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E-waste scenario in India, its management and implications
Get PDFElectronic waste or E-waste comprises of old, end-of-life electronic appliances such as computers, laptops, TVs, DVD players, refrigerators,freezers, mobile phones, MP3 players,
etc., which have been disposed of by their original users. E-waste contains many hazardous constituents that may negatively impact the environment and affect human health if not properly managed. Various organizations, bodies, and governments of many countries have adopted and/or developed the environmentally sound options and strategies for E-waste management to tackle the ever growing threat of E-waste to the environment and human health. This paper presents E-waste composition, categorization, Global and
Indian E-waste scenarios, prospects of recoverable,
recyclable, and hazardous materials found in the E-waste, Best Available Practices, recycling,and recovery processes followed, and their environmental and occupational hazards. Based on the discussion, various challenges for E-waste
management particularly in India are delineated,and needed policy interventions were discussed
Carbon composite beads for immobilization of carbonic anhydrase
No full textFixation of anthropogenic CO2 into calcium carbonate using carbonic anhydrase (CA) as a bio-catalyst
appears to be a promising option of CO2 sequestration. In the present study, carbonic anhydrase (CA) has
been immobilized on chitosan based activated alumina–carbon composite beads. Synthesized adsorbent
was thoroughly characterized using XRD, FTIR, SEM and BET-SA. Maximum adsorption capacities were
determined using Langmuir model and it was observed to be 172.41 mg/g. Mechanistic and kinetic aspects
have been addressed for immobilized as well as free enzyme. The Km and Vmax for immobilized enzyme
was 10.35mM and 0.99�mol/ml/min, whereas for free enzyme it was 1.89mM and 0.99�mol/ml/min
respectively. Proof of concept has been established for carbonation reaction. The carbonate has been
characterized using various tools such as XRD and SEM which confirms the calcite nature of calcium
carbonate. The CO2 sequestration capacity in terms of conversion of CO2 to carbonate was quantified by
gas chromatography (GC). The CO2 sequestration capacity of immobilized beads was found to be 19.22mg
of CaCO3/mg of enzyme as compared to 33.06mg of CaCO3/mg of enzyme for free enzyme
Effect of gypsum on moisture availability in vertisols under soybean gram sequence.
No full textA field experiment entitled, effect of gypsum on moisture availability in Vertisols in under soybean–gram sequence was conducted during season of 2008-2009 at extra assistant director (EAD) farm, College of Agriculture, Nagpur. The field experiment was laid out in randomized block design (RBD) with seven treatments replicated thrice. Highest yield and moisture use efficiency in soybean were obtained 3 t gypsum ha-1 whereas 1.5 t gypsum ha-1 also increased yield and MUE of soybean over control. Increasing level of gypsum also increased the yield and MUE efficiency of gram. Reduction in water dispersible clay, ESP, pH, exchangeable sodium, Mg. Improvement in HC, exchangeable Ca and Ca/Mg ratio was found with higher level of gypsum but low level of
gypsum i.e. 1.5 t ha-1 was also sufficient to give better result over control (no gypsum). Favourable changes in soil
physical and chemical properties were mostly found in surface soil (0-30 cm) and in sub-soil (30-60 cm) effect was
not significant. Increased in moisture storage in sub soil observed in gypsum applied plots over control. Result
revealed that 1.5 t gypsum ha-1 was found sufficient to maintain enough electrolyte concentration and maintaining
Ca/Mg ratio for improving H.C. and other physical properties resulted in better storage of moisture and increased in
yield of soybean and gram
Ag promoted La0.8Ba0.2MnO3 type perovskite catalyst for N2O decomposition in the presence of O2, NO and H2O
No full textLa0.8Ba0.2MnO3 and silver promoted La0.8Ba0.2MnO3 type perovskite catalysts have been studied for N2O
decomposition reaction. These catalysts were prepared by co-precipitation process followed by impregnation
method for Ag incorporation. These catalysts were characterized in detail by means of ICP-OES,
XRD, BET, SEM, STEM, EDX, XPS, O2-TPD and H2-TPR analysis. An appreciable increase in catalytic activity
was achieved by promoting the lanthanum manganate by Ba as well as Ag. The promotional effect
of Ag was observed maximum at 1 wt% optimized loading. The effect of O2, NO and H2O on the bare
and Ag promoted catalysts for N2O decomposition was also investigated. The catalytic activity for N2O
decomposition was significantly increased by Ba substitution as well as by Ag promotion. The activity
of these improved catalysts was also relatively less affected in presence of oxygen, water vapour and
NO, thereby showing promotional effect of silver on N2O decomposition. These catalysts were also prepared
in supported forms using ceramic honeycomb via in situ co-precipitation method, and then tested
for N2O decomposition reaction. Supported catalysts show equally good catalytic activity towards N2O
decomposition. XPS and O2-TPD studies suggest that Ag incorporation results in increase of Mn4+/Mn3+
ratio of La0.8Ba0.2MnO3 catalyst. TPR studies also provided the clear evidence to this effect. This improved
redox property of Ag promoted perovskite catalyst was correlated to its enhanced catalytic activity for
N2O decomposition
Region-Specific Bacterial Carbonic Anhydrase for Biomimetic Sequestration of Carbon Dioxide
No full textBiomimetic carbonic anhydrase (CA)-based CO2 sequestration for its conversion into carbonate is being pursued all
across the globe. For this purpose, partially purified enzyme CA has been isolated from three different microorganisms, including
Bacillus pumilus, Pseudomonas fragi, and Micrococcus lylae. Proof of concept has been established for the carbonation reaction. The
carbonate has been characterized using various tools, such as X-ray diffraction (XRD) and scanning electron microscopy (SEM),
which confirms the calcite phase of calcium carbonate. The formation of carbonate has been quantified using gas chromatography.
Partially purified CA isolated from P. fragi shows a significantly high CO2 sequestration capacity of 27.33 mg of CaCO3/mg of CA in
15 min compared to B. pumilus and M. lylae. The enzyme has been immobilized on surfactant-modified silylated chitosan. The
immobilized enzyme shows improved storage stability and retained 50% initial activity up to 30 days
A feasibility analysis of hydrogen delivery system using liquid organic hydrides
No full textThe paper discusses the techno-economic feasibility of a hydrogen storage and delivery
systemusing liquid organic hydrides (LOH).Wherein,LOH(particularly cycloalkanes) areused
for transporting the hydrogen inchemical bonded format ambienttemperatureandpressure.
The hydrogen is delivered through a catalytic dehydrogenation process. The aromatics
formed in the process are used for carrying more hydrogen by a subsequent hydrogenation
reaction. Cost economics were performed on a system which produces 10 kg/h of hydrogen
using methylcyclohexane as a carrier. With proprietary catalysts we have demonstrated the
possibility of hydrogen storage of 6.8 wt% and 60 kg/m3 of hydrogen on volume basis. The
energy balance calculation reveals the ratio of energy transported to energy consumed is
about 3.9. Moreover, total carbon footprint calculation for the process of hydrogen delivery
including transportation of LOH is also reported. The process can facilitate a saving of 345
tons/year of carbon dioxide emissions per delivery station by replacing gasoline with
hydrogen for passenger cars. There is animmense techno-economic potential for the process
Genetic polymorphism of CYP2D6*2 C? T 2850, GSTM1, NQO1 genes and their correlation with biomarkers in manganese miners of Central India
No full textManganese (Mn) intoxication is most often regarded as an occupational manifestation and occurs in
places such as manganese mines, dry cell battery plants and ceramic industries. In the present study,
the influence of genetic polymorphism in cytochrome P450 2D6 (CYP2D6*2), glutathione S-transferase
M1 (GSTM1) and NAD(P)H quinone oxidoreductase 1 (NQO1) genes on blood manganese and plasma prolactin
concentrations in manganese miners was investigated. Genotyping of CYP2D6*2 C ? T 2850 and
NQO1 C ? T 609 was carried out using polymerase chain reaction–restriction fragment length polymorphism
(PCR–RFLP) whereas the genotyping of GSTM1 was carried out by multiplex PCR using beta globin
as an internal control. Manganese miners with CYP2D6*2 C ? T 2850 variant genotype had relatively low
Mn concentration [GM: 21.4 ± 8.9 lg L1
] than the subjects with wild (GM: 36.3 ± 8.5 lg L1
) and heterozygous
(GM: 34.4 ± 6.9 lg L1
) genotypes. Miners with CYP2D6*2 variant genotypes showed low prolactin
levels (GM: 13.13 ± 1.6 ng mL1
) compared to the wild (GM: 16.4.4 ± 1.5 lg L1
) and heterozygous
(GM: 18.7 ± 1.6 ng mL1
) genotypes. Gene–gene interaction studies also revealed that the subjects with
CYP2D6*2 C ? T 2850 variant genotypes had low levels of Mn and prolactin. Our new findings suggest
that CYP2D6*2 C ? T 2850 variant genotypes can regulate plasma prolactin levels in manganese miners
of Central India and could be involved in the fast metabolism of blood manganese, compared to wild and
heterozygous genotypes.
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