the effect of recasting on the macrohardness of cobalt chromium (Co–Cr)alloy, and to evaluate the effect of finishing and polishing on it. Materials and methods: Two brand of Co–Cr alloys were used, divided into three groups, the specimens of the first group were casted from new materials, the second were casted from previously casted material without the addition of any new material (100% recast), the third were casted by combination 50% new material and 50% used material. Half of the specimens just finished and the other half were finished and polished , hardness for all of them were measured. Results: Showed that recasting, both 100% and 50%, significantly increase the macrohardness of Co–Cr alloys and no significant effect of finishing and polishing on it. Conclusion: Recasting may affect properties of Co–Cr alloy and new material should be used rather than recasted material.


Article
Biosorption of chromium ions by using black tea leaves waste and the effect of some parameters on the removal of ions
الامتصاص الحيوي لايونات الكروم باستخدام مخلفات أوراق الشاي الاسود وتاثير بعض العوامل على ازالة الايون

Author: Safaa Abdalrasool Ali صفاء عبد الرسول علي
Journal: Iraqi Journal of Biotechnology المجلة العراقية للتقانات الحياتية ISSN: 18154794 Year: 2014 Volume: 13 Issue: 2 Pages: 95-102
Publisher: Baghdad University جامعة بغداد

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Abstract

Abstract: Biosorption can be an effective technique for the treatment of heavy metals bearing waste water resulting from human and industrial activities. several bioadsorbents have the ability to remove the heavy metals and thereby making water contaminant free. In the present study the biosorption of heavy metals using the black tea leaves waste and parameters affecting the biosorption of Cr ion; such as contact time, pH, temperature, dosage and particles size have been investigated. The present study showed that the contact time taken for maximum sorption of Cr ion was 120 min. The maximum percent removal of Cr ions on adsorbent was observed at pH 6 and significantly decreased by reducing the pH values and slightly decreased at higher pH values. The results indicated that the increasing of temperature from 35°C to 50°C induced that the adsorption capacity of Cr ions with highest adsorption capacity at 45°C and the concentration of 2 g was sufficient for maximum biosorption. It was obvious that the adsorption capacity of metal ion on tea waste increased by decreasing the particle size and the best particles size was 200 μm. The experiment results showed that maximum removal of Chromium ion by tea waste is 89.5 % at optimum condition.

الخلاصة: يعتبر الامتصاص الحيوي تقنية فعالة لمعالجة العناصر الثقيلة الناتجة من الفعاليات الصناعية والحيوية وهنالك بعض المواد الحيوية ذات القابلية على ازالة هذه العناصر الثقيلة من المياه الملوثة. في هذه الدراسة تم استخدام مخلفات اوراق الشاي الاسود كمادة فعالة تستخدم للامتصاص الحيوي وتم دراسة بعض العوامل التي تؤثر على فعالية الامتصاص مثل زمن الاستبقاء,الرقم الهيدروجيني, درجة الحرارة ,كمية المستخدمة, حجم الجزيئات. اظهرت الدراسة ان افضل زمن استبقاء هو 120 ثانية للحصول على افضل امتصاص حيوي وان افضل رقم هيدروجيني هو . انخفاض واضح للامتصاصية عند خفض الرقم الهيدروجيني بصورة اقل عند الرقم الهيدروجيني العالي وجدت النتائج ان رفع درجة الحرارة من 35 الى 50 سوف يؤدي الى زيادة قابلية الامتصاص الحيوي لأيونات الكروم, كانت الامتصاصية الحيوية 2غم في درجة حرارة 45 م°. من الواضح ان قابلية الامتصاصية للايون تزداد بنقصان حجم الجزيئات وكانت افضل امتصاصية في حجم 200 مايكروميتر.اظهرت نتائج التجربة اعلى نسبة امتصاصية والتي بلغت 89.9% في الظروف المثلى.


Article
Bioremoval of Chromium by Local Isolates of Pseudomonas aeruginosa in Respect to its Genotype
الازالة الحيوية للكروم بوساطة عزلات محلية من بكتريا Pseudomonas aeruginosa بالأعتماد على النمط الوراثي

Authors: Qusay A. Hameed قصي عامر حميد --- Hind S. Abdulhay هند سهيل عبد الحي
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2016 Volume: 57 Issue: 1B Pages: 367-375
Publisher: Baghdad University جامعة بغداد

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Abstract

The current study included bioremoval of chromium metal ions from aqueous solution by using seventeen Pseudomonas aeruginosa species isolated from different environments. The experimental results showed that isolates Pseudomonas aeruginosa have high efficiency in removal of chromium where the P. aeruginosa p.8 was the most efficient (P≥0.001) in bioremoval of chromium with a removal capacity reached 92.5 mg/L and removal index reached (96.5%). While P. aeruginosa p.4 was the least efficient (P≥0.001) in bioremoval of chromium from aqueous solutions reached 74.6 mg/L and removal index reached (79.8%). The REP-PCR detection using BOX-primer, showed genetic relatedness among the isolates of P.aeruginosa. The isolates were grouped according to the REP-PCR to different genotyping, named clusters which included C1, C2, C3 and C4 with relatedness: 2 (88%), 2 (73%), 4 (73%) and 2 (77%), respectively. The REP-PCR analysis showed that the genetic relatedness between isolates regarded to the source of the isolation as well as their efficiency of bioremoval process.

تتضمن الدراسة الحالية الأزالة الحيوية لايونات الكروم من المحاليل المائية بأستخدام 17 عزلة بكتيرية منPseudomonas aeruginosa معزولة من مختلف البيئات. أظهرت النتائج التجريبية أن عزلات P.aeruginosa كانت تمتلك كفائة عالية في أزالة الكروم أذ كانت العزلة 8 لبكتريا P.aeruginosa الأكثر كفاءة (P≥0.001) في الأزالة الحيوية لايونات الكروم من المحاليل المائية مع كفاءة ازالة وصلت الى 92٫5 ملغم/لتر وبنسبة ازالة 96٫5%. بينما كانت العزلة 4 لبكتريا P.aeruginosa الاقل كفاءة (P≥0.001) في الأزالة الحيوية لايونات الكروم بلغت 74,6 ملغم/لتر وبنسبة 79٫8%. أظهرت عملية تنميط تفاعل REP-PCR بأستخدام BOX-primer, وجود قرابة وراثية بين عزلات P.aeruginosa . اذ قسمت العزلات الى مجاميع وفقا لتفاعل البلمرة الى انماط وراثية مختلفة سُميت بالمجموعات وتشمل C1، C2، C3 و C4 مع قرابة او درجة تشابه وصلت: 2(88) %, 2(73) %, 4(73) % و 2(77) % على التتالي. وبين تحليل نتائج سلسلة البوليميريز المتكرر REP-PCR أن هناك قرابة وراثية بين العزلات تبعاً لأماكن العزل فضلاً عن كفاءتها في عملية الأزالة الحيوية.


Article
Photochemical Study of 2-(6-methoxynaphthalen-2-yl)Propanoic Acid Chromium(III) in Different Organic Solvents

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Abstract

AbstractThe photochemistry of chelate complex 2-(6-methoxynaphthalen-2-yl)propanoic acid chromium (III) Cr(L)3 was studied in three polar aprotic solvents: Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF), Acetone (Ac). Monochromatic light of wavelength 311 nm was used for the irradiation processes at 25 oC. Uv-visible spectral changes indicates an intra oxidation-reduction reaction occuring during the photolysis of Cr(L)3 complex, with homolytic scission of Cr-L bond. The quantum yield (d), rate of photodecomption and reactivity ratio (k2/k-1) were determined in each solvent. These values always increase as the polarity of the solvent increases and follow the order: DMSO > DMF > AC . Mechanism of photodecomposition of this complex under the applied conditions was proposed.

الخلاصةتم دراسة الكيمياء الضوئية لمعقد الكروم الثلاثي مع الليكاند ثنائي السن:methoxynaphthalen-2-yl)propanoic acid - 2-(6 في ثلاث مذيبات قطبية لا بروتونيةة هةي: ثنةائيمثيةل سلاواوكسةايد وثنةائي مثيةل فورامايةد والأسةينون. وتةم اسةنودام ضةوء أحةادج وبطةو مةوجي قةدر 311نةانومينر وبدرجةة حةرار 25 ه. لقةد دلةت النتيةرات الطيايةة الحاظةلة وملاحلةات أ ةرع علةى ح ةو تااعةلأكسد ا نزا دا لي لا عملية النااعل الضوئي للمعقد - Cr(L)3 مع انا ام منجانس للآظةر .Cr-L لقةد تةمحساب الناتج الكمي ) Qd ( وسرعة الناكك الضوئي ونسبة الاعالية ) K2/K-1 ( في كل مةذيب مةن المةذيبات أعةلاووجد ان هذ القيم تزداد بزياد قطبية المذيب ووفق النرتيب الآتي:DMSO > DMF > ACووفقا للننائج العملية المسنح لة, تم أقنراح ميكانيكية الناكك الضوئي لمعقد الكروم الثلاثي.

Keywords

Photochemistry --- Spectroscopy --- Chromium --- III --- Solvents


Article
22- RESIDUAL DISTRIBUTION OF LEAD, CHROMIUM AND COBALT IN DAIRY PRODUCTS AND THEIR BY-PRODUCTS MANUFACTURED FROM MILK SPIKED WITH THESE METALS

Author: Hiba S. Al-Naemi
Journal: Basrah Journal of Veterinary Research. مجلة البصرة للابحاث البيطرية ISSN: Print:18138497 E; 24108456 Year: 2018 Volume: 17 Issue: 1 Pages: 257-276
Publisher: Basrah University جامعة البصرة

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The research study the distribution patterns and residues behavior of Pb, Cr and Cobetween dairy products [yoghurt, cheese and fatty dairy products ( kishfa, Gaymer andcream)] and their by-products (whey and skim milk) manufactured fromexperimentally polluted raw ewe̓ s, buffalo̓ s and cow̓ s milk were investigated usingAtomic Absorption Spectrophotometer (AAS). The studied metals (Pb, Cr and Co)were concentrated in both cheese and fatty dairy products (kishfa, gaymer and cream)as they recorded concentration factors in cheese produced from raw ewe̓ s, buffalo̓ sand cow̓ s milk of 3.849, 3.466 and 2.452, 3.804, 2.938 and 2.342 and 2.995, 2.682and 2.336 folds, respectively and 3.693, 3.164 and 2.339, 3.347, 2.773 and 2.242 and2.601, 2.156 and 2.14 folds, respectively in kishfa, gaymer and cream produced fromraw ewe̓ s, buffalo̓ s and cow̓ s milk compared with metals concentrations reported inraw milk used for preparing these products, whereas the by-products of cheese andfatty dairy products processing (whey and skim milk, respectively) contained Pb, Crand Co concentrations lower than these present in raw milk as they recorded reductionlevels of 71.6, 58 and 31.7, 63.7, 39.5 and 27 and 31.4, 20 and 9.5%, respectively inwhey and 37.3, 29.9 and 12.1, 41.7, 27 and 19.3 and 21.3, 7.8 and 5.2%, respectivelyin skim milk. Yoghurt processed from the raw ewe̓ s, buffalo̓ s and cow̓ s milkcontained Pb, Cr and Co metals at mean concentration levels similar to and slightlyless than those found in raw milk as the reduction levels amounted 0, 0.6 and 1, 0.1,0.7 and 1.4 and 0.6, 0.8 and 1.9%, respectively. Generally, metals exhibited significantdifferences (p˂0.05) in their distribution and residues behavior in dairy products andtheir by-products and comparable to raw milk used in processing as they arranged as follows: cheese> fatty dairy products (kishfa, Gaymer and cream)> raw milk>yoghurt> skim milk> whey, except yoghurt and raw milk which difference was notsignificant (p˂0.05). Also, metals found in studying dairy products in the order of Pb >Cr > Co, in contrast to their by-products as they arranged reversibly. Finally, metalsconcentrated in cheese and kishfa produced from raw ewe̓ s milk, in addition to cheeseand gaymer produced from raw buffalo̓ s milk at levels significantly higher (p˂0.05)than those present in cheese and cream produced from raw cow̓ s milk.

Keywords

Lead --- Chromium --- Cobalt --- Dairy products.


Article
Mycoremedation of total and hexavlent chromium from tannery wastewater using fungus Trichoderma harizianum

Authors: Nida'a S.Hamad --- Mayson M. Al-Taee --- Enas R.Al-kidsawey
Journal: Mesopotamia Environmental Journal بيئة وادي الرافدين ISSN: 24102598 Year: 2016 Volume: 2 Issue: 3 Pages: 34-41
Publisher: Babylon University جامعة بابل

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Abstract

The current study was conducted to study the ability of Trichoderma harizianum for removing total and hexavalent chromium from tannary wastewater in laboratory .The experiment continue for thirteen days ,chemical and physical characteristics total and hexavalent chromium concentration were tested in the days (1,4,7,10and 13) and biomass in the end of experimental is weighted. Results shows that pH value change from( 8.6-3.2) and removal percent for Total dissolved solids ,Total alkalinity, total hardness, calcium and magnesium hardness ,nitrite ,nitrate and ,sulphate, total chromium ,hexavalent chromium and biomass (97.54%,90%,97.77%,87.97%,99%,95%,84.66%,90%).While the removal percent for total and hexavalent chromium were 70.18% and 99.67% respectively . The experiment show increasing in fungus biomass in the end of experiment period .

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