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Assessment of carbon monoxide exposure in roadside food-vending shanties using coal cookstoves in Kolkata, India
No full textRoadside food-vending shanties using coal cookstoves may be an important source of carbon monoxide
(CO) exposure in megacities in India. The shanties are often small, congested and poorly ventilated, and
very little is known about the level of human exposure to CO. Here, we assessed the level of exposure to
CO in 25 roadside food-vending shanties using coal cookstoves in Kolkata, India. Portable electrochemical
CO monitors were used to measure CO concentrations during peak and non-peak customer-periods in
closed (blocked from three sides) and semi-closed (blocked from two sides) shanties. Measurements
were taken where customers sit indoor about 5e7 ft away from the cookstoves. The shanties' ventilation
rates were measured using tracer gas concentration-decay technique. Levels of blood carboxyhaemoglobin
(COHb) and exhaled CO were estimated using regression models. The 1-hr time weighted
average (TWA) indoor CO exposure levels ranged from 7.8 to 18.1 ppm during peak-periods, and 0.7
e3.1 ppm during non-peak-periods. The exposure levels during peak-periods exceeded the USEPA's
reference limit of 9 ppm in all cases in the closed shanties, and in 71% of cases in the semi-closed
shanties. The ventilation rates ranged from 5.5 to 23.4 and 14.8 to 32.5 cubic feet per minute (cfm)
per person for the closed and semi-closed shanties, respectively, indicating poor ventilation in some
shanties. There was significant variation (p ¼ 0.01) in the level of indoor CO exposure between peak and
non-peak periods, and between shanty types. The estimated levels of blood COHb during peak and nonpeak
hours were 0.78 ± 0.7% and 0.35 ± 0.07%, respectively, that were within the normal physiological
values in non-smokers
ASSESSMENT OF SOLID WASTE GENERATION AND ITS MANAGEMENT IN SELECTED SCHOOL CAMPUSES IN PUDUCHERRY REGION, INDIA
Full text linkAmong all the significant contributors of municipal solid waste, schools have been chosen for the study since the solid waste
generation rate and its corresponding composition has not been reported or has been underestimated in the schools of Puducherry
region. Hence, the present paper is an attempt to fill up this gap in our knowledge. The existing waste management system in
selected schools was disorganized and inadequate to meet the specific waste management objectives as specified in Municipal
Solid Waste (Management & Handling) Rules 2000, India. The study found that in the school, average per capita waste
generation rate was 0.092 (±0.025) kg/capita/day varying from a high of 0.117 (±0.021) kg/capita/day in higher secondary
schools to a low of 0.059 (±0.020) kg/capita/day in primary schools. The mean composition of school waste is made up of 39%
food waste; 33% paper; 11% silt, soil and mud (combined); 8% plastic; 2% wood, glass, metal and textile (combine); 2% clinical
and sanitary wastes; 1% E-waste; 4% other wastes. Approximately, 70 - 80% of generated solid waste is openly dumped or burnt
in the campus, 10 - 15% is collected by municipal authorities and the remaining 6 - 8% is recovered through informal recycling
and composting facilities. Based on the findings, recommendations to develop efficient waste prevention and management
practices were suggested. Establishing “waste avoidance, handling and recovery” policies and programs for food, paper, plastic
and soil wastes could significantly influence the success of sustainable solid waste management system at the school level
CO2 reforming of CH4: Effect of Gd as promoter for Ni supported over MCM-41 as catalyst
No full textBiogas, an emerging renewable replacement to natural gas (fossil fuel), is 60-70% methane and 30-40% CO2 by volume and can be produced from organic matter by anaerobic bacteria. Dry reforming of methane (DRM) technology has gained growing interest as this reaction converts natural gas/biogas into syngas that can be used for the generation of clean fuel, alcohols and variety of other chemicals. In this study, a Ni based catalyst supported over mesoporous silica (MCM-41) and promoted by gadolinium (Gd) metal was synthesized and tested for its activity for DRM reaction. The catalytic performance of the catalyst was found to be greatly enhanced with about 0.1 wt% Gd loading. Thus, Gd can act as promoter for Ni based catalyst in DRM reaction. This catalyst converts CH4 and CO2 with high conversions, i.e. >87% and >91% respectively, into syngas having H-2/CO ratio nearly equal to 1 showing potential for catalyzing this reaction. (C) 2019 Elsevier Ltd. All rights reserved
Role of fluoride induced epigenetic alterations in the development of skeletal fluorosis
No full textFluoride is an essential trace element required for proper bone and tooth development. Systemic high exposure
to fluoride through environmental exposure (drinking water and food) may result in toxicity causing a disorder
called fluorosis. In the present study, we investigated the alteration in DNA methylation profile with chronic
exposure (30 days) to fluoride (8 mg/l) and its relevance in the development of fluorosis. Whole genome bisulfite
sequencing (WGBS) was carried out in human osteosarcoma cells (HOS) exposed to fluoride. Whole genome
bisulfite sequencing (WGBS) and functional annotation of differentially methylated genes indicate alterations in
methylation status of genes involved in biological processes associated with bone development pathways.
Combined analysis of promoter DNA hyper methylation, STRING: functional protein association networks and
gene expression analysis revealed epigenetic alterations in BMP1, METAP2, MMP11 and BACH1 genes, which
plays a role in the extracellular matrix disassembly, collagen catabolic/organization process, skeletal morphogenesis/
development, ossification and osteoblast development. The present study shows that fluoride causes
promoter DNA hypermethylation in BMP1, METAP2, MMP11 and BACH1 genes with subsequent down-regulation
in their expression level (RNA level). The results implies that fluoride induced DNA hypermethylation of
these genes may hamper extracellular matrix deposition, cartilage formation, angiogenesis, vascular system
development and porosity of bone, thus promote skeletal fluorosis
Nitrogen-dependent induction of atrazine degradation pathway in Pseudomonas sp. strain AKN5
No full textSoil isolate Pseudomonas sp. strain AKN5 degrades atrazine as the sole source of nitrogen. The strain showed expeditious growth on medium containing citrate as the carbon source and ammonium chloride as the nitrogen source as compared to citrate plus atrazine or cyanuric acid. Biochemical and nitrogen-source dependent enzyme induction studies revealed that atrazine is metabolized through hydrolytic pathway and has two segments: the upper segment converts atrazine to cyanuric acid while the lower segment metabolizes cyanuric acid to CO2 and ammonia. Bioinformatics and co-transcriptional analyses suggest that atzA, atzB and atzC were transcribed as three independent transcripts while atzDEF were found to be transcribed as a single polycistronic mRNA indicating operonic arrangement. Transcriptional analysis showed inducible expression of atzA/B/C/DEF from atrazine grown cells while cyanuric acid grown cells showed significantly higher expression of atzDEF. Interestingly, growth profiles and enzyme activity measurements suggests that strain utilizes a simple nitrogen source (ammonium chloride) over the complex (atrazine or cyanuric acid) when grown on dual nitrogen source. These results suggest that atrazine degradation genes were up-regulated in the presence oAf atrazine but repressed in the presence of simple nitrogen source like ammonium chloride
Genome Sequencing and Analysis of Strains Bacillus sp. AKBS9 and Acinetobacter sp. AKBS16 for Biosurfactant Production and Bioremediation
No full textMicrobial genomics facilitates the analysis of microbial attributes, which can be
applied in bioremediation of pollutants and oil recovery process. The biosurfactants derived from
microbes can replace the chemical surfactants, which are ecologically detrimental. The aim of this
work was to study the genetic organization responsible for biodegradation of aromatics and
biosurfactant production in potential microbes isolated from polluted soil. Bacterial isolates were
tested for biosurfactant production, wherein Bacillus sp. AKBS9 and Acinetobacter sp. AKBS16
exhibited highest biosurfactant production potential. Whole genome sequencing and annotations
revealed the occurrence of sfp and NPRS gene in the Bacillibactin biosynthetic gene cluster in
AKBS9 strain and emulsan biosynthetic gene cluster in AKBS16 strain for biosurfactant
production. Various aromatic compound ring cleaving oxygenases scavenging organic molecules
could be annotated for strain AKBS16 using RAST annotations
Pharmaceuticals and personal care products in aquatic environment:chemicals of emerging concern?
No full textOutdoor microalgae cultivation in airlift photobioreactor at high irradiance and temperature conditions: effect of batch and fed-batch strategies, photoinhibition, and temperature stress
No full textThe microalgae Scenedesmus abundans cultivated in five identical airlift photobioreactors (PBRs) in batch and fed-batch
modes at the outdoor tropical condition. The microalgae strain S. abundans was found to tolerate high temperature (35–45 °C)
and high light intensity (770–1690 μmol m− 2 s− 1). The highest biomass productivities were 152.5–162.5 mg L− 1 day− 1 for
fed-batch strategy. The biomass productivity was drastically reduced due to photoinhibition effect at a culture temperature
of > 45 °C. The lipid compositions showed fatty acids mainly in the form of saturated and monounsaturated fatty acids
(> 80%) in all PBRs with Cetane number more than 51. The fed-batch strategies efficiently produced higher biomass and
lipid productivities at harsh outdoor conditions. Furthermore, the microalgae also accumulated omega-3 fatty acid (C18:3)
up to 14% (w/w) of total fatty acid at given outdoor condition
Amino acid‑imprinted polymers as highly selective CO2 capture materials
No full textThe recent atmospheric concentration of CO2
increase to 400 ppm is a cause of global climate change. There is therefore
an urgent need for selective and cost-effective CO2
capture technologies. Fossil fuel consumption during energy production
and transportation are two major sources of CO2
emission into the atmosphere. The capture of CO2
selectively from gaseous
mixtures using reusable adsorbent is thus a challenge. In this article, we report that nanoparticles functionalized with
imprinting of amino acids exhibit a significant increase in the selective adsorption capacities of CO2
in a gaseous mixture.
Molecular imprinting of taurine in the vinylbenzyl chloride-co-divinyl benzene polymer formed cavities of 1–3 nm size
and introduced –SOOH and –N–H functionalities, resulting in a very high CO2
adsorption capacity of 5.67 mmol g−1 at
30 °C/1 bar. The selectivity of CO2
over N2
and CH4
was 87–91% and 83–87%, respectively. The isosteric heat of adsorption
(Qst) for CO2
at 298 and 303 K showed an increase in Qst from 36.8 to 47.6 K kJ mol−1, and this would be responsible
for high CO2
adsorption energies and faster kinetics. This study reports first-time imprinting of CO2-
philic templates in the
polymers to capture small gas molecules at ambient conditions, and the results demonstrated that the polymers have a wide
scope for real-life applications of CO2
capture
An overview of environmental sustainability in cement and steel production
No full textEco-friendly industrial production is essential to save our environment. The present article reviews the
sustainability aspects for steel and cement industries, as both are highly demanding. Carbon dioxide
emissions from the steel industry can be reduced effectively by carbon sequestration methods. The
generation of by-products from steel can be used as raw materials in manufacturing of paints, cement
fertilizers etc. The major challenge in cement production is higher input of raw material and fuel in
clinker production. These problems can be rectified by adopting suitable co-processing method. Energy
requirement can be reduced by using blended cement with highly efficient clinker cooler, dryer, separators, calciner, pre-calciner and waste heat recovery system