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This study explores the detailed characterization of a biosorbent (Hen Feather) and its efficient use in eradicating the azo dye Metanil Yellow (MY) from its aqueous solutions. Effects of a range of experimental parameters, including pH, initial dye concentration, biosorbent dosage and contact time on the adsorption, were studied. A detailed physical and chemical characterization of the biosorbent was made using SEM, XRD, XPS and FTIR. During the optimization of adsorption parameters, the highest dye uptake of almost 99% was recorded at pH 2, dye concentration 2 × 10-5 M, 0.05 g of biosorbent and a contact period of 75 min. Various adsorption isotherm models were studied to gather different adsorption and thermodynamic parameters. The linearity of the Langmuir, Freundlich and D-R adsorption isotherms indicate homogeneous, multilayer chemisorption with high adsorption affinity between the dye and biosorbent. Values of the changes in the Gibbs free energy (ΔG°) and the enthalpy (ΔH°) of the adsorption process have been calculated, these values indicate that it is a spontaneous and endothermic process. Kinetics of the adsorption were also measured, and it was established that the adsorption of MY over Hen Feather follows a pseudo-second-order kinetic model at temperatures 30, 40 and 50 °C. The findings of this investigation clearly indicate that the studied biosorbent exhibits a high affinity towards the dye (MY), and it can be effectively, economically and efficiently used to sequestrate and eradicate MY from its aqueous solutions.
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2,4-Dinitrophenol (2,4-DNP) is a toxic compound that is widely used in many industrial and agricultural processes. This compound has low biodegradability in the environment due to its aromatic structure, and it is unsuccessfully eliminated by other chemical methods. Therefore, in this study, an integrated oxidation and reduction method was used to remove 2,4-DNP from the aqueous medium, in order to simultaneously use the benefits of oxidizing and reducing radicals in 2,4-DNP degradation. 2,4-DNP degradation was modeled by response surface methodology (RSM) and central composite design (CCD). According to the results obtained from RSM, the optimal values for the studied parameters were obtained at pH = 8.9, time = 25 min, ZnO dose = 0.78 g/L, SO3 = 1.89 mmolL-1 and 2,4-DNP concentration = 5 mg/L. Also, the removal efficiency with the integrated process was 3 to 4 times higher than the advanced oxidation or advanced reduction processes alone. Analysis of the data showed that at the time of the study, 2,4-DNP had been converted to linear hydrocarbons, and increased periods of time were required for complete mineralization. A decrease in the first-order model rate constant (kobs) and an increase in 2,4-DNP degradation rate (robs) were observed at higher DNP concentrations.
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Contaminantes Químicos del Agua , Óxido de Zinc , Aguas Residuales , 2,4-Dinitrofenol/análisis , 2,4-Dinitrofenol/química , Contaminantes Químicos del Agua/análisis , Oxidación-Reducción , Rayos UltravioletaRESUMEN
Herein, we report the synthesis of a novel bio-nanocomposite (Alg-Cst/Kal) for the effective removal of the dye "Crystal Violet" from its aqueous solutions. In order to observe the surface morphology and functional groups, the bio-nanocomposite was characterized using various techniques such as SEM, EDX, TEM, FTIR, XRD, and TGA. The effect of parameters like contact time, pH, concentration and temperature on the adsorption of the dye over adsorbent has been studied in detail. The dye - adsorbent system has been tested over various isotherm models and found to follow the Freundlich adsorption isotherm model at 303 K. The developed bio-nanocomposite material exhibits an excellent adsorption toward Crystal Violet with a maximum adsorption capacity of 169.49 mg.g-1. The experimental data has been further validated by applying various kinetic models and the pseudo-second order kinetic model was the best suited model. The calculated rate constant values ranged from 0.0046 to 0.0204 g.mg-1.min-1 for different dye concentrations. The positive values of change in enthalpy, ΔH° (9.765 kJ.mol-1) and change in entropy, ΔS° (0.0565 kJ.mol-1.K-1) obtained through thermodynamic studies demonstrate the endothermic nature and spontaneity of the adsorption process, respectively. The adsorption capacity of the adsorbent for the removal of the Crystal Violet dye was also compared with other adsorbents and found maximum. Novelty statement A novel bio-nanocomposite is synthesized by modifying the biopolymer alginate, cysteine and mixing the clay, kaolinite (Kal). The adsorption abilities of the material was tested the on the cationic hazardous dye, Crystal Violet. The material is novel and no attempt has so far been made to examine its batch adsorption abilities to remove hazardous dyes from the wastewater. The results are highly encouraging as out of all the adsorbents tested so far highest adsorption of the dye is observed in the present studies.
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Violeta de Genciana , Nanocompuestos , Adsorción , Biodegradación Ambiental , Colorantes , Concentración de Iones de Hidrógeno , Caolín , Cinética , Termodinámica , AguaRESUMEN
Layered double hydroxides (LDHs), also known as anionic clays, are lamellar inorganic solids with a brucite-like structure and consist of positively charged metal hydroxide sheets intercalated by anions and water molecules. Choice of LDH is beneficial as it displays properties like simple synthesis procedures, adjustable structure, stability, large surface area, homogeneous positive charge distribution over the surface, interplanar spacing, and versatility to synthesize a variety of composites. Due to these properties LDHs act as efficient adsorbents for wastewater treatment. This review presents a detailed overview of the removal of hazardous organic dyes using different LDHs and LDH-hybrids/composites. The review also incorporates methods of synthesis of various LDHs and composites and the effect of their morphology on dye removal capacity. The effects of adsorption variables such as pH, adsorbent dosage, initial concentration of dye, contact time on the adsorption of these materials are also explained along with adsorption isotherms, kinetics and operative mechanisms. This article incorporates 156 references, majority of which have been taken from the available literature of last 5 years.
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Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Colorantes , Hidróxidos , Hidróxido de Magnesio , Contaminantes Químicos del Agua/análisisRESUMEN
In the present study, a potential Guar gum/activated carbon nanocomposite as an adsorbent was synthesized and utilized for the sequestration of toxic congo red dye from synthetic wastewater. The nanocomposite was characterized using different techniques such as SEM, EDX, TEM, FTIR and XRD. Various physico-chemical parameters such as influence of contact time, pH, adsorbent dose, temperature and initial dye concentration were investigated to optimize conditions for maximum adsorption of congo red. Equilibrium data fitted well with Langmuir isotherm model having maximum adsorption capacity of 831.82 mgg-1 at 313â¯K. The kinetic studies demonstrated that the adsorption followed a pseudo-second order kinetic model. The thermodynamic study showed that the adsorption of congo red onto nanocomposite was spontaneous, exothermic with decreased in randomness at solid/liquid interface. The regeneration study indicated that the nanocomposite could be reused successfully upto five consecutive cycles. Therefore, the present material can be effectively and efficiently urilized for the removal of congo red dye from aqueous solution as well as industrial wastewater.
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AIM: The aim of this study was to evaluate the safety and efficacy of 4% articaine with epinephrine (1:200,000) vs 2% lidocaine with epinephrine (1:200,000) during surgical removal of impacted mandibular third molars. MATERIALS AND METHODS: The present study was undertaken in 20 patients belonging to American Society of Anesthesiologists (ASA) class I, of the age group between 18 and 30 years with bilaterally impacted mandibular third molars. Each patient underwent similar surgical procedure. In the first appointment, the patient was randomly selected to receive either 4% articaine or 2% lidocaine (both with epinephrine 1:200,000). Intraoperative and postoperative evaluation was done for both the anesthetic solutions. Following parameters were evaluated: total volume of anesthetic solution used during the surgery, onset of action of the anesthetic agent, duration of anesthesia, duration of postoperative analgesia, incidence, type and severity of adverse reactions, any need to reanesthetize the surgical zone and quality of anesthesia provided by the local anesthetic. Subjective pain evaluation was done with the aid of 100 mm length visual analog scale (VAS) both intraoperatively and postoperatively. RESULTS: In the present study, 4% articaine was found to have a significantly shorter onset of action than 2% lidocaine. Duration of anesthesia and postoperative analgesia of 4% articaine with epinephrine 1:200,000 was found to be significantly (1.44 and 1.28 times respectively) longer than 2% lidocaine with epinephrine 1:200,000. But no significant difference was found in other parameters. CONCLUSION: 4% articaine in comparison with 2% lidocaine (both with epinephrine 1:200,000) provided a shorter onset of action and longer duration of anesthesia. CLINICAL SIGNIFICANCE: No significant difference was recorded in the anesthetic efficacy between the two solutions.
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Anestesia Dental/métodos , Anestésicos Locales , Carticaína , Lidocaína , Tercer Molar/cirugía , Extracción Dental , Diente Impactado/cirugía , Anestésicos Locales/administración & dosificación , Carticaína/administración & dosificación , Humanos , Lidocaína/administración & dosificación , Mandíbula/cirugía , Dimensión del Dolor , Dolor Postoperatorio/prevención & control , Extracción Dental/métodosRESUMEN
There are complex considerations when planning to disclose an attenuated psychosis syndrome (APS) diagnosis. In this review, we evaluate ethical, legal, and clinical perspectives as well as caveats related to full, non- and partial disclosure strategies, discuss societal implications, and provide clinical suggestions. Each of the disclosure strategies is associated with benefits as well as costs/considerations. Full disclosure promotes autonomy, allows for the clearest psychoeducation about additional risk factors, helps to clarify and/or correct previous diagnoses/treatments, facilitates early intervention and bolsters communication between providers but there are important considerations involving heritability, comorbidity, culture, and stigma. Non-disclosure advances nonmaleficence by limiting stigma and stress (which may inadvertently exacerbate the condition), and confusion (related to the rapidly evolving diagnosis) in a sensitive developmental period but is complicated by varying patient preferences and the possibility that, as new treatments without adverse effects become available, the risk with false positives no longer justifies the accompanying loss of autonomy. Partial disclosure balances ethical considerations by focusing on symptoms instead of labels, but evidence that laypersons may interpret this information as a pseudo-diagnosis and that symptoms alone also contribute to stigma limits the efficacy of this approach. In addition, there are notable societal considerations relating to disclosure involving conservatorship, the reach of insurance companies, and discrimination. We advocate a hybrid approach to disclosure and recommend future research aimed at understanding the effects of stigma on clinical course and a renewed focus on those help-seeking cases that do not transition but remain clinically relevant.
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Revelación/legislación & jurisprudencia , Autonomía Personal , Trastornos Psicóticos , Estigma Social , Estrés Psicológico/prevención & control , Revelación de la Verdad/ética , Adolescente , Conducta del Adolescente , Desarrollo del Adolescente , Beneficencia , Comorbilidad , Características Culturales , Revelación/ética , Herencia , Humanos , Cobertura del Seguro , Seguro de Salud , Paternalismo , Educación del Paciente como Asunto , Prioridad del Paciente , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/prevención & control , Trastornos Psicóticos/psicología , Trastornos Psicóticos/terapia , Factores de Riesgo , Autoimagen , Discriminación SocialRESUMEN
This article describes the use of bottom ash [a power plant waste] and de-oiled soya [an agricultural waste] as effective adsorbents for the removal of a hazardous azo dye [Chrysoidine Y] from its aqueous solutions. This paper presents an experimental study and discussion of the adsorption characteristics of this dye on the two adsorbents. The adsorbents have been characterized, and also the effects of time, temperature, concentration, pH, and sieve size on the extent of adsorption have been evaluated. Batch adsorption measurements, kinetic studies, and column operations have been performed to elucidate the dye uptake capacity of the adsorbents. The monolayer adsorption capacities at 30 degrees C have been found from Langmuir analysis to be 7.27x10(-5) mol g(-1) and 3.35x10(-5) mol g(-1) for bottom ash and de-oiled soya, respectively. Adsorption kinetics experimental data are indicative of pseudo-second order kinetics during these processes. Column experiments indicate practical utility of the adsorbents for eradicating hazardous dyes from effluents. The recovery of the adsorbed dye from bottom ash and de-oiled soya, have been found to be 85% and 99%, respectively.
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Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , p-Aminoazobenceno/análogos & derivados , Adsorción , Cinética , Tamaño de la Partícula , Soluciones , Propiedades de Superficie , Agua/química , p-Aminoazobenceno/químicaRESUMEN
The adsorption performance of the materials bottom ash (BA), a power plant waste, and de-oiled soya (DOS), a soya bean industry waste for removal of crystal violet dye, has been investigated through batch and column experiments. Batch studies have been performed to describe the impact of parameters such as pH, amount of adsorbent, dye concentration, temperature, and contact time on the removal of the dye. Experimental data have been modeled by using Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich (D-R) isotherms. Thermodynamic parameters (DeltaG(o), DeltaH(o), and DeltaS(o)) were evaluated for the dye-adsorbent systems, which revealed that the adsorption process is endothermic in nature. Pseudo-first- and second-order kinetic models have been applied to the experimental data and pseudo-second-order kinetics was found to describe the adsorption of the dye (crystal violet) on the adsorbents. In order to achieve bulk removal of the dye, column operations were made. Recovery of the dye was made by eluting HCl solution through the exhausted columns and almost 95% and 78% of the dye was recovered from BA and DOS columns, respectively.
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Violeta de Genciana/química , Adsorción , Carbono/química , Colorantes/química , Concentración de Iones de Hidrógeno , Estructura Molecular , Tamaño de la Partícula , Termodinámica , Eliminación de Residuos Líquidos , Purificación del AguaRESUMEN
An agricultural industry waste, deoiled soya, and a waste of thermal power plants, bottom ash, have been tested for their adsorption ability to remove Light Green SF (Yellowish) dye from wastewaters. The effects of various essential experimental parameters (dye concentration, mesh size, temperature, and pH) have been investigated. A study of four isothermal models, Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich, has been made and important thermodynamic parameters have been calculated. The decreasing values of enthalpy show that the adsorption process is endothermic. Mechanistic studies reveal the involvement of a pseudo-second-order mechanism to drive the adsorption process in dye-bottom ash and dye-deoiled soya systems. It has been observed that a particle diffusion mechanism was prominent in the case of adsorption of the dye on bottom ash and deoiled soya. Column adsorption and desorption experiments further confirmed the practical application of the present research. The percentage adsorption has been obtained as 88.74% and 89.65% with percentage recovery of 99.82% and 99.08% for bottom ash and deoiled soya, respectively. The experimental results confirmed that triarylmethane dye Light Green SF (Yellowish) can be successfully removed and recovered from aqueous solutions economically and efficiently.
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The present investigation assesses the applicability of waste materials--bottom ash and deoiled soya--for the removal of the colorant Congo red from wastewaters. The adsorption characteristics and dye removal efficiency of adsorbents have been determined by investigating factors such as effect of pH, effect of concentration of the dye, amount of adsorbents, contact time, and temperature. Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich isotherm models have been used to evaluate the ongoing adsorption. With the help of adsorption isotherm data different thermodynamic parameters such as free energy; enthalpy, and entropy have been calculated. The estimated free energy has been obtained as -21.52 kJ mol(-1) for bottom ash and -16.88 kJ mol(-1) for deoiled soya. On the basis of pseudo-first-order and pseudo-second-order kinetic equations different kinetic parameters have been obtained. Column operations depicted good adsorptive tendencies for Congo red with 96.95% and 97.14% saturation of dye on bottom ash and deoiled soya, respectively. Regeneration of the saturated columns has been made by eluting NaOH solution and more than 90% dye has been recovered in both cases.
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Bottom ash, a waste of thermal power plants, and deoiled soya, an agricultural waste material, were employed for successful removal and recovery of hazardous phenol red dye from wastewaters. The adsorption characteristics and operational parameters were determined by monitoring different parameters such as effect of pH, effect of concentration of the dye, amount of adsorbents, contact time, and temperature. The equilibrium data were analyzed on the basis of various adsorption isotherm models, namely Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich. The highest monolayer adsorption capacity has been obtained for the phenol red-bottom ash system (2.6x10(-5) mol/g) at 50 degrees C. Different thermodynamic parameters such as free energy, enthalpy, and entropy have been calculated and it was concluded that with the increase in temperature adsorption increases, indicating the endothermic nature of the process for both adsorbent materials. Kinetic parameters were derived from pseudo-first-order and pseudo-second-order kinetics. Differentiation between particle and film diffusion mechanisms operative in the present study has been carried out. The column regeneration characteristic has been also investigated and recovery percentage greater than 90% was obtained for both adsorbents by utilizing acidic eluent.
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The present study deals with the application of bottom ash, a power plant waste, and deoiled soya, an agricultural waste, for the adsorptive removal of carmoisine A dye from its aqueous solutions. This paper incorporates a comparative study of the adsorption characteristics of the dye on these effective adsorbents along with effects of time, temperature, concentration, and pH. Analytical techniques have been employed to find pore properties and characteristics of adsorbent materials. Batch adsorption studies, kinetic studies, and column operations have also been performed to understand the dye extraction ability of the adsorbents. The adsorption behavior of the dye has been studied using Freundlich, Langmuir, Tempkin, and Dubinin-Radushkevich adsorption isotherm models. The monolayer adsorption capacity determined from the Langmuir adsorption equation has been found as 1.78 x 10(-5) and 5.62 x 10(-5) mol g(-1) at 323 K for bottom ash and deoiled soya, respectively. Kinetic measurements suggest the involvement of pseudo-second-order kinetics in both adsorptions and each case is controlled by a particle diffusion process. Column experiments demonstrated that both adsorbents could be practically utilized in elimination of hazardous dye from effluent and dye material can be recovered by eluting NaOH through the exhausted columns.
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De-Oiled Soya, an agricultural waste material and Bottom Ash a waste of power plants, have been used as adsorbents for the removal and recovery of a triarylmethane dye Fast Green FCF from wastewater. Batch studies have been carried by observing the effects of pH, temperature, concentration of the dye, amount of adsorbents, sieve size of adsorbent, contact time, etc. Graphical correlation of various adsorption isotherm models like, Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich have been carried out for both the adsorbents. The adsorption over both the materials has been found endothermic and feasible in nature. Various thermodynamic parameters, such as, Gibb's free energy, entropy and enthalpy of the on-going adsorption process have been calculated. The kinetic studies suggest the process following pseudo first order kinetics and involvement of particle diffusion mechanism. The bulk removal of the dye has been carried out by passing the dye solution through columns of Bottom Ash and De-Oiled Soya and saturation factor of each column has been calculated. Attempts have also been made to recover the dye by eluting dilute NaOH through the columns.
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Residuos Industriales , Colorantes Verde de Lisamina/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Colorantes/aislamiento & purificación , ResiduosRESUMEN
Deoiled soya, an agricultural waste material, and bottom ash, a waste of power plants, have been successfully used for the removal and recovery of the hazardous water-soluble dye brilliant green from water. To remove the dye from water, batch adsorption studies have been carried out by observing the effects of pH, concentration, amounts of adsorbents, size of adsorbent particles, etc. Attempts have also been made to monitor the adsorption process through Langmuir, Freundlich, Tempkin, and D-R adsorption isotherm models. Relevant thermodynamic parameters have also been calculated from these models. The adsorption process has been found endothermic and feasible at all the temperatures. The kinetics of the adsorption was also recorded and indicates pseudo-second-order kinetics in both cases. Kinetic operations also reveal the involvement of a film diffusion mechanism for the deoiled soya adsorption at all the temperatures, while bottom ash undergoes through a particle diffusion mechanism at only 30 degrees C and at higher temperatures a film diffusion mechanism operates. Bulk removal of the dye has been carried out through column studies for both adsorbents. Attempts have also been made to recover the dye from exhausted columns by eluting sulfuric acid of pH 3.
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Basic fuchsin, a triaminotriphenylmethane dye, was removed by adsorption utilizing two waste materials--"bottom ash," a power plant waste material, and "deoiled soya," an agriculture waste product. The adsorbents were characterized through IR spectroscopy and differential thermal analysis (DTA). Batch adsorption experiments were carried out by measuring effects of pH, adsorbate concentration, sieve size, amount of adsorbent, contact time, temperature, etc. The results have been verified on the basis of Langmuir and Freundlich adsorption isotherm models and data obtained have been applied to calculate thermodynamic parameters. Specific rate constants for the processes were calculated by kinetic measurements and a pseudo-second-order adsorption kinetics was observed in each case. To identify whether the ongoing process is particle diffusion or film diffusion, the treatment given by Boyd and Reichenberg was employed. To assess the practical utility of the adsorbent, the aqueous adsorbate samples were eluted through fixed-bed columns of respective adsorbents. Attempts were also made to recover the adsorbed dyes by passing suitable solvent through the columns.
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Bottom Ash and De-Oiled Soya have been used as adsorbents for the removal of a hazardous azo dye-Metanil Yellow from its aqueous solutions. Adsorption of Metanil Yellow on these adsorbents has been studied as function of time, temperature, concentration and pH. Batch adsorption studies, kinetic studies and column operations enabled extraction of lethal dye from wastewaters. Adsorption equilibrium data confirms both Langmuir and Freundlich isotherm models and monolayer coverage of dye over adsorbents. Kinetic data have been employed to calculate specific rate constants, indicating thereby involvement of first order kinetics in the on-going adsorption and activation energy was determined as 0.813 and 1.060 kJ mol(-1) for Bottom Ash and De-Oiled Soya, respectively. For both adsorbents, the adsorption process has been found governing by film diffusion, over the entire concentration range. Column operations have also been performed for the bulk removal of the dye and also to examine the practical utilization of fixed bed adsorption technique in elimination of dangerous effluent. Saturation factors for Bottom Ash and De-Oiled Soya columns have been calculated as 99.15 and 99.38%, respectively. Attempts have also been made to regenerate the dye from the exhausted columns using aqueous sodium hydroxide as eluent.
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Compuestos Azo/química , Colorantes/química , Sustancias Peligrosas/análisis , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Agua/química , Adsorción , Compuestos Azo/análisis , Colorantes/análisis , Concentración de Iones de Hidrógeno , Residuos Industriales , Cinética , Aceites/química , Aceites de Plantas , Solubilidad , Glycine maxRESUMEN
Bottom Ash a power plant waste material and De-Oiled Soya, an agricultural waste product have been successfully used for the removal and recovery of a hazardous triphenylmethane dye-Methyl Violet, from wastewaters. The characterization of each adsorbent has been carried out by I.R. and D.T.A. curves. Batch adsorption studies have been made by measuring effects of pH, sieve size, amount of adsorbent, contact time, temperature, concentration of the adsorbate solution, etc. Kinetic studies have been used to determine the nature of rate controlling step of the processes and confirm the applicability of the first order rate expression in the ongoing adsorption process. Various thermodynamic parameters have also been calculated by applying the linear forms of Langmuir and Freundlich adsorption isotherms. The linear nature of adsorption isotherms obtained shows the dependence of the processes on the Freundlich and Langmuir isotherm models. Furthermore, to ascertain the adsorption processes to be particle diffusion or film diffusion mechanism, Boyd and Reichenberg's expressions have been applied. For both the adsorbents, column operations have been carried out for the bulk removal of the dye. The adsorbed dye has been recovered by eluting hydrochloric acid of pH 3 through exhausted columns.
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Violeta de Genciana/aislamiento & purificación , Glycine max/química , Residuos Industriales/análisis , Adsorción , Carbono , Ceniza del Carbón , Concentración de Iones de Hidrógeno , Cinética , Tamaño de la Partícula , Material Particulado/química , Temperatura , TermodinámicaRESUMEN
De-Oiled Soya a waste of Soya oil industries and Bottom Ash a waste of thermal power plants have been used as effective adsorbent for recovery and removal of hazardous dye Methyl Orange from wastewater. During the studies effects of amount of dye and adsorbents, pH, sieve sizes, column studies etc. have been carried out. Adsorption of the dye over both the adsorbents has been monitored through Langmuir and Freundlich adsorption isotherm models and feasibility of the process is predicted in both the cases. Different thermodynamic parameters like Gibb's free energy, enthalpy and entropy of the undergoing process are also evaluated through these adsorption models. The kinetic studies confirm the first order process for the adsorption reaction and also play an important role in finding out half-life of the adsorption process and rate constants for both the adsorbents. It is also found that over the entire concentration range the adsorption on Bottom Ash takes place via particle diffusion process, while that of De-Oiled Soya undergoes via film diffusion process. In order to establish the practical utility of the developed process, attempts have been made for the bulk removal of the dye through column operations. For the two columns saturation factors are found as 98.61 and 99.8%, respectively, for Bottom Ash and De-Oiled Soya with adsorption capacity of each adsorbent as 3.618 and 16.664 mg/g, respectively. The dye recovery has been achieved by eluting dil. NaOH through the exhausted columns.
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Adsorción , Compuestos Azo/aislamiento & purificación , Residuos Industriales/prevención & control , Contaminantes del Agua/aislamiento & purificación , Conservación de los Recursos Naturales/métodos , Difusión , Cinética , Hidróxido de Sodio , TermodinámicaRESUMEN
Tartrazine, a yellow menace, is widely being used in cosmetics, foodstuffs, medicines and textile. It is carcinogenic and also catalyzes allergic problems. In the present work the ability to remove Tartrazine from aqueous solutions has been studied using waste material-hen feathers, as adsorbent. Effects of pH, concentration of the dye, temperature and adsorbent dosage have been studied. Equilibrium isotherms for the adsorption of the dye were measured experimentally. Results were analyzed by the Freundlich and Langmuir equation at different temperatures and determined the characteristic parameters for each adsorption isotherm. The adsorption process has been found endothermic in nature and thermodynamic parameters, Gibb's free energy (DeltaG degrees), change in enthalpy (DeltaH degrees) and change in entropy (DeltaS degrees) have been calculated. The paper also includes results on the kinetic measurements of adsorption of the dye on hen feathers at different temperatures. By rate expression and treatment of data it has been established that the adsorption of Tartrazine over hen feathers follows a first-order kinetics and a film diffusion mechanism operates at all the temperatures.