Browsing by Author "Majumder, Subhajit"

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Application of a hybrid biofilter column for the removal of Cr(VI) from aqueous solution using an indigenous bacterial strain Pseudomonas taiwanensis
(Taylor & Francis, 2016-02-01) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
In the present study, a laboratory-scale biofilter column was designed and fabricated. It was packed with a mixture of coal and compost as a packing medium. The column was enriched with an indigenous bacterial strain Pseudomonas taiwanensis isolated from aerobic mixed culture of Sewage Treatment Plant, BITS-Pilani, Pilani campus. The removal of hexavalent chromium [Cr(VI)] from aqueous solution was investigated in the biofilter column. The entire biofiltration operation was divided into five phases (I to V) for a period of 63 days. Biofilter column was subjected to shock loading conditions for 20 days immediately after 63 days of operation. The maximum removal efficiency of 89.4% was obtained during phase V for Cr(VI) inlet concentration of 40 mg L−1. During shock loading, maximum removal efficiency was obtained as 90% for 48.5–50 mg L−1 of initial Cr(VI) concentration. Kinetic parameters of biofiltration process for Cr(VI) removal were also determined by fitting Michaelis-Menten kinetic model with experimental data. The Michaelis-Menten kinetic constants were obtained as 0.258 mg L−1 min−1 and 26.83 mg L−1. It was found that Ottengraf-Van den Oever model with zero-order diffusion limitation fit the experimental data quite well for phases III, IV, and V with coefficient of determination (R2) values .97, .99, and .984, respectively. A possible method for safe disposal of packing medium was also presented in this study.
Biofilter column for removal of divalent copper from aqueous solutions: Performance evaluation and kinetic modeling
(INFOFNA, 2015) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
In recent years, the biofiltration technique has gained significant importance for the removal of toxic organic compounds. However, very limited studies on biofiltration were carried out for the removal of divalent copper [Cu(II)] from aqueous solution using indigenous packing material. There are no reports in the literature that deal with the performance evaluation and kinetic modeling of the biofilter column for the removal of Cu(II). In the present study, a lab- scale biofilter column was fabricated and packed with a mixture of compost and coal as a packing material. The seeding of the column was done using an indigenous bacterial strain Acinetobacter guillouiae. The removal of divalent copper [Cu(II)] was investigated in this column for a period of 55 days. The maximum removal efficiency of 97.5% was achieved during phase II for Cu(II) inlet concentration of 20 mg L−1. During shock loading, maximum removal efficiency obtained was 87% for initial Cu(II) concentration 28.5–30 mg L−1. The Michaelis–Menten kinetic constants obtained were 0.2 mg L−1 min−1 and 13.03 mg L−1. It was found that the Ottengraf model with zero-order diffusion-limitation fits the experimental data quite well for phase II, III and V.
Biofiltration: Essentials, Research and Applications
(Wiley, 2012-03-26) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
A comprehensive study on the behavior of a novel bacterial strain Acinetobacter guillouiae for bioremediation of divalent copper
(Springer, 2015-05-28) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
Biological methods have been successfully used to mitigate heavy metal pollution problem in wastewater. The present study was aimed towards isolation of a novel indigenous bacterial strain, Acinetobacter guillouiae from activated sludge and its subsequent application in remediation of copper (Cu2+) from aqueous solution. Kinetic study of bioremediation was performed for initial Cu2+ concentrations ranging from 40 to 150 mg L−1. Optimum values of nutrient dosage, pH, macronutrients [Nitrogen (N)–Phosphorus (P)–Potassium (K)] dosage, aerobic and facultative anaerobic conditions, temperature, and inoculum volume were determined by conducting separate batch bioremediation studies at 80 mg L−1 initial concentration of Cu2+. Kinetic study showed that A. guillouiae removed 98.7 % Cu2+ for 80 mg L−1 initial concentration of Cu2+ after 16 h at an optimum solution pH of 7.0. Results also revealed that A. guillouiae showed maximum growth at double the standard composition of N, P and standard composition of K in nutrient dosage. Experimental data obtained in present study were utilized to validate different growth kinetic models such as Monod, Powell, Haldane, Luong, and Edwards. Growth kinetics of A. guillouiae was better understood by Luong model (R 2 = 0.97). Higher values of coefficient of determination (R 2 = 0.97–0.99) confirmed the suitability of the three-half-order kinetic model for representing the Cu2+ bioremediation. A. guillouiae showed a robust removal mechanism for the bioremediation of Cu2+.
Estimation of Kinetic Parameters for Bioremediation of Cr(VI) from Wastewater Using Pseudomonas taiwanensis, an Isolated Strain from Enriched Mixed Culture
(Taylor & Francis, 2014-08-08) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
An aerobic mixed culture collected in the form of activated sludge was enriched for Cr(VI) reduction. An indigenous microorganism was isolated from the enriched aerobic mixed culture and identified as Pseudomonas taiwanensis. Bioremediation studies were carried out for treating Cr(VI)-contaminated wastewater using the indigenous microorganism. The kinetic studies were carried out for initial Cr(VI) concentrations ranging from 20 to 200 mg L−1. The maximum consumption of Cr(VI) obtained was 108.3 mg L−1 for an initial Cr(VI) concentration of 150 mg L−1 at a solution pH of 7.0. The effect of nutrient dosage and pH were studied to get their optimum values. The same isolated bacterial strain was also used to treat Cr(VI)-contaminated industrial wastewater collected from a local plating industry. Various growth kinetic models, such as Monod, Powell, Haldane, Luong, and Edward models, were fitted with the obtained experimental data. The obtained results for different growth kinetic models indicate that the growth kinetics of Pseudomonas taiwanensis for bioremediation of Cr(VI) can be better understood by the Luong model (R2 = .913). The rate kinetic analysis was performed using zero-order and three-half-order kinetic models. The three-half-order kinetic model was found to be suitable for the present bioremediation study.
Sequestration of Zn2+ from aqueous solution using Klebsiella pneumoniae: Batch kinetics and continuous studies
(INFOFNA, 2016) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
The present study was aimed to isolate, Klebsiella pneumoniae from activated sludge. It was used to remove Zn2+ from aqueous solution in batch and continuous modes. Batch study was conducted for 20–200mgL−1 of initial Zn2+ concentration to determine the optimum value of initial Zn2+ concentration. Batch bioremediation studies were also performed to determine the optimum values of solution pH, minimal salt medium (MSM) dosage, macronutrients amount, aerobic & facultative anaerobic conditions, temperature and inoculum volume. The optimum solution pH for the growth of K. pneumoniae was found as 7 for the Zn2+ bioremediation. The growth of K. pneumoniae was found optimum in aerobic condition and in the temperature range of 37–40°C.
Simultaneous sequestration of ternary metal ions (Cr6+, Cu2+ and Zn2+) from aqueous solution by an indigenous bacterial consortium
(Elsiever, 2016-07) Gupta, Suresh; Raghuvanshi, Smita; Majumder, Subhajit
Sequestration of single heavy metal contaminant from industrial wastewater using pure bacterial strains has received much attention. However, application of a bacterial consortium in multiple metals sequestration is scarce. The present study was aimed to develop a consortium from three bacterial strains for the simultaneous sequestration of ternary metal ions (Cr6+, Cu2+ and Zn2+) from aqueous solution. Kinetic studies showed that the individual strain, Pseudomonas taiwanensis; Acinetobacter guillouiae and Klebsiella pneumoniae were able to remove Cr6+, Cu2+ and Zn2+ respectively. These bacterial strains were utilized to develop an indigenous consortium based on metal removal affinities and positive interferences between them. Consortium showed improved performance over individual strains for the removal of single as well as simultaneous removal of three metal ions. Fourier transform infrared (FTIR) spectral analysis showed the possible involvement of carboxyl, amino, hydroxyl, methyl, phosphate and sulphonate groups in metal ions sequestration. Consortium exhibits greater adaptability in ternary metal ions mixture which indicates its robust growth mechanism over individual bacterial strains.