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Shifts in microbial community in response to dissolved oxygen levels in activated sludge
No full textThis study evaluates the degradative efficiency of activated biomass collected from a Common Effluent
Treatment Plant (CETP) under three different dissolved oxygen (DO) levels, 1, 2 and 4 mg l�1. The change
in bacterial diversity with reference to DO levels was also analyzed. Results demonstrate that degradative
efficiency was the highest, when the reactor was maintained at 4 mg l�1 DO, but amplicon library analysis
showed a greater diversity of bacteria in the reactor maintained at 2 mg l�1 DO. Bacteria belonging to the
order Desulfuromonadales, Entomoplasmatales, Pasteurellales, Thermales and Chloroflexales have only
been detected in this reactor. Ammonia and nitrate levels in all three reactors indicated efficient nitrification
process. Results of this study offer new insights into understanding the performance of activated
biomass vis-à-vis microbial diversity and degradative efficiency with reference to DO. This information
would be useful in improving the efficiency of any wastewater treatment plant
Bacteriophage against Filamentous Bacteria in Wastewater
No full textActivated sludge plants (ASP) are associated with the stable foaming problem worldwide. Apart from the physical and chemical treatment methods, biological treatment method have been least explored and may prove to be a novel and eco-friendly approach to tackle the problem of stable foam formation. In ASP Nocardia species are commonly found and are one of the major causes for forming sticky and stable foam. This book describes a piece of work where bacteriophages were isolated with a potential to control foam producing bacterial growth under laboratory conditions, suggesting that it may prove useful in the field as an alternative biocontrol agent to reduce the foaming problem. To the best of our knowledge to date no work has been documented from India related to biological approach for the control of foaming
Synthesis and visible light photocatalytic activity of nanocrystalline PrFeO3 perovskite for hydrogen generation in ethanol–water system
No full textNanocrystalline PrFeO3 perovskite type orthoferrite was synthesized at 700◦C by using three different
synthesis methods, namely sol–gel, template and combustion method. The synthesized materials were
characterized by XRD, BET-SA, SEM, HRTEM, XPS, FTIR and UV-DRS techniques to understand their
physico-chemical properties. Characterization data reveal the formation of nanocrystalline PrFeO3 perovskite
composition with improved physical properties, possibly due to lower synthesis temperature used. PrFeO3 synthesized
by sol–gel method consists of crystallite size of about 20 nm with absorption maxima at 595 nm
wavelength in visible light range. This photocatalyst shows hydrogen generation of about 2847 μmol.g−1.h−1,
under visible light irradiation in ethanol–water system. The photocatalyst was further investigated for various
operational parameters such as photocatalyst dose variation, illumination intensity, time, etc. in a view to optimize
the hydrogen generation as well as to understand mechanistic aspects. This material appears to follow a
semiconductor type mechanism for ethanol-assisted visible light photocatalyic water-splitting and can also be
an interesting candidate to develop hetero-junction type photocatalysts
Toxic effect of Ore Mining on Soil and Water Quality at Chhattisgarh, India
Get PDFPhysical pollutants such as noise, causes so much confusion regarding its effect, often take the back seat when deleterious effects to the environment are considered. Metropolitan city of South East Asian region was selected for the study where day and night noise is monitored in higher levels in festival seasons as well as in normal seasons in all zones. It was found that prescribed noise level were increased 19.23%, 19.33% and 23.08% near Courts, schools and hospitals respectively under the silent zone. Slum areas are already affected whole year and noise level in middle class areas recorded 7.69% higher in festival season where as high class residential areas are found safer than the other two types of areas under the residential zone. Almost 85% areas under commercial zone are affected by higher noise levels in both the seasons where as in festival season only 4% readings were increases in day and night. Over all 10.25% and 8.12% day & night noise level were increases where as hectic city traffic increases 36.58% rapidly in festival season in all the zones. The affects can also be seen in the form of variety of negative emotions including anger, disappointment, unhappiness, anxiety and even depression. Therefore to avoid the adverse effects there is an urgent need to control noise pollution by implementing strict rules and through launching awareness-campaign
Copper–manganese mixed oxides: CO2- selectivity, stable, and cyclic performance for chemical looping combustion of methane
No full textChemical looping combustion (CLC) is a key technology for oxy-fuel combustion with inherent
separation of CO2 from a flue gas, in which oxygen is derived from a solid oxygen carrier. Multi-cycle
CLC performance and the product selectivity towards CO2 formation were achieved using mixed oxide
of Cu and Mn (CuMn2O4) (Fd%3m, a = b = c = 0.83 nm) as an oxygen carrier. CuMn2O4 was prepared by
the co-precipitation method followed by annealing at 900 1C using copper(II) nitrate trihydrate and
manganese(II) nitrate tetrahydrate as metal precursors. CuMn2O4 showed oxygen-desorption as well as
reducibility at elevated temperatures under CLC conditions. The lattice of CuMn2O4 was altered
significantly at higher temperature, however, it was reinstated virtually upon cooling in the presence of
air. CuMn2O4 was reduced to CuMnO2, Mn3O4, and Cu2O phases at the intermediate stages, which
were further reduced to metallic Cu and MnO upon the removal of reactive oxygen from their lattice.
CuMn2O4 showed a remarkable activity towards methane combustion reaction at 750 1C. The reduced
phase of CuMn2O4 containing Cu and MnO was readily reinstated when treated with air or oxygen at
750 1C, confirming efficient regeneration of the oxygen carrier. Neither methane combustion efficiency
nor oxygen carrying capacity was altered with the increase of CLC cycles at any tested time. The
average oxygen carrying capacity of CuMn2O4 was estimated to be 114 mg g�1, which was not altered
significantly with the repeated CLC cycles. Pure CO2 but no CO, which is one of the possible toxic
by-products, was formed solely upon methane combustion reaction of CuMn2O4. CuMn2O4 shows
potential as a practical CLC material both in terms of multi-cycle performance and product selectivity
towards CO2 formation
Cytochrome P450 BM3 of Bacillus megaterium - a possible endosulfan biotransforming gene
No full textComputing chemistry was applied to understand biotransformation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 (cytochrome P450) on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification
Water pollution of Sabarmati River—a Harbinger to potential disaster
No full textRiver Sabarmati is one of the biggest and major
river of Gujarat that runs through two major cities of
Gujarat, Gandhinagar and Ahmedabad and finally meets
the Gulf of Khambhat (GoK) in the Arabian Sea. A study
was conducted to evaluate the water quality of this river, as
it could possibly be one of the major sources for filling up
Kalpasar, the proposed man-made freshwater reservoir
supposed to be the biggest one in the world. A total of
nine sampling stations were established covering 163 km
stretch of the river from upstream of Gandhinagar city to
Vataman near Sabarmati estuary. Physicochemical
(temprature, pH, salinity, chloride, total dissolved solids,
turbidity, dissolved oxygen, biochemical oxygen demand,
phenol, and petroleum hydrocarbons), biological (phytoplankton), and microbiological (total and selective
bacterial count) analyses indicated that the river stretch
from Ahmedabad-Vasana barriage to Vataman was highly
polluted due to perennial waste discharges mainly from
municipal drainage and industries. An implementation of
sustainable management plan with proper treatment of
both municipal and industrial effluents is essential to prevent further deterioration of the water quality of this river
Beta caryophyllene and caryophyllene oxide, isolated from Aegle marmelos, as the potent anti-inflammatory agents against lymphoma and neuroblastoma cells
No full textAegle Marmelos (Indian Bael) is a tree belonging to the family of Rutaceae. It holds a prominent position in both Indian medicine and culture. We have screened various fractions of Aegle marmelos extracts for its anti-cancer properties using in vitro cell models. Gas chromatography-Mass spectrometry (GC-MS) was employed to analyze the biomolecules present in the Aegle marmelos extract. Jurkat and human neuroblastoma (IMR-32) cells were treated with different concentrations of the fractionated Aegle marmelos extracts. Flow cytometric analysis revealed that optimal concentration (170µg/ml) of beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract can induce apoptosis in Jurkat cell line. cDNA expression profiling of pro-apoptotic and anti-apoptotic genes was carried out using real time PCR (RT-PCR). Down-regulation of anti-apoptotic genes (bcl-2, mdm2, cox2 and cmyb) and up-regulation of pro-apoptotic genes (bax, bak1, caspase-8, caspase-9 and ATM) in Jurkat and IMR-32 cells treated with the beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract revealed the insights of the downstream apoptotic mechanism. Furthermore, in-silico approach was employed to understand the upstream target involved in the induction of apoptosis by the beta caryophyllene and caryophyllene oxide fractions of Aegle marmelos extract. Herein, we report that beta caryophyllene and caryophyllene oxide isolated from Aegle marmelos can act as the potent anti-inflammatory agents and modulators of a newly established therapeutic target, 15-lypoxygenase (15-LOX). Beta caryophyllene and caryophyllene oxide can induce apoptosis in lymphoma and neuroblastoma cells via modulation of 15-LOX (up-stream target) followed by the down-regulation of anti-apoptotic and up-regulation of pro-apoptotic genes
Flow visualization of pollutant mixing in freshwater body near the density maximum
Get PDFMixing in water bodies forms a major part of the environmental hydraulic studies. In the present study, effects of density variations in freshwater manifested in the form of convection currents on the water quality parameters is studied. Convection forms a dominant mixing mechanism for near-stagnant lakes i.e. with high residence times. However, due to tedious computations involved in simulating natural convection, water quality models available commercially or open-source solve vertically hydrostatic equations which fail to capture the circulation currents. A hydrodynamic model is conceptualized for describing the setting up of vertical circulation currents driven by the buoyancy. 2D incompressible Navier-Stokes, plus equations for transport of scalars (heat and concentration) are formulated and solved. Concentration profile of a conservative parameter is simulated to study the anomaly in temperature-density relationship on mixing.Density is assumed to be a function of temperature only (at 0.1Mpa) and various formulations like linear, quadratic and IAWPS(The International Association for the Properties of Water and Steam)are used in the model. The phenomenon is investigated near 4°C i.e. at the anomalous behavior of temperature-density curve. Impact of this anomaly on the hydrodynamics and subsequently on the mixing of water quality parameter is studied and visualized to facilitate interpretation and use. Modeling and simulation results for the hydrodynamics are validated against reported work
Photodeposition of AuNPs on metal oxides: Study of SPR effect and photocatalytic activity
No full textEffect of photodeposition of AuNPs (gold nanoparticles) on TiO2, CeO2, Cu2O and Fe3O4 supports has been illustrated on sacrificial donor based hydrogen evolution. The synthesized samples were characterized by diffuse reflectance spectroscopy (DRS), and transmission electron microscopy (TEM). Highest photocatalytic activity was exhibited by Au/TiO2 followed by Au/Fe3O4, Au/CeO2 and Au/Cu2O. Au/TiO2 under optimized conditions has shown significantly high photocatalytic activity under both UV–visible and visible radiation. Au/TiO2 shows hydrogen evolution rate of 920 μmol h−1 and 32.4 μmol h−1 under UV–visible and visible radiation, respectively. Significant enhancement in hydrogen evolution rate under visible light is very encouraging and may be attributed to polydispersed nature of AuNPs wherein larger particles facilitate light absorption and the smaller function as catalytic sites. Further studies are in progress to study the influence of various parameters on photocatalytic activity of Au/TiO2.ISSN: 0360-319