Utilisation of raw oil shale as fine aggregate to replace natural sand in concrete: Microstructure, surface chemistry and macro properties

Data availability: Data will be made available on request.Copyright © 2023 The Author(s). This study set out to examine the unconventional use of raw oil shale (OS) as fine aggregate in concrete instead of its traditional utilisation as a pollutant energy source aiming to hinder the depletion of natural resources. Oil shale particles have been used to replace sand in concrete with 30 wt.-% and 50 wt.-% ratios. Part of the used OS particles was treated with silane prior to their addition in concrete. The fresh, mechanical, and durability properties, along with the micro-properties and surface chemistry of mixtures, were analysed by running the slump, compressive strength, permeability, scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR) tests, respectively. Five concrete mixtures consisting of 30 samples with the size of 150 mm x 150 mm x 150 mm were prepared to serve the testing programme of the study. The results revealed the formation of a well-bonded interfacial transition zone between untreated OS particles and the cementitious matrix due to the presence of pozzolanic materials in OS. However, micro cracks and enlarged capillary pores were witnessed in treated OS mixtures along with a weak interfacial transition zone between the treated OS and the cementitious matrix. Moreover, the use of 30 wt.-% untreated OS reduced the water absorption of concrete by 9% (absorption rate of 9.5%), while other mixtures experienced an increase in their water absorption with a maximum increase of 42% when using 50 wt.-% treated OS (absorption rate of 10.7%). All mixtures attained a reduction in their compressive strength compared to control sample when employing treated and untreated OS in concrete, with a minimum reduction of 13% when using 30 wt.-% untreated OS (compressive strength of 26 MPa). The strength reduction in untreated OS mixtures is due to the formation of free CaO and free SiO2, which promote concrete expansion. The interference between silane and kerogen in OS was the main reason behind the strength reduction in treated OS mixtures. However, this reduction in mixtures’ strength is considered minimal, allowing for their potential use in different construction applications like rigid pavement.Deanship of Academic Research at Mutah University (Fund No.: 428/2021)

Comprehensive investigation of recycled waste glass in concrete using silane treatment for performance improvement

Copyright © 2022 The Authors. An in-depth investigation of the incorporation of silane-treated and untreated glass waste in concrete is presented in this research. Coarse and fine aggregates were replaced with glass waste in 30 wt.-% and 50 wt.-% ratios, while glass powder was employed as an additive to concrete with 2 wt.-% and 5 wt.-% ratios. Physical, mechanical, microstructural and surface chemical properties of the produced concrete samples were studied by conducting water absorption test, compressive and splitting tensile strength tests, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analyses, respectively. The results showed that the combined influence of glass waste and silane coupling agent enhanced the impermeability of concrete by 87% when replacing sand with 50 wt.-% glass. In addition, all modified mixtures showed a reduction in their 28 days’ compressive strength compared to the control, except mixtures where untreated glass powder was used as an additive, which led to an increase in their compressive strength by 1%. Moreover, replacing sand with 50 wt.-% glass enhanced the splitting tensile strength of concrete by 25%. Microstructural analysis revealed a delaminated interface between glass and cement paste when using silane-treated coarse glass and the formation of Ettringite at later ages.Deanship of Academic Research at Mutah University (Fund No.: 404/2021)

Pyrolysis of Domestic Sewage Sludge: Effect of Process Parameters on Biochar Calorific Value

This research aims to look into a sustainable technique for the treatment, reuse and disposal of domestic sewage sludge (DSS). The purpose of the study was to examine the operating factors that influence the calorific value of the produced biochar from the pyrolysis of DSS. Based on the analysis of the full factorial design, the impacts of the pyrolysis conditions, specifically: temperature, heating rate, and isothermal time on the calorific value of biochar were evaluated. When the pyrolysis temperature was raised from 300 to 500 oC, the calorific value of biochar was decreased by 34%. A 14% decrease in the calorific content of the biochar was also noticed when the heating rate was increased from 5 to 35 oC/min. When the isothermal time was increased from 45 to 120 minutes, the calorific value of the biochar remained essentially unchanged. No interaction effects among process variables were found using the factorial design methodology. A first-order regression model was developed to predict the calorific value of biochar using the magnitude of the effects of the process factors and their interactions. The model predictions agreed very well with the obtained experimental results

A Techno-Economic Analysis of Sustainable Material Recovery Facilities: The Case of Al-Karak Solid Waste Sorting Plant, Jordan

Solid waste sorting facilities are constructed and operated to properly manage solid waste for both material and energy recovery. This paper investigates the possible technical and economic performance of the Al-Karak solid waste sorting plant in order to achieve financial sustainability and increase the profits that return on the plant to cover its operating costs. A standard procedure was followed to quantify and characterize the input materials of commercial solid waste by determining the recyclable materials in the sorting products. Thus, possible different equipment and material flows through the plant were proposed. An economic model was used in order to know the feasibility of the proposed options of the plant according to three economic factors, which are net present worth (NPW), return on investment (ROI), and payback period values. The results inferred that the characterization of the input materials contains a high portion of recyclable materials of paper, cardboard, plastic, and metals, which accounted for 63%. In this case, the mass of rejected waste to be landfilled was 9%. Results for the proposed options showed that the economic analysis is feasible when working loads on three and two shifts with ROI values of 4.4 and 3.5 with a payback period of the initial cost in 2 and 3 years, respectively. Working load on one shift was not feasible, which resulted in an ROI value of less than 2 and a payback period larger than 5 years. This paper recommended operating the sorting plant at a higher input feed with a working load on three shifts daily to ensure a maximum profit and to reduce the amount of commercial solid waste prior to landfilling through the concept of sorting and recycling

A Techno-Economic Analysis of Sustainable Material Recovery Facilities: The Case of Al-Karak Solid Waste Sorting Plant, Jordan

Solid waste sorting facilities are constructed and operated to properly manage solid waste for both material and energy recovery. This paper investigates the possible technical and economic performance of the Al-Karak solid waste sorting plant in order to achieve financial sustainability and increase the profits that return on the plant to cover its operating costs. A standard procedure was followed to quantify and characterize the input materials of commercial solid waste by determining the recyclable materials in the sorting products. Thus, possible different equipment and material flows through the plant were proposed. An economic model was used in order to know the feasibility of the proposed options of the plant according to three economic factors, which are net present worth (NPW), return on investment (ROI), and payback period values. The results inferred that the characterization of the input materials contains a high portion of recyclable materials of paper, cardboard, plastic, and metals, which accounted for 63%. In this case, the mass of rejected waste to be landfilled was 9%. Results for the proposed options showed that the economic analysis is feasible when working loads on three and two shifts with ROI values of 4.4 and 3.5 with a payback period of the initial cost in 2 and 3 years, respectively. Working load on one shift was not feasible, which resulted in an ROI value of less than 2 and a payback period larger than 5 years. This paper recommended operating the sorting plant at a higher input feed with a working load on three shifts daily to ensure a maximum profit and to reduce the amount of commercial solid waste prior to landfilling through the concept of sorting and recycling

Anaerobic Co-Digestion of Domestic Sewage Sludge with Food Waste: Incorporating Food Waste as a Co-Substrate Under Semi-Continuous Operation

Anaerobic co-digestion of domestic sewage sludge with food waste as a substrate for biogas production and as a mean for waste management was conducted. The food waste was incorporated into the bioreactor as a cosubstrate semi-continuously via replacement mode and addition mode of operations in ratios up to 50%. The methane gas yield under the replacement mode of operation ranged from 295 to 1358 ml/gVSadded and from 192 to 462 ml/gVSadded for the replacement mode of operation and the addition mode of operation, respectively. The results indicate that the methane gas yield increases along with the percentage share of food waste in the feed. Anaerobic co-digestion under semi-continuous operation enabled handling large organic loadings compared to batch co-digestion processes