Satindar Kaur

Effect of starch on the rheology of molasses

Rheological characteristics of molasses containing different levels of starch were investigated at 40, 45, 50, 55, and 60 °C. The molasses behaved as a shear thinning fluid and the power law model described well the shear stress shear rate behavior. The consistency index increased with the addition of starch and decreased with the rise in temperature. The flow behavior index was found to decrease with the increase in temperature but at 60 °C the values increased indicating the effect of temperature marring the effect of starch. Activation energy was determined using the Arrhenius equation and it was found that the activation energy of molasses decreased with the addition of starch and the Arrhenius constant seems to carry a definite weightage.

Tea waste as adsorbent for ionic dyes

AbstractToxic dyes can be removed from textile effluents and recovered using dead biomass obtained, as waste from the food industry. In this work, tea waste (TW) was employed to assess its adsorptive capacity for the acidic and basic dyes that usually are present in textile industry waste water. Equilibrium and kinetic experiments were performed in batch and column mode. Adsorption equilibrium and fluid solid mass transfer constant data were analyzed through the concept of ion-exchange sorption isotherm. The equilibrium data were fitted with Langmuir and Freundlich models. Several operation variables, such as TW dosage, contact time, initial pH, and temperature, on the removal of dyes were investigated. The removal efficiency increased with increase in TW dosage. The adsorption process followed pseudo-first-order kinetics. Thermodynamic parameters like ΔH°, ΔS°, and ΔG° were analyzed. The processes were spontaneous for the acidic as well as basic dyes. These results suggest that TW is a potential low-cost...

Mechanistic Study of Adsorption of Acid Orange-7 over Aluminum Oxide Nanoparticles

The adsorption behavior of acid orange-7 (AO-7) on aluminum oxide nanoparticles (ANP) generated by sol-gel method has been investigated to understand the physicochemical process involved and to explore the potential use of nano particles in textile effluent treatment and management. The results revealed that ANP can remove AO-7 dye up to 97.6 mg/g at 303 K. The adsorption process is found to be pH dependent and the optimum pH obtained is 2.0. The equilibrium was established in 1 h. Langmuir, Freundlich, and Temkin Isotherm models were applied on the system. Scanning electron microscopic analysis reveals eye-catching nanoporous morphology of the material. The results of FTIR spectroscopy reveal that the process is electrostatic complexation mechanism driven. XRD studies revealed nanocrystalline structure of ANP. BET surface area measurement suggests high pore volume and surface area of adsorbent. The kinetic measurements suggest pseudo-second-order kinetic processes. The thermodynamic measurements suggest that all processes are endothermic accompanied with negative ΔG° and positive ΔS°, ΔH°.

Ternary heat effects in ternary mixtures

Abstract Excess enthalpies of three ternary mixtures consisting of benzene + carbon tetrachloride + cyclohexane at 303.15 K, acetone + carbon tetrachloride + cyclohexane, and acetone + cyclohexane + chloroform at 298.15 K have been measured over the whole composition range using an adiabatic calorimeter. Ternary effects determined as the differences of the experimental excess heats from those of the sum of the binary contributions by the Nissema method are found to be positive for the first two systems and both positive and negative for the last system.

Efficient removal and separation of anionic dyes from aqueous medium by the application of reverse micelles of cationic surfactants

AbstractA new protocol based on liquid/liquid extraction using reverse micelles is proposed. The recovery of solvent and reuse of dye and surfactant, after extracting the dye molecules from the core of reverse micelles of surfactant is related to the economic viability of the process. Experiments were conducted by mixing a known quantity of dye in aqueous phase and solvent-containing surfactants in a simple mixer. The separation of solvent phase, containing encapsulated dye in reverse micelles, from aqueous phase due to gravity results in separation of dye from water. The removal of different anionic dyes (methyl orange, congo red and aniline blue) from aqueous phase in amyl alcohol solvent using different cationic surfactants was studied. The percentage removal of dye depends upon the size of the reverse micelle of the surfactant. The solvent used for the dye removal can be recovered by distillation method and can be reused. The dye is separated from reverse micelles by lowering the temperature below the...

Effect of pH, salt concentration and chain length of surfactants on the MO removal from water by pyridinium-based gemini surfactant

AbstractDye stuffs are an environmental problem, and their presence in drinking water and bio ecosystems such as rivers and water ways have long been recognized as deleterious. Current methods for their removal largely rely on adsorption techniques which are costly and produce another waste to be disposed off, whereas the concept of reverse micelles acting to encapsulate the dye in aqueous micro pool in solvent environment provides a useful chemistry. The removal of methyl orange from aqueous phase in amyl alcohol solvent using cationic surfactants was studied. Experiments were conducted by mixing a known quantity of dye in aqueous phase and solvent-containing surfactants in a simple mixer. The separation of solvent phase, containing encapsulated dye in reverse micelles, from aqueous phase due to gravity results in the separation of dye from water. The effects of dye and surfactant concentration, pH, salts like KCl and MgCl2 were studied. The percentage removal of the dye depends upon the size of the reve...

Ionic dye adsorption by zinc oxide nanoparticles

The adsorption behaviour of Basic Red 12, Acid Orange 7 and Acid Blue 1 on zinc oxide nanoparticles (ZNP) has been investigated to understand the physicochemical process involved and to explore the possible use of nanoparticles in the treatment and management of textile waste matter. The dye removal capacity of ZNP towards Basic Red 12, Acid Orange 7 and Acid Blue 1 was found to be 15.64, 6.78 and 6.38 mg g−1, respectively. The adsorption process was pH dependent and optimum pH values of 9.0, 2.0 and 4.0 were obtained for Basic Red 12, Acid Orange 7 and Acid Blue 1, respectively. Equilibrium was established after 1.0 h for all dyes. Langmuir, Freundlich and Temkin isotherm models were applied to the system. The adsorbent ZNP was characterised using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and Fourier transform infrared (FTIR) techniques. SEM analysis revealed the noticeable nanoporous morphology of the material. The results of FTIR spectroscopy showed that the process is driven by an electrostatic complexation mechanism. XRD studies revealed the nanocrystalline structure of ZNP. BET surface area measurement suggested a high pore volume and large surface area for the adsorbent. The kinetic measurements suggested pseudo-second-order kinetic processes with high regression coefficients and smaller standard error of estimate values and lower residual sum of squares. The thermodynamic measurements suggested that all processes were exothermic and accompanied by negative values for Δ G0, Δ S0 and Δ H0.

Synthesis and Evaluation of Surface Active Properties of Ester-Based Cationic Imidazolium Monomeric Surfactants

New imidazolium cationic surfactants have been synthesized by esterification of halogenated carboxylic acids with long-chain fatty alcohols furnishing respective esters (dodecyl-2-chloroacetate, tetradecyl-2-chloroacetate, hexadecyl-2-chloroacetate, dodecyl-2-bromoacetate, tetradecyl-2-bromoacetate, and hexadecyl-2-bromoacetate) followed by their subsequent treatment with 1-trifluoro acetyl imidazole resulting into the formation of title monomeric surfactants: 3-(2-(hexadecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium chloride (7); 3-(2-(tetradecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium chloride (8); 3-(2-(dodecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium chloride (9); 3-(2-(hexadecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium bromide (10); 3-(2-(tetradecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium bromide (11) and 3-(2-(dodecyloxy)-2-oxoethyl)-1-(2,2,2-trifluoroacetyl)-1H-imidazol-3-ium bromide (12). Their identifications are based on IR, 1H, 13C NMR, DEPT, and mass spectral studies. The dynamics of surface activity of these surfactants have also been investigated in the presence of sodium halides (NaCl and NaBr) by surface tension measurement. A series of useful parameters like critical micelle concentration (cmc), surface tension at the cmc (γcmc), adsorption efficiency (pC20), effectiveness of surface tension reduction (Πcmc), Gibbs free energy of the micellization (ΔG0mic), and Gibbs free energy of adsorption (ΔG0ads) have been determined from the measurements obtained by surface tension and conductivity method. Further with the application of the Gibbs adsorption isotherm, maximum surface excess concentration (Γmax), and minimum surface area/molecule (Amin) at the air-water interface were also estimated. Thermal stability of these long-chain cationics have been measured by thermal gravimetric analysis under nitrogen atmosphere. Analysis of thermal stability measurement indicated that the thermal stability of these long-chain imidazoliums increase with an increase in chain length.

Synthesis, Characterization, and Surface Properties of Cationic Gemini Surfactants

New pyridinium gemini surfactants have been synthesized by esterification of renewable fatty acids with mercaptoethanol furnishing respective esters (mercaptomethyl decanoate, mercaptomethyl dodecanoate, mercaptomethyl tetradecanoate, mercaptomethyl hexadecanoate) followed by their subsequent treatment with 4-dimethyl amino pyridine resulting in the formation of title gemini surfactants: 1-(5-(decanoyloxy)-2-hydroxypentyl)-4-((5-(decanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (9), 1-(5-(dodecanoyloxy)-2-hydroxypentyl)-4-((5-(dodecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (10), 1-(5-(tetradecanoyloxy)-2-hydroxypentyl)-4-((5-(tetradecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (11), and 1-(5-(hexadecanoyloxy)-2-hydroxypentyl)-4-((5-(hexadecanoyloxy)-2-hydroxypentyl)dimethyl ammonio)pyridin-1-ium chloride (12). Their identifications are based on infrared, 1H NMR, 13C NMR, distortionless enhanced polarization transfer, co-relational spectroscopy (COSY), and mass spectral studies. Their surface active properties are also evaluated on the basis of surface tension and conductivity measurements. Thermal stability of these long chain cationic gemini surfactants have been measured by thermal gravimetric analysis under nitrogen atmosphere.

Quantitative estimation of polysaccharides in molasses using Near Infra Red spectroscopy

Non-invasive near infrared spectroscopy (NIR) in transmittance mode between 1100–2500 nm was employed for the quantitative estimation of dextran, starch, gum and pectin in final molasses one at a time. Partial least square regression analyses was used to develop a calibration model with 40 samples each in 0th, 1st and 2nd derivatives which gave low SEC values. This method was applied for the estimation of unknown concentrations of the four polysaccharides in molasses, which gave low prediction error in the 0th derivative explaining the accuracy of the results with correlation coefficient of 0.98. Stepwise multi linear regression has also been applied and wavelengths have been identified specific to the polysaccharides and a correlation has been tried on the basis of the structure of the polysaccharides. The above results lead to the most promising future use of NIR spectroscopy as on-line processing tool in sugar industry.