M. Dharmendira Kumar

Accumulation of Methylene Blue Dye by Growing Lemna minor

In the present investigation bioaccumulation studies were performed for the removal of Methylene Blue dye from an aqueous solution using live Lemna minor. The effect of various parameters such as the biosorbent dosage (1–3 g), pH (3-8) and initial dye concentration (2–10 mg L−1) were studied. The maximum uptake capacity of the Methylene Blue using L. minor was observed as 10.93 mg g−1 at a biosorbent dosage of 1 g/300 mL, at pH 7 and at 10 mg L−1 initial dye concentration. The surface morphology was analyzed using Scanning Electron Micrograph (SEM) for analyzing micro and macropores present on the surface of the plant and the functional groups on the biosorbent were analyzed using Fourier transform infrared analyzer (FTIR) for increasing the electrostatic attraction between the plant surface and the dye molecules by adjusting the pH of the solution. Equilibrium data was analyzed using Langmuir and Freundlich adsorption isotherm models. The Freundlich adsorption isotherm was found to be fitted well. The effect of initial dye concentration on the growth of the plant was studied by obtaining the growth profile of the plant on the basis of the relative growth rate (RGR).

Effect of hydrotropes on solubility and mass transfer coefficient of amyl acetate

Abstract This paper presents a comprehensive study on the effect of citric acid, sodium benzoate, sodium salicylate and urea (hydrotropes) on the solubility and mass transfer coefficient for the extraction of amyl acetate in water. The influence of a wide range of hydrotrope concentration (0–3.0 mol/l) and different temperatures (303–333 K) on the solubility of amyl acetate has been studied. The influence of different hydrotrope concentrations on the mass transfer coefficients for amyl acetate–water system has been ascertained. Setschenow constant, Ks, a measure of the effectiveness of hydrotrope has been determined for each case. The solubility of amyl acetate increases with increase in hydrotrope concentration and also with system temperature. Consequent to the increase in the solubility of amyl acetate, the mass transfer coefficient was also found to increase with increase in hydrotrope concentration. A Minimum Hydrotropic Concentration (MHC) was found essential to show a significant increase in the solubility and mass transfer coefficient for amyl acetate–water system. The enhancement factor, which is the ratio of value in presence and absence of a hydrotrope is reported for both solubility and mass transfer coefficients.

Salt effect on the enthalpy of mixing of water+methanol at 303.15 K

The excess enthalpy of the miscible water–methanol system has been measured at 303.15 K in an isothermal batch calorimeter with vapour space. The effect of the salts NH4Cl, CdCl2 and HgCl2 on HE was studied. A decreasing trend in excess enthalpy for NH4Cl and HgCl2 but an increasing trend for CdCl2 with increasing salt concentrations have been observed. The experimental values of HE have been correlated using a modified Redlich–Kister equation and the binary parameters have been estimated. The deviations were calculated and reported.

Production and optimization of cellulase from agricultural waste and its application in bioethanol production by simultaneous saccharification and fermentation

Purpose – The purpose of this paper is to optimize production of cellulase enzyme from agricultural waste by using Aspergillus fumigatus JCF. The study also aims at the production of bioethanol using cellulase and yeast. Design/methodology/approach – Cellulase production was carried out using modified Mandel’s medium. The optimization of the cellulase production was carried out using Plackett-Burman and Response surface methodology. Bioethanol production was carried out using simultaneous saccharification and fermentation. Findings – Maximum cellulase production at optimized conditions was found to be 2.08 IU/ml. Cellulase was used for the saccharification of three different feed stocks, i.e. sugar cane leaves, corn cob and water hyacinth. Highest amount of reducing sugar was released was 29.1 gm/l from sugarcane leaves. Sugarcane leaves produced maximum bioethanol concentration of 9.43 g/l out of the three substrates studied for bioethanol production. Originality/value – The present study reveals that by...

Insoluble dendrimer-grafted poly(vinylimidazole) microbeads stabilized with mono/bimetallic nanoparticle catalysts for effective degradation of malachite green

Six types of insoluble bead-shaped stable heterogeneous nanoparticle catalysts were prepared using two categories of poly(N-vinylimidazole) microbeads grafted with D(G2) and D(G3) matrices derived from 2% (LC) and 10% (HC) cross-linking monomer load, viz., divinylbenzene, followed by individual stabilization/immobilization of AuNPs/AuPdNPs. All these catalysts were characterized using FT-IR, UV-Vis, SEM, EDAX, XRD and TGA analyses. These catalysts were individually employed for the degradation of malachite green as a model reaction under pseudo first-order condition. Among the bimetallic catalysts, LC-PVIm-D(G3)–AuPdNP (36.61 × 10−3 min−1) was shown to be superior; specifically, it was three times more active than the monometallic catalyst, LC-PVIm-D(G2)–AuNP (11.35 × 10−3 min−1). Hence, the superior catalyst was employed for detailed kinetic studies by varying the [substrate], [NaBH4] and [catalyst], and each experimental parameter was found to influence the reaction. The recycling efficiency of this superior catalyst was studied five times, and the activity was found to remain unaltered even at the fifth cycle, and hence, the catalyst was stable and suitable to carry out the reduction reaction in the logistic mode.

Extraction of bio-oil from non-edible novel source Senna occidentalis seeds

ABSTRACT Valuable oil within the seeds of Senna occidentalis is extracted by completely different strategy. However, ancient Soxhlet extraction was compared with microwave-assisted extraction. Soxhlet extraction was known to enhance the yield of bio-oil production. Three polar solvents specifically methanol, acetone, isopropyl alcohol and three non-polar solvents specifically chloroform, hexane, toluene were used. Soxhlet equipment has been established to be the simplest technique with the highest oil yield. Parameters like size fractions of the crushed seeds, extraction time, aging of seeds, and selection of solvents have been optimized in order to enhance oil yield. The bio-oil was characterized using (FT-IR) and GC/MS. Chemical reaction price, iodine variety, relative density, carbon residue content, flash purpose, fire point, hot price, and kinematic consistency were investigated to characterize fuel quality of the bio-oil. The maximum oil yield of 23.46% was obtained with isopropanol at 82.6°C and 3.5 h of optimum extraction time.

Extraction of bio-oil from nonedible urban waste source using Bauhinia variegata seeds

ABSTRACT This paper presents the production of biodiesel from Bauhinia variegata seeds using the solvent extraction technique. This process has attracted considerable attention recently in the renewable energy sector because it can reduce greenhouse gas emissions and subsidize energy security. The solvent extraction technique has a low production cost and low oil residue compared with the other methods. Six different solvents were employed for the separation process; among them, hexane proves to be the best solvent for bio-oil extraction (yield −28.43%) at the temperature of 68°C. The caloric value of B. variegata seeds is 4800 kcal/kg, which makes it a better choice of fuel. Its physicochemical properties such as acid value, calorific value, flash point, saponification value, iodine number, specific gravity, fire point, and kinematic viscosity were determined for bio-oil and compared with diesel. This result supports the production of biodiesel from B. variegata seeds oil as a viable alternative fuel to diesel in an eco-friendly manner.