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Solid Reductant Based Selective Catalytic Reduction System for Exhaust Emission Control of Compression Ignition Engines
2019
Caneon Kurien and Ajay Kumar Srivastava
Increasing concern over rising pollution levels in city limits has resulted in stringent emission regulations for automotive diesel engines. Exhaust emissions from diesel engines are composed of carbon monoxide, carbon dioxide, hydrocarbons, nitrates, soot particles and soluble organic faction. Post treatment, emission control technique including diesel oxidation catalysis system, diesel particulate filtration system and selective catalytic reduction system have been developed to reduce the emission levels from automotive engines to meet the latest emission norms. Selective catalytic reduction system, which is used for control of nitrate emission has to be intensified to bring down the emission levels as per the requirements for EURO VI and Bharat Stage VI emission norms. This paper provides a comprehensive overview on the post treatment exhaust emission control systems. A detailed literature survey has been conducted on the state of art nitrate emission control technologies including the use of alternate solid reactants for ammonia generation and catalysts for deNOx reactions, considering the adverse effects of byproducts released by these systems.
Show more [+] Less [-]Influencing Factors of the Energy Consumption Behaviour of Civil Buildings in Hubei Province, China
2019
Wei Xian Zhong
Civil buildings are among the structures that consume the most energy in society. Reducing the energy consumption of civil buildings has become an important component of China’s energy policy. Identifying the key influencing factors of the energy consumption of civil buildings and formulating effective energy-saving countermeasures are important to enhance the energy efficiency of civil buildings. This study conducted a systematic analysis of the influencing factors of the energy consumption of civil buildings in Hubei Province, China. First, existing studies on the influencing factors of the energy consumption of buildings in foreign developed countries were reviewed. The status of the population, economic life, and social life that influenced the energy consumption of civil buildings in Hubei Province in the past 10 years was summarized. Relevant influencing factors were estimated via ridge regression. Results demonstrated that developed countries generally investigated the influencing factors of the energy consumption of civil buildings from the energy supply-demand relation, family factors, and out-of-family factors. Gross domestic product (GDP), total population, tertiary industry development, per capita floor space, household consumption level, and urbanization facilitated the energy consumption of civil buildings in Hubei Province during the aforementioned period, and the regression coefficients were significant at the 5% level. Lastly, policy countermeasures were proposed to accelerate the energy-saving development of civil buildings. Research conclusions are important to enrich theories regarding the energy consumption reduction of civil buildings, to help relevant government sectors of Hubei Province recognize action points for the energy-saving development of civil buildings, and to accelerate the benign development of energy-saving buildings.
Show more [+] Less [-]Detection of Metallothionein Protein Biomarkers (MTs) and Pinocytosis Activity in Gambusia Fish (Gambusia affinis) Exposed to Cadmium
2019
Moh. Awaludin Adam, Maftuch, Yuni Kilawati and Yenny Risjani
This study aims at detecting the metallothionein protein that binds cadmium in Gambusia fish using MT ELISA kit and Western Blotting testing. The continuation of the detection is used as a basis for analysing the macrophage and pinocytosis activity on Gambusia fish exposed to cadmium. The methods used to detect metallothionein protein are the MT ELISA kit and Western Blotting test. Meanwhile, to check the fish immunity, macrophage cells and pinocytosis activity were tested. The results indicated that the total proteins detected by the method of MT ELISA kits showed an increasing number with concentrations of exposure to Cd good at acute doses and sub-chronic higher doses (treatment A: 0.066 ± 0.019 ng/mL; B: 0.053 ± 0.022 ng/mL; C: 0,045 ± 0,014 ng/mL; D : 0,021 ± 0,012 ng/mL; E : 0,032 ± 0,019 ng/mL; and control k : 0,018 ± 0,018 ng/mL). Similarly, in the pinocytosis activity, the number of macrophage cells between treatment and control was significantly different (Cd ³ 3x106 treatment; Cd ³ 1x106 no treatment) and the number of pinocytosis activity was significantly different (Cd ³ 24 PA treatment; Cd ³ 10 no PA treatment). Increasing pollutants from cadmium exposure affect the fish health. Pollution causes changes in macrophage’s immune cells and phagocytosis Gambusia affinis, which can change the overall innate immunity system and fish health. The change of immune cells associated with the species and biological conditions is not present. Analysis of the number of immune cells revealed that Gambusia has decreased its macrophage pinocytosis activity, thereby indicating that phagocyte activity is a sensitive biomarker and a good bio-indicator for cadmium pollution.
Show more [+] Less [-]Influence of Rainfall as an Environmental Factor on the Distribution of Faunal Biodiversity in Nallamala Forest (Kurnool District), Andhra Pradesh
2019
M. Nagabhushan Reddy, P. Kavitha, T. Baleeswaramma and K. Nirosha
Climate change ordinarily indicates a change in behaviour of the weather elements over an area during a time span. The change is attributable directly or indirectly to human activities or the natural causes that have the effect of altering the atmospheric composition. One aspect of this complexity is that climate change will impact unevenly across the ecosystems that prove vulnerable to climate changes. Biodiversity means variation of life forms within a given ecosystem. The present work attempts to trace down the nature of interrelationship between the climate change and faunal biodiversity especially with regard to rainfall variations in Nallamala forest (Kurnool district) of Andhra Pradesh. Rainfall is also one of the limiting factors of the species expansion that determines its distribution in boundaries of the area. The trend of rainfall time-series data indicates a decreasing trend in the rainfall pattern over forest and agricultural and grassland areas from 2014 along with northern, central and southern Western Ghats.
Show more [+] Less [-]Carbon Emission Efficiency of Construction Industry in Hunan Province and Measures of Carbon Emission Reduction
2019
Liu Hua and Zhu Min
The construction industry is among the pillars of China’s economic development. However, it causes high carbon emission and high energy consumption, which should be considered when drafting energy saving and emission reduction policies. The sustainable development of this industry lies in the effective estimation of carbon emission efficiency and implementation of energy-saving and emission reduction measures in accordance with local practical situations. First, investigations on the emission efficiency of the construction industry and relevant emission reduction policies in foreign developed countries were reviewed in this study. Second, the carbon emission efficiency of the construction industry in 13 prefecture-level cities in Hunan Province (China) from 2011 to 2017 were estimated using the SBM (Slack Based Measure) model involving unexpected outputs. Finally, specific suggestions on reducing the carbon emission of the construction industry were proposed. CO2 emissions in the construction industry increase annually as a response to economic development and urbanization. The carbon emission efficiency of Hunan Province’s construction industry maintained a stable growth rate in 2011-2017. The industry achieved an annual growth rate of 2.7% in 2017 from that in 2011. The carbon emission efficiency of Changsha City, Zhangjiajie City, and Yiyang City were relatively higher than those of other cities in the province. Such findings serve as a reference to the quantification of potential of Hunan Province in reducing the carbon emission, the formulation of specific carbon emission reduction goal, the augmentation of the means to evaluate energy saving and emission reduction, and the development of a low-carbon construction industry.
Show more [+] Less [-]Pollution Evaluation of a Phosphorus-Rich Area of Zhongxiang City
2019
Miao Song
An extensive survey was carried out to understand the spatial distribution and possible sources of soil heavy metals in a phosphorus-rich area. A total of 615 topsoil samples were gathered, utilizing a regular sampling grid of 1×1 km squares, and the contents of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), vanadium (V) and zinc (Zn) were analysed to investigate the spatial distribution of these heavy metals, identify their sources, and assess levels of pollution. The results showed that the enrichment factor (EF) of the studied metals decreased in the order Cd > As > Pb > Co > Ni > Cr = Cu > Zn, and the mean contents of Cd, As and Pb were significantly higher than the background values. According to potential ecological risk (RI), 11.2% of the study areas had considerable potential ecological risk and the other areas had low to moderate potential ecological risk. The results of multivariate and geostatistical analyses indicated that Co, Cr, Ni and V, and to a lesser extent Cu and Zn, mostly originated from natural sources; while As and Pb, and to a lesser extent Cd, Cu and Zn, mainly originated from phosphorus-related industrial activities. The results also showed that Cd was affected by water with Cd pollution from the Hanjiang River. These results are useful for establishing policies for protecting local soil quality.
Show more [+] Less [-]Estimation of Wood Residues Generation from Sawmilling Activities and Energy Potential in Kwara State, Nigeria
2019
E. A. Alhassan, J. O. Olaoye, T. A. Adekanye and C. E. Okonkwo
The global concerns about the rise in anthropogenic gases have resulted in alternative clean energy sources. Biomass is one of the most prominent renewable energy sources, which can be found in wood and wood wastes, agricultural crops and their waste byproducts, municipal solid waste (MSW), animal wastes, food processing, aquatic plants and algae. Wood and by-products obtained from forest biomass stand at the centre of Renewable Energy Source (RES) due to its availability and usefulness in most developing countries. Sawdust is one of the wood processing residues that is in excess of local demand because of the near absence of its industrial demand in Kwara State. Data relating to its availability, industrial usage and energy potential are rarely available in this study area. This study investigates its availability and inherent energy potential that can be a vital tool for energy policy, planning and development. Wood wastes generated in the state were estimated to be 8012.8 m3/yr with inherent energy potential of 31298 GJ. By putting sawdust, seen as wastes in most wood processing plants, into efficient use will help reduce the competition for wood as a source of heat for cooking and heating.
Show more [+] Less [-]Preparation of New Surfactant and Study on its Application in Ultra-low Emission of Flue Gas
2019
Zhang Lei, Jia Yang, Zhang Lei, Zeng Tianyou, Wen Xin and Kong Tingting
In this paper, with different types of optimal surfactant monomers and potentiators mixed, the optimum formula of the new surfactant was obtained. The new surfactant with low toxicity, low cost and good dust removal effect was developed by the simulated flue gas experiment and verified the removal efficiency of the new surfactant on the particulate matter in the flue gas. It provided a reference for the industrial application in ultra-low emission of coal smoke. The results showed that the new surfactant could effectively reduce particulate matter in the simulated flue gas, and be the best to the dust particle size less than or equal to 1 micron. The optimum formula was worked out to be: anionic surfactant sodium dodecylbenzene-sulfonate (SDBS) 0.06%, anionic surfactant rapid penetrant T 0.06% and inorganic salt NaCl 1%.
Show more [+] Less [-]Characteristic Behaviour of the Air Pollutant NO2 Over an Urban Coastal Area Along the Bay of Bengal
2019
B. Muthulakshmi, S. Johnson Jeyakumar and I. Kartharinal Punithavathy
To study the characteristic behaviour of NO2 is quite necessary. Nitrogen dioxide is a major pollutant in the atmosphere, being a precursor to acid rain, photochemical smog, and ozone accumulation. Measurements of NO2 data over a period of one year (October 2014-September 2015) have been used to evaluate the NO2 concentration levels. The frequency distribution of NO2 reveals that out of the total 8760 data points, about 86% of NO2 lies between 5 ppb and 20 ppb. The lowest distribution is found in the range of 0-5 ppb, while the highest lies in the range of 10-15 ppb. The NO2 measurement level has been examined on a diurnal and seasonal scale. The diurnal scale of NO2 shows lesser values during daytime and higher values during night hours. The NO2 concentration levels are high in summer and minimum in the north-east monsoon. The daytime and night-time NO2 concentration pattern is found to be similar to the global scenario. It is observed that the NO2 concentrations in the study area are not high enough to pose health problems. The observed NO2 concentration levels at the study area are well within the National Ambient Air Quality standard for the entire period of study.
Show more [+] Less [-]Detection of Sewage Discharge by Density Peak Search and Differential Expression Analysis
2019
Weiguo Sun, Xudong Zhao and Hong Chen
Nowadays, water pollution is a part of the major environmental problems. Industrial sewage that does not meet the emission standards will pollute the surface water and groundwater when it is discharged into water bodies, causing serious adverse impacts on human beings and environment. In view of industrial sewage privately discharged without properly monitoring, we present a method for detection of sewage discharge using clustering and differential analysis on image sequences derived from satellite photos taken when focusing on a certain place. The proposed method helps to indicate key images containing sewage, make the sewage area and leave evidence for the retrospective incident. Clustering based on the search of fast density peaks is used for detecting images containing sewage. In addition, two sample’s t-test and Fisher linear discriminant analysis are combined to extract the key pixels representing the area of sewage discharge. Experiments were made on 200 images corresponding to a certain area at different times of the day and 25 key frames with areas labelled to be sewage discharge were extracted, which indicated the effectiveness of this method.
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