Does the Antibacterial Activity of Silver Nanoparticles Depend on the Shape of the Nanoparticle? A Study of the Gram-Negative Bacterium Escherichia coli (Applied and environmental microbiology)
(Sukdeb Pal, Yu Kyung Tak, Joon Myong Song,Vol(73),Issue(6),Pages(1712-1720),,, Year: 2007)
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In this work we investigated the antibacterial properties of differently shaped silver nanoparticles against the gram-negative bacterium Escherichia coli, both in liquid systems and on agar plates. Energy-filtering transmission electron microscopy images revealed considerable changes in the cell membranes upon treatment, resulting in cell death. Truncated triangular silver nanoplates with a {111} lattice plane as the basal plane displayed the strongest biocidal action, compared with spherical and rod-shaped nanoparticles and with Ag+ (in the form of AgNO3). It is proposed that nanoscale size and the presence of a {111} plane combine to promote this biocidal property.
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RETRACTED: Adsorption of cyanuric acid on activated carbon from aqueous solution: Effect of carbon surface modification and thermodynamic characteristics (Journal of colloid and interface science)
(Sukdeb Pal, Kyeong-Hee Lee, Jong-Uk Kim, Seung-Hee Han, Joon Myong Song,Vol(303),Issue(1),Pages(39-48),,, Year: 2007)
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The performance of a conventional and two surface-modified activated carbon samples was investigated for the sorption of cyanuric acid from aqueous solution by varying the process parameters such as initial concentration, pH, temperature, dose of adsorbents, and agitation time. The modified carbon samples obtained by acid and ammonia treatment of the conventional sample had a higher BET surface area (989 and 1010 m2?g?1, respectively) and higher specific mesopore surface area (27.36 and 33.21 m2?g?1, respectively) compared to the untreated material (820 and 18.25 m2?g?1). The solute removal was found to be favored at lower solute concentration, increased agitation time, increased adsorbent dose, and lower temperature. The modified adsorbents outperformed the conventional activated carbon for sorption of cyanuric acid especially at higher pH (>7.5) and with increasing temperature.
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Spatio-temporal analysis of groundwater recharge and mound dynamics in an unconfined aquifer: a GIS-based approach (Hydrological Processes)
(Ritesh Vijay, Nikhil H. Panchbhai Apurba Gupta,21,,2760-2764, Year: 2007)
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Groundwater recharge and mounding of water?table is a complex phenomenon involving time? and space?dependent hydrologic processes. The effect of long?term groundwater mounding in the aquifer depends on soil, aquifer geometry and the area contributing to recharge. In this paper, a GIS?based spatio?temporal algorithm has been developed for the groundwater mound dynamics to estimate the potential rise in the water?table and groundwater volume balance residual in an unconfined aquifer. The recharge and mound dynamics as predicted using the methodology recommended here were compared with those using the Hantush equation, and the differences were quite significant. The significance of the study is to assess the effectiveness of the basin in terms of its hydrologic and hydraulic properties for sustainable management of groundwater recharge.
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Hydrodynamic Simulation of River Yamuna for riverbed assessment: a case study of Delhi region (Environmental Monitoring and Assessment)
(Ritesh Vijay Abha Sargoankar Apurba Gupta,130,1-3,381-387, Year: 2007)
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A well known river hydrodynamic model RiverCAD has been used to simulate and visualize flood scenarios for different designated flood flows under complex riverbed geometry with several man made structures like bridges and barrages. The model applied successfully for the stretch of 23 km in the Yamuna floodplain of Delhi region from Wazirabad barrage in the upstream to Okhla barrage. Flood flows for various return periods namely once in 10, 25, 50 and 100 years were estimated based on recorded flow data for the period of 1963 to 2003 using standard flood frequency analysis techniques. The simulation results were compared and the model was calibrated with water surface elevation records of the previous floods at various barrage and bridge locations. Simulation results enabled prediction of maximum water levels, submergence scenarios and land availability under different designated flood flows for riverbed assessment, development and management.
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Water conservation through implementation of ultrafiltration and reverse osmosis system with recourse to recycling of effluent in textile industry-A case study
(Tapas Nandy, Pravin Manekar, Rita Dhodapkar, Girish Pophali, Sukumar Devotta,51,1,64-77, Year: 2007)
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In compliance with the protection of the drinking water source in one of the state capital of India, a cluster of small scale textile industries implemented membrane processes based on treatability studies for recovery of boiler feed water quality with recourse to effluent recycling/reuse. The paper addresses to a case study in one of the textile units on upgradation of a full scale effluent treatment plant comprising chemical, biological, tertiary and advanced treatment processes. Based on the adequacy assessment of chemical and biological processes, improvement in the performance of the unit processes were achieved through optimization of coagulant dosage for chemical coagulation and build-up of active biomass in the activated sludge system. In addition, application of membrane separation processes comprising ultrafiltration and reverse osmosis units are also highlighted including disposal of reverse osmosis (RO) rejects through evaporator leading to zero liquid effluent discharge. The treatment scheme implemented resulted in conservation of around 55% of fresh water demand for industry.
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Removal of E. coli from Water Using Surface-Modified Activated Carbon Filter Media and Its Performance over an Extended Use (Environmental science & technology)
(Sukdeb Pal, J Joardar, Joon Myong Song,Vol(40),Issue(19),Pages(6091-6097),,, Year: 2006)
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Modification of activated carbon (AC) by aluminum hydroxychloride (AHC), and diatomaceous earth by zinc hydroxide changed the zeta potentials of these filter media from negative to positive. The modification method is amenable to room temperature, and eliminates the essential requirement of strong base treatment for making metal hydroxide coated filter media. Solid-state MAS 27Al NMR spectra suggested the presence of Al13-mer in the AHC-treated AC. AHC-modified AC samples were further treated with silver halide, and two antibacterial compounds to prevent microbial growth on filter media. In situ precipitation of silver bromide on AC resulted in formation of nanosized AgBr crystals. Bacteria removal performances of the modified media were tested in columns.
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Kyeong-Hee lee, Jong-Uk Kim, et al. Adsorption of cyanuric acid on activated carbon from aqueous solution: Effect of carbon surface modification and thermodynamic characteristics (Journal of colloid and interface science)
(Sukdeb Pal
,,,, Year: 2006)
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No information is available
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Oxovanadium (IV, V) complexes of salicylidene-2-picoloyl hydrazone Schiff base and related ligands (Journal of the Indian Chemical Society)
(Asit R SARKAR, Shipra MANDAL, Sukdeb PAL, Somnath CHAKRABARTY, Aniruddha CHAKRABARTY,Vol(83),Issue(2),Pages(185-190),,, Year: 2006)
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Oxovanadium (iv, v) complexes having O 4 N coordination environment have been synthesized in the solid state, formulated as M [VO 2 (L/L',/L")(H 2 O)], where M= K or NH 4; H 2 (L/L'/L") is the Schiff base ligand, obtained by condensation of salicylaldehyde with 2-picoloyl (L), 2-quinoloyl (L'), 8-quinoloyl (L") hydrazides. Dimeric complexes having the formulation [(VOL) 2 ?-O] have also been synthesized. Both the salicylidene-picoloyl hydrazone and the salicylidene-2-quinoloyl hydrazone ligands, in their dideprotonated form, coordinate to both vanadium in its+ 4 and+ 5 slate, through 0, N, O donor atoms, while, the ligand H 2 L" will act as a NNO donor ligand. Thus, in the dioxo vanadium complexes with the ligands L and L', the central vanadium core will have the O 4 N environment, which can be treated as a model to mimic the active site of vanadium haloperoxidases.
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Assessment of Environmental Water Demands (EWD) of Forests for Two Distinct Indian Ecosystems (Environmental Management)
(,,,37, Year: 2006)
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Sustainable use of water and land resources requires that these scarce resources be appropriately allocated among various competing human activities. Worldwide, there is a realization now that sustainable river basin management should be accorded the highest priority, because it deals not only with technical, but also with ecological and socioeconomic aspects, and thus calls for a multidisciplinary and integrated approach. However, most of the policy and planning documents have either remained silent, or have made only implicit reference to the importance of environmental water demand (EWD) and its quantification. Therefore, in the light of its importance, a methodology has been evolved in this article for quantifying EWD for various forested areas in two distinctly different Indian river basins: Brahmani (humid zone) and Sabarmati (dry zone). The article analyzes and discusses EWD estimates at three different spatial levels: river basins, states, and districts within them, and finally presents a comparative analysis of all these results. Findings of the present study will be immensely useful in understanding various ecological issues connected with water resource projects and proposals in these river basins.
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Kinetic analysis of treatment of textile wastewater in hybrid column upflow anaerobic fixed bed reactor (Chemical Engineering Journal)
( K.Swaminathan,122,,,87-92, Year: 2006)
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No information is available
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Microbial decolorization of reactive black-5 in a two stage anaerobic-aerobic reactor using acclimatized activated textile sludge
(Sagrika Mohanty, Nishant Dafale & Nageshwara Rao
,17,,403-413, Year: 2006)
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A two-stage anaerobic–aerobic treatment process based on mixed culture of bacteria isolated from textile dye effluent was used to degrade reactive black 5 dye (RB-5). The anaerobic step was studied in more detail by varying the dye concentration from 100 to 3000 mg l)1 . The results showed that major decolorization was achieved during the anaerobic process. The time required for decolorization by >90% increased as the concentration of the dye increased. It was also found that maintaining dissolved oxygen (DO) concentration below 0.5 mg l)1 and addition of a co-substrate viz., glucose, facilitates anaerobic decolorization reaction remarkably. An attempt was made to identify the metabolites formed in anaerobic process by using high performance liquid chromatography (HPLC) and UV–VIS spectrophotometry. A plate assay was performed for the detection of dominant decolorizing bacteria. Only a few bacterial colonies with high clearing zones (decolorization zones) were found. The results showed that under anaerobic condition RB-5 molecules were reduced and aromatic amines were generated. The aromatic amine metabolite was partly removed in subsequent aerobic bio-treatment. It was possible to achieve more than 90% decolorization and approximately 46% reduction in amine metabolite concentration through two-stage anaerobic–aerobic treatment after a reaction period of 2 days.
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Estimation of rainfall-runoff using Curve Number: a GIS based development of Sathanur reservoir catchment (Journal of Environmental Science and Engineering)
(Ritesh Vijay Ashutosh Pareek Apurba Gupta,48,4,267-270, Year: 2006)
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A GIS based algorithm has been developed to estimate the rainfall-runoff relationship of Sathanur reservoir catchment based on Soil Conservation Service (SCS) model. The landuse and soil maps were prepared in Arc/Info 9.0 and an arc macro language (AML) programme was developed to assign curve number based on landuse and soil classification including hydrological condition of the area. The algorithm was executed successfully by rainfall data for computation of runoff depth in all the sub watersheds. The study is important for a watershed, which does not have runoff records and can be used for planning of various water conservation measures.
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Quantitative assessment of annual runoff in sub-catchments using GIS: A case study of the Tapi river basin, India (International Journal of Environmental Studies)
(Abha Sargaonkar, Ritesh Vijay ,Apurba Gupta,63,, 189-19, Year: 2006)
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The Tapi is a major interstate, westerly flowing river with 14 tributaries, of which the left bank tributaries support large settlements in Maharashtra State. It has been identified as one of the water scarce basins of India. There are many dams and barrages in the basin to store and divert water for agricultural and industrial purposes. This results in low flow and deterioration of water quality in the region particularly in non?monsoon months. This paper presents the details of a GIS?based rainfall?runoff modelling study carried out to assess the runoff flow in the sub?catchments and at the outlet of the Tapi Basin. Using mean monthly rainfall data at seven gauging stations in the basin, and land use and soil characteristics as reported by the Central Pollution Control Board (CPCB), the annual runoff flow at the watershed outlet was estimated to be 18,814 MCM. A comparison of runoff generated in the sub?catchments and the observed runoff at Central Water Commission (CWC) monitoring stations is presented. Results of the simulation indicate that the reduced river flows caused by the number of dams/reservoirs constructed upstream are useful as a guideline for the development of environmental flow regulations for rivers and streams in the Tapi Basin.
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Single Nucleotide Polymorphism (SNP) Detection In Microfluidic Device Using Poly (NIsopropyDAcrylamide As Pseudostationary Phase
(PAL Sukdeb, SONG Joon Myong,Pages(489-489),,, Year: 2005)
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Akt-G SK 3p pathway underlies the cardioprotective effect of KR-32568, a novel sodium/hydrogen exchange r-1 inhibitor, in an isolated rat heart m odel of ischem iaand reperfusion heartinjury
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Single pathogenic bacteria detection using a compact CMOS biochip system
(PARK Ahyun, PAL Sukdeb, SONG Joon Myong,Pages(477-477),,, Year: 2005)
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No information is available
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A model study for vanadium protein interactions: synthesis, characterization of oxovanadium (IV and V) complexes with l-carnosine (SYNTHESIS AND REACTIVITY IN INORGANIC METAL-ORGANIC AND NANO-METAL CHEMISTRY)
(AR Sarkar, S Mandal, S Pal, S Chakrabarty, A Chakrabarty,Vol(35),Issue(2),Pages(127-132),,, Year: 2005)
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The potential metal binding sites of L-carnosine (beta-alanyl-L-histidine) with respect to vanadium has been investigated. Two novel oxovanadium complexes containing the dideprotonated L-carnosine anion were isolated having the composition NH4[VO2L] center dot 2H(2)O and [VOL] center dot 2H(2)O, where H2L = L-carnosine. The dideprotonated L-carnosine coordinates to vanadium in both the complexes through the three donor atoms, namely the oxygen atom of the carboxylate group and two nitrogen ( one each from the primary amine and the other from the amide group of the ligand). The imidazole moiety of L-carnosine undergoes a tautomeric change from N(3)-H to N(1)-H in the complex NH4[VO2L] center dot 2H(2)O.
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Health risks of NO2, SPM and SO2 in Delhi (India) (Atmospheric Environment)
(,,,39, Year: 2005)
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There is increasingly growing evidence linking urban air pollution to acute and chronic illnesses amongst all age groups. Therefore, monitoring of ambient concentrations of various air pollutants as well as quantification of the dose inhaled es quite important, specially in view of the fact that in many countries, policy decisions for reducing pollutant concentrations are mainly taken on the basis of their health impacts. The dose when gets combined with the likely responses, indicates the ultimate health risk (HR). Thus, as an extension of our earlier studies, HR has been estimated for three pollutants, namely, suspended particulate matter (SPM), nitrogen dioxide (NO2) and sulfur dioxide (SO2) for Delhi City in India. For estimation and analyses, three zones have been considered, namely, residential, industrial and commercial. The total population has been divided into three age classes (infants, children and adults) with different body weights and breathing rates. The exercise takes into account age-specific breathing rates, body weights for different age categories and occupancy factors for different zones. Results indicate that health risks due to air pollution in Delhi are highest for children. For all age categories, health risks due to SO2 (HR_SO2) are the lowest. Hence, HR_SO2 has been taken as the reference with respect to which HR values due to SPM and NO2 have been compared. Taking into account all the age categories and their occupancy in different zones, average HR values for NO2 and SPM turn out to be respectively 22.11 and 16.13 times more than that for SO2. The present study can be useful in generating public awareness as well as in averting and mitigating the health risks.
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Capability of 19-L polycarbonate plastic water cooler containers for efficient solar water disinfection (SODIS): Field case studies in India, Bahrain and Spain (Solar Energy)
(Keogh M. B., Castro-Alferez M., Polo-Lopez M.I., Fernandez Calderero Y.A., Al-Eryani C., Joseph-Titus, Sawant B., Dhodapkar R., Mathur C., McGuigan K.G., Fernandez-Ibanez P.,volume 116,,page 1-11, Year: 2005)
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No information is available
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Estimation and Allocation of Solid Waste to Bin Through Geographical Information System (GIS) (Waste Management & Research)
(Ritesh Vijay, A. Gupta, Ajay S. Kalamdhad, and Sukumar Devotta,23,5,479-484, Year: 2005)
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This study presents a geographical information system (GIS)-based procedure for the precise estimation of solid waste generation, computed using the local population density and income group distribution. Using a triangulated irregular network (TIN) in a GIS environment, the procedure further determines the command area for waste allocation to a particular bin which is generally located so the route slopes towards the collection points for ease of transportation by cart pullers. Computational results of bin location, type, size and the frequency of removal are presented for a typical urban area with known population density, income group distribution, road network and topology.
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Computation of reservoir storage capacity and submergence using GIS (Surveying and Land Information Science)
(Ritesh Vijay, Apurba Gupta and Sukumar Devotta,65,4,255-258, Year: 2005)
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Measurement of volumes is an important task in many civil engineering projects. In designing dams, the volumes that need to be determined are storage and submergence. In this paper, a GIS-based algorithm has been developed to compute storage capacities and submergence scenarios of reservoirs with varying dam height. The computation is based on a digital elevation model (DEM) of the topography and triangulated irregular networks (TIN). The method requires that real-world coordinates are used for the computations, which highlights the need for surveying.
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