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Ferns: heavy metal guzzlers can replace expensive methods of controlling pollution
Get PDFNow Indian ecotype of brake fern found in Kerala has been found to exhibit similar properties. A team of researchers from National Environmental Engineering Institute (NEERI) found that the fern could also help remove chromium from the soil and water. The study published in March 25 issue of Current Science says this particular ecotype of brake fern is found only in India. For most of the developing countries, including India, brake fern plantation could help in reducing the expenditure required on mitigating heavy metal pollution using modern technologies
Chemical Characterization of rainwater at Akkalkuwa, India
Get PDFThe chemical composition of rainwater changes from place to place and region to region under the influence of several major factors, viz., topography, its distance from sea and overall rainfall pattern. The present study investigated the chemical composition of precipitation at Akkalkuwa, district Nandurbar, in the State Maharashtra during southwest monsoon. The rainwater samples were collected on event basis during June-September 2008 and were analyzed for pH, major anions (F, Cl, NO3, SO4) and cations (Ca, Mg, Na, K, NH4). The pH varied from 6.0 and 6.8 with an average of 6.29 ± 0.23 indicating alkaline nature and dominance of Ca in precipitation. The relative magnitude of major ions in precipitation follows the pattern as Ca>Cl>Na>SO4>NO3>HCO3>NH4>Mg>K>F>H. The Neutralization factor (NF) was found to be NFCa = 0.95, NFNH4 = 0.31, NFMg = 0.27 and NFK = 0.08 indicating below cloud process in which crustal components are responsible for neutralization of anions. Significant correlation of NH4 with SO4 and NO3 was observed with correlation coefficient of r = 0.79 and 0.75, respectively
Low-cost catalysts for the control of indoor CO and PM emissions from solid fuel combustion
No full textCu–Mn based mixed oxide type low-cost catalysts have been prepared in supported form using mesoporous
Al2O3, TiO2 and ZrO2 supports. These supports have been prepared by templating method using
a natural biopolymer, chitosan. The synthesized catalysts have been characterized by XRD, BET-SA, SEM,
O2–TPD and TG investigations. The catalytic activity for CO as well as PM oxidation was studied, in a
view of their possible applications in the control of emissions from solid fuel combustion of rural cookstoves.
The trend observed for the catalytic activity of the synthesized catalysts for CO oxidation was
ZrO2 > TiO2 >Al2O3 while for PM oxidation it was observed to be TiO2 > ZrO2 >Al2O3. The effect of CO2,
SO2 and H2O on CO oxidation activity was also investigated, and despite partial deactivation, the catalysts
show good CO oxidation activity. An effective regeneration treatment was attempted by heating
the partially deactivated catalysts in presence of oxygen. Redox properties of TiO2 and ZrO2 and their
structure appeared to be responsible for their promotional activity for CO and PM oxidation reactions.
These unordered mesoporous materials could be useful for such reactions where mass transfer is more
important than shape and size selectivity
Transition metals supported on mesoporous ZrO2 for the catalytic control of indoor CO and PM emissions
No full textMesoporous ZrO2 support has been prepared by using a low cost natural biopolymer chitosan as template,
and different transition metals from the first row (Fe, Co, Ni, Cu and Mn) were impregnated on
the synthesized support. The synthesized catalysts have been characterized by XRD, BET-SA, SEM, TEM,
O2-TPD and TG analysis to study the material details as well as to understand the catalytic mechanism.
The activity of these catalysts has been investigated for CO and PM oxidation. Incorporation
of transition metals improved the activity for both CO and PM oxidation. It has been observed that
Co–ZrO2 is the most active catalyst for studied reactions while, Ni based catalysts show the lowest
activity for both the reactions. The transition metal supported catalysts follow the activity sequence
Co–ZrO2 > Mn–ZrO2 > Cu–ZrO2 > Fe–ZrO2 > Ni–ZrO2. The effect of CO2, SO2 and H2O on CO oxidation activity
was also investigated, and despite partial deactivation, the catalysts show good CO oxidation activity.
The characterization of the materials by O2-TPD studies explains the better catalytic performance for
the Co–ZrO2, Mn–ZrO2 and Cu–ZrO2 catalysts, as compared to Fe–ZrO2 and Ni–ZrO2. Such mesoporous
zirconia with reasonably good surface area and without ordered structure could be useful for both CO
and PM oxidation reactions
NON-SPECIFICITY OF PHAGE ENZYMES
No full textThe phage enzymes can lyse the host in which they resides, but it is not yet known whether they show any effect on the non-susceptible hosts on solid media (Consortia). It is
observed during our studies that the consortial lawn on the solid medium shows clear plaques irrespective of their specificity to the inoculated phages. The consortial studies indicate the combined application of phage enzymes for controlling pathogenic organisms. Our experiment thus proves the non-specificity of phage enzymes towards host cell components and states that the activity of phage enzymes is totally substrate (cell wall components) specific and is
independent of host type
Pulp and papermill wasterwater: can it solve the irrigation water scarcity problem
No full textChanges in physico-chemical properties of soils and crops grown with pulp and paper mill wastewater in field lysimeters were carried out for three years at the integrated pulp and paper mill, madhya pradesh (india). lysimeters were prepared by excavating pits of 5 m x 2 m x 2 m, lined with polyethylene sheet and filled with sandy loam, clay and loamy sand soils and provided with percolate collection system. treated wastewater was used for crop irrigation containing high salinity and specific ion toxicity. with respect to sodium adsorption ration (sar), it was categorized under group `no restriction on use’. sandy loam & loamy sand soils in lysimeter i and iii percolate was
17% and 20% of irrigation while clay soil in lysimeter ii it was only 15%. sandy loam & loamy sand soils respectively showed 97 & 96% removal of chemical oxygen demand (cod) while clay soil removed 99% of cod and the color removal in both cases was 100%. percolate initially showed leaching of calcium and magnesium and retention of sodium, which got adsorbed in soil matrix. Application of wastewater resulted in increase in water holding capacity, ph (0.6 - 1.3 units),
electrical conductivity of saturated extract (ece - 0.6 - 2.1 ms cm-1) and exchangeable sodium percent (esp - 8.1 - 11.6). organic carbon and available nitrogen, phosphorus and potash content of soils were also increasing. however, there was decrease in bulk density. the results showed that
the application of wastewater increased the grain and straw yield of jowar, wheat and moong as compared to plain water respectively. there was slight variation in micro and macro nutrient content of grains of crop irrigated with wastewater, but it did not affect the nutrient quality and there was no accumulation of toxic heavy metals in the food grain. we measured nutrient input by wastewater and output by leaching and harvest export on unfertilized crop. a semi quantitative nutrient balance showed that all lysimeters had negative balance of micronutrients, indicating open nutrient cycles on these soils. these results showed that the pulp and paper mill wastewater might be successfully utilized for crop productio
Segmental duplication as one of the driving forces underlying the diversity of the human immunoglobulin heavy chain variable gene region
Get PDFBackground: Segmental duplication and deletion were implicated for a region containing the human
immunoglobulin heavy chain variable (IGHV) gene segments, 1.9III/hv3005 (possible allelic variants of IGHV3-30) and
hv3019b9 (a possible allelic variant of IGHV3-33). However, very little is known about the ranges of the duplication
and the polymorphic region. This is mainly because of the difficulty associated with distinguishing between allelic
and paralogous sequences in the IGHV region containing extensive repetitive sequences. Inability to separate the
two parental haploid genomes in the subjects is another serious barrier. To address these issues, unique DNA
sequence tags evenly distributed within and flanking the duplicated region implicated by the previous studies were
selected. The selected tags in single sperm from six unrelated healthy donors were amplified by multiplex PCR
followed by microarray detection. In this way, individual haplotypes of different parental origins in the sperm donors
could be analyzed separately and precisely. The identified polymorphic region was further analyzed at the nucleotide
sequence level using sequences from the three human genomic sequence assemblies in the database.
Results: A large polymorphic region was identified using the selected sequence tags. Four of the 12 haplotypes were
shown to contain consecutively undetectable tags spanning in a variable range. Detailed analysis of sequences from
the genomic sequence assemblies revealed two large duplicate sequence blocks of 24,696 bp and 24,387 bp,
respectively, and an incomplete copy of 961 bp in this region. It contains up to 13 IGHV gene segments depending on
haplotypes. A polymorphic region was found to be located within the duplicated blocks. The variants of this
polymorphism unusually diverged at the nucleotide sequence level and in IGHV gene segment number, composition
and organization, indicating a limited selection pressure in general. However, the divergence level within the gene
segments is significantly different from that in the intergenic regions indicating that these regions may have been
subject to different selection pressures and that the IGHV gene segments in this region are functionally important.
Conclusions: Non-reciprocal genetic rearrangements associated with large duplicate sequence blocks could
substantially contribute to the IGHV region diversity. Since the resulting polymorphisms may affect the number,
composition and organization of the gene segments in this region, it may have significant impact on the function
of the IGHV gene segment repertoire, antibody diversity, and therefore, the immune system. Because one of the
gene segments, 3-30 (1.9III), is associated with autoimmune diseases, it could be of diagnostic significance to learn
about the variants in the haplotypes by using the multiplex haplotype analysis system used in the present study
with DNA sequence tags specific for the variants of all gene segments in this regio
Water conservation due to greywater treatment and reuse in urban setting with specific context to developing countries
No full textIn India, the per capita water availability is reducing day by day due to rapid growth in population and
increasing water demand. Greywater treatment and reuse is one of the feasible options in developing
countries like India to overcome this problem. A greywater collection, treatment and reuse system was
designed and implemented in an urban household having a water requirement of 165 liter per capita
per day (lpcd) and a greywater generation rate of 80 lpcd. An upflow–downflow greywater treatment
plant having a screening, sedimentation, filtration and disinfection as major treatment processes was
constructed and treated greywater is used for toilet flushing and to irrigate the vegetables in the backyard
of the household. Greywater characterisation indicates that COD and BOD are sufficiently reduced during
the treatment and there is also substantially reduction in Escherichia coli count. The payback period of
this greywater treatment and reuse system is estimated to be 1.6 year
Source identification and variation in the chemical composition of rainwater at coastal and industrial areas of India
No full textStudies on precipitation chemistry were carried out to understand the nature and
sources of rainwater at Rameswaram and NTPC Dadri, India representing coastal and
industrial region during 2010. The rainwater samples, collected at these locations, were
analyzed for major ions and pH. The data were assessed for its quality. The pH of rainwater
at two locations varied from 5.53 to 6.73 and 5.1–6.6, indicating alkaline nature except a few
acidic events. The dominance of Cl− and Na+ were observed in coastal environment
whereas dominance of Ca2+ was seen in industrial environment. The nss-SO42- (37.9%)
at Rameswaram is less influenced by anthropogenic activities whereas nss-SO42- (72.5%) at
NTPC Dadri is influenced by pollutants emitted by anthropogenic sources. The ratio of H+/
(NO3- + SO42-) was observed as 0.04 and 0.008 for Rameswaram and NTPC Dadri which
is close to zero, indicate 99.99% of acidity was neutralized in precipitation. Ca2+, NH4+ and
Mg2+ play an important role in neutralization of acidic ions in rainwater. For source
identification, correlation matrix analysis was established, which showed that in general,
at both sites; correlation between the acidic ions SO42- and NO3- indicating their origin
from similar sources, because of the similarity in their behavior in precipitation and the coemissions
of their precursors SO2 and NOX. The correlation coefficient of (SO42- + NO3-)
vs (Ca2+) at Rameswaram and NTPC Dadri were 0.77 and 0.87 indicates that CaCO3 is the
major neutralizing agent for both the region. Overall, the influence of marine, terrestrial and
anthropogenic sources was observed in the rain event
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