Mineralogical characterization and sorption properties of goethite rich iron ore from daitari, Orissa, India

The present study was an attempt to find alternative uses of goethite rich iron ore, usually not used as raw material for iron extraction, as an adsorbent for removal of anionic contaminants from water. Mineralogical characterization by optical microscope, XRD revealed the presence of substantial amount goethite in the iron ore which was also supported from the TG-DTA and FT-IR results. On heating in air, the goethite content was completely converted to hematite at 400°C. The sorption behaviour of the untreated (GRI-0) and heat treated iron ore were studied using aqueous phosphate solution as the adsorbate with respect to effect of pH, initial phosphate concentration, amount of adsorbent, interfering anions and heat treatment. Phosphate uptake was seen to increase with increasing temperature of heat treatment, attains a maximum value at 300°C and thereafter decreased on further increase of temperature. The experimental equilibrium adsorption data were fitted well to Langmuir isotherm model. The complete desorption of adsorbed phosphate at pH ≥ 12.0 indicated the adsorption of phosphate was reversible and may be reused further. The results obtained could be useful for considering GRI-0 as adsorbent for removal of phosphate ions from contaminated water bodies

An assessment of heavy metal accumulation in mangrove species of Bhitarkanika, Odisha, India

Mangroves are one of the most biologically important and productive ecosystemsin the world. Heavy metals are known to pose a potential threat to terrestrial and aquaticbiota. However, little is known on the toxic levels of heavy metals found in mangroveplants in India. To understand heavy metal toxicity, we analyzed heavy metalsaccumulation in sediment samples collected from surrounding root zone and in the leavesand stem of sixteen different plant species in the Bhitarkanika mangrove forest reserve inOdisha, India. Bhitarkanika mangrove ecosystem receives heavy metal pollution fromupstream areas of Brahmani and Baitarani estuary. Few studies were carried about thecapacity of mangrove plants to take up and store heavy metals in them. Hence, currentinvestigation was carried out to analyze trace metal accumulation in sediment and plantparts such as stems and leaves of different mangrove plants by Atomic AbsorptionSpectroscopy (Shimadzu, AA- 6300). The heavy metal concentration in sediment wasfound to be in the range of 5.99 to 92.00 μg/gm. Metals concentration in sediment samplesduring the study was in the order of accumulation : Zn>Cu>Pb. The accumulation ofheavy metal was higher in stem as compared to leaf

Calculation on Absorption Frequencies of Merophosphinines & Unsymmetrical Phosphocyanines by Free Electron MO Treatment

56-5

Correlation of the Lowest HMO Transition Energies with the Electronic Absorption Frequencies of Some Organic Dyestufts: s-Cyanines & Merocyanines

951-95

Kinetics & Mechanism of Oxidation of Benzoin & Its Derivatives by Tl(III) in Aqueous Acetic Acid

42-4

The enrichment of an alkaliphilic biofilm consortia capable of the anaerobic degradation of isosaccharinic acid from cellulosic materials incubated within an anthropogenic, hyperalkaline environment.

Anthropogenic hyper-alkaline sites provide an environment that is analogous to proposed cementitious geological disposal facilities (GDF) for radioactive waste. Under anoxic, alkaline conditions cellulosic wastes will hydrolyse to a range of cellulose degradation products (CDP) dominated by isosaccharinic acids (ISA). In order to investigate the potential for microbial activity in a cementitious GDF, cellulose samples were incubated in the alkaline (∼pH 12), anaerobic zone of a lime kiln waste site. Following retrieval, these samples had undergone partial alkaline hydrolysis and were colonised by a Clostridia dominated biofilm community, where hydrogenotrophic, alkaliphilic methanogens were also present. When these samples were used to establish an alkaline CDP fed microcosm, the community shifted away from Clostridia, methanogens became undetectable and a flocculate community dominated by Alishewanella sp. established. These flocs were composed of bacteria embedded in polysaccharides and protein stabilised by extracellular DNA. This community was able to degrade all forms of ISA with >60% of the carbon flow being channelled into extracellular polymeric substance (EPS) production. This study demonstrated that alkaliphilic microbial communities can degrade the CDP associated with some radioactive waste disposal concepts at pH 11. These communities divert significant amounts of degradable carbon to EPS formation, suggesting that EPS has a central role in the protection of these communities from hyper-alkaline conditions

Graphene-based electrochemical supercapacitors

Graphenes prepared by three different methods have been investigated as electrode materials in electrochemical supercapacitors. The samples prepared by exfoliation of graphitic oxide and by the transformation of nanodiamond exhibit high specific capacitance in aq. H2SO4, the value reaching up to 117 F/g. By using an ionic liquid, the operating voltage has been extended to 3.5 V (instead of 1 V in the case of aq. H2SO4), the specific capacitance and energy density being 75 F/g and 31.9 Wh kg−1 respectively. This value of the energy density is one of the highest values reported to date. The performance characteristics of the graphenes which are directly related to the quality, in terms of the number of layers and the surface area, are superior to that of single-walled and multi-walled carbon nanotubes