The capture and use of carbon dioxide to create valuable products might lower the net costs of reducing emissions or removing carbon dioxide from the atmosphere. Here we review ten pathways for the utilization of carbon dioxide. Pathways that involve chemicals, fuels and microalgae might reduce emissions of carbon dioxide but have limited potential for its removal, whereas pathways that involve construction materials can both utilize and remove carbon dioxide. Land-based pathways can increase agricultural output and remove carbon dioxide. Our assessment suggests that each pathway could scale to over 0.5 gigatonnes of carbon dioxide utilization annually. However, barriers to implementation remain substantial and resource constraints prevent the simultaneous deployment of all pathways. Ten pathways for the utilization of carbon dioxide are reviewed, considering their potential scale, economics and barriers to implementation.

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The technological and economic prospects for CO2 utilization and removal

The vast emission of greenhouse gases from industrial wastes is a global problem. The non-biodegradable nature of industrial wastes like silica fume , glass, bottom ash, and rubber tyres increases the severity of the problem. Past studies suggest that the use of waste materials in the cement and construction industry could be a viable solution to prevent natural resources from extinction. The chemical composition of silica fume and waste glass are attracting cement and concrete industries as a sustainable solution. In recent years, green concrete is very popular among researchers and academicians, but green concrete is still at an early stage. This paper studies the influence of silica fume and waste glass on the workability, strength, and durability properties of concrete . Moreover, the microstructural analysis was also studied.

Silica fume and waste glass in cement concrete production: A review

The past and future of sustainable concrete: A critical review and new strategies on cement-based materials

In this study, concentrations of bisphenol A (BPA) and seven other bisphenols (BPs) were measured in urine samples collected from people living in and around e-waste dismantling facilities, and in matched reference population from rural and urban areas in China. BPA, bisphenol S (BPS), and bisphenol F (BPF) were frequently detected (detection frequencies: > 90%) in urine samples collected from individuals who live near e-waste facilities, with geometric mean (GM) concentrations of 2.99 (or 3.75), 0.361 (or 0.469), and 0.349 (or 0.435) ng/mL (or μg/g Cre), respectively; the other five BPs were rarely found in urine samples, regardless of the sampling location. The urinary concentrations of BPA and BPF, but not BPS, were significantly higher in individuals from e-waste recycling locations than did individuals from a rural reference location. Our findings indicated that e-waste dismantling activities contribute to human exposure to BPA and BPF. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) was measured in urine as a marker of oxidative stress. In the e-waste dismantling location, urinary 8-OHdG was significantly and positively correlated (p < 0.001) with urinary BPA and BPS, but not BPF; a similar correlation was also observed in reference sites. These findings suggest that BPA and BPS exposures are associated with elevated oxidative stress.

Urinary Concentrations of Bisphenols and Their Association with Biomarkers of Oxidative Stress in People Living Near E-Waste Recycling Facilities in China

Treatment of municipal solid waste incineration fly ash: State-of-the-art technologies and future perspectives.

Carbon dioxide (CO2) is the predominant greenhouse gas on Earth and its atmospheric concentration is increasing at an exponential rate due to human activities. Cement production contributes about 7% of the total worldwide CO2 emissions, and thus finding a practical way to reduce the greenhouse gas emission is essential. Construction and demolition (C&D) waste rich in calcium hydroxide and calcium silica hydrate is considered to be a potential calcium source for CO2 sequestration, forming thermodynamically stable carbonate minerals. In the past decade, a major research effort was to study the influencing factors affecting the effectiveness of active carbonation of C&D waste. In this paper, active carbonation techniques adopted for crushed concrete aggregate and waste cement derived from the C&D waste, and the resulting properties of the CO2 cured concrete aggregate and cement waste are discussed. In addition, special features of concrete block products as a potential medium for CO2 sequestration are also highlighted. Lastly, based on the environmental benefit and cost analysis of CO2 sequestration through C&D waste and concrete block are also presented. We concluded that the mineral carbonation of C&D waste is technically feasible, economical and environmentally friendly approach of a future carbon sequestration strategy.

Potential of CO2 sequestration through construction and demolition (C&D) waste—An overview

This paper presents an experimental investigation on structural concrete with partial replacement of coarse aggregate using electronic plastic waste (E-plastic). In view of utilizing the non-degradable waste in the construction industry, the E-plastic from computer plastics was considered as coarse aggregate. Coarse aggregate was replaced with different percentages (10, 20, 30, 40 and 50 %) of E-plastic by volume. Tests were performed for properties of fresh and hardened concrete at different ages such as 7 and 28 days. From the investigation, it was noted that the workability of the mix was reduced against the increase in percentage of E-plastic. The compressive strength, split tensile strength, flexural strength of partially replaced concrete was comparatively less than that of the control concrete. The effect of adding the E-plastic in concrete reduced the dry density of the concrete and showed the high deformability behavior before failure. The lesser dry density may be having advantage in self-weight reduction in structural elements which leads to lesser attraction of pseudo inertia forces in the seismic prone area.

K. Senthil Kumar

Papers

Potential of CO2 sequestration through construction and demolition (C&D) waste—An overview

Recycling of E-plastic waste as a construction material in developing countries

Valorization of waste powders from cement-concrete life cycle: A pathway to circular future

Global perspective on application of controlled low-strength material (CLSM) for trench backfilling – An overview

Waste resources recycling in controlled low-strength material (CLSM): A critical review on plastic properties.