Preparation and characterization of granular zeolite material from construction and demolition waste for lead removal

<p>The release of landfill gas is responsible for approximately 3 % of the global greenhouse gas emissions. Especially a high content of organic matter in municipal solid waste (MSW) in wet areas may enhance the microbial activity and the production of landfill gas and leachate as metabolic products. Accordingly, the delineation of saturated zones and biogeochemically active and inactive areas is critical for designing adequate stabilization systems to limit the environmental impact of landfills on greenhouse gas production. Therefore, landfill investigations with high spatial resolution are critical for environmental protection. Geophysical methods are a cost-efficient possibility to obtain almost continuous information about subsurface properties at various spatial scales, which can help to identify biogeochemical active zones. Within this case study we investigate the applicability of three geophysical methods, namely (i) the electrical resistivity tomography (ERT), (ii) the induced polarization (IP) method and (iii) the transient electromagnetic (TEM) method to characterize the landfill geometry and to discriminate between biogeochemically active and inactive areas. The investigated landfill is located close to Vienna (Austria) and consists of a mixture of MSW, construction and demolition waste (CDW) and excavated soil. We conducted ERT and IP measurements along 17 profiles distributed over the area of the landfill to provide high resolution images of the subsurface down to 8 m depth. Additionally, we used transient electromagnetic measurements along selected profiles to provide information on deeper structures of the landfill as well as to evaluate the electrical conductivity obtained with ERT. Our results show that the electrical conductivity obtained by both ERT and TEM is mainly sensitive to the increase in the fluid conductivity associated to leachate production and migration. Additionally, a decrease in electrical conductivity is associated to CDW and dry MSW and can help to distinguish between different waste types. However, images of the polarization effect obtained with the IP method, expressed in terms of the phase of the complex conductivity, revealed an improved contrast to characterize variations in the architecture and biogeochemical activity of the landfill. Hence, our study demonstrates that the geophysical methods we applied are well-suited for landfill investigations permitting an improved characterization of landfill geometry and variation in waste composition. In particular, the IP method can delineate between biogeochemically active and inactive zones.</p>

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Mechanical characterization of concretes produced with construction and demolition waste

Research Society and Development ◽

10.33448/rsd-v9i1.1597 ◽

2020 ◽

Vol 9 (1) ◽

pp. e56911597

Author(s):

Pedro Valle Salles ◽

Thiago Marques Viana ◽

Camila Lacerda Gomes ◽

Flávia Cristina Silveira Braga ◽

Flávia Spitale Jacques Poggiali ◽

...

Keyword(s):

Mechanical Characterization ◽

Construction And Demolition Waste ◽

Partial Replacement ◽

The European Union ◽

Demolition Waste ◽

Environmental Liabilities ◽

Mixing Method ◽

Natural Aggregates ◽

Good Workability

The construction industry is responsible for the generation of large volumes of waste, known as construction and demolition waste (CDW). Around the world, millions of tons of these wastes are generated annually, which often become important environmental liabilities. The situation gets worse as the sector develops. In Europe, only 15 of the 27 countries in the European Union annually produce around 180 million tonnes of CDW, in Brazil, the data about this indicates that in 2014 the municipalities collected about 45 million tons of CDW, quantity 4.1% higher than in 2013. In this scenario, the present study aims to evaluate the partial replacement of natural aggregates by CDW (aggregates of concrete waste) in the production of concretes. In this sense, the effects of this substitution on the workability and mechanical characteristics of the concretes produced, as well as the influence of the mixing method and the percentage of superplasticizer additive on the same characteristics were evaluated. The methodology basically consists in the production of seven different traits, which are references and different combinations of mixing method, aggregate substitutions and superplasticizer percentages. Specimens of these traces were molded for mechanical characterization. Workability parameters were also evaluated. It is concluded that the workability is strongly affected by the addition of CDW, but a good workability can be obtained with the use of superplasticizer additives. The mixing method did not change the results obtained for this property. The results also indicate that the compressive and tensile strengths are not negatively affected by the substitution of aggregates, as well as being not significantly affected by the presence of the percentages of superplasticizer used, nor by the mixing methods.

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Mineralogical and chemical characterization of CDW as function of particle size and thermal treatments for potential recycling

Detritus ◽

10.31025/2611-4135/2021.15097 ◽

2021 ◽

pp. 40-50

Author(s):

Ababaikere Abudureheman ◽

Paola Stabile ◽

Michael Robert Carroll ◽

Carlo Santulli ◽

Eleonora Paris

Keyword(s):

Particle Size ◽

Glass Industry ◽

Central Italy ◽

Chemical Characterization ◽

Mineralogical Composition ◽

Construction And Demolition Waste ◽

Thermal Treatments ◽

Atmospheric Conditions ◽

Demolition Waste

Construction and Demolition Waste (CDW) originating from the rubble produced by the 2016 seismic events in the Marche Region (Central Italy) has been studied, focusing on its mineralogical and chemical characteristics, to investigate its recycling potentials as a component for eco-sustainable building material or in the glass industry. The aim was to obtain a full characterization of the behaviour of this material at high T in order to determine the most advantageous conditions for vitrification, considered as an effective process for volume reduction as well as for immobilization of potentially hazardous elements. Vitrification experiments, carried out with thermal treatments as function of temperature/duration/particle size and aimed at amorphization, were carried out under atmospheric conditions, at different temperatures (1000-1250°C) and durations (2-8 hours). The study demonstrated that mineralogical composition remains homogeneous for grainsize <4 mm, thus suggesting that no sieving is necessary for recycling of the fine fractions, which are the most difficult to treat. Vitrification, although not achieved for the CDW sample up to 1250°C, due to high-Ca and low-Si contents, demonstrated that this CDW can produce an interesting refractory material and a porous/insulating material. However, experiments showed that full vitrification can be easily achieved by mixing urban waste glass and CDW, suggesting applications in the glass industry. Based on the chemical and mineralogical features of the products, other significant upgrading alternatives of recycling the CDW in different fields of applications are highlighted.

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Development and characterization of lightweight aggregate recycled from construction and demolition waste mixed with other industrial by-products

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.125472 ◽

2021 ◽

Vol 313 ◽

pp. 125472

Author(s):

Hung Phong Nguyen ◽

Anette Mueller ◽

Van Tuan Nguyen ◽

Cong Thang Nguyen

Keyword(s):

Lightweight Aggregate ◽

Construction And Demolition Waste ◽

Demolition Waste ◽

By Products

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Mechanical Characterization of Gypsum Composites Containing Inert and Insulation Materials from Construction and Demolition Waste and Further Application as A Gypsum Block

Materials ◽

10.3390/ma13010193 ◽

2020 ◽

Vol 13 (1) ◽

pp. 193 ◽

Cited By ~ 2

Author(s):

Paola Villoria Sáez ◽

Mercedes del Río Merino ◽

Marica Sorrentino ◽

César Porras Amores ◽

Jaime Santa Cruz Astorqui ◽

...

Keyword(s):

Mechanical Characteristics ◽

Surface Hardness ◽

Expanded Polystyrene ◽

Raw Material ◽

Construction And Demolition Waste ◽

Demolition Waste ◽

Density Surface ◽

Reference Samples ◽

Physical And Mechanical Characteristics

This article analyzes the feasibility of using construction and demolition waste (expanded polystyrene, ceramic, and concrete waste) in a gypsum matrix to manufacture plaster for interior coatings or for prefabricated elements for interior partitions. To do this, several gypsum specimens were prepared (4 × 4 × 16 cm) incorporating different percentages of waste based on the weight of the gypsum (25%, 50%, and 75% of ceramic, concrete, and a mixture of both). Reference samples were also produced (without additions) to compare the results obtained. The compounds with the best performance were selected and lightened by preparing other samples in which 1/3 and 2/3 of the volume of ceramic, concrete, and mixed waste were replaced with expanded polystyrene (EPS). All samples were tested in the laboratory and the following physical and mechanical characteristics were determined: density, surface hardness, flexural strength, compressive strength, capillary water absorption, and thermal conductivity. Several applications were proposed for the selected compounds. A gypsum block with a sandwich configuration was obtained (40 × 20 × 10 cm) using the optimum compound. The block was further tested regarding its density and compression strength. A comparative analysis showed that it is possible to produce materials with a gypsum matrix by adding ceramic, concrete, and EPS waste, improving the behavior of the traditional gypsum and enabling them to be applied in various construction applications. These applications have a lower environmental impact than ordinary ones because they use less primary raw material, due to the reuse of waste.

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