Search

Your search keyword '"Pal, Anjali"' showing total 665 results
Start Over Author "Pal, Anjali"
665 results on '"Pal, Anjali"'

152. Sorption of anionic surfactants on a fixed bed of rubber granules

Author

Purakayastha, Paritosh Das, Pal, Anjali, and Bandyopadhyay, Manas

Subjects
Company business management, Environmental services industry
Abstract

Byline: Paritosh Das Purakayastha, Anjali Pal, Manas Bandyopadhyay The performance of a fixed-bed adsorber (FBR) column for the removal of anionic surfactants from aquatic environments has been studied. Waste tyre rubber granules were used as the adsorbent material, and sodium dodecyl sulfate, an anionic surfactant, as the adsorbate. The FBR column design parameters were evaluated using the column breakthrough data at different bed depths. The Bohert and Adams model was used with the bed depth service time approach for the design of the column. The bed efficiency obtained was 90.97%.

Published
2004

156. Leprosy–A raging persistent enigma.

Author

Galhotra, Abhiruchi, Panigrahi, Sunil, and Pal, Anjali

Subjects
HANSEN'S disease, RIDDLES
Abstract

Leprosy or Hansen's disease despite having achieved the elimination target across the world, the decrease in detection of new cases has almost stagnated for the last 10 years. Southeast Asia is having the highest prevalence of leprosy among all regions in the world. The review focuses on the programmatic laggards' post-achievement of elimination target in India, the most significant contributors to leprosy caseload in the world, and a way forward. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

157. Health concerns of migrants and refugees

Author

Mishra, Abhisek, Galhotra, Abhiruchi, Pal, Anjali, Giri, Anjan Kumar, Mishra, Abhisek, Galhotra, Abhiruchi, Pal, Anjali, and Giri, Anjan Kumar

Abstract

Migration is a process of social change during which a person moves from one cultural setting to another in order to settle for a longer period of time or permanently. If internal and international migrants are being taken in to account, it would be the third most populous country in the world, just after China and India. The collective health implications of this sizeable population are considerable and are not often in accordance with their need, thus raising concerns with regard to equity, social inclusion and cohesiveness. During different phases of migration, Linguistic, cultural and legal factors are amongst the major barriers in accessing basic health services for migrants. Hence a migrant sensitive inclusive health system equipped with trained work force should be formally established by inter country, inter regional and international framework to address this complex issue-Migration.

Published
2016

158. Size regime dependent catalysis by gold nanoparticles for the reduction of Eosin

Author

Sau, Tapan K., Pal, Anjali, and Pal, Tarasankar

Subjects
Chemistry, Physical and theoretical -- Research, Eosin -- Research, Gold compounds -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

The gold particle catalyzed eosin reduction is investigated in the presence of NaBH4. It is shown that the catalytic activity of the gold nanoparticles is different for different size regimes and the kinetics of the catalytic rate has a bearing with the particle size.

Published
2001

168. Adsorption Thermodynamics of Arsenic on Laterite Soil

Author

Maji, Sanjoy Kumar; Civil Engineering Department, Indian Institute of Technology, Kharagpur, 721302, Pal, Anjali; Civil Engineering Department, Indian Institute of Technology, Kharagpur, 721302, Pal, Tarasankar; Chemistry Department, Indian Institute of Technology, Kharagpur, 721302, Adak, Asok; Civil Engineering Department, Jalpaiguri Government Engineering College, Jalpaiguri, 735102, Maji, Sanjoy Kumar; Civil Engineering Department, Indian Institute of Technology, Kharagpur, 721302, Pal, Anjali; Civil Engineering Department, Indian Institute of Technology, Kharagpur, 721302, Pal, Tarasankar; Chemistry Department, Indian Institute of Technology, Kharagpur, 721302, and Adak, Asok; Civil Engineering Department, Jalpaiguri Government Engineering College, Jalpaiguri, 735102

Abstract

Adsorption equilibrium of arsenic (in both As(III) and As(V) states) onto laterite soil was studied at the temperatures of 298, 308 and 318 K. Batch experiments were conducted to find out the arsenic removal capacity. The effects of process parameters such as contact time, adsorbent dose, adsorbent size, temperature and pH were investigated. Detailed studies on adsorption isotherms (Langmuir, Freundlich and Dubinin-Radushkevich) were conducted. By using the Dubinin-Radushkevich (D-R) isotherm, the energy (E) related with adsorption was calculated and the results showed that the adsorption was mostly physisorption. It was observed by calculating the value of the dimensionless equilibrium parameter (RL) that the adsorption was favorable. The standard free energy change (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were determined and the calculated values showed that the adsorption process for both As(III) and As(V) was exothermic and spontaneous. Regeneration of the adsorbent was possible using 1M NaOH solution and the regenerated adsorbent could further be used for arsenic removal.

Published
2015

169. Adsolubilization of Organic Compounds in Surfactant-Modified Alumina

Author

Adak, Asok; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302, Bandyopadhyay, Manas; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302, Pal, Anjali; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302, Adak, Asok; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302, Bandyopadhyay, Manas; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302, and Pal, Anjali; Civil Engineering Department, Indian Institute of Technology, Kharagpur-721302

Abstract

Adsolubilization is the solubilization of organics into the three dimensional micelle like structures formed by the adsorption of ionic surfactants at high concentration on oppositely charged surfaces. Adsolubilization process could efficiently be used for the removal of different organic pollutants like dyes, phenolic compounds, etc. from water environment. In the present work, the adsorption characteristics of sodium dodecyl sulfate (SDS), an anionic surfactant (AS) on neutral alumina were studied in detail. Alumina was found to be an efficient adsorbent for SDS and could be used for the removal of SDS from its highly concentrated (several thousand ppm) solution. The equilibrium time found was 2 h. Though the removal efficiency was low (∼ 65%) at neutral pH, but at slightly acidic condition and in the presence of NaCl, the efficiency could be increased drastically (>98%). The adsorption isotherm study showed four distinct regions. The effects of various other parameters such as adsorbent dose, the presence of different ions (Cl-, NO3-, SO42- and Fe3+), and non-ionic surfactant on the SDS adsorption were also studied. It was observed that the adsorption capacity was increased due to the presence of these ions in general. After the adsorption of SDS on alumina, the alumina, which was then called the surfactant-modified alumina (SMA), was used for the removal of crystal violet (CV), a well-known cationic dye and phenol from aquatic environment. The kinetic studies showed that 1 h shaking time was sufficient to achieve the equilibrium for CV. The equilibrium time for phenol was 1.5 h. Studies were conducted to see the effects of adsorbent dose on the removal of CV and phenol separately using the SMA. The pH was maintained at 6.7±0.1. The SMA was found to be very efficient, and ∼ 99% and ∼ 90% efficiency could be achieved under optimised conditions for the removal of CV and phenol when present even at a high concentration (200 ppm for CV and 50 ppm for phenol

Published
2015

170. Adsorption Thermodynamics of Arsenic on Laterite Soil

Author

Maji, Sanjoy Kumar, Pal, Anjali, Pal, Tarasankar, Adak, Asok, Maji, Sanjoy Kumar, Pal, Anjali, Pal, Tarasankar, and Adak, Asok

Abstract

Adsorption equilibrium of arsenic (in both As(III) and As(V) states) onto laterite soil was studied at the temperatures of 298, 308 and 318 K. Batch experiments were conducted to find out the arsenic removal capacity. The effects of process parameters such as contact time, adsorbent dose, adsorbent size, temperature and pH were investigated. Detailed studies on adsorption isotherms (Langmuir, Freundlich and Dubinin-Radushkevich) were conducted. By using the Dubinin-Radushkevich (D-R) isotherm, the energy (E) related with adsorption was calculated and the results showed that the adsorption was mostly physisorption. It was observed by calculating the value of the dimensionless equilibrium parameter (RL) that the adsorption was favorable. The standard free energy change (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were determined and the calculated values showed that the adsorption process for both As(III) and As(V) was exothermic and spontaneous. Regeneration of the adsorbent was possible using 1M NaOH solution and the regenerated adsorbent could further be used for arsenic removal.

Published
2015

171. Adsolubilization of Organic Compounds in Surfactant-Modified Alumina

Author

Adak, Asok, Bandyopadhyay, Manas, Pal, Anjali, Adak, Asok, Bandyopadhyay, Manas, and Pal, Anjali

Abstract

Adsolubilization is the solubilization of organics into the three dimensional micelle like structures formed by the adsorption of ionic surfactants at high concentration on oppositely charged surfaces. Adsolubilization process could efficiently be used for the removal of different organic pollutants like dyes, phenolic compounds, etc. from water environment. In the present work, the adsorption characteristics of sodium dodecyl sulfate (SDS), an anionic surfactant (AS) on neutral alumina were studied in detail. Alumina was found to be an efficient adsorbent for SDS and could be used for the removal of SDS from its highly concentrated (several thousand ppm) solution. The equilibrium time found was 2 h. Though the removal efficiency was low (∼ 65%) at neutral pH, but at slightly acidic condition and in the presence of NaCl, the efficiency could be increased drastically (>98%). The adsorption isotherm study showed four distinct regions. The effects of various other parameters such as adsorbent dose, the presence of different ions (Cl-, NO3-, SO42- and Fe3+), and non-ionic surfactant on the SDS adsorption were also studied. It was observed that the adsorption capacity was increased due to the presence of these ions in general. After the adsorption of SDS on alumina, the alumina, which was then called the surfactant-modified alumina (SMA), was used for the removal of crystal violet (CV), a well-known cationic dye and phenol from aquatic environment. The kinetic studies showed that 1 h shaking time was sufficient to achieve the equilibrium for CV. The equilibrium time for phenol was 1.5 h. Studies were conducted to see the effects of adsorbent dose on the removal of CV and phenol separately using the SMA. The pH was maintained at 6.7±0.1. The SMA was found to be very efficient, and ∼ 99% and ∼ 90% efficiency could be achieved under optimised conditions for the removal of CV and phenol when present even at a high concentration (200 ppm for CV and 50 ppm for phenol)

Published
2015

182. Surfactant modification of chitosan hydrogel beads for Ni@NiO core-shell nanoparticles formation and its catalysis to 4-nitrophenol reduction.

Author

Kongarapu, Rama Jyothi, Mahamallik, Prateeksha, and Pal, Anjali

Subjects
SURFACE active agents, CHITOSAN, SODIUM dodecyl sulfate
Abstract

Chitosan (CS) in its hydrogel bead form is widely used to remove metal ions from aqueous medium. In the present work CS gel beads were modified with sodium dodecyl sulfate (SDS), an anionic surfactant, in a novel way, with formation of bilayer (admicelle) on to it. The concentration of SDS used for CS bead modification was 6000 mg/L. These surfactant-modified chitosan beads were designated as POSTCS beads. In the next step, Ni(II) was loaded on the SDS bilayer present in the POSTCS beads through a process called ‘adsolubilization'. The loading of nickel was ∼4 times higher in POSTCS beads compared to that in normal CS beads. The property of surfactant to form admicelle helped in enhanced Ni(II) adsorption, and its stabilization. Further Ni@NiO core-shell type particles were formed on POSTCS beads by borohydride reduction. The particles were characterized by XRD, FTIR, SEM/EDX and TEM analysis. The as-prepared particles exhibited excellent catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of borohydride. The reduction was carried out with various catalyst doses, and it was found to follow first order rate. The turn over number (TON) and turn over frequency (TOF) of the catalyst at a dose of 2.0 g/L and 1 × 10 −4 M 4-NP concentration were found to be 3.0115 × 10 19 molecules/g and 5.019 × 10 16 molecules/g/s, respectively. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

183. Modifications of Chitosan for Cadmium Removal: A Short Review.

Author

PAL, PREETI and PAL, ANJALI

Subjects
*BIOPOLYMERS, *CHITOSAN, *CADMIUM, *FUNCTIONAL groups, *HEAVY metals
Abstract

Chitosan is an eminent biopolymer which is deacetylated form of chitin. It has the -OH and - NH2 groups on its surface. The presence of these functional groups makes it feasible for ample of amendments. Chitosan is widely used in heavy metal removal from wastewater. Among all the heavy metals, cadmium is one of the deadly toxic elements on earth. Various researches published on the removal of cadmium from wastewater using chitosan/modified chitosan have been compiled up in the present review paper. [ABSTRACT FROM AUTHOR]

Published
2017

185. Broad-spectrum photocatalytic tetracycline degradation performance of an in-situ plasmonic Bi nanoparticle doped 0D/2D Z scheme heterostructure.

Author

Ghosh, Utpal and Pal, Anjali

Subjects
*TETRACYCLINE, *PHOTODEGRADATION, *PLASMONICS, *NANOPARTICLES, *SOLAR spectra, *QUANTUM dots
Abstract

[Display omitted] • Synthesis of a plasmonic Bi-doped 0D Bi 2 O 3 /2D SnO 2 Z scheme heterostructure is reported. • Plasmonic Bi doping extends the light absorption capacity of the composite to NIR region. • The composite demonstrated excellent broad-spectrum tetracycline degradation efficiency. • h+ and.O 2 – was the responsible radical in the degradation process. Fabrication of broad-spectrum (UV–vis-NIR) active photocatalysts for effectively harnessing the abundant NIR light in the solar spectrum is the biggest challenge. Herein, the facile one-pot solid-state synthesis of an in-situ plasmonic bismuth-doped 0D/2D Z scheme heterostructure (BS) by loading Bi 2 O 3 quantum dots (B) on 2D SnO 2 nanosheets (S) is reported. The successful heterostructure fabrication was confirmed using various characterization techniques. The composites demonstrated excellent broad-spectrum photocatalytic degradation efficacy toward TC. When irradiated with an 18 W LED, the 2BS composite exhibited a 35.1 and 2.03-fold increased TC degradation rate co-efficient compared to S and B, respectively. Further, the 2BS composite showed a 5.5 times higher degradation rate constant than B after NIR light irradiation. Moreover, the composite displayed commendable stability after a four-cycle recycling experiment. At last, a plausible charge transfer mechanism under LED and NIR light illumination has been proposed following the results of the radical trapping experiment. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

186. Fluorimetric determination of dopamine via its derivatization with 1,2-phenylenediamine

Author

Kundu, Subrata, Ghosh, Sujit Kumar, Mandal, Madhuri, Pal, Anjali, and Tarasankar Pal

Subjects
Fluorimetric determination, temperature, UV-adsorption study, alcoholic solutions
Abstract

Department of Chemistry, Department of Civil Engineering, Indian Institute of Technology, Kharagpur-721 302, India E-mail: tpal@chem.iitkgp.ernet.in Fax : 91-3222-255303 Manuscript received 1 April 2004, accepted 20 April 2004 A simple, rapid and sensitive fluorimetric method for the determination of dopamine is developed. It is based on the chemical reaction of quinone of dopamine hydrochloride (produced in situ from dopamine hydrochloride in presence of oxygen and alkali) with 1,2-phenylene diamine (OPDA) in alcoholic medium under alkaline condition at RT. The reaction leads to a fluorescent product and the effects of organic solvents on fluorescence spectra were examined and discussed. Among the common organic solvents tested, methanol was selected because of its efficient sensitizing capability. Effects of pH, temperature, reaction time and the foreign ions on the determination of dopamine have been examined. The behavior of dopamine in acid-base medium was studied both by spectrofluorimetry and spectrophotometry. The fluorescence intensity was measured at λem 530 nm (λex 450 nm). Under optimum condition a linear relationship was obtained between the relative fluorescence intensity and concentration of dopamine in the concentration range of 1.0 x 10-6 mol dm-3 to 6.6 x 10-5 mol dm-3 of dopamine. The linear regression equation of the calibration graph is F.I. = 1.376 x C (mol dm-3) + 4.112, with a correlation coefficient of 0.9921. The limit of detection is 2.114 x 10-6 mol dm-3, which is obviously lower than the other fluorimetricmethods reported.

Published
2004
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results