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471.
Moti L. Mittal Chhemendra Sharma Richa Singh 《Environmental monitoring and assessment》2014,186(10):6857-6866
This study aims to estimate the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) for coal combustion in thermal power plants in India using plant-specific emission factors during the period of 2001/02 to 2009/10. The mass emission factors have been theoretically calculated using the basic principles of combustion under representative prevailing operating conditions in the plants and fuel composition. The results show that from 2001/02 to 2009/10 period, total CO2 emissions have increased from 324 to 499 Mt/year; SO2 emissions have increased from 2,519 to 3,840 kt/year; and NO emissions have increased from 948 to 1,539 kt/year from the Indian coal-fired power plants. National average emissions per unit of electricity from the power plants do not show a noticeable improvement during this period. Emission efficiencies for new plants that use improved technology are found to be better than those of old plants. As per these estimates, the national average of CO2 emissions per unit of electricity varies between 0.91 and 0.95 kg/kWh while SO2 and NO emissions vary in the range of 6.9 to 7.3 and 2.8 to 2.9 g/kWh, respectively. Yamunagar plant in Haryana state showed the highest emission efficiencies with CO2 emissions as 0.58 kg/kWh, SO2 emissions as 3.87 g/kWh, and NO emissions as 1.78 g/kWh, while the Faridabad plant has the lowest emission efficiencies with CO2 emissions as 1.5 kg/kWh, SO2 emissions as 10.56 g/kWh, and NO emissions as 4.85 g/kWh. Emission values at other plants vary between the values of these two plants. 相似文献
472.
Purpose
Biodesulfurization (BDS) has the potential to desulfurize dibenzothiophene (DBT) and its alkylated derivatives, the compounds that are otherwise refractory to hydrodesulfurization (HDS). Thermophilic microorganisms are more appropriate to be used for BDS applications following HDS. The aim of the present study was to isolate a thermophilic microorganism and to explore its commercial relevance for BDS process.Methods
The desulfurizing thermophilic strain was isolated and enriched from various soil and water samples using sulfur free medium (SFM) supplemented with DBT. Microbiological and genomic approach was used to characterize the strain. Desulfurization reactions were carried out using DBT and petroleum oils at 45°C followed by different analytical procedures.Results
We report the isolation of a thermophilic bacterium Klebsiella sp. 13T from contaminated soils collected from petroleum refinery. HPLC analysis revealed that Klebsiella sp. 13T could desulfurize DBT to 2-hydroxybiphenyl (2-HBP) at 45°C through 4S pathway. In addition, adapted cells of Klebsiella sp. 13T were found to remove 22?C53% of sulfur from different petroleum oils with highest sulfur removal from light crude oil.Conclusion
Klebsiella sp. 13T is a potential candidate for BDS because of its thermophilic nature and capability to desulfurize petroleum oils. 相似文献473.
K. Michael A. Golab V. Shulakova J. Ennis-King G. Allinson S. Sharma T. Aiken 《International Journal of Greenhouse Gas Control》2010,4(4):659-667
The experience from CO2 injection at pilot projects (Frio, Ketzin, Nagaoka, US Regional Partnerships) and existing commercial operations (Sleipner, Snøhvit, In Salah, acid-gas injection) demonstrates that CO2 geological storage in saline aquifers is technologically feasible. Monitoring and verification technologies have been tested and demonstrated to detect and track the CO2 plume in different subsurface geological environments. By the end of 2008, approximately 20 Mt of CO2 had been successfully injected into saline aquifers by existing operations. Currently, the highest injection rate and total storage volume for a single storage operation are approximately 1 Mt CO2/year and 25 Mt, respectively. If carbon capture and storage (CCS) is to be an effective option for decreasing greenhouse gas emissions, commercial-scale storage operations will require orders of magnitude larger storage capacity than accessed by the existing sites. As a result, new demonstration projects will need to develop and test injection strategies that consider multiple injection wells and the optimisation of the usage of storage space. To accelerate large-scale CCS deployment, demonstration projects should be selected that can be readily employed for commercial use; i.e. projects that fully integrate the capture, transport and storage processes at an industrial emissions source. 相似文献
474.
Application of CCME Water Quality Index to Monitor Water Quality: A Case Study of the Mackenzie River Basin, Canada 总被引:2,自引:0,他引:2
All six ecosystem initiatives evolved from many years of federal, provincial, First Nation, local government and community attention to the stresses on sensitive habitats and species, air and water quality, and the consequent threats to community livability. This paper assesses water quality aspect for the ecosystem initiatives and employs newly developed Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) which provides a convenient mean of summarizing complex water quality data that can be easily understood by the public, water distributors, planners, managers and policy makers. The CCME WQI incorporates three elements: Scope – the number of water quality parameters (variables) not meeting water quality objectives (F
1); Frequency – the number of times the objectives are not met (F
2); and Amplitude. the extent to which the objectives are not met (F
3). The index produces a number between 0 (worst) to 100 (best) to reflect the water quality. This study evaluates water quality of the Mackenzie – Great Bear sub-basin by employing two modes of objective functions (threshold values): one based on the CCME water quality guidelines and the other based on site-specific values that were determined by the statistical analysis of the historical data base. Results suggest that the water quality of the Mackenzie-Great Bear sub-basin is impacted by high turbidity and total (mostly particulate) trace metals due to high suspended sediment loads during the open water season. Comments are also provided on water quality and human health issues in the Mackenzie basin based on the findings and the usefulness of CCME water quality guidelines and site specific values. 相似文献
475.
A new trematode, collected in 1971 from Ratnagiri, India, is described as Follicovitellosum indicum sp. nov. A new subfamily, Follicovitellotrematinae is created within the family Zoogonidae Odhner, 1911, to receive the new genus Follicovitellosum, with its genotype F. indicum. The new species is characterized by the follicularized nature of its ovary; the ovarian follicles are posttesticular. The vitellarium is further divided into several follicles which are largely in the pre-ovarian zone, but post-acetabular and posttesticular in location. 相似文献
476.
Asbjørn Aaheim Ranjith Gopalakrishnan Rajiv Kumar Chaturvedi N. H. Ravindranath Anitha D. Sagadevan Nitasha Sharma Taoyuan Wei 《Mitigation and Adaptation Strategies for Global Change》2011,16(2):229-245
We examine the potential for adaptation to climate change in Indian forests, and derive the macroeconomic implications of
forest impacts and adaptation in India. The study is conducted by integrating results from the dynamic global vegetation model
IBIS and the computable general equilibrium model GRACE-IN, which estimates macroeconomic implications for six zones of India.
By comparing a reference scenario without climate change with a climate impact scenario based on the IPCC A2-scenario, we
find major variations in the pattern of change across zones. Biomass stock increases in all zones but the Central zone. The
increase in biomass growth is smaller, and declines in one more zone, South zone, despite higher stock. In the four zones
with increases in biomass growth, harvest increases by only approximately 1/3 of the change in biomass growth. This is due
to two market effects of increased biomass growth. One is that an increase in biomass growth encourages more harvest given
other things being equal. The other is that more harvest leads to higher supply of timber, which lowers market prices. As
a result, also the rent on forested land decreases. The lower prices and rent discourage more harvest even though they may
induce higher demand, which increases the pressure on harvest. In a less perfect world than the model describes these two
effects may contribute to an increase in the risk of deforestation because of higher biomass growth. Furthermore, higher harvest
demands more labor and capital input in the forestry sector. Given total supply of labor and capital, this increases the cost
of production in all the other sectors, although very little indeed. Forestry dependent communities with declining biomass
growth may, however, experience local unemployment as a result. 相似文献
477.
This work deals with the use of polysaccharide-based beads for controlled release of the herbicide atrazine. This article discusses the release of the herbicide atrazine from neem-alginate-clay-based beads. Formulation characteristics such as entrapment efficiency, bead size, and diffusion mechanism for release of atrazine have been evaluated. 相似文献
478.
Biodiversity conservation and management of natural resources are the best options to restore and increase productivity of
degrading pastureland in dry areas. Hence, arthropod abundance, organic matter, respiration, and dehydrogenase activity were
measured in canopy zone soil of Prosopis cineraria (PC), Acacia nilotica (AN), Zizyphus nummularia (ZN), Capparis decidua (CD), and Acacia senegal (AS) associated with grasses with a view to establish interrelation for productivity enhancement of pastureland. Pure grass
bock outside tree canopy was control plot. Acari, Myriapoda, Coleoptera, Isoptera, Collembola, and other soil arthropods were
the major soil faunal groups. Integration of tree in pastureland enhanced population of soil arthropod by 9–65-fold in May
2001 and 8–13-fold in August/September as compared with control. The trends of changes in soil organic matter (SOM), soil
respiration (SR), and dehydrogenase activity (DHA) were similar to the changes in soil arthropod population, indicating the
role of soil fauna in facilitating biochemical processes and soil fertility. Two, eight, and nine times greater SOM, SR, and
DHA, respectively, in silvipastoral system than the values in control suggest the beneficial effects of trees on improvement
in biochemical processes and thus biodiversity in pastureland, as supported by negative values of relative tree effects (RTE).
Microbial activities were highest in the ZN system, which had highest abundance of soil arthropods. In the other systems,
CD and AS systems showed greater soil arthropod abundance and biological activities than with the PC and AN systems. Therefore,
Z. nummularia-, C. decidua-, and A. senegal-based silvipastoral systems and related soil fauna may be promoted for enhancement of biological activity and productivity
of pastureland in desert. The strategy may be adopted for developing a sustainable pedoecosystem in a region of the world
where agriculture is notoriously difficult. 相似文献
479.
The present investigation covers immobilization of TiO2 using a simple solid state dispersion technique over mesoporous Al-MCM-41 support for the treatment of isoproturon herbicide. Catalysts are characterized by XRD, X-ray photo electron spectroscopy (XPS), surface area, UV-Vis diffused reflectance spectra (DRS), SEM and TEM. A detailed photocatalytic degradation study of isoproturon under solar light in aqueous suspensions is reported. The 10 wt% TiO2/Al-MCM-41 composite system found to be optimum with high degradation activity. The reaction follows pseudo-first order kinetics. The parameters like TiO2 loading over Al-MCM-41, amount of catalyst, concentration of substrate, pH effect, durability of the catalyst, activity comparison of TiO2 and Al-MCM-41 supported system are studied. The mineralization of isoproturon is monitored by TOC. Based on the degradation products detected through LC-MS, a plausible degradation mechanism is proposed. The data indicates that TiO2/Al-MCM-41 composite system is an effective photocatalyst for treatment of isoproturon in contaminated water. 相似文献
480.
Jai Gopal Sharma 《毒物与环境化学》2013,95(2):367-371
Scanning electron microscopic (SEM) study of gills of Catla catla catla (17-day-old) exposed to UV-B radiation (145?µW?cm?2 at the water surface) for three different exposure times: 5, 10 and 15?min was conducted. Fish without UV-B exposure served as control. UV-B radiation damaged both gill filaments and lamellae. The intensity of damage was minimal in 5?min exposed fish, followed by 10?min exposed fish and maximal in 15?min. The gill epithelium was severely damaged in 15?min irradiated fish compared to control. Pavement cells (PVCs) were damaged and the numbers of microridges within PVCs decreased. The deep boundary of PVC was not clear. In some area of gill epithelium, PVCs were destroyed and mitochondrion-rich cells (MRCs) were exposed. The 5?min exposure reduced the number of microridges in the PVCs, but the boundary of PVCs was still visible. MRCs in the gill epithelium were not exposed in 5?min exposed fish. The damage to PVCs and subsequent exposure of MRCs in UV-B irradiated fish may hamper respiratory functions and disturb osmoregulation in catla. 相似文献