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Diurnal-, Seasonal- and Site-Dependent Variability in Ground-level Total Non-Methane Hydrocarbon in Nagpur City of Central India
Full text linkTemporal & spatial variations in ground-level total non-methane hydrocarbon
(TNMHC) were studied in Nagpur urban agglomeration (UA) for a year over three seasons
viz. post-monsoon (September-October), winter (January-February) and summer
(May-June) in 2013-14. Ground-level TNMHC showed low to moderate spatial (over residential,
commercial, traffic intersections, residential cum commercial sites) and temporal
(at 7:00, 13:00; 18:00 and 23:00 h in all three seasons) variations. There was no specific
increasing or decreasing trend with time, either within a day or a season. Daily mean concentration
of TNMHC (averaged over concentrations at 7:00, 13:00; 18:00 and 23:00 h)
ranged from 0.88-1.73 ppmV, 1.75-4.04 ppmV and 1.20-1.53 ppmV at residential sites;
2.99-6.47 ppmV, 1.52-7.38 ppmV and 0.98-1.63 ppmV at traffic site; 0.83-1.15 ppmV, 2.03-
3.24 ppmV, 1.1-1.70 ppmV at residential cum commercial sites and 1.05-4.79 ppmV, 6.2-
8.58 ppmV, 0.34-0.64 ppmV at the purely commercial site, during post-monsoon, winter
and summer, respectively. Occasional spikes (TNMHC>10 to <13.6 ppmV) were observed
on three occasions over two sites in winter but reasons thereof remained unidentified. During\ud
Diwali Festival (in post-monsoon) marked by large-scale firecrackers bursting, observed
TNMHC concentrations hovered around 3-5 ppmV, which almost matched with 90th percentile
of other post-monsoon concentrations. Highest mean seasonal TNMHC concentration
was observed during winter, followed by means of post monsoon and summer seasons
while mean ground-level TNMHC concentrations on weekdays were slightly higher
(1.17-1.21 times) than weekends over all seasons
Importance of Graphene in the Electro-Fenton Process
No full textGraphene-based nanomaterials have attracted researchers
from various fields due to their extraordinary physical, chemical, and
electrochemical properties. An emerging class of graphene-based nanostructures and nanocomposites is considered to be a promising solution to
various types of environmental pollution. The electro-Fenton process is one
of the easy and effective approaches to treating a wide range of organic
pollutants in a liquid medium. The usage of graphene-based electrodes in
the electro-Fenton process is considered to be a promising and cleaner way
to produce reactive oxygen species to mineralize organic contaminants
rapidly. Graphene derivatives are used to immobilize various heterogeneous
Fenton catalysts for improved catalytic activity, stability, and reusability. In
this review, the importance of graphene-based materials in improving the
performance efficiency in the electro-Fenton process is presented along with
an enhancement mechanism through the following discussions: (i) the significance of oxygen functional groups and nitrogen doping
on graphene layers to enhance the two-electron oxygen reduction reactions; (ii) the advantages of iron-loaded graphene-based
materials as catalysts and composite electrodes for the enhanced production of reactive oxygen species; (iii) a summary of various
forms of graphene-based materials, modifications in their chemical structure, properties, and applications in the electro-Fenton
process to remove organic contaminants
Treatment of dairy industry wastewater by combined aerated electrocoagulation and phytoremediation process
No full textAs dairy industries has been emerged as one of the most rapidly developing industry in both small as
well as large scale, the volume of effluent generated is also very high. In the present study, aerated
electrocoagulation combined with phytoremediation treatment was conducted in dairy industry
wastewater. Electrocoagulation was performed with aluminium and iron electrodes and effect of various
operating parameters such as electrode combination, pH, and voltage were tested. Electrocoagulation
was found effective at neutral pH and its efficiency increased with increase in applied voltage. The
maximum COD removal efficiency of 86.4% was obtained in case of AleFe electrode combination with
aeration at 120 min reaction time, initial pH 7, voltage 5 V. Significant growth of Canna indica was
observed in electrocoagulation treated wastewater compared to raw dairy wastewater. COD removal of
97% was achieved when combined electrocoagulation and phytoremediation process was used. Thus, it
proves to be a proficient method for the treatment of dairy industry wastewater. In addition to the above,
bacterial toxicity tests were performed to investigate the toxic nature of wastewater and the results
showed that both treated and untreated wastewater favoured bacterial growth
Evaluation of Hydrochemical Facies and Suitability of Water in Tilaiya Dam Reservoir of the Jharkhand State in India
No full textThe reservoir at Tilaiya Dam in the Jharkhand state of India is one of the most important
freshwater sources in the region. The water of the reservoir is primarily used for domestic, drinking, and
irrigation. Water quality of the reservoir was monitored at five locations during pre-monsoon, monsoon, and
post-monsoon seasons in 2017-2018 to understand spatiotemporal variation and also, the suitability of water
for existing uses. A hydro-geochemical analysis of reservoir water was undertaken with the help of Piper
Diagram, Schoeller-Berkaloff diagram, Stiff diagram, U.S Salinity Laboratory diagram, Water Quality Index,
Salinity Index, Sodium Percentage, Sodium Absorption Ratio, Magnesium Hazard, etc. The hydrochemical
facies in the present study showed that water was of Ca-HCO3 water type. Factor analysis revealed two
predominating factors, both geogenic in nature, that influenced reservoir water quality, accounting for 81.992 %
of the variance in data. Slight variation in water quality was observed with time and space but it was nonsignificant
statistically. Water Quality Index had increasing trends at three sites from monsoon to pre-monsoon
through post-monsoon and winter seasons. The study revealed that the water of the reservoir is good and
suitable for drinking, domestic use, irrigation, and industry in all the seasons during 2017-18
Eco-rejuvenation of degraded land by microbe assisted bamboo plantation
No full textEco-restoration is a technique for rejuvenation of degraded ecosystem to their near original state. It also helps to control soil erosion, develop microbial ecology, enhance biomass production and socio-economic development. The present study was focused on a new approach called Eco-Rejuvenation Technology (ERT) for reclamation and ecological/biodiversity restoration of degraded land. To demonstrate this technology, plantation of seedlings of 5 different bamboo species (Bambusa balcooa Roxb., Bambusa vulgaris var. vittata (Schrad. ex Wendl) (Green), Bambusa vulgaris var. striata (Yellow), Bambusa nutans Wall. ex Munro and Dendrocalamus asper
(Schult.f.) Backer ex Heyne) was carried out in a village community degraded land located in Central India where
organic amendments, such as press mud, farmyard manure and bio-fertilizers were apllied. This study showed
how ERT benefited the growth of bamboo (viz., increased height, diameter, number of culms) and further explained
how it could help in increasing soil biomass and carbon sequestration capacity over a period of one year. The results reflected that the success of a rural wasteland restoration program depends on community participation and socio-economic factors as well as ecological improvement. In this study, the soil organic carbon (SOC) was restored to nearly 1% within a year. It clearly suggested that ERT is a potential tool for sustainable rural development through native biodiversity development on degraded land
An Integrated Process of Value Addition to Citrus Waste and Performance of Fenton Process for Its Conversion to Biogas
No full textCitrus fruits are commercially important fruit crop all over the world. About 50–60% of citrus fruit is considered waste including peels and its handling is costly at municipal and industry levels. Citrus wastes in general show a low pH (3–4), relatively high water content and organic matter. Its composting is not recommended, as it has inherent low pH and presence
of high concentration of limonene in essential oils that slow down its biological decomposition due to inhibitory activity. Anaerobic digestion for biogas production seems to be a technically sustainable way to valorise by suitable pre-treatment methods. Present study shows extraction of essential oil in minimum requirement of water (1:1 w/v) for hydro-distillation that yields about 2% essential oil from fresh peels. Further, pre-treatment of left over de-oiled biomass with of 30% Fenton’s
reagent treatment show biogas and methane production up to 322.63 ml biogas/g VS feed and 122.48 ml methane/g VS feed, respectively under mesophilic condition which is superior to conventional treatment
Biomimetic lipophilic activated carbon for enhanced removal of triclosan from water
No full textTriclosan, an antimicrobial micro-pollutant with a high bio-accumulation potential represented by its
high octanol-water partition coefficient (log Kow) of 4.76 is commonly encountered in water and wastewater
worldwide. The present study focuses on biomimetic surface modification of commercial activated
carbon (PAC) with long chain fatty acid namely docosahexaenoic acid (DHA) resulting in enhanced affinity
for the hydrophobic micro-pollutant; triclosan (TCS). The sorption process of the resulting modified
lipophilic carbon (PACM) was investigated for the effect of various experimental conditions. The
Freundlich isotherm and pseudo-second-order kinetic models had a better fit. PACM exhibited the maximum
adsorption capacity of 395.2 mg g�1 in contrast to 71.5 mg g�1 obtained for PAC. The surface morphology
in terms of surface area, surface acidity, pore size, contact angle, etc. and were also evaluated.
The contact angle of 134.3� obtained for PACM confirmed its highly hydrophobic nature. The efficacy of
PACM was also evaluated using real-world secondary treated effluent containing triclosan confirming
its applicability for tertiary treatment of wastewater. The study established that the biomimetic approach
of creating lipid-like sites on the carbon surface results in the enhanced removal of lipophilic micropollutants.
It can also be utilized for the removal and recovery of a wide variety of other organic
micro-pollutants
Catalytic oxidation and selective sensing of carbon monoxide for sense and shoot device using ZnO–CuO hybrids
No full textIn the present work, we have demonstrated that ZnO–CuO based hetero-composites exhibit selective CO sensing
with T 100 is in close proximity to T opt to yield simultaneous CO sensing together with its 100% catalytic oxidation
for sense and shoot devices. When these heterocomposites are exposed to CO, reduction of Cu 2 + ions in CuO grains
leads to a strong metal semiconductor interaction (SMSI) between Cu 2 + /Cu + /Cu 0 species (in CuO grains) and
ZnO grains across the ZnO-CuO interface. The SMSI interaction promotes the generation of oxygen vacancies in
neighboring ZnO lattice. Eventually activated oxygen (O ∗ ads ) and CO (CO ∗ ads ) are preferentially chemisorbed on
zinc oxide (in its vacant oxygen sites) and CuO (on the surface of Cu 2 + /Cu + /Cu 0 ions) respectively. The activated
oxygen reacts immediately with adsorbed CO to yield selective CO sensing together with 100% CO oxidation.
For ZnO–CuO (1:1) composites, the measured T opt ( ∼175 °C) and T 100 ( ∼200 °C) temperatures are significantly
lowered as compared to the respective temperatures measured for indium doped ZnO (T opt ∼300 °C, T 100 ∼550 °C)
and CuO (T opt ∼200 °C,T 100 ∼300 °C) catalysts. Fine tuning of the mole fraction of ZnO and CuO are necessary for
these hetero-composites to yield T 100 of catalytic activity close to T opt for maximum CO sensing
Measurements on Stationary Source Emissions and Assessing Impact on Ambient Air Quality around Two Indian Refineries
Full text linkEmissions of particulate matter (PM), SO2 and NO2 from stationary sources
and their concentration along with benzene and CO in ambient air around two Indian
refineries were studied. Prediction of ground level concentration (GLC) of SO2, NO2 and
PM was made by dispersion modeling. In Refinery 1, highest SO2 emission (646 mg Nm-3)
were detected in Sulphur Recovery Unit while NOx emissions ranged from 57.8 to 445.0
mg Nm-3, respectively from various units. In Refinery 2, highest SO2 emission (935 mg
Nm-3) was observed from Utility Boiler while NO2 emissions ranged from 13 to 235 mg
Nm-3. Above emissions were within the stipulated emission standards prescribed by Central
Pollution Control Board of India. Further, ambient concentrations of the above in the
vicinity of these refineries were below their prescribed national ambient air quality standards.
Air quality in terms of air quality index (AQI) was moderate or good at the study
sites. Dispersion modelling exercise indicated that the observed GLC of SO2 and NO2 could
be reasonably predicted by ISC-AERMOD model for both refineries while there was moderate
to substantial difference between observed and modeled PM values due to presence
of several sources of particulate emissions in the region that could not be considered
in the model
Review of processes controlling arsenic retention and release in soils and sediments of Bengal basin and suitable iron based technologies for its removal
No full textArsenic in the soil environment has gained renewed interest because of the emerging cognizance that arsenic
poisoning is a global concern. Groundwater in the Bengal Basin is significantly polluted by naturally occurring
arsenic (As), a toxic metalloid, which adversely affects human health and among the countries facing As contamination
problems, India and Bangladesh are the most affected. In soils and sediments, arsenic is often associated
with Fe(III) (hydr)oxides and multiple processes/reactions govern its release into groundwater, including
abiotic or biotically mediated oxidation-reduction and ligand exchange reactions. Reductive dissolution
of arsenic-bearing Fe(III) (hydr)oxides and As(V) reduction to As(III) are the two main mechanisms controlling
arsenic partitioning in soils, sediments and groundwater. Even though arsenic reduction is favourable over a
wide range of conditions, Fe(III) reduction in nature is dependent on the biotic systems. This review reflects the
current state of research for the understanding of arsenic in the soil environment with an emphasis on iron based
technologies for its removal. It attempts to collate all the relevant literature such that it can be a useful resource
for researchers or policy makers to help recognize and explore useful treatment options