| 1. |
- Ambashta, Ritu D., et al.
(författare)
-
Supported iron-based catalysts under influence of static magnetic field for the removal of TBP and EDTA
- 2015
-
Ingår i: Desalination and Water Treatment. - : Informa UK Limited. - 1944-3994 .- 1944-3986. ; 54:10, s. 2700-2709
-
Tidskriftsartikel (refereegranskat)abstract
- Zerovalent metals offer decontamination of organic toxins in aqueous medium. In the present study, alumina-based iron and iron-nickel in the presence and the absence of magnetic field for the decontamination of tributyl phosphate (TBP) and ethylene diamine tetraacetic acid (EDTA) has been compared. TBP decontamination was improved in the presence of zerovalent metals. EDTA decontamination was not enhanced in the presence of zerovalent metals. The decontamination of TBP using iron-based alumina was higher than iron-nickel. The surface interaction on alumina surface, as characterized by attentuated total reflectance-Fourier transform infrared spectroscopy, and the surface interaction on metallic elements, as characterized by evaluating the magnetic moment values helped to understand the reason for the difference in role of alumina-based iron and iron-nickel on decontamination of TBP and EDTA.
|
|
| 2. |
- Bhatnagar, Amit, et al.
(författare)
-
An overview of the modification methods of activated carbon for its water treatment applications
- 2013
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 219, s. 499-511
-
Forskningsöversikt (refereegranskat)abstract
- Activated carbon has been recognized as one of the oldest and widely used adsorbent for the water and wastewater treatment for removing organic and inorganic pollutants. The application of activated carbon in adsorption process is mainly depends on the surface chemistry and pore structure of porous carbons. The method of activation and the nature of precursor used greatly influences surface functional groups and pore structure of the activated carbon. Therefore, the main focus of researchers is to develop or modifies the activation/treatment techniques in an optimal manner using appropriate precursors for specific pollutants. In recent years, emphasis is given to prepare the surface modified carbons using different procedures to enhance the potential of activated carbon for specific contaminants. Various methods such as, acid treatment, base treatment, impregnation treatment, ozone treatment, surfactant treatment, plasma treatment and microwave treatment have been studied to develop surface modified activated carbons. In this paper, these modification methods have been reviewed and the potential of surface modified activated carbons towards water treatment has been discussed. This review article is aimed at providing precise information on efforts made by various researchers in the field of surface modification of activated carbon for water pollution control. (C) 2012 Elsevier B.V. All rights reserved.
|
|
| 3. |
- Bhatnagar, Amit, et al.
(författare)
-
Applications of chitin- and chitosan-derivatives for the detoxification of water and wastewater - A short Review
- 2009
-
Ingår i: Advances in Colloid and Interface Science. - : Elsevier BV. - 0001-8686 .- 1873-3727. ; 152, s. 26-38
-
Tidskriftsartikel (refereegranskat)abstract
- Chitin and chitosan-derivatives have gained wide attention as effective biosorbents due to low cost and high contents of amino and hydroxyl functional groups which show significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of chitin- and chitosan-derivatives from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented. This paper will give an overview of the principal results obtained during the treatment of water and wastewater utilizing chitin and chitosan-derivatives for the removal of: (a) metal cations and metal anions; (b) radionuclides; (c) different classes of dyes; (d) phenol and substituted phenols; (e) different anions and other miscellaneous pollutants. The review provides a summary of recent information obtained using batch studies and deals with the various adsorption mechanisms involved. It is evident from the literature survey that chitin- and chitosan-derivatives have shown good potential for the removal of various aquatic pollutants. However, still there is a need to find out the practical utility of such developed adsorbents on commercial scale.
|
|
| 4. |
- Bhatnagar, Amit, et al.
(författare)
-
Assessment of the biosorption characteristics of lychee ( Litchi chinensis) peel waste for the removal of Acid Blue 25 dye from water
- 2010
-
Ingår i: Environmental technology. - : Informa UK Limited. - 0959-3330 .- 1479-487X. ; 31, s. 97-105
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to examine the adsorption potential of lychee (Litchi chinensis) peel waste for the removal of Acid Blue 25 dye from aqueous solutions. The adsorption was studied as a function of contact time, initial dye concentration and temperature by batch method. Equilibrium sorption isotherms showed that the lychee peel adsorbent possessed a high affinity and sorption capacity for Acid Blue 25, with a monolayer sorption capacity of ca. 200 mg g-1. The equilibrium adsorption data were well described by the Langmuir model. Kinetic studies revealed that the present system of dye adsorption on lychee peel adsorbent could be described more favourably by the pseudo-second-order kinetic model. The thermodynamic parameters, namely free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) changes, were determined for the process. The results of the present study suggest that lychee peel waste can be used beneficially as an adsorbent in treating industrial effluents containing dyes.
|
|
| 5. |
- Bhatnagar, Amit, et al.
(författare)
-
Bromate removal from water by granular ferric hydroxide (GFH)
- 2009
-
Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 170:1, s. 134-140
-
Tidskriftsartikel (refereegranskat)abstract
- The feasibility of granular ferric hydroxide (GFH) for bromate removal from water has been studied. Batch experiments were performed to study the influence of various experimental parameters such as effect of contact time, initial bromate concentration, temperature, pH and effect of competing anions on bromate removal by GFH. The adsorption kinetics indicates that uptake rate of bromate was rapid at the beginning and 75% adsorption was completed in 5 min and equilibrium was achieved within 20 min. The sorption process was well described by pseudo-second-order kinetics. The maximum adsorption potential of GFH for bromate removal was 16.5 mg g−1 at 25 °C. The adsorption data fitted well to the Langmuir model. The increase in OH peak and absence of Br–O bonding in FTIR spectra indicate that ion-exchange was the main mechanism during bromate sorption on GFH. The effects of competing anions and solution pHs (3–9) were negligible. Results of the present study suggest that GFH can be effectively utilized for bromate removal from drinking water.
|
|
| 6. |
- Bhatnagar, Amit, et al.
(författare)
-
Coconut based biosorbents for water treatment : A review of the recent literature
- 2010
-
Ingår i: Advances in Colloid and Interface Science. - : Elsevier BV. - 0001-8686 .- 1873-3727. ; 160:1-2, s. 1-15
-
Tidskriftsartikel (refereegranskat)abstract
- Biosorption is an emerging technique for water treatment utilizing abundantly available biomaterials (especially agricultural wastes). Among several agricultural wastes studied as biosorbents for water treatment, coconut has been of great importance as various parts of this tree (e.g. coir, shell, etc.) have been extensively studied as biosorbents for the removal of diverse type of pollutants from water. Coconut-based agricultural wastes have gained wide attention as effective biosorbents due to low-cost and significant adsorption potential for the removal of various aquatic pollutants. In this review, an extensive list of coconut-based biosorbents from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented. Available abundantly, high biosorption capacity, cost-effectiveness and renewability are the important factors making these materials as economical alternatives for water treatment and waste remediation. This paper presents a state of the art review of coconut-based biosorbents used for water pollution control, highlighting and discussing key advancement on the preparation of novel adsorbents utilizing coconut wastes, its major challenges together with the future prospective. It is evident from the literature survey that coconut-based biosorbents have shown good potential for the removal of various aquatic pollutants. However, still there is a need to find out the practical utility of such developed adsorbents on commercial scale, leading to the superior improvement of pollution control and environmental preservation.
|
|
| 7. |
- Bhatnagar, Amit, et al.
(författare)
-
Hunting for valuables from landfills and assessing their market opportunities : A case study with Kudjape landfill in Estonia
- 2017
-
Ingår i: Waste Management & Research. - : Sage Publications. - 0734-242X .- 1096-3669. ; 35:6, s. 627-635
-
Tidskriftsartikel (refereegranskat)abstract
- Landfill mining is an alternative technology that merges the ideas of material recycling and sustainable waste management. This paper reports a case study to estimate the value of landfilled materials and their respective market opportunities, based on a full-scale landfill mining project in Estonia. During the project, a dump site (Kudjape, Estonia) was excavated with the main objectives of extracting soil-like final cover material with the function of methane degradation. In total, about 57,777 m(3) of waste was processed, particularly the uppermost 10-year layer of waste. Manual sorting was performed in four test pits to determine the detailed composition of wastes. 11,610 kg of waste was screened on site, resulting in fine (<40 mm) and coarse (>40 mm) fractions with the share of 54% and 46%, respectively. Some portion of the fine fraction was sieved further to obtain a very fine grained fraction of <10 mm and analyzed for its potential for metals recovery. The average chemical composition of the <10 mm soil-like fraction suggests that it offers opportunities for metal (Cr, Cu, Ni, Pb, and Zn) extraction and recovery. The findings from this study highlight the importance of implementing best available site-specific technologies for on-site separation up to 10 mm grain size, and the importance of developing and implementing innovative extraction methods for materials recovery from soil-like fractions.
|
|
| 8. |
|
|
| 9. |
- Bhatnagar, Amit, et al.
(författare)
-
Removal of anionic dyes from water using Citrus limonum (lemon) peel: Equilibrium studies and kinetic modeling
- 2009
-
Ingår i: Separation science and technology (Print). - : Informa UK Limited. - 0149-6395 .- 1520-5754. ; 44, s. 316-334
-
Tidskriftsartikel (refereegranskat)abstract
- The present study was undertaken to evaluate the adsorption potential of Citrus limonum (lemon) peel as an adsorbent for the removal of two anionic dyes, Methyl orange (MO) and Congo red (CR) from aqueous solutions. The adsorption was studied as a function of contact time, initial concentration, and temperature by batch method. The adsorption capacities of lemon peel adsorbent for dyes were found 50.3 and 34.5 mg/g for MO and CR, respectively. The equilibrium adsorption data was well described by the Langmuir model. Three simplified kinetic models viz. pseudo-first-order, pseudo-second-order, and Weber and Morris intraparticle diffusion model were tested to describe the adsorption process. Kinetic parameters, rate constants, equilibrium sorption capacities, and related correlation coefficients for each kinetic model were determined. It was found that the present system of dyes adsorption on lemon peel adsorbent could be described more favorably by the pseudo-first-order kinetic model. The results of the present study reveal that lemon peel adsorbent can be fruitfully utilized as an inexpensive adsorbent for dyes removal from effluents.
|
|
| 10. |
|
|
