Search results for: organic filler

Authors: Ankush Verma, Rohit Bishist

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The present investigation was carried out at different locations of Shimla and Kinnaur district and nutrient analysis was done in the laboratory of Department of Silviculture and Agroforestry, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Distt. Solan, Himachal Pradesh during 2019-2020 with the objectives to study the seasonal variation in the nutritive value of different Quercus species and to study the farmers’ preference rating of fodder tress species. From each location leaf samples were collected at 3 months interval from each Quercus spp. The findings of the present study revealed that the nutritional traits of leaves of different Quercus species varied among different seasons throughout the year. The dry matter (61.12 to 64.99%), ether extract (4.07 to 4.42%), crude fibre (34.38 to 37.85%), neutral detergent fibre (57.70 to 61.54%), acid detergent fibre (44.64 to 48.51%), total ash (3.57 to 3.91%), acid insoluble ash (44.64 to 48.51%) and calcium (1.31 to 1.53%) increased with the maturity in the leaves of different Quercus species. While, crude protein (9.10 to 10.61%), nitrogen free extract (44.73 to 47.41%), organic matter (96.09 to 96.43%), and phosphorus (0.16 to 0.31%) decreased with the advancing maturity in the leaves of different Quercus species. Maximum mean values for dry matter (65.05%), ether extract (4.45%), crude fibre (40.82%), neutral detergent fibre (61.48%), acid detergent fibre (48.44%), and organic matter (96.67%) among different Quercus species were recorded in Quercus ilex, while, Maximum mean values for crude protein (10.54%), nitrogen free extract (50.53%), total ash (4.05%), acid insoluble ash (0.59%), calcium (1.61%) and phosphorus (0.40%) were recorded in Quercus leucotrichophora.

Keywords: nutritional evaluation, fodder species, crude protein, carbohydrates

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Authors: Shu Tao

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Based on a global fuel consumption data product (PKU-FUEL-2007) compiled recently and a series of databases for emission factors of various sources, global emission inventories of a number of greenhouse gases and air pollutants, including CO2, CO, SO2, NOx, primary particulate matter (total, PM 10, and PM 2.5), black carbon, organic carbon, mercury, volatile organic carbons, and polycyclic aromatic hydrocarbons, from combustion sources have been developed. The inventories feather high spatial and sectorial resolutions. The spatial resolution of the inventories are 0.1 by 0.1 degree, based on a sub-national disaggregation approach to reduce spatial bias due to uneven distribution of per person fuel consumption within countries. The finely resolved inventories provide critical information for chemical transport modeling and exposure modeling. Emissions from more than 60 sources in energy, industry, agriculture, residential, transportation, and wildfire sectors were quantified in this study. With the detailed sectorial information, the inventories become an important tool for policy makers. For residential sector, a set of models were developed to simulate temporal variation of fuel consumption, consequently pollutant emissions. The models can be used to characterize seasonal as well as inter-annual variations in the emissions in history and to predict future changes. The models can even be used to quantify net change of fuel consumption and pollutant emissions due to climate change. The inventories has been used for model ambient air quality, population exposure, and even health effects. A few examples of the applications are discussed.

Keywords: air pollutants, combustion, emission inventory, sectorial information

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Authors: Maharani Yulisti, Amin Mugera, James Fogarty

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Food safety standards have received significant attention in the fisheries global market due to health issues, free trade agreements, and increasing aquaculture production. Vertical coordination throughout the supply chain of fish producing and exporting countries is needed to meet food safety demands imposed by importing countries. However, the complexities of the supply chain governance structures and difficulties in standard implementation can generate safety uncertainty and high transaction costs. Using a Transaction Cost Economics framework, this paper examines the alignment between food safety standards and the governance structures in the shrimp supply chain in Indonesia. We find the supply chain is organized closer to the hierarchy-like governance structure where private standard (organic standard) are implemented and more towards a market-like governance structure where public standard (IndoGAP certification) are more prevalent. To verify the statements, two cases are examined from Sidoarjo district as a centre of shrimp production in Indonesia. The results show that public baseline FSS (Food Safety Standards) need additional mechanism to achieve a coordinated chain-wide response because uncertainty, asset specificity, and performance measurement problems are high in this chain. Organic standard as private chain-wide FSS is more efficient because it has been achieved by hierarchical-like type of governance structure.

Keywords: governance structure, shrimp value chain, food safety standards, transaction costs economics

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Authors: Sharmila Pradhan, Ralf Lach, George Michler, Jean Mark Saiter, Rameshwar Adhikari

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Ethylene/1-octene copolymer was modified incorporating three types of nanofillers differed in their dimensionality in order to investigate the effect of filler dimensionality on mechanical properties, for instance, tensile strength, microhardness etc. The samples were prepared by melt mixing followed by compression moldings. The microstructure of the novel material was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) method and Transmission electron microscopy (TEM). Other important properties such as melting, crystallizing and thermal stability were also investigated via differential scanning calorimetry (DSC) and Thermogravimetry analysis (TGA). The FTIR and XRD results showed that the composites were formed by physical mixing. The TEM result supported the homogeneous dispersion of nanofillers in the matrix. The mechanical characterization performed by tensile testing showed that the composites with 1D nanofiller effectively reinforced the polymer. TGA results revealed that the thermal stability of pure EOC is marginally improved by the addition of nanofillers. Likewise, melting and crystallizing properties of the composites are not much different from that of pure.

Keywords: copolymer, differential scanning calorimetry, nanofiller, tensile strength

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Authors: Alvarez Barrantes, Robert Dorrell, Christopher Hackney, Anne Baar, Roberto Fernandez, Daniel Parsons

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Microplastic particles entering fluvial environments are deposited with natural sediments. Their settling properties can change by the absorption or adsorption of contaminants, organic matter, and organisms. These deposits include positively, neutrally, and negatively buoyant particles. This study aims to understand how plastic particles of different densities interact with natural sediments as they settle and how they are stored within the sediment deposit. The results of this study contribute to a better understanding of the deposition of microplastic particles and associated pollution in rivers. A set of 48 experiments was designed to investigate the settling process of microplastic particles in freshwater. The experimental work describes the vertical variation of cohesive and/or non-cohesive sediment versus microplastic densities in deposited sediment. The experiment consisted of adding microplastic particles, sediment, and water in a waterproof carton tube of a height of 24 cm and a diameter of 5 cm. The plastic selected is positively, neutrally, and negatively buoyant. The sediments consist of sand and clay with four different concentrations. The mixture of materials was shaken until is thoroughly mixed and left to settle for 24 hours. After the settlement, the tubes were frozen at -20 °C to be able to cut them and measure the thickness of the deposits and analyze the sediment and plastic distribution. The most representative experiments were repeated in a glass tube of the same size; to analyse the influences of current flows and depositional process. Finally, the glass tube experiments were used to study organic materials adsorption in plastic, settling the sample for four months. Defined microplastic layers were identified as the density of the plastic change. Preliminary results show that most of the positive buoyancy particles floated, neutral buoyancy particles form a layer above the sediment and negative buoyancy particles mixed with the sediment. The vertical grain size distribution of the deposits was analysed to determine deposition variation with and without plastic. It is expected that the positively buoyant particles are trapped in the sediment by the currents flows and sink due to organic material adsorption. Finally, the experiments will explain how microplastic particles, including positively buoyant ones, are stored in natural sediment deposits.

Keywords: microplastic adsorption process, microplastic deposition in natural sediment, microplastic pollution in rivers, storages of positive buoyancy microplastic particles

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Authors: K. Paradkar, S. N. Mudliar, A. Sharma, A. B. Pandit, R. A. Pandey

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The study explores the hybrid combination of Hydrodynamic Cavitation (HC) and Subcritical Wet Air Oxidation-based pretreatment of complex industrial effluent to enhance the biodegradability selectively (without major COD destruction) to facilitate subsequent enhanced downstream processing via anaerobic or aerobic biological treatment. Advanced oxidation based techniques can be less efficient as standalone options and a hybrid approach by combining Hydrodynamic Cavitation (HC), and Wet Air Oxidation (WAO) can lead to a synergistic effect since both the options are based on common free radical mechanism. The HC can be used for initial turbulence and generation of hotspots which can begin the free radical attack and this agitating mixture then can be subjected to less intense WAO since initial heat (to raise the activation energy) can be taken care by HC alone. Lab-scale venturi-based hydrodynamic cavitation and wet air oxidation reactor with biomethanated distillery wastewater (BMDWW) as a model effluent was examined for establishing the proof-of-concept. The results indicated that for a desirable biodegradability index (BOD: COD - BI) enhancement (up to 0.4), the Cavitation (standalone) pretreatment condition was: 5 bar and 88 min reaction time with a COD reduction of 36 % and BI enhancement of up to 0.27 (initial BI - 0.17). The optimum WAO condition (standalone) was: 150oC, 6 bar and 30 minutes with 31% COD reduction and 0.33 BI. The hybrid pretreatment (combined Cavitation + WAO) worked out to be 23.18 min HC (at 5 bar) followed by 30 min WAO at 150oC, 6 bar, at which around 50% COD was retained yielding a BI of 0.55. FTIR & NMR analysis of pretreated effluent indicated dissociation and/or reorientation of complex organic compounds in untreated effluent to simpler organic compounds post-pretreatment.

Keywords: hybrid, hydrodynamic cavitation, wet air oxidation, biodegradability index

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Authors: Jian Zheng

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Three-dimensional (3D) network structure has been recognized as an effective approach to enhance the mechanical and thermal conductive properties of polymeric composites. However, it has not been applied in energetic materials. In this work, a fluoropolymer based composite with vertically oriented and interconnected 3D graphite network was fabricated for polymer bonded explosives (PBXs). Here, the graphite and graphene oxide platelets were mixed, and self-assembled via rapid freezing and using crystallized ice as the template. The 3D structure was finally obtained by freezing-dry and infiltrating with the polymer. With the increasing of filler fraction and cooling rate, the thermal conductivity of the polymer composite was significantly improved to 2.15 W m⁻¹ K⁻¹ by 1094% than that of pure polymer. Moreover, the mechanical properties, such as tensile strength and elastic modulus, were enhanced by 82% and 310%, respectively, when the highly ordered structure was embedded in the polymer. We attribute the increased thermal and mechanical properties to this 3D network, which is beneficial to the effective heat conduction and force transfer. This study supports a desirable way to fabricate the strong and thermal conductive fluoropolymer composites used for the high-performance polymer bonded explosives (PBXs).

Keywords: mechanical properties, oriented network, graphite polymer composite, thermal conductivity

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Authors: Elene Tatunashvili, Bun Chan, Philippe E. Nashar, Christopher S. P. McErlean

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The reduction of aryl diazonium salts is one of the most efficient ways to generate aryl radicals for use in a wide range of transformations, including Sandmeyer-type reactions, Meerwein arylations of olefins and Gomberg-Bachmann-Hey arylations of heteroaromatic systems. The aryl diazonium species can be reduced electrochemically, by UV irradiation, inner-sphere and outer-sphere single electron transfer processes (SET) from metal salts, SET from photo-excited organic catalysts or fragmentation of adducts with weak bases (acetate, hydroxide, etc.). This paper details an approach for the metal-free reduction of aryl diazonium salts, which facilitates the efficient synthesis of various aromatic compounds under exceedingly mild reaction conditions. By measuring the oxidation potential of a number of organic molecules, a series of nucleophiles were identified that reduce aryl diazonium salts via the addition-fragmentation mechanism. This approach leads to unprecedented operational simplicity: The reactions are very rapid and proceed in the open air; there is no need for external irradiation or heating, and the process is compatible with a large number of radical reactions. We illustrate these advantages by using the addition-fragmentation strategy to regioselectively arylate a series of heterocyclic compounds, to synthesize ketones by arylation of silyl enol ethers, and to synthesize benzothiophene and phenanthrene derivatives by radical annulation reactions.

Keywords: diazonium salts, hantzsch esters, oxygen, radical reactions, synthetic methods

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Authors: Zexiao Zheng, Irene M. C. Lo

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Organic pollutants, ammonia, and bacteria are major contaminants in sewage, which may adversely impact ecosystems without proper treatment. Conventional wastewater treatment plants (WWTPs) are operated to remove these contaminants from sewage but suffer from high carbon emissions and are powerless to remove emerging organic pollutants (EOPs). Herein, we have developed a low operational carbon emissions multifunctional photoelectrochemical (PEC) system for saline sewage treatment to simultaneously remove organic compounds, ammonia, and bacteria, coupled with H2 evolution. A reduced BiVO4 (r-BiVO4) with improved PEC properties due to the construction of oxygen vacancies and V4+ species was developed for the multifunctional PEC system. The PEC/r-BiVO4 process could treat saline sewage to meet local WWTPs’ discharge standard in 40 minutes at 2.0 V vs. Ag/AgCl and completely degrade carbamazepine (one of the EOPs), coupled with significant evolution of H2. A remarkable reduction in operational carbon emissions was achieved by the PEC/r-BiVO4 process compared with large-scale WWTPs, attributed to the restrained direct carbon emissions from the generation of greenhouse gases. Mechanistic investigation revealed that the PEC system could activate chloride ions in sewage to generate reactive chlorine species and facilitate •OH production, promoting contaminants removal. The PEC system exhibited operational feasibility at different pH and total suspended solids concentrations and has outstanding reusability and stability, confirming its promising practical potential. The study combined the simultaneous removal of three major contaminants from saline sewage and H2 evolution in a single PEC process, demonstrating a viable approach to supplementing and extending the existing wastewater treatment technologies. The study generated profound insights into the in-situ activation of existing chloride ions in sewage for contaminants removal and offered fundamental theories for applying the PEC system in sewage remediation with low operational carbon emissions. The developed PEC system can fit well with the future needs of wastewater treatment because of the following features: (i) low operational carbon emissions, benefiting the carbon neutrality process; (ii) higher quality of the effluent due to the elimination of EOPs; (iii) chemical-free in the operation of sewage treatment; (iv) easy reuse and recycling without secondary pollution.

Keywords: contaminants removal, H2 evolution, multifunctional PEC system, operational carbon emissions, saline sewage treatment, r-BiVO4 photoanodes

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Authors: Amar Boukerrou, Ouerdia Belhadj, Dalila Hammiche, Jean Francois Gerard, Jannick Rumeau

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The main goal of this study is the investigation of alfa fiber content, treated with alkali treatment, on the thermal and mechanical properties of epoxy-amine matrix-based composites. The fibers were treated with 5% of sodium hydroxide solution and varied between 10% to 30% weight fractions. The tensile, flexural, and hardness tests are carried out to investigate the mechanical properties of composites. The results show those composites’ mechanical properties are higher than the neat epoxy-amine. It was noticed that the alkali treatment is more effective in the case of the tensile and flexural modulus than the tensile and flexural strength. The decline of both the tensile and flexural behavior of all composites with the increasing of the filler content was due probably to the random dispersion of the fibers in the epoxy resin The Fourier transform infrared (FTIR) was employed to analyze the chemical structure of epoxy resin before and after curing with amine hardener. FTIR and DSC analysis confirmed that epoxy resin was completely cured with amine hardener at room temperature. SEM analysis has highlighted the microstructure of epoxy matrix and its composites.

Keywords: alfa fiber, epoxy resin, alkali treatment, mechanical properties

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Authors: O. Sunantha, S. Zhenfeng, S. Phattraporn, A. Zeeshan

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The decline of soil organic carbon (SOC) in global agriculture is a critical issue requiring rapid and accurate estimation for informed policymaking. While it is recognized that SOC predictors vary significantly when derived from remote sensing data and environmental variables, identifying the specific parameters most suitable for accurately estimating SOC in diverse agricultural areas remains a challenge. This study utilizes remote sensing data to precisely estimate SOC and identify influential factors in diverse agricultural areas, such as paddy, corn, sugarcane, cassava, and perennial crops. Extreme gradient boosting (XGBoost), random forest (RF), and support vector regression (SVR) models are employed to analyze these factors' impact on SOC estimation. The results show key factors influencing SOC estimation include slope, vegetation indices (EVI), spectral reflectance indices (red index, red edge2), temperature, land use, and surface soil moisture, as indicated by their averaged importance scores across XGBoost, RF, and SVR models. Therefore, using different machine learning algorithms for SOC estimation reveals varying influential factors from remote sensing data and environmental variables. This approach emphasizes feature selection, as different machine learning algorithms identify various key factors from remote sensing data and environmental variables for accurate SOC estimation.

Keywords: factors influencing SOC estimation, remote sensing data, environmental variables, machine learning

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Authors: Stepan Hysek, Premysl Sedivka, Petra Gajdacova

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Currently, structural composite materials contain cellulose-based particles (wood chips, fibers) bonded with synthetic adhesives containing formaldehyde (urea-formaldehyde, melamine-formaldehyde adhesives and others). Formaldehyde is classified as a volatile substance with provable carcinogenic effects on live organisms, and an emphasis has been put on continual reduction of its content in products. One potential solution could be the development of an agglomerated material which does not contain adhesives releasing formaldehyde. A potential alternative to formaldehyde-based adhesives could be polyurethane adhesives containing no formaldehyde. Such adhesives have been increasingly used in applications where a few years ago formaldehyde-based adhesives were the only option. Advantages of polyurethane adhesive in comparison with others in the industry include the high elasticity of the joint, which is able to resist dynamic stress, and resistance to increased humidity and climatic effects. These properties predict polyurethane adhesives to be used in OSB/EPS panel production. The objective of this paper is to develop an adhesive for bonding of sandwich panels made of material based on wood and other materials, e.g. SIP) and optimization of input components in order to obtain an adhesive with required properties suitable for bonding of the given materials without involvement of formaldehyde. It was found that polyurethane recyclate as a filler is suitable modification of polyurethane adhesive and results have clearly revealed that modified adhesive can be used for OSB/EPS panel production.

Keywords: adhesive, polyurethane, recyclate, SIP

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Authors: Brayan Daniel Riascos Arteaga, Carlos Costa Perez

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Landfill leachate has an important fraction of humic substances, mainly humic acids (HAs), which often represent more than half value of COD, specially in liquids proceeded from composting processes of organic fraction of solid wastes. We propose in this article a new method of pH sensitive flocculation for COD and colour reduction in landfill leachate based on the chemical properties of HAs. Landfill leachate with a high content of humic acids can be efficiently treated by pH sensitive flocculation at pH 2.0, reducing COD value in 86.1% and colour in 84.7%. Mechanism of pH sensitive flocculation is based in protonation first of phenolic groups and later of carboxylic acid groups in the HAs molecules, resulting in a reduction of Zeta potential value. For pH over neutrality, carboxylic acid and phenolic groups are ionized and Zeta potential increases in absolute value, maintaining HAs in suspension as colloids and conducting flocculation to be obstructed. Ionized anionic groups (carboxylates) can interact electrostatically with cations abundant in leachate (site binding) aiding to maintain HAs in suspension. Simulation of this situation and ideal visualization of Zeta potential behavior is described in the paper and aggregation of molecules by H-bonds is proposed as the main step in separation of HAs from leachate and reduction of COD value in this complex liquid. CHNS analysis, FT-IR spectrometry and UV–VIS spectrophotometry show chemical elements content in the range of natural and commercial HAs, clear aromaticity and carboxylic acids and phenolic groups presence in the precipitate from landfill leachate

Keywords: landfill leachate, humic acids, COD, chemical treatment, flocculation

Procedia PDF Downloads 71

Authors: Hayder Kamil Shanbara, Felicite Ruddock, William Atherton, Nassier A. Nassir

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Cold bitumen emulsion mixture (CBEM) offers a series benefits as compared with hot mix asphalt (HMA); these include environmental factors, energy saving, the resolution of logistical challenges that can characterise hot mix, and the potential to reserve funds. However, this mixture has some problems similar to any bituminous mixtures as it has low early strength, long curing time that needed to obtain the maximum performance, high air voids and considered inferior to HMA. Thus, CBEM has been used in limited applications such as lightly trafficked roads, footways and reinstatements. This laboratory study describes the development of CBEM using ordinary Portland cement (OPC) instead of the traditional mineral filler. Stiffness modulus, moisture damage and temperature sensitivity tests were used to evaluate the mechanical properties of the produced mixtures. The study concluded that there is a substantial improvement in the mechanical properties and moisture damage resistance of CBEMs containing OPC. Also, the produced cement modified CBEM shows a considerable lower thermal sensitivity than the conventional CBEM.

Keywords: cold bitumen emulsion mixture, moisture damage, OPC, stiffness modulus, temperature sensitivity

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Authors: Pradeep Kumar, Shalinee Shukla

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Pavement plays a vital role in the socio-economic development of a country. Bituminous roads construction with conventional paving grade bitumen obtained from hot mix plant creates pollution and involves emission of greenhouse gases, also the construction of pavements at very high temperature is not feasible or desirable for high rainfall and snowfall areas. This problem of overheating can be eliminated by the construction of pavements with the usage of emulsified cold mixes which will eliminate emissions and help in the reduction of fuel requirement at mixing plant, which leads to energy conservation. Cold mix is a mixture of unheated aggregate and emulsion or cutback and filler. The primary objective of this research is to assess the volumetric mix design parameters of recycled aggregates with cold mixing technology and also to assess the impact of additives on volumetric mix characteristics. In this present study, bituminous pavement materials are reclaimed using cold mix technology, and Marshall specimens are prepared with the help of slow setting type 2 (SS-2) cationic bitumen emulsion as a binder for recycled aggregates. This technique of road construction is more environmentally friendly and can be done in adverse weather conditions.

Keywords: cold mixes, bitumen emulsion, recycled aggregates, volumetric properties

Procedia PDF Downloads 137

Authors: Gela Gelashvili, David Gelenidze, Sulkhan Nanobashvili, Irakli Nanobashvili, George Tavkhelidze, Tsiuri Sitchinava

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Development of new highly efficient plasma arc combustion system of pulverized coal is presented. As it is well-known, coal is one of the main energy carriers by means of which electric and heat energy is produced in thermal power stations. The quality of the extracted coal decreases very rapidly. Therefore, the difficulties associated with its firing and complete combustion arise and thermo-chemical preparation of pulverized coal becomes necessary. Usually, other organic fuels (mazut-fuel oil or natural gas) are added to low-quality coal for this purpose. The fraction of additional organic fuels varies within 35-40% range. This decreases dramatically the economic efficiency of such systems. At the same time, emission of noxious substances in the environment increases. Because of all these, intense development of plasma combustion systems of pulverized coal takes place in whole world. These systems are equipped with Non-Transferred Plasma Arc Torches. They allow practically complete combustion of pulverized coal (without organic additives) in boilers, increase of energetic and financial efficiency. At the same time, emission of noxious substances in the environment decreases dramatically. But, the non-transferred plasma torches have numerous drawbacks, e.g. complicated construction, low service life (especially in the case of high power), instability of plasma arc and most important – up to 30% of energy loss due to anode cooling. Due to these reasons, intense development of new plasma technologies that are free from these shortcomings takes place. In our proposed system, pulverized coal-air mixture passes through plasma arc area that burns between to carbon electrodes directly in pulverized coal muffler burner. Consumption of the carbon electrodes is low and does not need a cooling system, but the main advantage of this method is that radiation of plasma arc directly impacts on coal-air mixture that accelerates the process of thermo-chemical preparation of coal to burn. To ensure the stability of the plasma arc in such difficult conditions, we have developed a power source that provides fixed current during fluctuations in the arc resistance automatically compensated by the voltage change as well as regulation of plasma arc length over a wide range. Our combustion system where plasma arc acts directly on pulverized coal-air mixture is simple. This should allow a significant improvement of pulverized coal combustion (especially low-quality coal) and its economic efficiency. Preliminary experiments demonstrated the successful functioning of the system.

Keywords: coal combustion, plasma arc, plasma torches, pulverized coal

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Authors: Violina R. Angelova, Mariana N. Perifanova-Nemska, Galina P. Uzunova, Krasimir I. Ivanov, Huu Q. Lee

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A field study was conducted to evaluate the efficacy of the sunflower (Helianthus annuus L.) for phytoremediation of contaminated soils. The experiment was performed on an agricultural field contaminated by the Non-Ferrous-Metal Works near Plovdiv, Bulgaria. Field experiments with a randomized, complete block design with five treatments (control, compost amendments added at 20 and 40 t/daa, and vemicompost amendments added at 20 and 40 t/daa) were carried out. The accumulation of heavy metals in the sunflower plant and the quality of the sunflower oil (heavy metals and fatty acid composition) were determined. The tested organic amendments significantly influenced the uptake of Pb, Zn and Cd by the sunflower plant. The incorporation of 40 t/decare of compost and 20 t/decare of vermicompost to the soil led to an increase in the ability of the sunflower to take up and accumulate Cd, Pb and Zn. Sunflower can be subjected to the accumulators of Pb, Zn and Cd and can be successfully used for phytoremediation of contaminated soils with heavy metals. The 40 t/daa compost treatment led to a decrease in heavy metal content in sunflower oil to below the regulated limits. Oil content and fatty acids composition were affected by compost and vermicompost amendment treatments. Adding compost and vermicompost increased the oil content in the seeds. Adding organic amendments increased the content of stearic, palmitoleic and oleic acids, and reduced the content of palmitic and gadoleic acids in sunflower oil. The possibility of further industrial processing of seeds to oil and use of the obtained oil will make sunflowers economically interesting crops for farmers of phytoremediation technology.

Keywords: heavy metals, phytoremediation, polluted soils, sunflower

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Authors: Tobias Schnabel

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Naphthalene and naphthalene similar compounds are a common problem in the indoor air of buildings from the 1960s and 1970s in Germany. Often tar containing roof felt was used under the concrete floor to prevent humidity to come through the floor. This tar containing roof felt has high concentrations of PAH (Polycyclic aromatic hydrocarbon) and naphthalene. Naphthalene easily evaporates and contaminates the indoor air. Especially after renovations and energetically modernization of the buildings, the naphthalene concentration rises because no forced air exchange can happen. Because of this problem, it is often necessary to change the floors after renovation of the buildings. The MFPA Weimar (Material research and testing facility) developed in cooperation a project with LEJ GmbH and Reichmann Gebäudetechnik GmbH. It is a technical solution for the disintegration of naphthalene in naphthalene, similar compounds in indoor air with photocatalytic reforming. Photocatalytic systems produce active oxygen species (hydroxyl radicals) through trading semiconductors on a wavelength of their bandgap. The light energy separates the charges in the semiconductor and produces free electrons in the line tape and defect electrons. The defect electrons can react with hydroxide ions to hydroxyl radicals. The produced hydroxyl radicals are a strong oxidation agent, and can oxidate organic matter to carbon dioxide and water. During the research, new titanium oxide catalysator surface coatings were developed. This coating technology allows the production of very porous titan oxide layer on temperature stable carrier materials. The porosity allows the naphthalene to get easily absorbed by the surface coating, what accelerates the reaction of the heterogeneous photocatalysis. The photocatalytic reaction is induced by high power and high efficient UV-A (ultra violet light) Leds with a wavelength of 365nm. Various tests in emission chambers and on the reformer itself show that a reduction of naphthalene in important concentrations between 2 and 250 µg/m³ is possible. The disintegration rate was at least 80%. To reduce the concentration of naphthalene from 30 µg/m³ to a level below 5 µg/m³ in a usual 50 ² classroom, an energy of 6 kWh is needed. The benefits of the photocatalytic indoor air treatment are that every organic compound in the air can be disintegrated and reduced. The use of new photocatalytic materials in combination with highly efficient UV leds make a safe and energy efficient reduction of organic compounds in indoor air possible. At the moment the air cleaning systems take the step from prototype stage into the usage in real buildings.

Keywords: naphthalene, titandioxide, indoor air, photocatalysis

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Authors: Abubakar Aminu

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Sand dunes, as a major product of desertification, is well known to affect soil resources, water resources and vegetation, especially in arid and semi-arid region; this scenario disrupt the livelihood security of people in the affected areas. The research assessed the episode of sand dune accumulation on water resources, soil and vegetation in Gada local government of Sokoto State, Nigeria. In this paper, both qualitative and quantitative methods were used to generate data which was analyzed and discussed. The finding of the paper shows that livelihood was affected by accumulations of sand dunes as water resources and soils were affected negatively thereby reducing crop yields and making livestock domestication a very difficult and expensive task; the finding also shows that 60% of the respondents agreed to planting of trees as the major solution to combat sand dunes accumulation. However, the soil parameters tested indicated low Organic carbon, low Nitrogen, low Potassium, Calcium and Phosphorus but higher values were recorded in Sodium and Cation exchange capacity which served as evidence of the high or strong aridity nature of the soil in the area. In line with the above, the researcher recommended a massive tree planting campaign to curtail desertification as well as using organic manures for higher agricultural yield and as such, improvement in livelihood security.

Keywords: soils, vegetatio, water, desertification

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Authors: Shefaa Mansour, Hassan Arafat, Shadi Hasan

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Management of reverse osmosis (RO) brine has become a major area of research due to the environmental concerns associated with it. This study worked on studying the feasibility of the direct contact membrane distillation (DCMD) system in the treatment of this RO brine. The system displayed great potential in terms of its flux and salt rejection, where different operating conditions such as the feed temperature, feed salinity, feed and permeate flow rates were varied. The highest flux of 16.7 LMH was reported with a salt rejection of 99.5%. Although the DCMD has displayed potential of enhanced water recovery from highly saline solutions, one of the major drawbacks associated with the operation is the fouling of the membranes which impairs the system performance. An operational run of 77 hours for the treatment of RO brine of 56,500 ppm salinity was performed in order to investigate the impact of fouling of the membrane on the overall operation of the system over long time operations. Over this time period, the flux was observed to have reduced by four times its initial flux. The fouled membrane was characterized through different techniques for the identification of the organic and inorganic foulants that have deposited on the membrane surface. The Infrared Spectroscopy method (IR) was used to identify the organic foulants where SEM images displayed the surface characteristics of the membrane. As for the inorganic foulants, they were identified using X-ray Diffraction (XRD), Ion Chromatography (IC) and Energy Dispersive Spectroscopy (EDS). The major foulants found on the surface of the membrane were inorganic salts such as sodium chloride and calcium sulfate.

Keywords: brine treatment, membrane distillation, fouling, characterization

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Authors: Musa Najimu, Isam Aljundi

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In this study, the development of mixed matrix membrane (MMM) containing carbide-derived carbon (CDC) for the separation of CO₂ was investigated. MMM with four different loadings (0.1 to 2 wt%) were prepared by the dry/wet phase inversion technique. Prior to this, the formula of the control polysulfone (PSF) membrane was optimized in terms of the PSF concentration in a mixture of NMP/THF solvents and ethanol. Prepared samples were characterized and tested for CO₂ and CH₄ gas permeation. The optimization of the control PSF membrane revealed that 30 wt% PSF is the critical polymer concentration in the formulation. Characterization results unveiled reinforcement of thermal stability and improved polarity imparted by CDC in the MMM, in addition to uniform dispersion of filler up to 1 wt% loading. Furthermore, the incorporation of CDC in PSF membrane formulation enhanced both the CO₂ permeance and ideal selectivity over the control membrane. A CDC loading of 0.5 wt% resulted in the highest CO₂ permeance of 5.5 GPU corresponding to 120% increase in permeance while a CDC loading of 1 wt% resulted in the highest selectivity (CO₂ /CH₄) of 27 corresponding to 29% increase in selectivity. Studies of operating temperature effect showed that an optimum operating temperature for M1.0 membrane is 20 ⁰C. In addition, the feed pressure studies showed that high pressure feeds will favor high performance of the membrane and a good CO₂ /CH₄ separation.

Keywords: carbide derived carbon, mixed matrix membrane, CO₂ separation, polysulfone

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Authors: Danila Merino, Leandro N. Ludueña, Vera A. Alvarez

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Clays are commonly used to reinforce polymeric materials. In order to modify them, long-chain quaternary-alkylammonium salts have been widely employed. However, the application of these clays in biological fields is limited by the toxicity and poor biocompatibility presented by these modifiers. Meanwhile, soy lecithin, acts as a natural biosurfactant and environment-friendly biomodifier. In this report, we analyse the effect of content of soy lecithin-modified bentonite on the properties of polycaprolactone (PCL) nanocomposites. Commercial grade PCL (CAPA FB 100) was supplied by Perstorp, with Mw = 100000 g/mol. Minarmco S.A. and Melar S.A supplied bentonite and soy lecithin, respectively. Clays with 18, 30 and 45 wt% of organic content were prepared by exchanging 4 g of Na-Bent with 1, 2 and 4 g of soy lecithin aqueous and acid solution (pH=1, with HCl) at 75ºC for 2 h. Then, they were washed and lyophilized for 72 h. Samples were labeled A, B and C. Nanocomposites with 1 and 2 wt.% of each clay were prepared by melt-intercalation followed by compression-moulding. An intensive Brabender type mixer with two counter-rotating roller rotors was used. Mixing temperature was 100 ºC; speed of rotation was 100 rpm. and mixing time was 10 min. Compression moulding was carried out in a hydraulic press under 75 Kg/mm2 for 10 minutes at 100 ºC. The thickness of the samples was about 1 mm. Thermal and mechanical properties were analysed. PCL nanocomposites with 1 and 2% of B presented the best mechanical properties. It was observed that an excessive organic content produced an increment on the rigidity of PCL, but caused a detrimental effect on the tensile strength and elongation at break of the nanocomposites. Thermogravimetrical analyses suggest that all reinforced samples have higher resistance to degradation than neat PCL.

Keywords: chemical modification, clay, nanocomposite, characterization

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Authors: Ali Alattabi, Clare Harris, Rafid Alkhaddar, Ali Alzeyadi

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Petroleum refinery wastewater (PRW) can be considered as one of the most significant source of aquatic environmental pollution. It consists of oil and grease along with many other toxic organic pollutants. In recent years, a new technique was implemented using different types of membranes and sequencing batch reactors (SBRs) to treat PRW. SBR is a fill and draw type sludge system which operates in time instead of space. Many researchers have optimised SBRs’ operating conditions to obtain maximum removal of undesired wastewater pollutants. It has gained more importance mainly because of its essential flexibility in cycle time. It can handle shock loads, requires less area for operation and easy to operate. However, bulking sludge or discharging floating or settled sludge during the draw or decant phase with some SBR configurations are still one of the problems of SBR system. The main aim of this study is to develop and innovative design for the SBR optimising the process variables to result is a more robust and efficient process. Several experimental tests will be developed to determine the removal percentages of chemical oxygen demand (COD), Phenol and nitrogen compounds from synthetic PRW. Furthermore, the dissolved oxygen (DO), pH and oxidation-reduction potential (ORP) of the SBR system will be monitored online to ensure a good environment for the microorganisms to biodegrade the organic matter effectively.

Keywords: petroleum refinery wastewater, sequencing batch reactor, hydraulic retention time, Phenol, COD, mixed liquor suspended solids (MLSS)

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Authors: Kolela J Nyembwe, Darlington C. Ashiegbu, Herman J. Potgieter

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Over the past few decades, the demand for metals has increased significantly. This has led to a decrease and decline of high-grade ore over time and an increase in mineral complexity and matrix heterogeneity. In addition to that, there are rising concerns about greener processes and a sustainable environment. Due to these challenges, the mining and metal industry has been forced to develop new technologies that are able to economically process and recover metallic values from low-grade ores, materials having a metal content locked up in industrially processed residues (tailings and slag), and complex matrix mineral deposits. Several methods to address these issues have been developed, among which are ionic liquids (IL), heap leaching, and bioleaching. Recently, the gas phase extraction technique has been gaining interest because it eliminates many of the problems encountered in conventional mineral processing methods. The technique relies on the formation of volatile metal complexes, which can be removed from the residual solids by a carrier gas. The complexes can then be reduced using the appropriate method to obtain the metal and regenerate-recover the organic extractant. Laboratory work on the gas phase have been conducted for the extraction and recovery of aluminium (Al), iron (Fe), copper (Cu), chrome (Cr), nickel (Ni), lead (Pb), and vanadium V. In all cases the extraction revealed to depend of temperature and mineral surface area. The process technology appears very promising, offers the feasibility of recirculation, organic reagent regeneration, and has the potential to deliver on all promises of a “greener” process.

Keywords: gas-phase extraction, hydrometallurgy, low-grade ore, sustainable environment

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Authors: Abel Mahowe

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Furrow erosion is the major problem menacing sustainability of irrigation in Malawi and polluting water bodies resulting in death of many aquatic animals. Many rivers in Malawi are drying due to some poor practices that are being practiced around these water bodies, furrow erosion is one of the cause of sedimentation in these rivers although it has gradual effect on deteriorating of these rivers hence neglected, but has got long term disastrous effect on water bodies. Many aquatic animals also suffer when these sediments are taken into these water bodies. An assessment of effect of manure treatment on furrow erosion was carried out in Sagawika irrigation scheme located in Kasungu District north part of Malawi. The soil on the field was clay loam and had just been tilled. The average furrow slope of 0.2% and was divided into two blocks, A and B. Each block had 20V-shaped furrow having a length of 10 m. Three different manure were used to construct these furrows by mixing it with soil which was moderately moist and 5 furrows from each block were constructed without manure. In each block 5furrow were made using a specific type of manure, and one set of five furrows in each block was made without manure treatment. The types of manure that were used were goat manure, pig manure, and manure from crop residuals. The manure application late was 5 kg/m. The furrow was constructed at a spacing of 0.6 m. Tomato was planted in the two blocks at spacing of 0.15 m between rows and 0.15 m between planting stations. Irrigation water was led from feeder canal into the irrigation furrows using siphons. The siphons discharge into each furrow was set at 1.86 L/S. The ¾ rule was used to determine the cut-off time for the irrigation cycles in order to reduce the run-off at the tail end. During each irrigation cycle, samples of the runoff water were collected at one-minute intervals and analyzed for total sediment concentration for use in estimating the total soil sediment loss. The results of the study have shown that a significant amount of soil is lost in soils without many organic matters, there was a low level of erosion in furrows that were constructed using manure treatment within the blocks. In addition, the results have shown that manure also differs in their ability to control erosion since pig manure proved to have greater abilities in binding the soil together than other manure since they were reduction in the amount of sediments at the tail end of furrows constructed by this type of manure. The results prove that manure contains organic matters which helps soil particles to bind together hence resisting the erosive force of water. The use of manure when constructing furrows in soil with less organic matter can highly reduce erosion hence reducing also pollution of water bodies and improve the conditions of aquatic animals.

Keywords: aquatic, erosion, furrow, soil

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Authors: Carlos Alberto Ríos-Reyes, Efraín Casadiego-Quintero

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We propose a generalized workflow for mineralogy investigation of unconventional reservoirs using multi-scale imaging and pore-scale analyses. This workflow can be used for the integral evaluation of these resources. The Cretaceous La Luna Formation´s mudstones in the Middle Magdalena Valley Basin (Colombia) inherently show a heterogeneous pore system with organic and inorganic pores. For this reason, it is necessary to carry out the integration of high resolution 2D images of mapping by conventional petrography, scanning electron microscopy and quantitative evaluation of minerals by scanning electron microscopy to describe their organic and inorganic porosity to understand the transport mechanism through pores. The analyzed rocks show several pore types, including interparticle pores, organoporosity, intraparticle pores, intraparticle pores, and microchannels and/or microfractures. The existence of interconnected pores in pore system of these rocks promotes effective pathways for primary gas migration and storage space for residual hydrocarbons in mudstones, which is very useful in this type of gas reservoirs. It is crucial to understand not only the porous system of these rocks and their mineralogy but also to project the gas flow in order to design the appropriate strategies for the stimulation of unconventional reservoirs. Keywords: mudstones; La Luna Formation; gas storage; migration; hydrocarbon.

Keywords: mudstones, La luna formation, gas storage, migration, hydrocarbon

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Authors: Dernie Taganna Olguera

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Marginal uplands are fragile ecosystems in the tropics that need to be evaluated for sustainable utilization and land degradation mitigation. Thus, this study evaluated the dominant soil degradation processes in selected marginal uplands of Samar Island, Philippines; evaluated the important factors influencing soil degradation in the selected sites and identified the indicators of soil degradation in marginal uplands of the tropical landscape of Samar Island, Philippines. Two (2) sites were selected (Sta. Rita, Samar and Salcedo, Eastern, Samar) representing the western and eastern sides of Samar Island respectively. These marginal uplands represent different agro-climatic zones suitable for the study. Soil erosion is the major soil degradation process in the marginal uplands studied. It resulted in not only considerable soil losses but nutrient losses as well. Soil erosion varied with vegetation cover and site. It was much higher in the sweetpotato, cassava, and gabi crops than under natural vegetation. In addition, soil erosion was higher in Salcedo than in Sta. Rita, which is related to climatic and soil characteristics. Bulk density, porosity, aggregate stability, soil pH, organic matter, and carbon dioxide evolution are good indicators of soil degradation. The dominance of Saccharum spontaneum Linn., Imperata cylindrica Linn, Melastoma malabathricum Linn. and Psidium guajava Linn indicated degraded soil condition. Farmer’s practices particularly clean culture and organic fertilizer application influenced the degree of soil degradation in the marginal uplands of Samar Island, Philippines.

Keywords: soil degradation, soil erosion, marginal uplands, Samar island, Philippines

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Authors: Jessica Carolina Hernandez Galeano, Juan Carlos Moreno Pirajan, Liliana Giraldo

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Carbon gels are materials whose structure and porous texture can be designed and controlled on a nanoscale. Among their characteristics it is found their low density, large surface area and high degree of porosity. These materials are produced by a sol-gel polymerization of organic monomers using basic or acid catalysts, followed by drying and controlled carbonization. In this work, the synthesis and characterization of carbon aerogels from resorcinol, phenol and formaldehyde in ethanol is described. The aim of this study is obtaining different carbonaceous materials in the form of spheres using the Stöber method to perform a further evaluation of CO₂ adsorption of each material. In general, the synthesis consisted of a sol-gel polymerization process that generates a cluster (cross-linked organic monomers) from the precursors in the presence of NH₃ as a catalyst. This cluster was subjected to specific conditions of gelling and curing (30°C for 24 hours and 100°C for 24 hours, respectively) and CO₂ supercritical drying. Finally, the dry material was subjected to a process of carbonization or pyrolysis, in N₂ atmosphere at 350°C (1° C / min) for 2 h and 600°C (1°C / min) for 4 hours, to obtain porous solids that retain the structure initially desired. For this work, both the concentrations of the precursors and the proportion of ammonia in the medium where modify to describe the effect of the use of phenol and the amount of catalyst in the resulting material. Carbon aerogels were characterized by Scanning Electron Microscope (SEM), N₂ isotherms, infrared spectroscopy (IR) and X-ray Powder Diffraction (XRD) showing the obtention of carbon spheres in the nanometric scale with BET areas around 500 m2g-1.

Keywords: carbon aerogels, carbon spheres, CO₂ adsorption, Stöber method

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Authors: Abimbola M. Enitan, Josiah Adeyemo, Sheena Kumari, Feroz M. Swalaha, Faizal Bux

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With the competing demand on water resources and water reuse, discharge of industrial effluents into the aquatic environment has become an important issue. Much attention has been placed on the impact of industrial wastewater on water bodies worldwide due to the accumulation of organic and inorganic matter in the receiving water bodies. The scope of the present work is to assess the physic-chemical composition of the wastewater produced from one of the brewery industry in South Africa. This is to estimate the environmental impact of its discharge into the receiving water bodies or the municipal treatment plant. The parameters monitored for the quantitative analysis of brewery wastewater include biological oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids, volatile suspended solids, ammonia, total oxidized nitrogen, nitrate, nitrite, phosphorus, and alkalinity content. In average, the COD concentration of the brewery effluent was 5340.97 mg/l with average pH values of 4.0 to 6.7. The BOD and the solids content of the wastewater from the brewery industry were high. This means that the effluent is very rich in organic content and its discharge into the water bodies or the municipal treatment plant could cause environmental pollution or damage the treatment plant. In addition, there were variations in the wastewater composition throughout the monitoring period. This might be as a result of different activities that take place during the production process, as well as the effects of the peak period of beer production on the water usage.

Keywords: Brewery wastewater, environmental pollution, industrial effluents, physic-chemical composition

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Authors: Sandrine Andriantsimietry, Hantanirina Ravaosendrasoa

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Madagascar, in 2018, set up the first best available technology, autoclave, to treat the health care waste in public hospitals according the best environmental practices in health care waste management. Incineration of health care waste, frequently through open burning is the most common practice of treatment and elimination of health care waste across the country. Autoclave is a best available technology for non-incineration of health care waste that permits recycling of treated waste and prevents harm in environment through the reduction of unintended persistent organic pollutants from the health sector. A Global Environment Fund project supported the introduction of the non-incineration treatment of health care waste to help countries in Africa to move towards Stockholm Convention objectives in the health sector. Two teaching hospitals in Antananarivo and one district hospital in Manjakandriana were equipped respectively with 1300L, 250L and 80L autoclaves. The capacity of these model hospitals was strengthened by the donation of equipment and materials and the training of the health workers in best environmental practices in health care waste management. Proper segregation of waste in the wards to collect the infectious waste that was treated in the autoclave was the main step guaranteeing a cost-efficient non-incineration of health care waste. Therefore, the start-up of the switch of incineration into non-incineration treatment was carried out progressively in each ward with close supervision of hygienist. Emissions avoided of unintended persistent organic pollutants during these four months of autoclaves use is 9.4 g Toxic Equivalent per year. Public hospitals in low income countries can be model in best environmental practices in health care waste management but efforts must be made internally for sustainment.

Keywords: autoclave, health care waste management, model hospitals, non-incineration

Procedia PDF Downloads 163