Search results for: nitrogen dioxide

Authors: Zoe M. G. Skalkos, Sam N. Dowland, James U. Van Dyke, Camilla. M. Whittington

Abstract:

Syngnathid fishes (seahorses, pipefishes, and seadragons) are unique because embryos develop on or in the male in a specialised brooding structure. Many seahorse species are endangered or vulnerable, while others are popular in the ornamental fish trade. Seahorses are capable of nutrient provisioning (patrotrophy) of lipids during pregnancy via their fully enclosed brood pouch. Protein is vital for gene regulation and tissue growth during embryogenesis. We tested the hypothesis that protein is paternally transported to developing embryos during pregnancy in the Australian Pot-bellied seahorse, Hippocampus abdominalis. We compared the dry masses and nitrogen content in recently fertilised H. abdominalis embryos and newborns. We calculated an updated patrotrophy index, 1.34, but without a significant difference in dry mass between the two developmental stages. There was, however, a significant increase in total protein content from recently fertilised embryos to neonates. This suggests paternal protein transport is essential for H. abdominalis embryogenesis because protein yolk reserves are depleted by embryonic metabolism, and supplementation is required. This study is the first to provide evidence for paternal protein transport during pregnancy in seahorses. It furthers our understanding of the paternal influence on embryonic development in male pregnancy and how a protein-deficient diet during pregnancy may limit the allocation of resources to embryos, reducing offspring fitness. This research contributes to a deeper understanding of the fundamental reproductive biology of seahorses, which can help improve conservation and farming production outcomes.

Keywords: brood pouch, embryonic provisioning, nitrogen, parentotrophy, paternal investment, reproduction

Procedia PDF Downloads 71

Authors: Koppula Prawan, Kehinde D. Oyeyemi, Kushal P. Singh

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As people become more conscious of the detrimental consequences of conventional agricultural practices on the environment and human health, organic, sustainable agriculture and plant protection employing microorganisms have grown in importance. Although the use of microorganisms in agriculture is a centuries-old tradition, it has recently attracted renewed interest as a sustainable alternative to chemical-based plant protection and fertilization. Healthy soil is the cornerstone of sustainable agriculture, and microbes are essential to this process. Synthetic fertilizers and pesticides can destroy the beneficial microorganisms in the soil, upsetting the ecosystem's equilibrium. By utilizing organic farming's natural practices, such as the usage of microbes, it aims to maintain and improve the health of the soil. Microbes have several functions in agriculture, including nitrogen fixation, phosphorus solubilization, and disease suppression. Nitrogen fixation is the process by which certain microbes, such as rhizobia and Azotobacter, convert atmospheric nitrogen into a form that plants can use. Phosphorus solubilization involves the conversion of insoluble phosphorus into a soluble form that plants can absorb. Disease suppression involves the use of microbes to control plant diseases by competing with pathogenic organisms for resources or by producing antimicrobial compounds. Microbes can be applied to plants through seed coatings, foliar sprays, or soil inoculants. Seed coatings involve applying a mixture of microbes and nutrients to the surface of seeds before planting. Foliar sprays involve applying microbes and nutrients to the leaves of plants during the growing season. Soil inoculants involve adding microbes to the soil before planting. The use of microbes in plant protection and fertilization has several advantages over conventional methods. Firstly, microbes are natural and non-toxic, making them safe for human health and the environment. Secondly, microbes have the ability to adapt to changing environmental conditions, making them more resilient to drought and other stressors. Finally, the use of microbes can reduce the need for synthetic fertilizers and pesticides, reducing costs and minimizing environmental impact. In conclusion, organic, sustainable agriculture and plant protection using microbes are an effective and sustainable alternatives to conventional farming practices. The use of microbes can help to preserve and enhance soil health, increase plant productivity, and reduce the need for synthetic fertilizers and pesticides. As the demand for organic and sustainable agriculture continues to grow, the use of microbes is likely to become more widespread, providing a more environmentally friendly and sustainable future for agriculture.

Keywords: microbes, inoculants, fertilization, soil health, conventional.

Procedia PDF Downloads 61

Authors: Jinhoa Lee

Abstract:

The relationships between environmental quality, energy use and economic output have created growing attention over the past decades among researchers and policy makers. Focusing on the empirical aspects of the role of carbon dioxide (CO2) emissions and energy use in affecting the economic output, this paper is an effort to fulfill the gap in a comprehensive case study at a country level using modern econometric techniques. To achieve the goal, this country-specific study examines the short-run and long-run relationships among energy consumption (using disaggregated energy sources: crude oil, coal, natural gas, electricity), CO2 emissions and gross domestic product (GDP) for Egypt using time series analysis from the year 1980-2010. To investigate the relationships between the variables, this paper employs the Augmented Dickey-Fuller (ADF) test for stationarity, Johansen maximum likelihood method for co-integration and a Vector Error Correction Model (VECM) for both short- and long-run causality among the research variables for the sample. The long-run equilibrium in the VECM suggests some negative impacts of the CO2 emissions and the coal and natural gas use on the GDP. Conversely, a positive long-run causality from the electricity consumption to the GDP is found to be significant in Egypt during the period. In the short-run, some positive unidirectional causalities exist, running from the coal consumption to the GDP, and the CO2 emissions and the natural gas use. Further, the GDP and the electricity use are positively influenced by the consumption of petroleum products and the direct combustion of crude oil. Overall, the results support arguments that there are relationships among environmental quality, energy use, and economic output in both the short term and long term; however, the effects may differ due to the sources of energy, such as in the case of Egypt for the period of 1980-2010.

Keywords: CO2 emissions, Egypt, energy consumption, GDP, time series analysis

Procedia PDF Downloads 603

Authors: Natalia Bustos Sierra, Katrien Tersago

Abstract:

It is currently proven that both extremes of temperature are associated with increased mortality and that air pollution is associated with temperature. This relationship is complex, and in countries with important seasonal variations in weather such as Belgium, some effects can appear as non-significant when the analysis is done over the entire year. We, therefore, analyzed the effect of short-term outdoor air pollution exposure on cardiovascular mortality during the warmer and colder months separately. We used daily cardiovascular deaths from acute cardiovascular diagnostics according to the International Classification of Diseases, 10th Revision (ICD-10: I20-I24, I44-I49, I50, I60-I66) during the period 2008-2013. The environmental data were population-weighted concentrations of particulates with an aerodynamic diameter less than 10 µm (PM₁₀) and less than 2.5 µm (PM₂.₅) (daily average), nitrogen dioxide (NO₂) (daily maximum of the hourly average) and ozone (O₃) (daily maximum of the 8-hour running mean). A Generalized linear model was applied adjusting for the confounding effect of season, temperature, dew point temperature, the day of the week, public holidays and the incidence of influenza-like illness (ILI) per 100,000 inhabitants. The relative risks (RR) were calculated for an increase of one interquartile range (IQR) of the air pollutant (μg/m³). These were presented for the four hottest months (June, July, August, September) and coldest months (November, December, January, February) in Belgium. We applied both individual lag model and unconstrained distributed lag model methods. The cumulative effect of a four-day exposure (day of exposure and three consecutive days) was calculated from the unconstrained distributed lag model. The IQR for PM₁₀, PM₂.₅, NO₂, and O₃ were respectively 8.2, 6.9, 12.9 and 25.5 µg/m³ during warm months and 18.8, 17.6, 18.4 and 27.8 µg/m³ during cold months. The association with CV mortality was statistically significant for the four pollutants during warm months and only for NO₂ during cold months. During the warm months, the cumulative effect of an IQR increase of ozone for the age groups 25-64, 65-84 and 85+ was 1.066 (95%CI: 1.002-1.135), 1.041 (1.008-1.075) and 1.036 (1.013-1.058) respectively. The cumulative effect of an IQR increase of NO₂ for the age group 65-84 was 1.066 (1.020-1.114) during warm months and 1.096 (1.030-1.166) during cold months. The cumulative effect of an IQR increase of PM₁₀ during warm months reached 1.046 (1.011-1.082) and 1.038 (1.015-1.063) for the age groups 65-84 and 85+ respectively. Similar results were observed for PM₂.₅. The short-term effect of air pollution on cardiovascular mortality is greater during warm months for lower pollutant concentrations compared to cold months. Spending more time outside during warm months increases population exposure to air pollution and can, therefore, be a confounding factor for this association. Age can also affect the length of time spent outdoors and the type of physical activity exercised. This study supports the deleterious effect of air pollution on cardiovascular mortality (CV) which varies according to season and age groups in Belgium. Public health measures should, therefore, be adapted to seasonality.

Keywords: air pollution, cardiovascular, mortality, season

Procedia PDF Downloads 146

Authors: Lakshmikanth Reddy, Bhavin Desai, Chandrakala Kari, Sanjay Sarkar, Pradeep Binu

Abstract:

The sulphur dioxide gases generated as a by-product of smelting and converting operations of copper concentrate contain selenium apart from zinc, lead, copper, cadmium, bismuth, antimony, and arsenic. The gaseous stream is treated in waste heat boiler, electrostatic precipitator and scrubbers to remove coarse particulate matter in order to produce commercial grade sulfuric acid. The gas cleaning section of the acid plant uses water to scrub the smelting gases. After scrubbing, the sludge settled at the bottom of the scrubber, was analyzed in present investigation. It was found to contain 30 to 40 wt% copper and selenium up to 40 wt% selenium. The sludge collected during blow-down is directly recycled to the smelter for copper recovery. However, the selenium is expected to again vaporize due to high oxidation potential during smelting and converting, causing accumulation of selenium in sludge. In present investigation, a roasting process has been developed to recover the selenium before the copper recovery from the sludge at smelter. Selenium is associated with copper in sludge as copper selenide, as determined by X-ray diffraction and electron microscopy. The thermodynamic and thermos-gravimetry study revealed that the copper selenide phase present in the sludge was amenable to oxidation at 600°C forming oxides of copper and selenium (Cu-Se-O). However, the dissociation of selenium from the copper oxide was made possible by sulfatation using sulfur dioxide between 450 to 600°C, resulting into the formation of CuSO₄ (s) and SeO₂ (g). Lab scale trials were carried out in vertical tubular furnace to determine the optimum roasting conditions with respect to roasting time, temperature and molar ratio of O₂:SO₂. Using these optimum conditions, selenium up to 90 wt% in the form of SeO₂ vapors could be recovered from the sludge in a large-scale commercial roaster. Roasted sludge free from the selenium and containing oxides and sulfates of copper could now be recycled in the smelter for copper recovery.

Keywords: copper, selenium, copper selenide, sludge, roasting, SeO₂

Procedia PDF Downloads 182

Authors: Titin Handayani, Adi Mulyanto, Fajar Eko Priyanto

Abstract:

It is generally recognized, that algae could be an interesting option for reducing CO₂ emissions. Based on light and CO₂, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient feeding of CO₂, especially on a large scale, is one of them. Current methods for CO₂ feeding to algae cultures rely on the sparging pure CO₂ or directly from flue gas. The limiting factor in this system is the solubility of CO₂ in water, which demands a considerable amount of energy for an effective gas to liquid transfer and leads to losses to the atmosphere. Due to the current ineffective methods for CO₂ introduction into algae ponds very large surface areas would be required for enough ponds to capture a considerable amount of the CO₂. The purpose of this study is to assess technology to capture carbon dioxide (CO₂) emissions generated by industry by utilizing of microalgae Chlorella sp. The microalgae were cultivated in a bioreactor culture pond raceway type. The result is expected to be useful in mitigating the effects of greenhouse gases in reducing the CO₂ emissions. The research activities include: (1) Characterization of boiler flue gas, (2) Operation of culture pond, (3) Sampling and sample analysis. The results of this study showed that the initial assessment absorption of the flue gas by microalgae using 1000 L raceway pond completed by heat exchanger were quite promising. The transfer of CO₂ into the pond culture system was run well. This identified from the success of cooling the boiler flue gas from the temperature of about 200 °C to below ambient temperature. Except for the temperature, the gas bubbles into the culture media were quite fine. Therefore, the contact between the gas and the media was well performed. The efficiency of CO₂ absorption by Chlorella sp reached 6.68 % with an average CO₂ loading of 0.29 g/L/day.

Keywords: Chlorella sp., CO2 emission, heat exchange, microalgae, milk industry, raceway pond

Procedia PDF Downloads 197

Authors: Indu Bhushan Sharma, Rashmi Saraswat

Abstract:

The thermotolerant, solvent stable and alkalophilic lipase producing bacterial strain was isolated from the water sample of the foothills of Trikuta Mountain in Kakryal (Reasi district) in Jammu and Kashmir, India. The lipase-producing microorganisms were screened using tributyrin agar plates. The selected microbe was optimized for maximum lipase production by subjecting to various carbon and nitrogen sources, incubation period and inoculum size. The selected strain was identified as Bacillus subtilis strain kakrayal_1 (BSK_1) using 16S rRNA sequence analysis. Effect of pH, temperature, metal ions, detergents and organic solvents were studied on lipase activity. Lipase was found to be stable over a pH range of 6.0 to 9.0 and exhibited maximum activity at pH 8. Lipolytic activity was highest at 37°C and the enzyme activity remained at 60°C for 24hrs, hence, established as thermo-tolerant. Production of lipase was significantly induced by vegetable oil and the best nitrogen source was found to be peptone. The isolated Bacillus lipase was stimulated by pre-treatment with Mn2+, Ca2+, K+, Zn2+, and Fe2+. Lipase was stable in detergents such as triton X 100, tween 20 and Tween 80. The 100% ethyl acetate enhanced lipase activity whereas, lipase activity were found to be stable in Hexane. The optimization resulted in 4 fold increase in lipase production. Bacillus lipases are ‘generally recognized as safe’ (GRAS) and are industrially interesting. The inducible alkaline, thermo-tolerant lipase exhibited the ability to be stable in detergents and organic solvents. This could be further researched as a potential biocatalyst for industrial applications such as biotransformation, detergent formulation, bioremediation and organic synthesis.

Keywords: bacillus, lipase, thermotolerant, alkalophilic

Procedia PDF Downloads 232

Authors: S. R. H. Baqri, T. Shahina, M. T. Hasan

Abstract:

Pakistan is facing acute shortage of energy and looking for indigenous resources of the energy mix to meet the short fall. After the discovery of huge coal resources in Thar Desert of Sindh province, focus has shifted to coal power generation. The government of Pakistan has planned power generation of 20000 MW on coal by the year 2025. This target will be achieved by mining and power generation in Thar coal Field and on imported coal in different parts of Pakistan. Total indigenous coal production of around 3.0 million tons is being utilized in brick kilns, cement and sugar industry. Coal-based power generation is only limited to three units of 50 MW near Hyderabad from nearby Lakhra Coal field. The purpose of this presentation is to identify and redressal of issues of coal mining and utilization with reference to environmental hazards. Thar coal resource is estimated at 175 billion tons out of a total resource estimate of 184 billion tons in Pakistan. Coal of Pakistan is of Tertiary age (Palaeocene/Eocene) and classified from lignite to sub-bituminous category. Coal characterization has established three main pollutants such as Sulphur, Carbon dioxide and Methane besides some others associated with coal and rock types. The element Sulphur occurs in organic as well as inorganic forms associated with coals as free sulphur and as pyrite, gypsum, respectively. Carbon dioxide, methane and minerals are mostly associated with fractures, joints local faults, seatearth and roof rocks. The abandoned and working coal mines give kerosene odour due to escape of methane in the atmosphere. While the frozen methane/methane ices in organic matter rich sediments have also been reported from the Makran coastal and offshore areas. The Sulphur escapes into the atmosphere during mining and utilization of coal in industry. The natural erosional processes due to rivers, streams, lakes and coastal waves erode over lying sediments allowing pollutants to escape into air and water. Power plants emissions should be controlled through application of appropriate clean coal technology and need to be regularly monitored. Therefore, the systematic and scientific studies will be required to estimate the quantity of methane, carbon dioxide and sulphur at various sites such as abandoned and working coal mines, exploratory wells for coal, oil and gas. Pressure gauges on gas pipes connecting the coal-bearing horizons will be installed on surface to know the quantity of gas. The quality and quantity of gases will be examined according to the defined intervals of times. This will help to design and recommend the methods and procedures to stop the escape of gases into atmosphere. The element of Sulphur can be removed partially by gravity and chemical methods after grinding and before industrial utilization of coal.

Keywords: atmosphere, coal production, energy, pollutants

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Authors: Wen-Chyan Tsai, Syed S. H. Rizvi

Abstract:

Organic solvent residues are always associated with liposomes produced by the traditional techniques like the thin film hydration and reverse phase evaporation methods, which limit the applications of these vesicles in the pharmaceutical, food and cosmetic industries. Our objective was to develop a novel and benign process of liposomal microencapsulation by using supercritical carbon dioxide (SC-CO2) as the sole phospholipid-dissolving medium and a green substitute for organic solvents. This process consists of supercritical fluid extraction followed by rapid expansion via a nozzle and automatic cargo suction. Lecithin and cholesterol mixed in 10:1 mass ratio were dissolved in SC-CO2 at 20 ± 0.5 MPa and 60 oC. After at least two hours of equilibrium, the lecithin/cholesterol-laden SC-CO2 was passed through a 1000-micron nozzle and immediately mixed with the cargo solution to form liposomes. Liposomal micro-encapsulation was conducted at three pressures (8.27, 12.41, 16.55 MPa), three temperatures (75, 83 and 90 oC) and two flow rates (0.25 ml/sec and 0.5 ml/sec). Liposome size, zeta potential and encapsulation efficiency were characterized as functions of the operating parameters. The average liposomal size varied from 400-500 nm to 1000-1200 nm when the pressure was increased from 8.27 to 16.55 MPa. At 12.41 MPa, 90 oC and 0.25 ml per second of 0.2 M glucose cargo loading rate, the highest encapsulation efficiency of 31.65 % was achieved. Under a confocal laser scanning microscope, large unilamellar vesicles and multivesicular vesicles were observed to make up a majority of the liposomal emulsion. This new approach is a rapid and continuous process for bulk production of liposomes using a green solvent. Based on the results to date, it is feasible to apply this technique to encapsulate hydrophilic compounds inside the aqueous core as well as lipophilic compounds in the phospholipid bilayers of the liposomes for controlled release, solubility improvement and targeted therapy of bioactive compounds.

Keywords: liposome, micro encapsulation, supercritical carbon dioxide, non-toxic process

Procedia PDF Downloads 413

Authors: Jonni Guiller Madeira, Angel Sanchez Delgado, Ronney Mancebo Boloy

Abstract:

The use bioenergy, in recent years, has become a good alternative to reduce the emission of polluting gases. Several Brazilian and foreign companies are doing studies related to waste management as an essential tool in the search for energy efficiency, taking into consideration, also, the ecological aspect. Brazil is one of the largest cassava producers in the world; the cassava sub-products are the food base of millions of Brazilians. The repertoire of results about the ecological impact of the production, by steam reforming, of biohydrogen from cassava wastewater biogas is very limited because, in general, this commodity is more common in underdeveloped countries. This hydrogen, produced from cassava wastewater, appears as an alternative fuel to fossil fuels since this is a low-cost carbon source. This paper evaluates the environmental impact of biohydrogen production, by steam reforming, from cassava wastewater biogas. The ecological efficiency methodology developed by Cardu and Baica was used as a benchmark in this study. The methodology mainly assesses the emissions of equivalent carbon dioxide (CO₂, SOₓ, CH₄ and particulate matter). As a result, some environmental parameters, such as equivalent carbon dioxide emissions, pollutant indicator, and ecological efficiency are evaluated due to the fact that they are important to energy production. The average values of the environmental parameters among different biogas compositions (different concentrations of methane) were calculated, the average pollution indicator was 10.11 kgCO₂e/kgH₂ with an average ecological efficiency of 93.37%. As a conclusion, bioenergy production using biohydrogen from cassava wastewater treatment plant is a good option from the environmental feasibility point of view. This fact can be justified by the determination of environmental parameters and comparison of the environmental parameters of hydrogen production via steam reforming from different types of fuels.

Keywords: biohydrogen, ecological efficiency, cassava, pollution indicator

Procedia PDF Downloads 177

Authors: Jinhoa Lee

Abstract:

The relationships between environmental quality, energy use and economic output have created growing attention over the past decades among researchers and policy makers. Focusing on the empirical aspects of the role of CO2 emissions and energy use in affecting the economic output, this paper is an effort to fulfill the gap in a comprehensive case study at a country level using modern econometric techniques. To achieve the goal, this country-specific study examines the short-run and long-run relationships among energy consumption (using disaggregated energy sources: crude oil, coal, natural gas, electricity), carbon dioxide (CO2) emissions and gross domestic product (GDP) for Israel using time series analysis from the year 1980-2010. To investigate the relationships between the variables, this paper employs the Phillips–Perron (PP) test for stationarity, Johansen maximum likelihood method for cointegration and a Vector Error Correction Model (VECM) for both short- and long-run causality among the research variables for the sample. The long-run equilibrium in the VECM suggests significant positive impacts of coal and natural gas consumptions on GDP in Israel. In the short run, GDP positively affects coal consumption. While there exists a positive unidirectional causality running from coal consumption to consumption of petroleum products and the direct combustion of crude oil, there exists a negative unidirectional causality running from natural gas consumption to consumption of petroleum products and the direct combustion of crude oil in the short run. Overall, the results support arguments that there are relationships among environmental quality, energy use and economic output but the associations can to be differed by the sources of energy in the case of Israel over of period 1980-2010.

Keywords: CO2 emissions, energy consumption, GDP, Israel, time series analysis

Procedia PDF Downloads 630

Authors: Patrick Mueller, Alan Martin, Justin Stockwell, Robert Goldblatt

Abstract:

Elevated concentrations of inorganic nitrogen (N) compounds (nitrate, nitrite, and ammonia) are a ubiquitous feature to mine-influenced drainages due to the leaching of blasting residues and use of cyanide in the milling of gold ores. For many mines, the management of N is a focus for environmental protection, therefore understanding the factors controlling the speciation and behavior of N is central to effective decision making. In this paper, the passive attenuation of ammonia and nitrite is described for three northern water bodies (two lakes and a tailings pond) influenced by mining activities. In two of the water bodies, inorganic N compounds originate from explosives residues in mine water and waste rock. The third water body is a decommissioned tailings impoundment, with N compounds largely originating from the breakdown of cyanide compounds used in the processing of gold ores. Empirical observations from water quality monitoring indicate nitrification (the oxidation of ammonia to nitrate) occurs in all three waterbodies, where enrichment of nitrate occurs commensurately with ammonia depletion. The N species conversions in these systems occurred more rapidly than chemical oxidation kinetics permit, indicating that microbial mediated conversion was occurring, despite the cool water temperatures. While nitrification of ammonia and nitrite to nitrate was the primary process, in all three waterbodies nitrite was consistently present at approximately 0.5 to 2.0 % of total N, even following ammonia depletion. The persistence of trace amounts of nitrite under these conditions suggests the co-occurrence denitrification processes in the water column and/or underlying substrates. The implications for N management in mine waters are discussed.

Keywords: explosives, mining, nitrification, water

Procedia PDF Downloads 292

Authors: Yetti Marlida, Harnentis, Yuliaty Shafan Nur

Abstract:

Background: Tempoyak is a dish derived from fermented durian fruit. Tempoyak is a food consumed as a side dish when eating rice. Besides being eaten with rice, tempoyak can also be eaten directly. But this is rarely done because many cannot stand the sour taste and aroma of the tempoyak itself. In addition, tempoyak can also be used as a seasoning. The taste of tempoyak is acidic, this occurs because of the fermentation process in durian fruit meat which is the raw material. Tempoyak is already very well known in Indonesia, especially in Padang, Bengkulu, Palembang, Lampung, and Kalimantan. Besides that, this food is also famous in Malaysia. The purpose of this research is to improvement production of γ-aminobutyric acid (GABA) by Lactobacillus plantarum isolated from indigenous fermented durian (tempoyak). Selected Lactic Acid Bacteria (LAB) previously isolated from indigenous fermented durian (tempoyak) that have ability to produce γ-aminobutyric acid (GABA). The study was started with identification of selected LAB by 16 S RNA, followed optimation of GABA production by culture condition using different initial pH, temperature, glutamate concentration, incubation time, carbon and nitrogen sources. Results: The result from indentification used polymerase chain reaction of 16S rRNA gene sequences and phylogenetic analysis was Lactobacillus plantarum (coded as Y3) with a sequenced length of 1400bp. The improvement of Gaba production was found highest at pH: 6.0; temperature: 30 °C; glutamate concentration: 0.4%; incubation time: 60 h; glucose and yeast extract as carbon and nitrogen sources. Conclusions: GABA can be produced with the optimum condition fermentation were 66.06 mM.

Keywords: lactic acid bacteria, γ-amino butyric acid, indigenous fermented durian, PCR

Procedia PDF Downloads 122

Authors: Mustapha Babatunde, Bassam Tawabini, Ole John Nielson

Abstract:

Air dispersion (AD) models such as AERMOD are important tools for estimating the environmental impacts of air pollutant emissions into the atmosphere from anthropogenic sources. The outcome of these models is significantly linked to the climate condition like air temperature, which is expected to differ in the future due to the global warming phenomenon. With projections from scientific sources of impending changes to the future climate of Saudi Arabia, especially anticipated temperature rise, there is a potential direct impact on the dispersion patterns of air pollutants results from AD models. To our knowledge, no similar studies were carried out in Saudi Arabia to investigate such impact. Therefore, this research investigates the effects of climate temperature change on air quality in the Dammam Metropolitan area, Saudi Arabia, using AERMOD coupled with Station data using Sulphur dioxide (SO₂) – as a model air pollutant. The research uses AERMOD model to predict the SO₂ dispersion trends in the surrounding area. Emissions from five (5) industrial stacks on twenty-eight (28) receptors in the study area were considered for the climate period (2010-2019) and future period of mid-century (2040-2060) under different scenarios of elevated temperature profiles (+1ᵒC, + 3ᵒC and + 5ᵒC) across averaging time periods of 1hr, 4hr and 8hr. Results showed that levels of SO₂ at the receiving sites under current and simulated future climactic condition fall within the allowable limit of WHO and KSA air quality standards. Results also revealed that the projected rise in temperature would only have mild increment on the SO₂ concentration levels. The average increase of SO₂ levels was 0.04%, 0.14%, and 0.23% due to the temperature increase of 1, 3, and 5 degrees, respectively. In conclusion, the outcome of this work elucidates the degree of the effects of global warming and climate changes phenomena on air quality and can help the policymakers in their decision-making, given the significant health challenges associated with ambient air pollution in Saudi Arabia.

Keywords: air quality, sulfur dioxide, dispersion models, global warming, KSA

Procedia PDF Downloads 55

Authors: Nicholas V. Scott, Jack McCarthy

Abstract:

Military, law enforcement, and counter terrorism organizations are often tasked with target detection and image characterization of scenes containing explosive materials in various types of environments where light scattering intensity is high. Mitigation of this photonic noise using classical digital filtration and signal processing can be difficult. This is partially due to the lack of robust image processing methods for photonic noise removal, which strongly influence high resolution target detection and machine learning-based pattern recognition. Such analysis is crucial to the delivery of reliable intelligence. Polarization filters are a possible method for ambient glare reduction by allowing only certain modes of the electromagnetic field to be captured, providing strong scene contrast. An experiment was carried out utilizing a polarization lens attached to a hyperspectral imagery camera for the purpose of exploring the degree to which an imaged polarized scene of potassium, phosphorus, and nitrogen mixture allows for improved target detection and image segmentation. Preliminary imagery results based on the application of machine learning algorithms, including competitive leaky learning and distance metric analysis, to polarized hyperspectral imagery, suggest that polarization filters provide a slight advantage in image segmentation. The results of this work have implications for understanding the presence of explosive material in dry, desert areas where reflective glare is a significant impediment to scene characterization.

Keywords: explosive material, hyperspectral imagery, image segmentation, machine learning, polarization

Procedia PDF Downloads 118

Authors: Mohamed Emran, Giovanni Pardini, Maria Gispert, Mohamed Rashad

Abstract:

Land use and abandonment in semi-arid degraded ecosystems may cause regressive dynamics in vegetation cover affecting organic matter contents, soil nutrients and structural stability, thus reducing soil resistance to erosion. Mediterranean areas are generally subjected to climatic fluctuations, which modify soil conditions and hydrological processes, such as runoff and water infiltration within the upper soil horizons. Low erosion rates occur in very fragile and shallow soils with minor clay content progressively decrease organic carbon C and nitrogen N pools in the upper soil horizons. Seven soils were selected representing variant context of land use and abandonment at the Cap de Creus Peninsula, Catalonia, NE Spain, from recent cultivated vines and olive groves, mid abandoned forests standing under cork and pine trees, pasture to late abandoned Cistus and Erica scrubs. The aim of this work was to study the effect of changes in land use and abandonment on the depletion of soil organic carbon and nitrogen transported by runoff water in shallow soils after natural rainfall events during two years with different rainfall patterns (1st year with low rainfall and 2nd year with high rainfall) by i) monitoring the most significant soil erosion parameters at recorded rainfall events, ii) studying the most relevant soil physical and chemical characteristics on seasonal basis and iii) analysing the seasonal trends of depleted carbon and nitrogen and their interaction with soil surface compaction parameters. Significant seasonal variability was observed in the relevant soil physical and chemical parameters and soil erosion parameters in all soils to establish their evolution under land use and abandonment during two years of different rainfall patterns (214 and 487 mm per year), giving important indications on soil response to rainfall impacts. Erosion rates decreased significantly with the increasing of soil C and N under low and high rainfall. In cultivated soils, C and N depletion increased by 144% and 115%, respectively by 13% increase in erosion rates during the 1st year with respect to the 2nd year. Depleted C and N were proportionally higher in soils under vines and olive with vulnerable soil structure and low soil resilience leading to degradation, altering nutrients cycles and causing adverse impact on environmental quality. Statistical analysis underlined that, during the 1st year, soil surface was less effective in preserving stocks of organic resources leading to higher susceptibility to erosion with consequent C and N depletion. During the 2nd year, higher organic reserve and water storage occurred despite the increasing of C and N loss with an effective contribution from soil surface compaction parameters. The overall estimation during the two years indicated clear differences among soils under vines, olive, cork and pines, suggesting on the one hand, that current cultivation practices are inappropriate and that reforestation with pines may delay the achievement of better soil conditions. On the other hand, the natural succession of vegetation under Cistus, pasture and Erica suggests the recovery of good soil conditions.

Keywords: land abandonment, land use, nutrient's depletion, soil erosion

Procedia PDF Downloads 322

Authors: Mustapha Babatunde, Bassam Tawabini, Ole John Nielson

Abstract:

Air dispersion (AD) models such as AERMOD are important tools for estimating the environmental impacts of air pollutant emissions into the atmosphere from anthropogenic sources. The outcome of these models is significantly linked to the climate condition like air temperature, which is expected to differ in the future due to the global warming phenomenon. With projections from scientific sources of impending changes to the future climate of Saudi Arabia, especially anticipated temperature rise, there is a potential direct impact on the dispersion patterns of air pollutants results from AD models. To our knowledge, no similar studies were carried out in Saudi Arabia to investigate such impact. Therefore, this research investigates the effects of climate temperature change on air quality in the Dammam Metropolitan area, Saudi Arabia, using AERMOD coupled with Station data using Sulphur dioxide (SO2) – as a model air pollutant. The research uses AERMOD model to predict the SO2 dispersion trends on the surrounding area. Emissions from five (5) industrial stacks, on twenty-eight (28) receptors in the study area were considered for the climate period (2010-2019) and future period of mid-century (2040-2060) under different scenarios of elevated temperature profiles (+1oC, + 3oC and + 5oC) across averaging time periods of 1hr, 4hr and 8hr. Results showed that levels of SO2 at the receiving sites under current and simulated future climactic condition fall within the allowable limit of WHO and KSA air quality standards. Results also revealed that the projected rise in temperature would only have mild increment on the SO2 concentration levels. The average increase of SO2 levels were 0.04%, 0.14%, and 0.23% due to the temperature increase of 1, 3, and 5 degrees respectively. In conclusion, the outcome of this work elucidates the degree of the effects of global warming and climate changes phenomena on air quality and can help the policymakers in their decision-making, given the significant health challenges associated with ambient air pollution in Saudi Arabia.

Keywords: air quality, sulphur dioxide, global warming, air dispersion model

Procedia PDF Downloads 112

Authors: Hendrick Maxil Zárate Rocha, Ricardo da Silva Pereira, Manoel Fernandes Martins Nogueira, Carlos R. Pereira Belchior, Maria Emilia de Lima Tostes

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This study investigates experimentally the effects of hydrogen addition in the intake manifold of a diesel generator operating with a 7% biodiesel-diesel oil blend (B7). An experimental apparatus setup was used to conduct performance and emissions tests in a single cylinder, air cooled diesel engine. This setup consisted of a generator set connected to a wirewound resistor load bank that was used to vary engine load. In addition, a flowmeter was used to determine hydrogen volumetric flowrate and a digital anemometer coupled with an air box to measure air flowrate. Furthermore, a digital precision electronic scale was used to measure engine fuel consumption and a gas analyzer was used to determine exhaust gas composition and exhaust gas temperature. A thermopar was installed near the exhaust collection to measure cylinder temperature. In-cylinder pressure was measured using an AVL Indumicro data acquisition system with a piezoelectric pressure sensor. An AVL optical encoder was installed in the crankshaft and synchronized with in-cylinder pressure in real time. The experimental procedure consisted of injecting hydrogen into the engine intake manifold at different mass concentrations of 2,6,8 and 10% of total fuel mass (B7 + hydrogen), which represented energy fractions of 5,15, 20 and 24% of total fuel energy respectively. Due to hydrogen addition, the total amount of fuel energy introduced increased and the generators fuel injection governor prevented any increases of engine speed. Several conclusions can be stated from the test results. A reduction in specific fuel consumption as a function of hydrogen concentration increase was noted. Likewise, carbon dioxide emissions (CO2), carbon monoxide (CO) and unburned hydrocarbons (HC) decreased as hydrogen concentration increased. On the other hand, nitrogen oxides emissions (NOx) increased due to average temperatures inside the cylinder being higher. There was also an increase in peak cylinder pressure and heat release rate inside the cylinder, since the fuel ignition delay was smaller due to hydrogen content increase. All this indicates that hydrogen promotes faster combustion and higher heat release rates and can be an important additive to all kind of fuels used in diesel generators.

Keywords: diesel engine, hydrogen, dual fuel, combustion analysis, performance, emissions

Procedia PDF Downloads 335

Authors: Z. Jamalzadeh, A. Niaei, H. Erfannia

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Due to developing industries, the emission of pollutants such as NOx, SOx, and CO2 are rapidly increased. Generally, NOx is attributed to the mono nitrogen oxides of NO and NO2 that is one of the most important atmospheric contaminants. Hence, controlling the emission of nitrogen oxides is environmentally urgent. Selective catalytic reduction of NOx is one of the most common techniques for NOx removal in which zeolites have wide application due to their high performance. In zeolitic processes, the catalytic reaction occurs mostly in the pores. Therefore, investigation of the adsorption phenomena of the molecules in order to gain an insight and understand the catalytic cycle is of important. Hence, in current study, benefiting from molecular simulations, the adsorption phenomena in the nanocatalysts of SCR of NOx process was investigated in order to get a good insight of the catalysts’ behavior. The effect of cation addition to the support in the catalysts’ behavior through adsorption step was explored by Mont Carlo (MC) using Materials Studio Package. Simulation time of 1 Ns accompanying 1 fs time step, COMPASS27 Force Field and the cut off radios of 12.5 Ȧ was applied for performed runs. It was observed that the adsorption capacity increases in the presence of cations. The sorption isotherms demonstrated the behavior of type I isotherm categories and sorption capacity diminished with increase in temperature whereas an increase was observed at high pressures. Besides, NO sorption showed higher sorption capacity than NH3 in H–ZSM5. In this respect, the energy distributions signified that the molecules could adsorb in just one sorption site at the catalyst and the sorption energy of NO was stronger than the NH3 in H-ZSM5. Furthermore, the isosteric heat of sorption data showed nearly same values for the molecules; however, it indicated stronger interactions of NO molecules with H-ZSM5 zeolite compared to the isosteric heat of NH3 which was low in value.

Keywords: Monte Carlo simulation, adsorption, NOx, ZSM5

Procedia PDF Downloads 334

Authors: R. Kerbachi, S. Chikhi, M. Boughedaoui

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The study presents an analysis of the Algerian vehicle fleet and resultant emissions. The emission measurement of air pollutants emitted by road transportation (CO, THC, NOX and CO2) was conducted on 17 light duty vehicles in real traffic. This sample is representative of the Algerian light vehicles in terms of fuel quality (gasoline, diesel and liquefied petroleum gas) and the technology quality (injection system and emission control). The experimental measurement methodology of unit emission of vehicles in real traffic situation is based on the use of the mini-Constant Volume Sampler for gas sampling and a set of gas analyzers for CO2, CO, NOx and THC, with an instrumentation to measure kinematics, gas temperature and pressure. The apparatus is also equipped with data logging instrument and data transfer. The results were compared with the database of the European light vehicles (Artemis). It was shown that the technological injection liquefied petroleum gas (LPG) has significant impact on air pollutants emission. Therefore, with the exception of nitrogen oxide compounds, uncatalyzed LPG vehicles are more effective in reducing emissions unit of air pollutants compared to uncatalyzed gasoline vehicles. LPG performance seems to be lower under real driving conditions than expected on chassis dynamometer. On the other hand, the results show that uncatalyzed gasoline vehicles emit high levels of carbon monoxide, and nitrogen oxides. Overall, and in the absence of standards in Algeria, unit emissions are much higher than Euro 3. The enforcement of pollutant emission standard in developing countries is an important step towards introducing cleaner technology and reducing vehicular emissions.

Keywords: on-board measurements of unit emissions of CO, HC, NOx and CO2, light vehicles, mini-CVS, LPG-fuel, artemis, Algeria

Procedia PDF Downloads 260

Authors: Tripti Nayak, R. K. Bajpai

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An ongoing field experiment was conducted at Long term fertilizer experiment, Raipur, to study the Effect of fertilization (both organic and inorganic) on soil Physical properties (infiltration rate) of Vertisol of ten treatments viz. The treatment combinations for were T1(Control),T2(50%NPK), T3(100%NPK), T4(150%NPK), T5(100%NPK+Zn), T6(100%NP), T7(100%N), T8(100%NPK+FYM), T9 (50%NPK+BGA) and T10(50%NPK+GM). Farmyard manure and green manure is applied at the treatment of T8 (100%NPK+FYM) and T10 (50%NPK+GM). Result showed that the highest infiltration rate recorded T8(100%NPK+FYM) and T10 (50%NPK+GM). These considerations have led to a renewed interest in the organic manures such as FYM, compost and green manures, which are formulations helps in sustainable agriculture production either by providing plants with fixed nitrogen, available P or by other plant growth promoting substances. Organic matter (OM) is the life of the soil because it contains all the essential elements required for plant growth. It also serves as food for soil bacteria. Decomposed OM, known as humus, improves the soil tilth, quality and helps the plant to grow. In general among all the other treatments and control gave poorest infiltration rate. Incorporation of organic sources considerably improved the soil physical properties such as decrease in bulk density and increase in infiltration rate and available NPK status of the soil. Study showed that wherever, nitrogen was substituted through GM, FYM or crop residue (rice straw) in rice, Corresponding decrease in bulk density favorably enhanced the infiltration rate and it was found to be highest in the green-manured plot, FYM and lowest in control. Concluded that Continuous monitoring of physical properties should be carried out for maintaining soil health and enhancing the crop production.

Keywords: long term effect, FYM, green manure, infiltration rate, soil health, crop productivity, vertisol

Procedia PDF Downloads 348

Authors: Adrian Niewiadomski, Barbara Surma, Katarzyna Kolodziejak, Dorota A. Pawlak

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Oxide-oxide eutectic is attracting increasing interest of scientific community because of their unique properties and numerous potential applications. Some of the most interesting examples of applications are metamaterials, glucose sensors, photoactive materials, thermoelectric materials, and photocatalysts. Their unique properties result from the fact that composite materials consist of two or more phases. As a result, these materials have additive and product properties. Additive properties originate from particular phases while product properties originate from the interaction between phases. MnTiO3-TiO2 eutectic is one of such materials. TiO2 is a well-known semiconductor, and it is used as a photocatalyst. Moreover, it may be used to produce solar cells, in a gas sensing devices and in electrochemistry. MnTiO3 is a semiconductor and antiferromagnetic. Therefore it has potential application in integrated circuits devices, and as a gas and humidity sensor, in non-linear optics and as a visible-light activated photocatalyst. The above facts indicate that eutectic MnTiO3-TiO2 constitutes an extremely promising material that should be studied. Despite that Raman spectroscopy is a powerful method to characterize materials, to our knowledge Raman studies of eutectics are very limited, and there are no studies of the MnTiO3-TiO2 eutectic. While to our knowledge the papers regarding this material are scarce. The MnTiO3-TiO2 eutectic, as well as TiO2 and MnTiO3 single crystals, were grown by the micro-pulling-down method at the Institute of Electronic Materials Technology in Warsaw, Poland. A nitrogen atmosphere was maintained during whole crystal growth process. The as-grown samples of MnTiO3-TiO2 eutectic, as well as TiO2 and MnTiO3 single crystals, are black and opaque. Samples were cut perpendicular to the growth direction. Cross sections were examined with scanning electron microscopy (SEM) and with Raman spectroscopy. The present studies showed that maintaining nitrogen atmosphere during crystal growth process may result in obtaining black TiO2 crystals. SEM and Raman experiments showed that studied eutectic consists of three distinct regions. Furthermore, two of these regions correspond with MnTiO3, while the third region corresponds with the TiO2-xNx phase. Raman studies pointed out that TiO2-xNx phase crystallizes in rutile structure. The studies show that Raman experiments may be successfully used to characterize eutectic materials. The MnTiO3-TiO2 eutectic was grown by the micro-pulling-down method. SEM and micro-Raman experiments were used to establish phase composition of studied eutectic. The studies revealed that the TiO2 phase had been doped with nitrogen. Therefore the TiO2 phase is, in fact, a solid solution with TiO2-xNx composition. The remaining two phases exhibit Raman lines of both rutile TiO2 and MnTiO3. This points out to some kind of coexistence of these phases in studied eutectic.

Keywords: compound materials, eutectic growth and characterization, Raman spectroscopy, rutile TiO₂

Procedia PDF Downloads 174

Authors: Olga Sukhoveeva

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Carbon dioxide (CO2) is the main component of carbon biogeochemical cycle and one of the most important greenhouse gases (GHG). Agriculture, particularly arable soils, are one the largest sources of GHG emission for the atmosphere including CO2.Models may be used for estimation of GHG emission from agriculture if they can be adapted for different countries conditions. The only model used in officially at national level in United Kingdom and China for this purpose is DNDC (DeNitrification-DeComposition). In our research, the model DNDC is offered for estimation of GHG emission from arable soils in Russia. The aim of our research was to create the method of DNDC using for evaluation of CO2 emission in Russia based on official statistical information. The target territory was European part of Russia where many field experiments are located. At the first step of research the database on climate, soil and cropping characteristics for the target region from governmental, statistical, and literature sources were created. All-Russia Research Institute of Hydrometeorological Information – World Data Centre provides open daily data about average meteorological and climatic conditions. It must be calculated spatial average values of maximum and minimum air temperature and precipitation over the region. Spatial average values of soil characteristics (soil texture, bulk density, pH, soil organic carbon content) can be determined on the base of Union state register of soil recourses of Russia. Cropping technologies are published by agricultural research institutes and departments. We offer to define cropping system parameters (annual information about crop yields, amount and types of fertilizers and manure) on the base of the Federal State Statistics Service data. Content of carbon in plant biomass may be calculated via formulas developed and published by Ministry of Natural Resources and Environment of the Russian Federation. At the second step CO2 emission from soil in this region were calculated by DNDC. Modelling data were compared with empirical and literature data and good results were obtained, modelled values were equivalent to the measured ones. It was revealed that the DNDC model may be used to evaluate and forecast the CO2 emission from arable soils in Russia based on the official statistical information. Also, it can be used for creation of the program for decreasing GHG emission from arable soils to the atmosphere. Financial Support: fundamental scientific researching theme 0148-2014-0005 No 01201352499 ‘Solution of fundamental problems of analysis and forecast of Earth climatic system condition’ for 2014-2020; fundamental research program of Presidium of RAS No 51 ‘Climate change: causes, risks, consequences, problems of adaptation and regulation’ for 2018-2020.

Keywords: arable soils, carbon dioxide emission, DNDC model, European Russia

Procedia PDF Downloads 173

Authors: Hamadi Cherif, Christophe Coquelet, Paolo Stringari, Denis Clodic, Laura Pellegrini, Stefania Moioli, Stefano Langè

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Biogas is a promising technology which can be used as a vehicle fuel, for heat and electricity production, or injected in the national gas grid. It is storable, transportable, not intermittent and substitutable for fossil fuels. This gas produced from the wastewater treatment by degradation of organic matter under anaerobic conditions is mainly composed of methane and carbon dioxide. To be used as a renewable fuel, biogas, whose energy comes only from methane, must be purified from carbon dioxide and other impurities such as water vapor, siloxanes and hydrogen sulfide. Purification of biogas for this application particularly requires the removal of hydrogen sulfide, which negatively affects the operation and viability of equipment especially pumps, heat exchangers and pipes, causing their corrosion. Several methods are available to eliminate hydrogen sulfide from biogas. Herein, reactive absorption in structured packed column by means of chemical absorption in aqueous sodium hydroxide solutions is considered. This study is based on simulations using Aspen Plus™ V8.0, and comparisons are done with data from an industrial pilot plant treating 85 Nm3/h of biogas which contains about 30 ppm of hydrogen sulfide. The rate-based model approach has been used for simulations in order to determine the efficiencies of separation for different operating conditions. To describe vapor-liquid equilibrium, a γ/ϕ approach has been considered: the Electrolyte NRTL model has been adopted to represent non-idealities in the liquid phase, while the Redlich-Kwong equation of state has been used for the vapor phase. In order to validate the thermodynamic model, Henry’s law constants of each compound in water have been verified against experimental data. Default values available in Aspen Plus™ V8.0 for the properties of pure components properties as heat capacity, density, viscosity and surface tension have also been verified. The obtained results for physical and chemical properties are in a good agreement with experimental data. Reactions involved in the process have been studied rigorously. Equilibrium constants for equilibrium reactions and the reaction rate constant for the kinetically controlled reaction between carbon dioxide and the hydroxide ion have been checked. Results of simulations of the pilot plant purification section show the influence of low temperatures, concentration of sodium hydroxide and hydrodynamic parameters on the selective absorption of hydrogen sulfide. These results show an acceptable degree of accuracy when compared with the experimental data obtained from the pilot plant. Results show also the great efficiency of sodium hydroxide for the removal of hydrogen sulfide. The content of this compound in the gas leaving the column is under 1 ppm.

Keywords: biogas, hydrogen sulfide, reactive absorption, sodium hydroxide, structured packed column

Procedia PDF Downloads 326

Authors: Monkiz Khasreen

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In the context of the global trend towards reducing new buildings carbon footprint, the design team is required to make early decisions that have a major influence on embodied and operational carbon. Sustainability strategies should be clear during early stages of building design process, as changes made later can be extremely costly. Life-Cycle Assessment (LCA) could be used as the vehicle to carry other tools and processes towards achieving the requested improvement. Although LCA is the ‘golden standard’ to evaluate buildings from 'cradle to grave', lack of details available on the concept design makes LCA very difficult, if not impossible, to be used as an estimation tool at early stages. Issues related to transparency and accessibility of information in the building industry are affecting the credibility of LCA studies. A verified database derived from LCA case studies is required to be accessible to researchers, design professionals, and decision makers in order to offer guidance on specific areas of significant impact. This database could be the build-up of data from multiple sources within a pool of research held in this context. One of the most important factors that affects the reliability of such data is the temporal factor as building materials, components, and systems are rapidly changing with the advancement of technology making production more efficient and less environmentally harmful. Recent LCA studies on different building functions, types, and structures are always needed to update databases derived from research and to form case bases for comparison studies. There is also a need to make these studies transparent and accessible to designers. The work in this paper sets out to address this need. This paper also presents life-cycle case study of a new-build educational building in England. The building utilised very current construction methods and technologies and is rated as BREEAM excellent. Carbon emissions of different life-cycle stages and different building materials and components were modelled. Scenario and sensitivity analyses were used to estimate the future of new educational buildings in England. The study attempts to form an indicator during the early design stages of similar buildings. Carbon dioxide emissions of this case study building, when normalised according to floor area, lie towards the lower end of the range of worldwide data reported in the literature. Sensitivity analysis shows that life cycle assessment results are highly sensitive to future assumptions made at the design stage, such as future changes in electricity generation structure over time, refurbishment processes and recycling. The analyses also prove that large savings in carbon dioxide emissions can result from very small changes at the design stage.

Keywords: architecture, building, carbon dioxide, construction, educational buildings, England, environmental impact, life-cycle assessment

Procedia PDF Downloads 98

Authors: Arlene López-Sampson, Tony Page, Betsy Jackes

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Aquilaria genus produces a highly valuable fragrant oleoresin known as agarwood. Agarwood forms in a few trees in the wild as a response to injure or pathogen attack. The resin is used in perfume and incense industry and medicine. Cultivation of Aquilaria species as a sustainable source of the resin is now a common strategy. Physiological traits are frequently used as a proxy of crop and tree productivity. Aquilaria species growing in Queensland, Australia were studied to investigate relationship between leaf-productivity traits with tree growth. Specifically, 28 trees, representing 12 plus trees and 16 trees from yield plots, were selected to conduct carbon isotope analysis (δ13C) and monitor six leaf attributes. Trees were grouped on four diametric classes (diameter at 150 mm above ground level) ensuring the variability in growth of the whole population was sampled. Model averaging technique based on the Akaike’s information criterion (AIC) was computed to identify whether leaf traits could assist in diameter prediction. Carbon isotope values were correlated with height classes and leaf traits to determine any relationship. In average four leaves per shoot were recorded. Approximately one new leaf per week is produced by a shoot. Rate of leaf expansion was estimated in 1.45 mm day-1. There were no statistical differences between diametric classes and leaf expansion rate and number of new leaves per week (p > 0.05). Range of δ13C values in leaves of Aquilaria species was from -25.5 ‰ to -31 ‰ with an average of -28.4 ‰ (± 1.5 ‰). Only 39% of the variability in height can be explained by δ13C in leaf. Leaf δ13C and nitrogen content values were positively correlated. This relationship implies that leaves with higher photosynthetic capacities also had lower intercellular carbon dioxide concentrations (ci/ca) and less depleted values of 13C. Most of the predictor variables have a weak correlation with diameter (D). However, analysis of the 95% confidence of best-ranked regression models indicated that the predictors that could likely explain growth in Aquilaria species are petiole length (PeLen), values of δ13C (true13C) and δ15N (true15N), leaf area (LA), specific leaf area (SLA) and number of new leaf produced per week (NL.week). The model constructed with PeLen, true13C, true15N, LA, SLA and NL.week could explain 45% (R2 0.4573) of the variability in D. The leaf traits studied gave a better understanding of the leaf attributes that could assist in the selection of high-productivity trees in Aquilaria.

Keywords: 13C, petiole length, specific leaf area, tree growth

Procedia PDF Downloads 486

Authors: Tahar Ghnaya, Majda Mnasri, Hanen Zaier, Rim Ghabriche, Chedly Abdelly

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It is known that the symbiotic association between plant and microorganisms are beneficial for plant growth and resistance to metal stress. Hence, it was demonstrated that Arbuscular mycorrhizal fungi have a positive effect on host plants growing in metal polluted soils. Legume plants are those which normally associate to rhizobacteria in order to fix atmospheric nitrogen. The aim of this work was to evaluate the effect this type of symbiosis on the tolerance and the accumulation of Cd. We chose Medicago sativa, as a modal for host legume plants and Rhizobium mililoti 2011 as rhizobial strain. Inoculated and non-inoculated plants of M. sativa were submitted during three month to 0, 50, and 100 mgCd/kg dry soil. Results showed that the presence of Cd in the medium induced, in both inoculated and non-inoculated plants, a chlorosis and necrosis. However, these symptoms were more pronounced in non-inoculated plants. The beneficial effect of inoculation of M. sativa with R. meliloti, on plant growth was confirmed by the measurement of biomass production which showed that the symbiotic association between host plant and rhizobacteria alleviates significantly Cd effect on biomass production, so inoculated plants produced more dry weight as compared to non-inoculated ones in the presence of all Cd tretments. On the other hand, under symbiosis conditions, Cd was more accumulated in different plant organs. Hence, in these plants, shoot Cd concentration reached 425 and it was 280 µg/gDW in non-inoculated ones in the presence of 100 ppm Cd. This result suggests that symbiosis enhances the absorption and translocation of Cd in this plant. In nodules and roots, we detected the highest Cd concentrations, demonstrating that these organs are able to concentrate Cd in their tissues. These data confirm that M. sataiva, cultivated in symbiosis with Rhizobium mililoti could be used in phytoextraction of Cd from contaminated soils.

Keywords: Cd, phytoremediation, Medicago sativa, Arbuscular mycorrhizal

Procedia PDF Downloads 256

Authors: Marcin Debowski, Marcin Zielinski, Miroslaw Krzemieniewski, Agata Glowacka-Gil, Paulina Rusanowska, Magdalena Zielinska, Agnieszka Cydzik-Kwiatkowska

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Technologies of biogas upgrading are now perceived as competitive solution combustion and production of electricity and heat. Biomethane production will ensure broader application as energy carrier than biogas. Biomethane can be used as fuel in internal combustion engines or introduced into the natural gas transmission network. Therefore, there is a need to search for innovative, economically and technically justified methods for biogas enrichment. The aim of this paper is to present a technology solution for biogas upgrading with immobilized algae biomass. Reactor for biogas upgrading with immobilized algae biomass can be used for removing CO₂ from the biogas, flue gases and the waste gases especially coming from different industry sectors, e.g. from the food industry from yeast production process, biogas production systems, liquid and gaseous fuels combustion systems, hydrocarbon processing technology. The basis for the technological assumptions of presented technology were laboratory works and analyses that tested technological variants of biogas upgrading. The enrichment of biogas with a methane content of 90-97% pointed to technological assumptions for installation on a technical scale. Reactor for biogas upgrading with algae biomass is characterized by a significantly lower cubature in relation to the currently used solutions which use CO₂ removal processes. The invention, by its structure, assumes achieving a very high concentration of biomass of algae through its immobilization in capsules. This eliminates the phenomenon of lowering the pH value, i.e. acidification of the environment in which algae grow, resulting from the introduction of waste gases at a high CO₂ concentration. The system for introducing light into algae capsules is characterized by a higher degree of its use, due to lower losses resulting from the phenomenon of absorption of light energy by water. The light from the light source is continuously supplied to the formed biomass of algae or cyanobacteria in capsules by the light tubes. The light source may be sunlight or a light generator of a different wavelength of light from 300 nm to 800 nm. A portion of gas containing CO₂, accumulated in the tank and conveyed by the pump is periodically introduced into the housing of the photobioreactor tank. When conveying the gas that contains CO₂, it penetrates the algal biomass in capsules through the outer envelope, displacing, from the algal biomass, gaseous metabolic products which are discharged by the outlet duct for gases. It contributes to eliminating the negative impact of this factor on CO₂ binding processes. As a result of the cyclic dosing of gases containing carbon dioxide, gaseous metabolic products of algae are displaced and removed outside the technological system. Technology for biogas upgrading with immobilized algae biomass is suitable for the small biogas plant. The advantages of this technology are high efficiency as well as useful algae biomass which can be used mainly as animal feed, fertilizers and in the power industry. The construction of the device allows effective removal of carbon dioxide from gases at a high CO₂ concentration.

Keywords: biogas, carbon dioxide, immobilised biomass, microalgae, upgrading

Procedia PDF Downloads 138

Authors: Sarah Alamolhoda, Kevin J. Smith, Xiaotao Bi, Naoko Ellis

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For millennials, biomass has been the most important source of fuel used to produce energy. Energy derived from biomass is renewable by re-growth of biomass. Various technologies are used to convert biomass to potential renewable products including combustion, gasification, pyrolysis and fermentation. Gasification is the incomplete combustion of biomass in a controlled environment that results in valuable products such as syngas, biooil and biochar. Syngas is a combustible gas consisting of hydrogen (H₂), carbon monoxide (CO), carbon dioxide (CO₂), and traces of methane (CH₄) and nitrogen (N₂). Cleaned syngas can be used as a turbine fuel to generate electricity, raw material for hydrogen and synthetic natural gas production, or as the anode gas of solid oxide fuel cells. In this work, syngas as a product of woody biomass gasification in British Columbia, Canada, was introduced to two consecutive fixed bed reactors to perform a catalytic water gas shift reaction followed by a catalytic methanation reaction. The water gas shift reaction is a well-established industrial process and used to increase the hydrogen content of the syngas before the methanation process. Catalysts were used in the process since both reactions are reversible exothermic, and thermodynamically preferred at lower temperatures while kinetically favored at elevated temperatures. The water gas shift reactor and the methanation reactor were packed with Cu-based catalyst and Ni-based catalyst, respectively. Simulated syngas with different percentages of CO, H₂, CH₄, and CO₂ were fed to the reactors to investigate the effect of operating conditions in the unit. The water gas shift reaction experiments were done in the temperature of 150 ˚C to 200 ˚C, and the pressure of 550 kPa to 830 kPa. Similarly, methanation experiments were run in the temperature of 300 ˚C to 400 ˚C, and the pressure of 2340 kPa to 3450 kPa. The Methanation reaction reached 98% of CO conversion at 340 ˚C and 3450 kPa, in which more than half of CO was converted to CH₄. Increasing the reaction temperature caused reduction in the CO conversion and increase in the CH₄ selectivity. The process was designed to be renewable and release low greenhouse gas emissions. Syngas is a clean burning fuel, however by going through water gas shift reaction, toxic CO was removed, and hydrogen as a green fuel was produced. Moreover, in the methanation process, the syngas energy was transformed to a fuel with higher energy density (per volume) leading to reduction in the amount of required fuel that flows through the equipment and improvement in the process efficiency. Natural gas is about 3.5 times more efficient (energy/ volume) than hydrogen and easier to store and transport. When modification of existing infrastructure is not practical, the partial conversion of renewable hydrogen to natural gas (with up to 15% hydrogen content), the efficiency would be preserved while greenhouse gas emission footprint is eliminated.

Keywords: renewable natural gas, methane, hydrogen, gasification, syngas, catalysis, fuel

Procedia PDF Downloads 89

Authors: D. Abid, A. Guettar, A. Toubane, A. Bouda, K. Daoud

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The aim of this work is to study coating formulations rheology. Fourteen solutions were prepared with Hydroxypropyl methylcellulose (HPMC) percentage which varies from 2 to 20 %, Ethyl cellulose (EC) percentage varying from 1 to 3 % and Titanium dioxide (TiO2) percentage which vary from 1 to 3%, Opadry solution (25%) was used as a reference for this study. Two behaviors appeared obviously ‘pseudo plastic’ and ‘dilatant’ related to the percentage of HPMC, this allowed us to define that HPMC is the polymer which influence the behavior of coating solutions.

Keywords: rheology, opadry, HPMC, B1-B6 tablets

Procedia PDF Downloads 244