خيارات البحث
النتائج 2461 - 2470 من 4,921
Enzymatic Analysis and Effect of Vermicompost Production from Banana Leaves Waste Using Epigeic Earthworm Eudrillus euginea
2019
Jannathul Firdous, V. Bharathi, S. Durga Devi and J. Jayachitra
Recycling of organic waste with enormous nutrients gives soil fertility when added to the soil and reduce the usage of chemical fertilizers. Vermicomposting process of recycling the bio-organic waste by earthworms contains efficient nutrients with low levels of toxic contents. In the present study, banana leaves waste was mixed with cow dung in different ratios. The earthworm Eudrillus euginea was later added to the compost. Total organic matter (TOM), total organic carbon (TOC), pH, EC, total alkalinity and phosphorus were analysed and compared for different ratios of vermicompost at different day intervals. Microorganisms present in vermicompost were isolated and analysed for their enzymatic activities. Compost maturity was also observed by FTIR application. Results showed that the vermicompost quality was improved with positive catalase and protease enzymatic activity. FTIR analysis showed the proper maturation of vermicompost with reduced complex structures such as aromatic compounds, polysaccharides and polypeptides. It was concluded that composting of organic wastes by vermicomposting promote humification, increased microbial activity and enzyme production, which in turn increase the aggregate stability of soil particles resulting in better aeration with pollutionfree technique.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Development Performance and Influencing Factors of Environmental Protection Industry in China
2019
Ming Wei
As a strategic emerging industry, environmental protection industry is important in the development of national economy. However, few empirical studies on the performance of environmental protection industry are carried out. In order to explore development performance and influencing factors of environmental protection industry in China, the selection of development data of China’s 31 provincial regions under the environmental protection industry was conducted based on industrial efficiency, economic contribution, industrial scale, and development speed. Development performance of environmental protection industry was qualitatively analysed and influencing factors were explored by using the method of factor analysis. Results show that the factor score of the eastern region is positive in both industry scale and pollution treatment. Factor score of industry scale, industry contribution and pollution treatment in the central region is positive. Development of environmental protection industry in the western region lags far behind other areas, and only factor score of industry contribution are positive and significantly higher than other areas. Factor score of industrial scale, industrial contribution, and pollution treatment in the northeast region is lower than that in the eastern and central region. Suggestions and countermeasures are proposed to promote the development of the environmental protection industry.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Biosorption of Chromium by Bacillus subtilis Isolated from Ganga River
2019
Vani Sharma and Padma Singh
Water pollution by heavy metals due to discharge of industrial and anthropogenic waste leads to serious environmental and health problems as most of these heavy metals are carcinogenic in nature. In the present study chromium biosorption capacity of live and dead biomass of bacterial strain HGB1 isolated from Ganga River in Haridwar, which was examined as Bacillus subtilis, following 16S rDNA sequence analysis, was examined for different physical parameters such as pH, time of incubation and temperature. Experimental results indicate that the Bacillius subtilis has maximum tolerance capacity up to 1000 mg.L-1 with highest metal uptake of 95.64%, 97.25% and 97.11% at pH 3, 60 minutes, 2.5 mg/mL biomass respectively in case of dead biomass. In case of living biomass, highest metal uptake was 81.64%, 96.79 % and 95.89% at pH 7, 72hr and 32°C respectively. The surface chemical functional groups of Bacillus subtilis identified by FTIR were amino, carboxyl, hydroxyl and carbonyl groups. The morphological changes were examined by SEM analysis.
اظهر المزيد [+] اقل [-]Performance, Emission and Combustion Characteristics of Safflower, Neem and Corn Biodiesels Fuelled in a CI Engine
2019
K. Balasubramanian and K. Purushothaman
Renewable fuels are desirable as alternate fuels with ignition quality equivalent to diesel and its combustion parameters, but unsuitable for direct operation in diesel engines as fuel because of their higher viscosity. Hence, fuel and engine-based modifications are being developed to improve the performance, emission and combustion behaviour of the compression ignition engines. The higher viscosity of fuel oil does not let it vaporize even after it is being injected into the combustion chamber. Therefore, converting the higher viscosity of vegetable oil into biodiesel improves the atomization resulting in better combustion. Issues related to the use of biodiesel as working fuel are its oxidation stability and performance. In this study, safflower oil, neem oil and corn oil are used as fuel oils. The experimental results displayed a significant increase in the brake thermal efficiency of 28.25% for corn oil methyl ester (COME). HC and CO emissions are lower with corn oil methyl ester. At full load, the smoke emission reduces slightly with corn oil methyl ester about 58% opacity respectively, but it is still lower than diesel having 66.2% opacity.
اظهر المزيد [+] اقل [-]Adsorption Kinetics and Isotherms of Cr(VI) Ions in Aqueous Solution by Biochar Derived from Torreya grandis Nutshell
2019
Chengcai Huang, Rui Qin, Linli Zhang, Muqing Qiu and Linfa Bao
Biochar is thought to be a good adsorption material for the adsorption of heavy metals. In this study, biochar derived from Torreya grandis nutshell was prepared through to be pyrolyzed under oxygen limited conditions in a muffle furnace. The adsorption experiments of Cr(VI) were carried out. Through Elemental Analyzer, Specific Surface Area Meter, Scanning Electron Microscopy, Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy, a fundamental understanding of the physical and chemical properties of biochar was gained. The results showed that it was a smooth sheet and irregular arrangement structure. The elements of C, H, O and N of biochar are 45.21%, 5.18%, 46.16% and 3.45% respectively. BET specific surface area of biochar is 42.24 m2/g. A lot of oxygencontaining functional groups (– OH, COO –, – C – OH and so on ) appeared on the surface of biochar. It can be described by the pseudo-second order kinetic rate model and Langmuir isotherm model. The adsorption process is a monolayer chemical process. The adsorption mechanism of biochar on heavy metal Cr(VI) contains the electrostatic attraction between biochar and Cr2O7 2-, HCrO4 - and CrO4 2- ions in aqueous solution and complexation reaction of oxygen-containing functional groups (– OH, – COOH and so on) and Cr2O7 2- , HCrO4 - and CrO4 2- ions on the surface of biochar.
اظهر المزيد [+] اقل [-]In-Situ Water Quality Improvement by Hypolimnion Oxygenation and Artificially Induced Mixing in a Drinking Water Reservoir
2019
Zhou Zi-zhen, Huang Ting-lin, Gong Wei-jin, Li Yang, Liu Yue, Zhao Fu-wang, Bai Yang, Dou Yan-yan, Lv Jing-jing and Liu Hai-fang
Faced with the problems of hypolimnion dissolved oxygen (DO) depletion and water quality deterioration, a newly designed water quality improvement technology named water-lifting aerators (WLAs) was put into utilization to solve these problems in Jinpen Reservoir. During the hypolimnion oxygenation period, after 20 days operation of 8 WLAs with compressed air volume of 10 m3/h, the thickness of anaerobic layer was compressed from 17 m to 3.2 m. As for artificially induced mixing, after 18 days operation of 8 WLAs with compressed air volume of 50 m3/h (full capacity), the reservoir was mixed, and DO of the bottom water increased to more than 8 mg/L. Removal rates of TN, TP, NH4-N and TOC reached 25.5%, 50%, 29.8% and 19.4% respectively. Results of Biolog method showed that the activity of microbes and carbon source utilization were improved in the water of the controlled area compared with the uncontrolled area during the operation. WLAs have been proved to be an efficient technology in water quality improvement especially in hypolimnion oxygenation and artificially induced mixing.
اظهر المزيد [+] اقل [-]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.
اظهر المزيد [+] اقل [-]Life Cycle Assessment of the Oil Palm Production in the Philippines: A Cradle to Gate Approach
2019
Ma. Theresa M. Espino, Rocky Marius Q. de Ramos and Luzvisminda M. Bellotindos
Despite its small share of 0.15% in the global market, the oil palm production in the Philippines is being contested with environmental issues on continued deforestation, increased emissions from illegal burning of trees, and the marginalization of indigenous communities. As a developing industry, there is a need to further conduct of social and environmental impact studies to gain more acceptance, thereby, pursue growth and expansion. In view of the environmental concerns, this study aimed to conduct a life cycle assessment of the crude oil palm with North Cotabato, Philippines as the case study. Using cradle to gate approach, the potential environmental impacts were established: non-renewable energy of 0.394 MJ/kg oil, carbon footprint of 1.150 kgCO2/kg oil, ozone creation potential of 2.429×10-3 kg NOx /kg oil, acidification potential of 0.0138×10-3 kg SO2 /kg oil and water footprint of 5,797.3 L/kg oil. Compared to six locations in Indonesia, Malaysia and Thailand, the environmental impacts and performance of the oil palm production in North Cotabato were satisfactory given the same topographical conditions. Opportunities to mitigate and decrease the impacts were also identified, namely improving oil extraction rates; increasing ratio of shell as biomass fuel; prudent application of nitrogen fertilizers and optimizing delivery loads and schedules. The results of this study can be a reference for future environmental assessments in other locations.
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