Papers by Keyword: Waste

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Authors: María Antonia Mas, Mauro M. Tashima, J. Payá, M.V. Borrachero, Lourdes Soriano, J.M. Monzó
Abstract: Nowadays, scientific community is looking for alternatives to reduce the problem of CO2 emissions, making more sustainable binders and reusing wastes from other industries.In this line, the technology of geopolymers was born, in which, binders based on alkali-activation can be produced entirely or almost entirely from waste materials. In alkali-activation a source of aluminosilicate is dissolved by a highly alkaline solution previous to precipitation reactions that form a gel binder.The use of alumino-silicate minerals such as metakaolin, blast furnace slag and fly ash to produce alkali-activated cements has been extensively studied and it’s increasing the interest in investigating the suitability of using other materials. Different wastes containing silica and alumina, such as hydrated-carbonated cement, glass, fluid catalytic cracking catalyst residues (FCC) have been activated.The aim of this study is to verify if the use of geopolymers is compatible with the manufacturing technology of typical building elements, in this case roof tiles.Mechanical properties of mortars and roof tiles using as source of aluminosilicates FCC have been studied, with different mixtures and variating the proportions of NaOH and waterglass.Compressive strength development was evaluated in mortars cured at 20oC for 7 and 28 days and flexural strength, impermeability and impact resistance were evaluated in roof tiles. The results obtained demonstrated the feasibility on the use of geopolymers in the design of new products with less CO2 emissions and then the contribution to the sustainability in the construction sector.
Authors: Wei Cao, Wen Wei Zha, Wen Long Ni
Abstract: A novel and improved waste pyrolysis test system is developed by process design, pyrolysis host type design and the corresponding counterpart type design. It contains the design of waste pyrolysis pretreatment device, the sealing feeding device, the pyrolysis slag cooling device, the high temperature pyrolysis gas dust removal device and the pyrolysis gas desulfurization dust removal device. This study proposes a good testing model and a production validation on waste combustion under the oxygen-free and high-temperature condition. Thus it offers an effective technical support and guidance on improving the utilization of waste calorific value and preventing the generation of dioxin.
Authors: Yan Jiang, Ye Hong Wang, Li Jiang
Abstract: An efficiency new cleaning treatment on printing and dyeing waste water was designed on the basis such as the iron-carbon original cell reaction, the redox reaction, as well as the magnetization synergy effect. Further experiments to prove all these principles and theories worked well were carried out. Meanwhile, some of the best groups of parameters were found. With this new treatment named as magnetized waste iron filter column treatment, the COD removal rate could be as high as 88% while the decolorization rate was 95%.
Authors: A. H. Abbas, M. Fadhil, Mohmd Shiraz Aris, A.B.A. Ibrahim, Mohammed Termzy Nor Aniza
Abstract: Poultry processing dewatered sludge which consisting of trimmings, fat, feathers and liquid discharges from processing slaughtered chicken is typically land filled in specialized sites. It is a costly process to manage and if not handled according to stringent procedures can be harmful to the surrounding environment. The use of this waste material as an alternative fuel can be an effective solution, as it not only contributes as an energy source but also solves environmental issues related to poultry sludge disposal. Combustion, gasification and pyrolysis are efficient techniques of utilizing energy effectively from poultry sludge. The performances of mathematical models to predict the product gas quality is rely on characterization of feed materials as well as the reaction kinetics of their thermal degradation. The aim of this study is to determine selected physical and chemical properties of poultry sludge associated with thermochemical conversion. Thermogravimetric analyses were performed at heating rates of 10, 20, 30, and 40 K/min in an air (oxidizing) atmosphere. The parameters of the reaction kinetics such as activation energy and reaction order were obtained by the application of OzawaFlynn Wall and Vyazovkin kinetic models.
Authors: Ahmad Azrem Azmi, Mohd Mustafa Abdullah Al Bakri, Che Mohd Ruzaidi Ghazali, Andrei Victor Sandu, Kamarudin Hussin, Donny Arief Sumarto
Abstract: Utilization of waste materials such as waste tire rubber in the building industry can help prevent environmental pollution whilst contributing to the design of more economical buildings. Preliminary studies show that workable rubberized portland cement concrete mixtures can be made provided that appropriate percentages of tire rubber are used in such mixtures. This article provides the overview of some of published paper using tire waste rubber in portland cement concrete. The researchers mostly investigated the properties of fresh and hardened concrete. The workability, density, air content, unit weight, compressive strength, modulus of elasticity, freezing and thawing resistance, abrasion resistance and thermal properties of the waste tire rubber in concrete were discussed.
Authors: Decio Lopes Cardoso, Talita Bassegio Kaminski, Francine Stelle Goldoni, Guilherme Irineu Venson, Camila Daiane Cancelier
Abstract: The soil is a brittle material compared to other engineering materials such as steel, concrete and wood. The clayey nature of the soils of western Paraná causes them to be chemically reactive towards certain compounds, thereby improving their engineering properties, especially its mechanical strength. The study involved treating the typical soil of the region with two residues from industrial and human activities: rice husk ash (RHA) at doses 0; 2.5; 5; 7.5 and 10%; and burned sewage sludge (BSS) at doses 0; 5; 10; 15 to 20%; in the dry soil mass. The test samples were compacted in Mini-MCV equipment and broken in triaxial compression tests of consolidated undrained type, with confining pressures of 25; 50 and 100 kPa. The results showed that both the RHA change dramatically as the BSS which passes viscoelastic plastic-linear mechanical behavior of the composites. There was a significant increase in deviator tension and elasticity modulus, implying a gain in strength and stiffness of the composite compared to the natural soil. The most striking effect was observed in the RHA cohesion parameter; while the substantial effect of BSS was observed in the interparticles friction angle. These results suggest that RHA promoted the formation of new products filling the pore space of the composite, changing the clayey material in a nature of a continuum, while the BSS promoted a substantial aggregation of the particles, wherein the soil reinforcement transformed clay in a particulate material coarser grain size.
Authors: K.C. Gomes, Bruno Diniz Rocha, Debora T.A. Ferreira, Elder Cunha de Lira, Sandro Marden Torres, Silvio Romero de Barros, Normando Perazzo Barbosa
Abstract: In the state of Paraíba, one of the activities of great economic importance is that of the kaolin processing industry. This type of processing generates large amounts of waste that are displayed randomly in the environment, which has attracted attention, because the environmental impact caused by it and the lack of established process of recycling. The University Federal o Paraíba has been developing several research to explore the potential for recycling of industrial waste from Paraíba, mainly waste of kaolin. This research have pointed to the feasibility of using waste as aggregate and pozzolan in the development of mortars use multiple. These wastes have different size fractions, depending on the stage of processing: a sandy (termed in this study of RGC) containing mainly quartz, mica and calcite; and other clay (termed in this study of RFC) is thinner, containing higher amounts of kaolinite. This study aims to evaluate the potential of alkaline activation from waste kaolin (RGC and RFC) by comparing the activation using sodium silicate and hidroxide of calcium. With the objective of studying the potential of waste as a material pozzolanic, it was processing through grinding at 80.000, 60.000, 40.000, 20.000 and 10.000 rotations and with the purpose of evaluating the reactivity of materials, these wastes were calcined at 750°C/2h. For the mechanical characterization was using an equipment universal testing of Shimadzu Servopulser, where it was observed that only RFC, when calcined, developed strength in both activations, and the activated with silicate sodium with higher strength. The RGC, both in the state in natura and calcined did not show satisfactory mechanical strength to the test under the conditions of synthesis used in this research. Thus, the waste RFC's studied in this work has the potential to be used as constituent materials for building blocks in terms of its mechanical properties.
Authors: Tao Guo, Peng Fei Li, Yan Han, Fan Luo
Abstract: Traditional road green growing material does not take into account the particularity of green traffic areas. Characteristic of the road greening and ordinary green standard is not the same. In road greening projects, vegetation planting layer is required to meet the basic conditions for plant growth, in addition vegetation planted layer need structural requirements. Fired brick and tile waste material have microporous structure. The pore structure is capable of storing water and nutrients, fired brick and tile waste materials have the stronger crushing strength and frost resistance. Fired brick and tile waste can satisfy the dual needs of the structure and plant growth. These characteristics determine fired brick and tile waste to have enormous potential in the road greening projects.
Abstract: Understanding the dynamics of bubbles is necessary in an effort to increase the efficiency of separation of flotation process. The purpose of this research was to study characteristics of small bubbles (bubbles with diameter of 0.2-1 mm), which rise in a liquid column. Experimental set up was a column made of an acrylic pipe with inner diameter of 8.4 cm and length of 200 cm. Small bubbles were generated by copper cathode. The dynamics of bubbles were observed using a video camera. Video images were processed using image processing software. The results indicate that at height of 50 cm from cathode tip bubbles in average have reached its terminal velocity. It has been proven that effect of alum surfactant can reduce the bubbles terminal velocity.
Authors: Valeria Bennack, L.V.O. Dalla Valentina, Marilena Valadares Folgueras
Abstract: Economic and environmental issues are directly related to industrial processes which, not only employ natural resources but also generate by-products that may impact the environment. In order to achieve sustainable development, reducing the use of natural resources and lowering cost through adequate destination of waste becomes a crucial issue. The aim of this paper is to analyze the suitability of reusing waste (wood ash) resulting from the combustion process at wood product industries for manufacturing cement based materials used in civil engineering. The material assessed is ash from the combustion process of a wood product industry. In this study, physical and chemical properties such as grain size, mineral and chemical composition of this by-product were characterized. Thermal analysis and X-ray diffraction techniques were used for this purpose. Preliminary results show the suitability of using the waste (wood ash) for manufacturing cement based materials
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