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Book ChapterDOI

Removal of Cr(VI) from Wastewater Using Red Gram Husk as Adsorbent

14 Oct 2016-pp 109-118
Abstract: Pure water is very important for human life All agriculture, industrial and commercial sector need water of required quality Pollution of water is due to all these sectors Waste from all sectors is entering freshwater everyday The demand for water is increasing while water availability is less because of improper waste disposal The removing pollutant from all water resources is costly so there is need for new technologies, which are less expensive, require less maintenance and are energy effective Chromium is widely used in electroplating, alloying, leather tanning, corrosion protection, etc [1] Chromite mining and processing units produce waste and effluent containing chromium in two oxidation states, for example, Cr(VI) and Cr(III) in aqueous solution Cr(VI) oxidizing properties is dangerous due to carcinogenicity [2] The potable water allows only 005 mg/lit Cr(VI) because of toxicity [3] Higher concentrations are in the industrial and mining effluents, which crosses permissible limit

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Topics: Waste disposal (58%), Effluent (55%), Wastewater (54%)
References
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Journal ArticleDOI
Abstract: The kinetics for soybean oil hydrogenation using a commercial Ni/Al2O3 catalyst were investigated in a 2 × 10-3 m3 agitated reaction calorimeter operating under a wide range of temperatures (383−44...

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53 citations


Journal ArticleDOI
Abstract: In the present paper the performance of commercial Ni catalyst in edible oil hydrogenation is evaluated under different operating conditions Particularly, the influence of mass transport resistance on the trans-isomers selectivity is analyzed Initially a series of experiments aim to analyze the effect of four process variables (reaction temperature, hydrogen bubbling device, agitation rate and stirrer design) on catalyst activity and selectivity to trans-isomers These experiments are conducted in diffusional regimes A simpler set of experiments is carried out operating under conditions that allow the authors to neglect some diffusional resistances although those associated to the catalyst are still present In the first case activity and selectivity appear to be independent of the hydrogen bubbling system and the catalyst loading The whole set of data analyzed in terms of the C18:1/C18:20 ratio as a function of the C18:2/C18:20 ratio shows that the former, a sort of selectivity, depends on the agitation regime The formation of trans-isomers however, appears to be a function of the reaction extent only

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52 citations


Journal ArticleDOI
Andrea Schmidt1, Reinhard Schomäcker1Institutions (1)
Abstract: Partial hydrogenation of sunflower oil was carried out in a membrane reactor in pore-flow-through mode in n-heptane as solvent. The membrane reactor consisted of a porous α-Al2O3 membrane impregnated with Pd or Pt as the active catalyst and was constructed as a loop of saturation vessel and membrane module. Hydrogenation experiments were performed at different temperatures, hydrogen pressures and noble metals as catalysts. The experiments in the membrane reactor were compared with experiments in a slurry reactor with a powder catalyst for benchmarking. The stearic acid content at an iodine value (IV) of about 80 was 10–15% in the membrane reactor and 45% in the slurry reactor, respectively. The selectivity for the monoene fatty acids could be improved with decreasing hydrogen pressures. The content of trans fatty acids at IV ≈ 80 was 30–45% in the membrane reactor, whereas in the slurry reactor 12% were obtained. For the trans-isomer formation, the influence of hydrogen pressure and temperature in the membrane reactor was rather low. Pd showed a higher activity and selectivity compared to Pt, but promoted the trans-isomerization to a greater extent.

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35 citations


Journal ArticleDOI
W. D. Pocklington1Institutions (1)
Abstract: This report outlines the study protocols and compares the results obtained for the iodine values of a wide range of fats and oils when using the published standardised method (which specifies the use of carbon tetrachloride) with the results obtained when using a mixture of cyclohexane and glacial acetic acid The values reported for the iodine values indicate that the latter solvent system can be recommended for use in place of carbon tetrachloride in the determination of iodine value without loss of precision

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32 citations