خيارات البحث
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Spectrophotometer-based student education program on health hazard assessment due to Cr(VI) and Pb contamination in surface and groundwaters of Hyderabad City, India
2015
Das Sharma, Mala | Juyal, Archana | Karuna, Mantha | Das Sharma, Subrata
A student-centric research education program with the active participation of undergraduate students is initiated. The aim is to imbibe ―responsible citizenship behavior‖ in them so that each member becomes conscious and well trained to take up environmental-related issues and challenges for long-term sustainability of the ecosystem. In this work, we report spectrophotometer-based estimation of hexavalent chromium (57-268 gL-1) and lead (34–158 gL-1) concentrations in different surface waters and groundwater samples in and around the city of Hyderabad, India. Our results indicate that the studied surface water bodies and aquifers are contaminated to variable degrees and pose a serious threat to the ecosystem. In view of low geochemical baseline values for chromium and lead, the origin of heavy metal pollution is inferred to be anthropogenic, mainly originating from industrial effluents. The toxicological data are integrated with health data for risk assessment and impending health hazard. Finally, the novelty of this student-centric research program is highlighted.
اظهر المزيد [+] اقل [-]Isolation and molecular characterization of bacteria to heavy metals isolated from soil samples in Bokaro Coal Mines, India
2015
Gandhi, Vikram | Priya, Anshu | Priya, Suman | Daiya, Vivek | Kesari, Jitendra | Prakash, Krishna | Kumar Jha, Amrit | Kumar, Kundan | Kumar, Nitish
In recent years, environmental pollution by coal mining is a long-established human activity affecting all levels of life with various environmental impacts by generating heavy metals. The presence of heavy metals even in trace amount is toxic and detrimental to all living organisms. The coal mine area in Bokaro is one of the “Toxic Hotspot” in India. Bacteria have evolved uptake and efflux mechanisms to adapt in heavy metals contaminated environments and thus represent a potential source for bioremediation processes. In the present study, we isolated and characterized eight heavy metal resistant bacteria (NK-1 to 8) from soil sample in Bokaro coal mines, India. Isolates were selected based on high level of heavy metal resistance and its biochemical characterization. The following bacteria were identified based on 16S rRNA gene sequencing Enterobacter ludwigii (KM029957; NK-1), Klebsiella pneumonia (KM029958; NK-2), Enterobacter ludwigii (KM029959; NK-3), Enterobacter ludwigii (KM029960; NK-4), Klebsiella oxytoca (KM029961; NK-5), Enterobacter cloacae (KM029962; NK-6), Acinetobacter gyllenbergii (KM029963; NK-7), Enterobacter cloacae (KM029964; NK-8). A high degree of metal resistance associated with multiple antibiotic resistances was also detected in the selected isolate which was confirmed by the presence of plasmid. These isolates can further be used for bioremediation of heavy metals from contaminated site.
اظهر المزيد [+] اقل [-]Evaluation of kinetics and adsorption isotherms for the Elimination of Pb(II) from aqueous solutions using Aloe barbadensis Miller Leaf Powder
2015
Malik, R | Lata, Suman | Singhal, Sushila
An adsorbent was developed from matured leaves of the Aloe barbadensis miller plant for removing Pb(II) from aqueous solutions. Adsorption was carried out in a batch process with several different concentrations of Pb(II) by varying amount of adsorbent, pH, agitation time and temperature. The uptake of the metal was initially very fast, but gradually slowed down indicating penetration into the interior of the adsorbent particles. The experimental data closely followed both Langmuir and Freundlich isotherms. A small amount of the adsorbent (1 g/50ml) could remove as much as 86% of Pb(II) in 35 min from a solution of concentration 0.3 mg/50ml at 25°C. The adsorption continuously increased in the pH range of 2.0–5.0, beyond which the adsorption could decrease up to pH 7.0 when the adsorption could not be carried out due to precipitation of the metal. The adsorption was exothermic at ambient temperature and computation of the parameters, ΔH, ΔS and ΔG, which indicated the interactions to be thermodynamically favorable.
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