RESUMO
The aim of this work was the estimation of resveratrol content in two successive extracts (EtOAc and MeOH) of peanuts (Arachis hypogaea L.) pericarp of Egypt, by TLC and HPLC methods. Results showed the presence of 3.0 and 0.5 microg/mL resveratrol in EtOAc and MeOH extracts respectively. The in vitro carbohydrate hydrolyzing enzyme inhibition activity showed higher percentage of inhibition of alpha-amylase, alpha-glucosidase and beta-galactosidase with EtOAc (4.32, 5.93 and 13.7%) than with MeOH extract (3.9, 4.9 and 14.1%) but lower than the standard resveratrol concentration (5.18, 5.94 and 13.26%) and the reference acarbose (5.88, 5.9 and 13.0%). It could be concluded that the content of resveratrol in peanut pericarp is related to the percentage of inhibition activity of carbohydrate hydrolyzing enzymes. These results strongly reflect the benefit of using peanut pericarp, the waste product, as a natural antidiabetic agent.
Assuntos
Antioxidantes/análise , Antioxidantes/farmacologia , Arachis/química , Metabolismo dos Carboidratos/efeitos dos fármacos , Estilbenos/análise , Estilbenos/farmacologia , Calibragem , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Inibidores Enzimáticos/farmacologia , Inibidores de Glicosídeo Hidrolases , Espectroscopia de Ressonância Magnética , Extratos Vegetais/farmacologia , Controle de Qualidade , Padrões de Referência , Resveratrol , Espectrofotometria Ultravioleta , alfa-Amilases/antagonistas & inibidores , beta-Galactosidase/antagonistas & inibidoresRESUMO
A magnetic micro porous structure composite based on alginate and Prussian blue (M-SA-PB) was simply prepared for cesium removal from the aqueous solutions. The gelation and formation of PB proceeded through the same step, which made the PB homogenously distributed and firmly attached to the alginate matrix. The homogenizer was applied to break down the bulky gel structure into micro-ones, and the lyophilizer will provide the porous structure. Batch cesium sorption experiments showed that the adsorption kinetics and isotherms were attributed to the pseudo-second-order model and Langmuir isotherm. Moreover, the Cs-ion is favorably adsorbed on the M-SA-PB composite surface as a monolayer towards Cs, with a maximum adsorption capacity reach of 191.0 mg/g. Furthermore, the M-SA-PB adsorbent showed excellent adsorption selectivity of Cs from multiple-ion solutions. Our work was extended to use the M-SA-PB composite in dynamic cesium sorption. The column studies showed that the removal efficiency of Cs+ increased with increasing bed depth as well as the initial cesium concentration. Finally, as previously mentioned, the M-SA-PB could be considered an excellent Cs+ scavenger employing both batch and dynamic approaches, which makes it a promising adsorbent for practical investigations.
Assuntos
Césio , Poluentes Químicos da Água , Césio/química , Hidrogéis , Adsorção , Alginatos/química , Cinética , Fenômenos Magnéticos , Poluentes Químicos da Água/química , Concentração de Íons de HidrogênioRESUMO
The adsorption characteristics of palladium from chloride aqueous solution onto the silica alginate (SA-Si) nanomaterial have been investigated. The prepared nanomaterial (SA-Si) was characterized by various advanced techniques that ensured a successful preparation process. Different adsorption parameters including the solution pH, shaking time, palladium ion concentration, adsorbent dosage, and temperature were investigated. The experimental results showed that the pseudo-first-order model provided the best fitting for the palladium ions adsorption, and the time required to reach equilibrium was 90.0 min. The adsorption isotherm result from palladium was well described by the Langmuir isotherm model and the maximum adsorption capacity of (SA-Si) nanomaterial was estimated as 12.50 mg/g for Pd(II). Moreover, the thermodynamic results demonstrated that Pd(II) sorption onto (SA-Si) nanomaterial was endothermic and spontaneous. Additionally, the SA-Si nanomaterial can be used as an effective adsorbent for the sorption of Pd(II) from various metal ions present in fission products.
Assuntos
Nanoestruturas , Poluentes Químicos da Água , Purificação da Água , Paládio/química , Cloretos , Adsorção , Dióxido de Silício/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica , Água/químicaRESUMO
OBJECTIVE: It is well documented that oxidative stress is a basic mechanism behind the development of diabetic state. The current study was undertaken to elucidate the hypoglycemic role of zinc, selenium and vitamin E and their mixture in comparison with the antidiabetic drug glibenclamide. MATERIALS AND METHODS: Male Wistar rats weighing 250 +/- 50 g were made diabetic by injection with a single i.p. dose of streptozotocin (STZ) (65 mg/kg b. wt). Diabetic groups were simultaneously i.p. injected either with zinc chloride (ZnCI2) (5 mg/kg) or with selenium and vitamin E (1.5 mg/kg as sodium selenite and vitamin E 1000 mg/kg) or with zinc, selenium and vitamin E each element i.p. injected according to its corresponding therapeutic dose daily for one month. Another group was orally treated daily with glibenclamide drug (5 mg/kg) for one month. RESULTS: Blood and tissue samples were collected at day 3 post STZ injection (from one group serum glucose level significantly elevated < or = 300, p < or = 0.05) and at day 30 post-treatment in other groups. Liver function, nitric oxide (NO), malondialdehyde (MDA) and phosphoenol pyruvate carboxykinase (PEPCK) were significantly increased, while superoxide dismutase (SOD), reduced glutathione (GSH), total protein, lactate dehydrogenase (LDH), pyruvate kinase (PK) and hexokinase (HK) were inhibited after STZ treatment. Histological examination of diabetic liver showed necrosis and degenerative changes of hepatocytes. Treatment of diabetic rats with ZnCI2, selenium and vitamin E or their combination blunted the increment in serum glucose induced by STZ, preserved liver architecture and ameliorated all the previous mentioned biochemical parameters. CONCLUSIONS: It was found that, the combined administration of zinc, selenium and vitamin E exhibited a more remarkable effect than either zinc or selenium and vitamin E. So, the results clearly indicate the beneficial effects of micronutrients combination in controlling hyperglycemia.
Assuntos
Antioxidantes/farmacologia , Metabolismo dos Carboidratos/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Selênio/farmacologia , Vitamina E/farmacologia , Zinco/farmacologia , Animais , Análise Química do Sangue , Glicemia/metabolismo , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/metabolismo , Glibureto/farmacologia , Fígado/química , Fígado/enzimologia , Fígado/patologia , Masculino , Ratos , Ratos WistarRESUMO
OBJECTIVE: The schistosomicidal properties of garlic (Allium sativum) and onion (Allium cepa) powder were tested in vitro against Schistosoma mansoni miracidia, schistosomula, cercaria and adult worms. Results indicate their strong biocidal effects against all stages of the parasite and also show scavenging inhibitory effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO). MATERIALS AND METHODS: In the present work, the in vivo effects of A. sativum and A. cepa on lipid peroxide and some antioxidant enzymes; thioredoxin reductase (TrxR), sorbitol dehydrogenase (SDH), superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) (as they have a crucial role in host protection against invading parasite) were also studied. RESULTS: The data demonstrate that, there was a significant inhibition in SOD, CAT, GR, TrxR and SDH in infected liver while, significant elevation was detected in lipid peroxide as compared to the normal control. The current resultS clearly revealed that, the used both edible plants enhance the host antioxidant system indicated by lowering in lipid peroxide and stimulation of SOD, CAT, GR, TrxR and SDH enzyme levels. CONCLUSIONS: Enhancement of such enzymes using A. sativum and A. cepa could in turn render the parasite vulnerable to damage by the host and may play a role in the antischistosomal potency of the used food ingredients.
Assuntos
Alho/química , Cebolas/química , Extratos Vegetais/farmacologia , Schistosoma mansoni/efeitos dos fármacos , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Sequestradores de Radicais Livres/isolamento & purificação , Sequestradores de Radicais Livres/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/parasitologia , Camundongos , Óxido Nítrico/metabolismo , Esquistossomicidas/isolamento & purificação , Esquistossomicidas/farmacologiaRESUMO
BACKGROUND AND OBJECTIVES: Malachite green (MG) is a triarylaminmethane dye used in the fish industry as an anti-fungal agent. Concern over MG is due to the potential for consumer exposure, suggestive evidence of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. In order to evaluate the risks associated with exposure to MG, we examined the mutagenicity and biochemical effect of MG. MATERIALS AND METHODS: For genotoxic effect we use the doses 27, 91, 272 and 543 mg/kg b.wt. for different period of time (7, 14, 21 and 28 days) to evaluate chromosomal aberrations in mouse somatic and germ cells as well as sister chromatid exchanges in bone marrow cells. For DNA fragmentation assay from mouse liver the same doses of MG were used for 28 days. For measuring biochemical parameters such as glycolysis and gluconeogenesis enzyme pathways, antioxidant indices, hepatic marker enzymes, total protein, glucose, glycogen levels and liver function enzyme activities were evaluated. Mice were treated orally up to 28 days with the two high doses of MG 272 and 543 mg/kg b.wt. RESULTS AND CONCLUSIONS: Our results show that MG induce elevation in the percentage of SCE's and chromosomal aberrations (p < 0.01) after treatment with the high doses for long period of time. MG also induces DNA damage in mice liver in a dose dependent manner. Beside, MG treatment either in low or high doses causes biochemical disturbances in the major glucolytic-gluconeogenic pathways, hepatic marker enzymes, depleted glutathione and increased free radical as determined by increasing lipid peroxide. Histopathological observations revealed that MG induced sinusoidal, congestion, focal necrosis and degenerating in hepatic cells, hypertrophy and vacuolization followed by necrosis and cirrhosis.
Assuntos
Antifúngicos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Aberrações Cromossômicas/induzido quimicamente , Fragmentação do DNA , Metabolismo Energético/efeitos dos fármacos , Fígado/efeitos dos fármacos , Corantes de Rosanilina/toxicidade , Troca de Cromátide Irmã/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Pesqueiros , Gluconeogênese/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Hipertrofia , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Testes de Mutagenicidade , Necrose , Medição de Risco , Fatores de TempoRESUMO
Lanthanides are widely used in several advanced technologies, and the presence of heavy metal ions as traces reduce their efficiencies. Hence, adsorption of some heavy metals from Lanthanides aqueous solution using previously prepared graphene oxide-citrate (GO-C) composite was reported. In this regard, the GO-C was applied to remove various heavy metal ions (Fe, Ni, Mn) through the batch technique. The GO-C after the adsorption process was characterized by various advanced techniques. The results obtained from the experimental investigations revealed that the GO-C showed a rapid equilibrium adsorption time (1.0 min) for all the studied heavy metal ions. Moreover, the adsorption isotherm data for Fe3+, Mn2+, and Ni2+ was fit by the Langmuir isotherm model with excellent adsorption capacity for Fe3+ (535.0 mg/g), Mn2+ (223.22 mg/g), and Ni2+ (174.65 mg/g). Furthermore, the GO-C can be reused over five times to enhance the removal efficiency. Interestingly, the GO-C adsorbent achieved removal performance reached 95.0% for the Fe3+ and ≥ 35.0% for Ni, Mn, Co, and Cu compared to < 1% for lanthanides metal ions.
RESUMO
This work addressed one step preparation method to form a novel nano material composite of graphene oxide nanosheet (GO) functionalized with low-cost tri-sodium citrate (C), using, teteraethylorthosilicate (TEOS) as a cross-linker. The prepared composite (GO-C) was characterized using various advanced techniques. Among these techniques, the TGA provided interesting information concerning the functionalization process. Within this process, the (-OH) groups that located at the GO-surface were consumed in the modification process which leads to increase the thermal stability of the resulted composite. Cationic organic methylene blue (MB) and crystal violet (CV), and inorganic copper (Cu2+) and cobalt (Co2+) pollutants were displayed as a model to assess their removal performance by the developed composite (GO-C) from aqueous solution, through batch technique. According to Langmuir isotherm the GO-C present an excellent adsorption capacity for MB (222.22 mg g-1), CV (270.27 mg g-1), Cu2+ (163.4 mg g-1) and Co2+ (145.35 mg g-1) which were more than the adsorption capacities found in literature. Additionally, the regenerated composite presents higher removal ability than the original composite.
RESUMO
Phosphogypsum (PG) is the main by-product of phosphoric acid, which is produced by the sulfuric acid attack of phosphate rocks, wet process. This by-product, which contains around 2.0% phosphoric acid, is used as a low-cost soil fertilizer, PGF. PGF consists mainly of gypsum (CaSO4·2H2O), P2O5, SiO2, and other impurities, including a minor amount of rare earth elements, REEs. In general, phosphate rocks contain from about 0.04 to 1.0% REE, which are precipitated with PG. Now, REEs are considered as strategic elements. Therefore, PG is now regarded as a secondary source of REE. This paper address a process for the separation of REEs and sodium sulphate as a product from PGF. This paper is based on the metathesis of the bulk of PGF with sodium carbonate to obtain calcium carbonate precipitated contain REEs. Furthermore, sodium sulphate was obtained as a product. Calcium carbonate containing REEs was leached out by citric acid as a green acid or nitric acid. At optimum conditions, maximum leaching of REEs from CaCO3 after one cycle of leaching by 3.0 mol/L nitric acid at L/S = 3/1, agitation time of 180.0 min., and at a temperature of 25 °C is 75.1%, 361.10 mg/kg from the total REEs present in PGF. While, the maximum leaching of 87.4%, 420.2 mg/kg of REEs from CaCO3 after one cycle of leaching by 1.0 mol/L citric acid, L/S = 5/1, agitation time of 15.0 min., and 85 °C. The REEs that were obtained in the leaching citrate solutions were purified by solvent extraction using 10% of di-2-ethyl hexyl phosphoric acid, HDEHP, in kerosene. The extracted REEs were stripped by 0.5 mol/L H2SO4. The stripped solutions were further treated with 10.0% oxalic acid to precipitate the REEs. The developed procedure can recover REEs from PGF with an efficiency of 85.2% and a purity of 97.7%.
RESUMO
The presence of dyes in industrial wastewater is a serious problem that hazards the surrounding environment. Therefore, this work investigates the removal of a binary dye system composed of Methylene Blue (MB) and Crystal Violet (CV) using an innovative composite (cotton fiber-graphene oxide (C-GO)). The simultaneous determination of the concentrations of the dyes in the binary system is a challenge. Thus, a new method was investigated to simultaneously detect the concentration of the dyes in the binary system using first-order derivative UV spectra to avoid the complex overlap of the maximum peaks in the original zero-order absorption spectra. Different parameters affecting the filter sorption mode, such as the concentration of the dyes, the dose of the (C-GO) composite, the dose of NaCl, flow rate, temperature, and pH, were investigated. The data obtained showed high adsorption efficiency for the binary dye system (>99%). This was approved based on the maximum sorption capacity (Q°) value obtained for the Langmuir model. Furthermore, this technique was developed, evaluated and applied to treat real industrial waste. The obtained data showed that the C-GO composite was highly efficient in treating industrial wastewater containing such dyes when a sufficient quantity is used. Therefore, it can be used as a promising adsorbent for such dyes in wastewater treatment processes.
RESUMO
A new approach for extraction of 99Mo tracer as a lighter homolog of Seaborgium (Sg) by three different the ionic liquids are studied. Aliquat-336 [Aliq-336.Cl-] as anion exchange has been used for the preparation of three ionic liquid, namely: ([Aliq-336]+ [SCN]-), ([Aliq-336]+ [S]- ) and ([Aliq-336]+ [Fe(CN)6]-). Their potential extraction of carrier free 99Mo from HNO3 solutions has been evaluated. The obtained results demonstrated that successful extraction of carrier free 99Mo from HNO3 solutions is achieved. The ([Aliq-336]+ [Fe(CN)6]-) is found to give the highest extraction affinity for 99Mo than the others ionic liquids investigated. The preliminary results could be useful for the upcoming aqueous experiments of Seaborgium.
RESUMO
Cotton fiber-graphene oxide (C-GO) composite with high adsorptive properties towards the cationic dye, crystal violet (CV), was successfully fabricated by simple mixing of cotton fiber and GO in aqueous solution using a homogenizer. The as-prepared composite was characterized using TEM, SEM, LOM, XRD, FTIR, Raman and TGA. The characterization indicated that the formation of a homogeneous composite occurred via adequate mixing of the cotton fiber and GO. The fine structure of the obtained composite was successfully used in two adsorption techniques, namely batch adsorption and filter adsorption. Various parameters affecting batch adsorption, such as contact time, dye concentration, composite dose, NaCl dose, temperature and pH were investigated. In the filter adsorption mode, dye concentration, composite dose, NaCl dose, temperature, flow rate and pH were studied. A comparison study between the two techniques, i.e., batch adsorption and filter adsorption, are reported. The filter adsorption technique shows higher adsorption efficiency than the batch one, which was evident from the maximum adsorption capacity (Q°) values, obtained from the Langmuir isotherm. Further, the filter technique was developed and evaluated. This was achieved by regeneration, scaling-up and, finally, using another model of cationic dye (methylene blue).
RESUMO
Phosphogypsum (PG) precipitates as a by-product of the phosphoric acid industry when treating phosphate rocks with H2SO4. Lanthanides and trivalent yttrium content, Ln-Y, in the rock are mostly found in the PG. After a slight modification of the precipitated PG, some portion of the PG containing Ë2.0% P2O5 is used as a low-grade phosphogypsum fertilizer (PGF). In this work, studies on Ln-Y, leaching from PGF were carried out using different concentration of weak acids such as boric acid, malic acid and citric acid at different retention time (Rt). It was found that the leaching efficiency of the total Ln-Y by citric acid solution is more favorable than that using boric or malic acid solutions. In this concern, 1.0â¯mol/L citric acid solution leach about 40.9% of Ln-Y, when the acid volume (L) to solid mass of PGF (S) ratio equals 2.0, L/Sâ¯=â¯2.0, after Rt of 15â¯min at temperature of 298.0â¯K. Therefore, leaching of total Ln-Y from PGF by citric acid was investigated in terms of the acid concentration, Rt, and L/S as well as temperature. It is found that one leaching cycle by 1.0â¯mol/L citric acid solution using L/S ratio of 5.0 and Rt 15.0â¯min at temperature of 358â¯K, produced 53.3% from the total Ln-Y present in the used PGF sample. From these result a flow sheet was developed based on three leaching cycles to give a maximum leaching efficiency of 83.4%. Analysis of different Ln-Y in the final product indicated that 1.0â¯mol/L citric acid solution has high leaching selectivity for Er (89.4%), Ce (88.2%) and La (81.8%) and lower leaching selectivity for Pr (71.9%) and Y(40.7%).
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The current research aims to demonstrate the therapeutic effect of sour orange albedo extract (SOAE) and two flavanones loaded-tetraethylorthosilicate (TEOS) using sol-gel technique, in adose100 mg/kg body weight taken orally or45 days against acrylamide (ACR)toxicity in rats. This was achieved through measuring the activities of specific biochemical parameters related to liver functions in tissue of ACR intoxicated rats as compared to normal one. Liver functions included alanine and aspartate aminotransferases, antioxidants and oxidative stress biomarkers; superoxide dismutase, catalase, glutathione and lipid peroxide (malondialdehyde, MDA). Moreover, histological examination of liver was performed to confirm the biochemical findings. The present results clearly indicated disturbances in all biochemical parameters, such as increase in the liver function enzyme activities and MDA level. Results of ATPase enzyme activities revealed significant decrease in ACR intoxicated rats and liver biomarker enzymes declared significant decrease. On the other hand, treatment of intoxicated rats with the previous different nano-particles natural product demonstrated improvement in all biochemical parameters under investigation.
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Three structurally related novel extractants namely: N,N-dihexylcyanamide (DHCY), N,N-di(2-ethylhexyl)cyanamide (DEHCY) and N,N-di-octylcyanamide (DOCY) were synthesized in our laboratory and characterized by different techniques. The general method for synthesizing these extractants was based on the reaction of relevant secondary amines with cyanogen bromide in presence of sodium acetate anhydride. Their extracting ability in toluene as a diluent for Pd(II), Pt(IV), Fe(III), Zn(II), Cu(II) and Ag(I) from hydrochloric acid media has been studied. The extraction of hydrochloric acid was studied also. Pd(II) was strongly extracted by these extractants at low hydrochloric acid concentrations and the extraction decreased with increasing hydrochloric acid concentration while the reverse was obtained in the extraction of Pt(IV), Fe(III) and Zn(II). Under similar extraction conditions Cu(II) and Ag(I) were found poorly extracted. Hydrochloric acid was extracted only in its high concentration region. A systematic investigation has been carried out on the extraction of Pd(II) using two of the synthesized extractants. Pd(II) was extracted as a solvated complex with the composition, metal:chloride ion:extractant=1:2:2. The extracted species were studied also using IR spectra.
Assuntos
Cianamida/química , Ácido Clorídrico/química , Metais Pesados/química , Alquilação , Íons/química , Estrutura Molecular , Soluções , Espectrofotometria InfravermelhoRESUMO
Mg(OH)(2) was identified as a component in the magnesia cement being adsorbent for Cr(VI). Modified magnesia cement was prepared by the addition of ferric chloride and humic acid. The equilibrium adsorption of Cr(VI) on magnesia cement adsorbents (MF5-1) and (MF5-2) was investigated as a function of contact time, adsorbent weight, solute concentration and temperature. Tests of different isotherms have shown that the adsorption data fit the Langmiur and Freundlich isotherms at 25+/-1 degrees C. The nature of the diffusion process responsible for adsorption of Cr(VI) on (MF5-1) and (MF5-2) adsorbents was discussed. The kinetics and mechanism of diffusion of Cr(VI) into (MF5-1) and (MF5-2) adsorbents from aqueous solution have been studied as a function of Cr(VI) concentrations and reaction temperatures. The adsorption of Cr(VI) on the MF5-1 and MF5-2 adsorbents follows first-order reversible kinetics. The forward and backward constants, k(1) and k(2) have been calculated at different temperatures between 10 and 50 degrees C. The heat of activation of the adsorption, DeltaH(*) and DeltaS(*) were calculated for Cr(VI) at 25 degrees C. The values of DeltaH(*) were found 18.1 and 10.7 kJ mol(-1) for MF5-1 and MF5-2, respectively, while entropy change, DeltaS(*), were found -106.8 and -118.6 J mol(-1)K(-1) for MF5-1 and MF5-2, respectively. The study showed that pore diffusion is the rate-determining step in the adsorption of Cr(VI) ions for MF5-1 and MF5-2. MF5-2 was found more efficient for Cr(VI) adsorption than MF5-1. Also Cr(VI) can be adsorbed on MF5-2, whereas Cr(III) cannot. So, the competitive adsorption of multi-metals onto the MF5-2 adsorbent was studied. The studies showed that this adsorbent can be used as an efficient adsorbent material for the removal of Cr(VI) from water and nuclear power plant coolant water.
Assuntos
Cromo/isolamento & purificação , Termodinâmica , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Difusão , CinéticaRESUMO
Spent batteries represent a source of hazardous materials when discarded without appropriate treatment. Investigations on the recovery of zinc from the black paste of spent MnO(2)-Zn cell batteries were carried out. Leaching of zinc and manganese from the black paste of spent batteries using sulfuric or hydrochloric acid solutions was studied. It was found that leaching with sulfuric acid solution is more efficient than with HCl solution. Different parameters affecting the leaching of Zn(II) and Mn(II) with sulfuric acid were further studied. Extraction of Zn(II) and Mn(II) from the leaching sulfate medium by bis(2,4,4-trimethylpentyl) dithiophosphinic acid (CYANEX 301) diluted with kerosene was investigated. The factors affecting the extraction process, separately studied, include the effect of contact time, sulfuric acid concentration, CYANEX 301 concentration, phase ratio as well as temperature. The results indicated that, from sulfate medium, Zn(II) is more extracted than Mn(II). Selective stripping of Zn(II) was obtained using 5M HCl. Application of the method on the leaching sulfate solution of the spent MnO(2)-Zn dry cell black paste show the efficiency of the process, where the extraction and stripping of Zn(II) are 98% and 99%, respectively.
Assuntos
Manganês/isolamento & purificação , Zinco/isolamento & purificação , Conservação dos Recursos Naturais , Resíduos Perigosos , Ácido Clorídrico/química , Querosene , Compostos Organotiofosforados/química , Ácidos Sulfúricos/química , TemperaturaRESUMO
The feasibility of using surfactants as extracting agent for the removal of radium species from TENORM sludge produced from petroleum industry is evaluated. In this investigation cationic and nonionic surfactants were used as extracting agents for the removal of radium radionuclides from the sludge waste. Two surfactants namely cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX100) were investigated as the extracting agents. Different parameters affecting the removal of both (226)Ra and (228)Ra by the two surfactants as well as their admixture were studied by the batch technique. These parameters include effect of shaking time, surfactants concentration and temperature as well as the effect of surfactants admixture. It was found that, higher solution temperature improves the removal efficiency of radium species. Combined extraction of nonionic and cationic surfactants produces synergistic effect in removal both (226)Ra and (228)Ra, where the removals reached 84% and 80% for (226)Ra and (228)Ra, respectively, were obtained using surfactants admixture.
Assuntos
Rádio (Elemento)/análise , Esgotos/análise , Tensoativos/análise , Poluentes Radioativos da Água/análise , Monitoramento de RadiaçãoRESUMO
Different factors affecting separation of the tervalent actinides curium and californium by ion-exchange chromatography are discussed in the light of the resolution factor. The fact that resolution is inversely proportional to resin particle diameter and directly proportional to column length has been confirmed experimentally. The effects influencing resolution due to changes in flow-rate of the mobile phase used are dependent on resin particle diameter. Changes in temperature affect a number of variables influencing resolution.
RESUMO
The reaction of 2-hydrazino-4-(4-methoxyphenyl)-6-pheny-nicotinonitrile 3 with halo compounds yielded 4a-c,5,6. Heating 3 with carbon disulphide gave 7-(4-methoxyphenyl)-5-phenyl-3-thioxo-2,3-dihydro [1,2,4-] triazolo [4,3-a] pyridine-8-carboxylic amide 7. The behaviour of 3 towards some alpha,beta-unsaturated nitriles ,ethoxymethylene and ketene dithioacetal derivatives has been investigated, affording 9a-c,11a-c,13a-c,16a,b respectively. The activity of compounds 4a,5,6 and 7 have been investigated as molluscicidal.