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Copper Content (copper + content)
Selected AbstractsA study of copper recovery from copper-contaminated sludge with ferrite and selective leaching processesENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2007S.H. Hu Abstract The purpose of this study was to develop an effective resource recovery and leached residue stabilization process for copper-contaminated sludge. To this end, a treatment procedure utilizing ferrite and selective leaching processes was developed. The XRD examination of ferrite complex revealed the crystalline phases to be mainly Fe3O4, CuO, and 6CuO·Cu2O. A selective leaching process was followed to recover the copper content of the ferrite complex. To promote the dissolution percentage of copper and repress that of iron, additional 0.5 N sulfuric acid was added at intervals to the suspension in the second step of the selective leaching process. The purpose of this operation was to return the suspension pH back to 3 to promote the dissolution of copper oxide and repress the dissolution of iron. Finally, the heavy metal (i.e., Cu, Pb, Cr, and Cd) dissolution of the above residue was examined with toxicity characteristic leaching procedure (TCLP) testing and all met the regulatory standard. © 2007 American Institute of Chemical Engineers Environ Prog 26:104,112, 2007 [source] Alkaline leaching of printed circuit board sludgeENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 3 2006S.H. Hu Abstract The purpose of this study was to develop a treatment procedure for processing aluminum-contaminated sludge produced from the coagulation/flocculation process of wastewater treatment in the manufacture of printed circuit boards (PCBs). In this study, the reagent sodium hydroxide (2 N) was used to leach the heavy metal sludge and the dissolution of sludge's aluminum content was roughly 70%. The weight loss of the heavy metal sludge was caused by the dissolution of aluminum content of nearly 20%. Although dissolution of a small amount of copper occurred simultaneously during this leaching process, the dissolution of copper content was restricted within 0.72% in the leaching operation and the copper content was concentrated in the residue to increase the copper level. The large amounts of sodium hydroxide and Al3+ remaining in the leachate were recycled as neutralization and coagulation agents in wastewater treatment. Synthetic heavy metal wastewater was neutralized with the preceding leachate to estimate the reuse feasibility of recovered coagulant. The heavy metal concentration of the effluent met regulation standards after neutralization and precipitation. The settling rate could be significantly enhanced by the addition of 100 ppm supplemental polyacrylamide (PAM). © 2006 American Institute of Chemical Engineers Environ Prog, 2006 [source] Relationship between soil copper content and copper content of selected crop plants in central ChileENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Ricardo Badilla-Ohlbaum Abstract A survey of copper levels in agricultural soils of central Chile revealed two soil clusters,one with a mean copper level of 162 mg/kg and one with a mean copper level of 751 mg/kg of soil. Samples of soils from both soil clusters were characterized on the basis of physicochemical characteristics, and copper extractability was compared by saturation and CaCl2 extraction as well as an acid-leaching procedure (TCLP). We also measured the copper content of various tissues of tomato (Lycopersicon esculentum) and onion (Allium cepa) crops growing on these soils. Other than copper levels, soils from the two clusters were quite similar, with slightly greater levels of molybdenum and cadmium in the high-copper soils. Within each cluster, extracted copper levels and total soil copper levels were not correlated. However, the three extraction procedures solubilized significantly more copper from the high-Cu soils. Mineralogical characterization of the soil particles and depth profiles of soil metal levels in a subsample of sites suggested that highly insoluble copper ore and mining wastes might account for the high copper levels. Neither total nor extractable copper levels allowed statistical prediction of the levels of copper in plant tissue. The edible tissues of both crops had the same mean copper content, regardless of the copper soil level. However, copper contents of stems and leaves were significantly higher for plants growing on the high-Cu soils. These results show that in these soils, high copper levels are associated with very insoluble copper species and thus low bioavailability of copper to crop plants. [source] The effects of organic and inorganic fertilizer applications to Miscanthus×giganteus, Arundo donax and Phalaris arundinacea, when grown as energy crops in Wales, UKGCB BIOENERGY, Issue 4 2010R. SMITH Abstract Two pot trials and one field trial were established to investigate the effects of organic and inorganic fertilizer applications to energy crops grown in mid-Wales. Chicken litter and sewage cake applied at a high level in excess of MAFF recommendations produced an increased yield response in Miscanthus and Arundo plants. Miscanthus plants exhibited an increased growth response to all fertilizers applied in its second year. Fertilizer applications in accordance with MAFF recommendations produced no significant differences in yields for Miscanthus or Arundo potted plants. In the field there was an increased yield response of Miscanthus to inorganic nitrogen applications compared with organic manures, but not with control plots. Analysis of the Miscanthus plant material at harvest showed significant differences in the nitrogen, potassium and copper content between treatments. No mineral content differences were shown for Miscanthus rhizome material or Arundo plant material. The Phalaris plants did not exhibit significant differences in growth or yield parameters, but their plant matter showed differences in nitrogen, phosphorus, potassium, calcium, sulphur and boron content between treatments. [source] The lowering effect of high copper intake on selenium retention in weanling rats depends on the selenium concentration of the dietJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2001S. Yu The question addressed was whether the influence of dietary copper concentration on selenium metabolism depends on the amount of selenium in the diet. Weanling, male rats were fed purified diets containing either 1 (low), 4 (normal) or 42 (high) mg Cu/kg diet and either 0.03 (low), 0.05 (normal) or 1.0 (high) mg Se/kg diet in a 32 factorial design. Extra copper was added to the diets in the form of CuSO4,·,5H2O and selenium as Na2SeO3,·,5H2O. In rats fed either the low or normal amounts of selenium, higher intakes of copper decreased the apparent intestinal selenium absorption and increased urinary selenium excretion. The effects of copper on selenium absorption, excretion and retention were not seen in rats fed the high-selenium diets. An increase in dietary copper concentrations elevated selenium concentrations in the liver and kidneys, but slightly lowered those in the spleen of rats that were fed the diets with the normal level of selenium. In rats that were fed the diets with either low or high selenium concentration, copper intake had no effect on organ selenium concentrations. Glutathione peroxidase activity in erythrocytes was raised by feeding the diets which contained either normal or high copper content instead of those that were low in copper. It is concluded that the amount of selenium in the diet determines whether or not an increase in dietary copper concentration affects selenium metabolism. [source] Susceptibility of channel catfish, Ictalurus punctatus (Rafinesque), to Edwardsiella ictaluri challenge following copper sulphate exposureJOURNAL OF FISH DISEASES, Issue 10 2007B R Griffin Abstract Channel catfish, Ictalurus punctatus (Rafinesque), with or without a preliminary 24 h exposure to 2 mg copper sulphate L,1, were challenged with 7.5 × 106 colony forming units L,1 of Edwardsiella ictaluri to determine the effect of copper sulphate on disease resistance. Catfish previously exposed to copper sulphate were significantly more resistant to the bacterial challenge than those not exposed. Catfish not exposed to copper sulphate suffered 35.5% mortality while catfish exposed to copper sulphate experienced 14.1% mortality. Copper concentrations were the same in tank waters of both exposed and control fish at the time of challenge, eliminating the possibility that copper in the water may have been toxic to bacteria. Copper concentrations in freeze dried and ground tissues of unexposed, exposed, and purged channel catfish were highest in fish before copper sulphate exposures suggesting that elevated tissue levels of copper were not responsible for the increased resistance to bacterial challenge. Competition for sites of bacterial attachment to gill or epithelial cells may account for the reduction in mortality; although this is not supported by the low copper content of fish tissue after copper exposure. [source] Copper stimulates human oral fibroblasts in vitro: a role in the pathogenesis of oral submucous fibrosisJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 8 2001C. Trivedy Abstract: Copper is implicated in the pathogenesis of several fibrotic disorders. Areca nut has been shown to have a high copper content and areca chewing is associated with oral submucous fibrosis (OSF). The effects of copper on human oral fibroblasts were investigated in vitro. Human oral fibroblasts were incubated with copper chloride (CuCl2) at concentrations ranging from 0.01 ,M to 500 ,M for 24 h, and in vitro cell proliferation was assayed by incorporation of tritiated,thymidine; soluble and non-soluble collagen synthesis was assayed using tritiated-proline. Addition of copper chloride at concentrations ranging from 0.1 ,M to 50 ,M increased the collagen synthesis by the oral fibroblasts compared with growth without copper (P<0.05). The addition of copper chloride neither increased the synthesis of non-collagenous proteins by the fibroblasts nor influenced their proliferation rate. We conclude that copper upregulates collagen production in oral fibroblasts. This appears to be concentration dependent, with peak collagen synthesis at 50 ,M CuCl2. These in vitro results taken together with the recent findings of copper in oral biopsies from OSF subjects support the hypothesis that copper in areca nut acts as a mediator of OSF. [source] Efficient oxidative coupling polymerization for synthesis of thermosetting poly(phenylene ether) copolymer with a low dielectric lossJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2008Jun Nunoshige A novel oxidative coupling polymerization using a water/toluene heterogeneous system for the synthesis of thermosetting Poly(phenylene ether) copolymer (Allyl-PPE) was developed. Allyl-PPE with a narrow molecular weight distribution and a low copper content was obtained in the presence of a Cu/TMEDA catalyst dissolved in water droplets. This method solved the problems during the synthesis of the Allyl-PPE with conventional Cu/pyridine catalysts. The resulting Allyl-PPE exhibited excellent dielectric properties (,, = 2.4, tan , = 0.002 at 10 GHz), and it will be useful for applications to high-speed and high-frequency printed circuit boards. [source] Preparation and thermal properties of zirconium tungstate/copper compositesMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 9 2008X. Yan Metall-Matrix-Verbundwerkstoffe; thermische Eigenschaften; Pulver Prozess Abstract ZrW2O8/Cu composites were prepared by the powder metallurgy method. Electroless plating was used to deposit copper on ZrW2O8 powder before sintering. The thermal expansion and thermal conductivity of composites were measured in the temperature range from 25 oC to 200 oC and compared with those predicted from various theoretical models. The results show that the coefficient of thermal expansion of ZrW2O8/ Cu composites with a different volume fraction of ZrW2O8 is greater than the theoretically calculated value. The thermal conductivities of ZrW2O8/ Cu composites increase with a higher copper content and decrease upon elevated temperature. The thermal conductivity of composites with a different volume fraction of ZrW2O8 is lower than the theoretically calculated value. Fertigungsverfahren und thermische Eigenschaften von Zirkonium Wolfram/Kupfer Verbundwerkstoffen No Abstract [source] Beurteilung von Loten und Lötverbindungen unter dem Einfluss steigender Kupfergehalte in verunreinigten bleifreien LotbädernMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 1 2008B. Wielage Lead-free solders; phase selection; deep-etching; intermetallic compounds Abstract Zuverlässigkeit und Degradationsverhalten bleifreier Lote sind aufgrund von Widersprüchlichkeiten und notwendiger Problemlösungen nach wie vor Aspekte weiterer Untersuchungen. Die vorliegende Arbeit zeigt anhand von Phasenselektion der intermetallischen Phasen Ag3Sn und Cu6Sn5 sowie (Cu,Ni)6Sn5 und (Ni,Cu)3Sn4 morphologisch-mikrostrukturelle Zusammenhänge in Verbindung mit mechanischen Eigenschaften auf. Dazu wurden insbesondere das metallografische Tiefätzen und die instrumentierte Eindringprüfung genutzt. Die Lotlegierungen SnAg3,8CuX und SnCuXNi0,07 und deren Lötverbindungen wurden durch verschiedene Methoden komplex evaluiert. Es konnte nachgewiesen werden, dass das Zulegieren von Nickel als degradationsvermindernde Maßnahme des Kupfer-Leachings zur Versprödung der Legierung durch das Wachstum der Phase (Cu,Ni)6Sn5 führen kann. Evaluation of solders and solder joints processed in lead free solder baths with increasing copper content Reliability and degradation behavior of lead-free solders are due to contradictions and necessary problem solving remaining aspects of further investigations. This paper shows morphologic and microstructural relationships in conjunction with mechanical properties on the intermetallic phases Ag3Sn and Cu6Sn5 as well as (Cu, Ni)6Sn5 and (Ni, Cu)3Sn4. In particular, the methods of metallographic deep-etching and the instrumented indentation hardness test were applied. The solders SnAg3,8CuX and SnCuXNi0,07 and their solder joints were comprehensively evaluated by various methods. It has been shown that alloying with nickel as a method of decreasing copper-leaching can induce embrittlement by growth of the (Cu,Ni)6Sn5 phase. [source] Extrapyramidal symptoms in Wilson's disease are associated with olfactory dysfunctionMOVEMENT DISORDERS, Issue 9 2006Antje Mueller MD Abstract Wilson's disease is a rare autosomal recessive disorder characterized by the accumulation of copper, mainly in the liver and the brain. As copper accumulation in the brain leads to disturbances in basal ganglia function, neurological-type patients typically present with hypo- and hyperkinetic extrapyramidal symptoms, with Parkinsonism being very common. Although there are numerous reports on olfactory deficits in primary neurodegenerative disorders, olfactory function has not been investigated in metabolic disorders presenting with extrapyramidal features. Twenty-four patients with Wilson's disease participated in the investigation. All patients were treated pharmacologically. They comprised patients with liver disease alone (including mild enzyme elevation in asymptomatic individuals; n = 11) and/or neurological symptoms (n = 13) at the time of testing. Twenty-one patients underwent both [18F]fluoro-2-deoxy-D-glucose positron emission tomography ([18F]FDG-PET) and magnetic resonance imaging (MRI). The severity of extrapyramidal symptoms was judged using a clinical score system ranging from 0 (no symptoms) to 3 (severe symptoms). In all patients, psychophysical testing was performed using the "Sniffin' Sticks," which involved tests for odor threshold, discrimination, and identification. Results from the present study revealed that Wilson's disease patients with neurological symptoms show a significant olfactory dysfunction compared to hepatic-type patients. Individuals who are more severely neurologically affected also present with a more pronounced olfactory deficit. Of interest, there was no significant effect of long-term treatment with penicillamine on olfactory function. Olfactory function did not correlate significantly with the presence of MRI visible lesions in the basal ganglia or with any regional glucose metabolism as measured by [18]F-FDG-PET. In conclusion, these findings indicate that the underlying pathological alterations with degeneration in the basal ganglia and neuronal loss in association with a marked increase of the copper content in this brain region play a role in the olfactory deficit. © 2006 Movement Disorder Society [source] Proteomic analysis of sera of asymptomatic, early-stage patients with Wilson's diseasePROTEOMICS - CLINICAL APPLICATIONS, Issue 10 2009Jung-Young Park Abstract Wilson's disease (WD) is characterized by excessive accumulation of intracellular copper in liver and extrahepatic tissues, leading to significant oxidative stress and tissue damage. To date, several diagnostic biomarkers for WD such as serum ceruloplasmin, serum or urine copper levels and copper content in liver have been identified. However, these biomarkers may not be convincing for the diagnosis in some WD patients. To identify additional novel diagnostic biomarkers, we compared the serum protein profiles of asymptomatic childhood WD patients (n=20), without neurologic manifestation or liver cirrhosis, with normal controls (n=13). Fourteen spots, five up-regulated and nine down-regulated (>2-fold), were differentially expressed in WD patients in comparison to normal control on 2-DE. Among them, three spots were down-regulated in both male and female WD. MS/MS analysis revealed that the three spots were complement component C3, complement factor B and alpha-2 macroglobulin. By comparative proteome analysis, complement component C3, complement factor B and alpha-2 macroglobulin, which are related to oxidative stress and inflammation, turned out to be good candidates for novel diagnostic biomarkers for early stages of WD. [source] Feed intake, growth and nutrient utilization in Atlantic halibut (Hippoglossus hippoglossus) fed diets containing a bacterial protein mealAQUACULTURE RESEARCH, Issue 4 2007Turid Synnøve Aas Abstract Triplicate groups of Atlantic halibut were fed diets containing 0%, 9% or 18% of a bacterial protein meal (BPM) produced from natural gas in a 9-week trial. Growth rates, relative feed intake, feed efficiency ratio and retention of all indispensable amino acids were significantly lower in fish fed the 18% BPM diets than in those fed the 0% and 9% BPM diets. There were no significant treatment effects on urea levels in plasma, liver or muscle, or in uric acid levels in plasma. The hepatosomatic index was lowest in fish fed the 18% BPM diet. Although the concentration of copper, an element abundant in BPM, increased in the liver as dietary BPM level increased, the total copper content in liver decreased. Fish fed the 0% and 9% BPM diets had a higher degree of supranuclear vacuolization of pyloric caeca and mid-intestine epithelia compared with fish fed the 18% BPM diet. In conclusion, the halibut fed the 9% BPM diet performed equally well as the control group regarding growth, feed intake and feed efficiency ratio, whereas performance was reduced in the fish fed the 18% BPM diet. [source] Voltammetric Monitoring and Speciation of Copper Ions in Italian "Grappa" with Platinum MicroelectrodesELECTROANALYSIS, Issue 7 2006Antonietta Baldo Abstract A linear sweep voltammetric (LSV) investigation and the anodic stripping voltammetric (ASV) detection of copper ions in ethanol-water mixtures and grappa samples are reported. The measurements are carried out by using platinum microdisk electrodes. Ethanol-water mixtures with ethanol content in the range 40,100,vol%, commercially available and raw grappa samples having ethanol content in the above range are examined. From LSV measurements of copper (II) ions added to the samples, the formation of intermediate copper (I) soluble species, which are stabilized mainly by the naturally occurring organic compounds present in the real samples, is observed. The analysis of LSV and ASV current responses against added Cu2+ ions provides linear trends over the concentration range 5×10,5,5×10,3,M and 5×10,7,5×10,5,M, respectively. The sensitivity depends on the ethanol content in the mixture and, as expected, it is the higher the lower the viscosity of the medium. In particular, it varies from 1.54 to 3.53,nA mM,1 and from 0.114 to 0.263,nA ,M,1 for LSV and ASV measurements, respectively, upon changing the ethanol content from 40 to 100,vol%. In the same range of ethanol content, detection limits obtained by ASV vary from 0.27 to 0.15,,M, respectively. Labile or total copper contents in the grappa samples are determined by ASV measurements performed in the untreated matrices or in the samples acidified with 0.1,M HClO4, respectively. Finally, acidification of the samples with different amounts of HClO4 allows also some speciation investigations to be performed. [source] Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of SugarcaneENTOMOLOGICAL RESEARCH, Issue 3 2005Abdul KHALIQ ABSTRACT Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval. [source] Relationship between soil copper content and copper content of selected crop plants in central ChileENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Ricardo Badilla-Ohlbaum Abstract A survey of copper levels in agricultural soils of central Chile revealed two soil clusters,one with a mean copper level of 162 mg/kg and one with a mean copper level of 751 mg/kg of soil. Samples of soils from both soil clusters were characterized on the basis of physicochemical characteristics, and copper extractability was compared by saturation and CaCl2 extraction as well as an acid-leaching procedure (TCLP). We also measured the copper content of various tissues of tomato (Lycopersicon esculentum) and onion (Allium cepa) crops growing on these soils. Other than copper levels, soils from the two clusters were quite similar, with slightly greater levels of molybdenum and cadmium in the high-copper soils. Within each cluster, extracted copper levels and total soil copper levels were not correlated. However, the three extraction procedures solubilized significantly more copper from the high-Cu soils. Mineralogical characterization of the soil particles and depth profiles of soil metal levels in a subsample of sites suggested that highly insoluble copper ore and mining wastes might account for the high copper levels. Neither total nor extractable copper levels allowed statistical prediction of the levels of copper in plant tissue. The edible tissues of both crops had the same mean copper content, regardless of the copper soil level. However, copper contents of stems and leaves were significantly higher for plants growing on the high-Cu soils. These results show that in these soils, high copper levels are associated with very insoluble copper species and thus low bioavailability of copper to crop plants. [source] The electrical behavior of thermosetting polymer composites containing metal plated ceramic fillerPOLYMER COMPOSITES, Issue 1 2005Hedva Bar This paper describes the electrical behavior of a thermosetting system, based on epoxy resin, containing metal plated fillers. Ceramic fillers such as chopped glass fibers and mica flakes were coated with copper by electroless plating and incorporated into an epoxy resin based on di-glycidyl ether of bisphenol A (DGEBA) with tri-ethylenetetramine (TETA) curing agent. The percolation threshold in these systems is obtained at very low copper contents of 0.11,0.44 vol%. The epoxy/copper coated mica system is characterized by an extremely large positive temperature coefficient (PTC) effect, which is not followed by a negative temperature coefficient (NTC) effect. Increasing the copper coated mica concentration raises the PTC temperature of the first temperature cycle, and exposing the material to continuous heating-cooling cycles results in a decrease in the PTC temperature and an increase of its room temperature resistivity. Inverse relations were found between the coefficient of thermal expansion and the PTC temperature. Accordingly, the mechanism governing the PTC effect in the epoxy/copper coated mica composite is based on a larger thermal expansion coefficient of the matrix compared with the ceramic filler. POLYM. COMPOS., 26:12,19, 2005. © 2004 Society of Plastics Engineers. [source] Ultrasound-facilitated electro-oxidation for treating cyan ink effluentTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2008Chee-Yong Chua Abstract The feasibility of using ultrasonication in combination with the Fenton's reaction was investigated for treating cyan ink effluent. A two-step treatment process was developed,the first step was an ultrasound-assisted electro-oxidation, while the second was chemical oxidation through the addition of hydrogen peroxide. The use of electro-oxidation in the first step significantly reduced the amount of iron needed compared with the conventional Fenton's reaction, resulting in a 98% reduction in the amount of sludge produced. A simple technique based on refractive index measurements was introduced as a rapid way to quantify the amount of sludge produced. It was postulated that ultrasonication in the presence of iron (from electrolysis) in the first step converted the ink components into reaction intermediates which were more amenable to peroxide oxidation in the second step. These intermediates were quantified by ultra-violet absorption at wavelengths of 275,400 nm. The two-step treatment process was able to reduce the COD and copper contents in the ink waste water to within the discharge limit, which conventional Fenton's reaction was unable to meet for copper discharge. The same COD removal was also achieved in about half the time. Kinetics study performed to further understand the reaction mechanisms show second-order kinetics for both steps with activation energies of 18.2 and 20.4 kJ/mol for steps 1 and 2, respectively. On a étudié la possibilité de recourir à l'ultrasonification combinée à la réaction de Fenton pour traiter l'effluent d'encre de cyan. Un procédé de traitement en deux étapes a été mis au point: la première étape consiste en une électro-oxydation assistée par ultrasons, tandis que la seconde consiste en une oxydation chimique par ajout de peroxyde d'hydrogène. Le recours à l'électro-oxydation dans la première étape réduit significativement la quantité de fer requis comparé à la réaction de Fenton classique, entraînant une réduction de 98% de la quantité de suspension produite. Une technique simple basée sur des mesures d'indice de réfraction a été introduite comme une façon rapide d'établir la quantité de suspension produite. On a posé comme postulat que l'ultrasonification en présence de fer (de l'électrolyse) dans la première étape convertit les composantes de l'encre en des intermédiaires de réaction qui étaient plus propices à l'oxydation du peroxyde dans la seconde étape. Ces intermédiaires ont été quantifiés par l'absorption des ultraviolets à des longueurs d'ondes de 275 nm à 400 nm. Ce procédé de traitement en deux étapes a permis de réduire la DCO et les teneurs en cuivre dans l'eau usée de l'encre pour les amener à la limite des normes de rejet, ce que la réaction de Fenton classique n'a pu permettre de réaliser pour le cuivre. Le même retrait de DCO a été également réalisé dans un temps inférieur de 50%. L'étude de cinétique effectuée pour mieux comprendre les mécanismes de réaction montre une cinétique de second ordre pour les deux étapes avec des énergies de désactivation de 18,2 et 20,4 kJ/mol pour les étapes 1 et 2, respectivement. [source] | ||||||||||||||||||||||