Environmental Performance of Wood Bioconcretes with Different Wood Shavings Treatments

Author(s):  
Amanda Lorena Dantas Aguiar ◽  
Carolina Goulart Bezerra ◽  
Lucas Rosse Caldas ◽  
Anna S. Bernstad ◽  
Romildo Dias Toledo Filho

The wood bio-concrete (WBC) production is a solution for the advancement of sustainable construction, since it has the potential to recycle waste in the form of shavings generated in wood processing and stock CO2, contributing for climate change reduction. However, the chemical incompatibility between plant biomass and cementitious matrix leads to the need for previous treatment of wood shavings to application in bio-concretes. In the present study, one heat treatment and two alkaline treatments with immersion in Ca (OH)2 solution were evaluated using Life Cycle Assessment (LCA) methodology. The environmental modeling was performed by SimaPro, using the Ecoinvent database, and primary data collected in the laboratory. The potential environmental impacts were related to the compressive strength of produced WBC (in MPa) as an ecoefficiency indicator. Considering the functional unit of mechanical performance, the alkaline treatment with two immersions was the one that generated less environmental impacts.

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4960
Author(s):  
Adam Koniuszy ◽  
Małgorzata Hawrot-Paw ◽  
Cezary Podsiadło ◽  
Paweł Sędłak ◽  
Ewa Możdżer

Biomass from cup plant (Silphium perfoliatum L.) is considered a renewable energy source that can be converted into alternative fuel. Calorific syngas, a promising type of advanced fuel, can be produced through thermochemical biomass gasification. In this study, the suitability of cup plant biomass for gasification was assessed, including the process energy balance and environmental impacts of waste from syngas purification. Silphium perfoliatum L. was cultivated as a gasification feedstock in different conditions (irrigation, fertilization). The experiments were performed in a membrane gasifier. All obtained energy parameters were compared to the biomass yield per hectare. The toxic effects of liquid waste were assessed using tests analyzing germination/seed root elongation of Sinapsis alba. Leachates collected from condensation tanks of a gas generator were introduced to soil at the following doses: 100, 1000 and 10,000 mg kg−1 DM of soil. The usefulness of Silphium perfoliatum L. for gasification was confirmed. The factors of plant cultivation affected the biomass yield, the volume and calorific value of syngas and the amount of biochar. It was determined that the components found in condensates demonstrate a phytotoxic effect, restricting or inhibiting germination and root elongation of Sinapsis alba. Due to this potential hazard, the possibility of its release to the environment should be limited. Most of the biomass is only used for heating purposes, but the syngas obtained from the cup plant can be used to power cogeneration systems, which, apart from heat, also generate electricity.


Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 22
Author(s):  
Mateus Manabu Abe ◽  
Marcia Cristina Branciforti ◽  
Michel Brienzo

The volume of discarded solid wastes, especially plastic, which accumulates in large quantities in different environments, has substantially increased. Population growth and the consumption pattern of societies associated with unsustainable production routes have caused the pollution level to increase. Therefore, the development of materials that help mitigate the impacts of plastics is fundamental. However, bioplastics can result in a misunderstanding about their properties and environmental impacts, as well as incorrect management of their final disposition, from misidentifications and classifications. This chapter addresses the aspects and factors surrounding the biodegradation of bioplastics from natural (plant biomass (starch, lignin, cellulose, hemicellulose, and starch) and bacterial polyester polymers. Therefore, the biodegradation of bioplastics is a factor that must be studied, because due to the increase in the production of different bioplastics, they may present differences in the decomposition rates.


2021 ◽  
pp. 0734242X2110291
Author(s):  
Navarro Ferronato ◽  
Gabriela Edith Guisbert Lizarazu ◽  
Marcelo Antonio Gorritty Portillo ◽  
Luca Moresco ◽  
Fabio Conti ◽  
...  

Construction and demolition waste (CDW) management in developing countries is a global concern. The analysis of scenarios and the implementation of life cycle assessment (LCA) support decision-makers in introducing integrated CDW management systems. This paper introduces the application of an LCA in La Paz (Bolivia), where CDW is mainly dumped in open areas. The aim of the research is to evaluate the benefits of inert CDW recycling in function of the selective collection rate, defined as the amount of waste (%wt.) sorted at the source in relation to the total waste amount produced, and the distances from the CDW generation to the material recycling facility. The outcomes of the research suggest that increasing the selective collection rates (5% to 99%) spread the importance of transportation distances planning since it affects the magnitude of the environmental impacts (1.05 tCO2-eq to 20.7 tCO2-eq per km traveled). Transportation limits have been found to be lower than about 40 km in order to make recycling beneficial for all environmental impacts and for all selective collection rate, with the eutrophication potential as the limiting indicator. The theoretical analysis suggests implementing LCA with primary data and involving statistics related to the transportation of virgin materials avoided thanks to recycling. The outcomes of the research support the implementation of CDW recycling in developing countries since it has been found that material recovery is always beneficial.


BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6431-6441
Author(s):  
Jianguo Wu ◽  
Yuanyuan Wang ◽  
Zhao Zhang ◽  
Xuanxian Luo ◽  
Chi Wang ◽  
...  

Wood processing waste, poplar wood shavings, were used for fiberboard production, and the pretreatment conditions using cellulase were studied using response surface methodology (RSM). After single factors optimization, central level of temperature, dosage, and liquid/solid ratio (LSR) of cellulase pretreatment conditions were obtained. Further optimization to study the influence of the factors was carried out using Box-Behnken design of experiments. A second-order polynomial equation was obtained, and the low p-value (<0.007) implied that the model was highly significant by analysis of variance (ANOVA). The optimized cellulase pretreatment conditions for maximum bending strength (BS) of the fiberboard were determined by ridge analysis as 44.4 °C of temperature, 1.23 U/g of dosage, 4.2 of LSR, and 5 h of pretreatment time. Under the optimized conditions, the BS of the fiberboard reached 25.12 ± 0.35 MPa by validation experiment, which was twice that of the fiberboard without pretreatment. Thus, the cellulase pretreatment should be a good choice to produce high-strength binderless fiberboard.


Author(s):  
Amanda Lorena Dantas Aguiar ◽  
M’hamed Yassin Rajiv da Gloria ◽  
Romildo Dias Toledo Filho

The use of wood wastes in the production of bio-concrete shows high potential for the development of sustainable civil construction, since this material, in addition to having low density, increases the energy efficiency of buildings in terms of thermal insulation. However, a concern arising from the production of bio-concretes with high amounts of plant biomass is how this material behaves when subjected to high temperatures. Therefore, this work aims to evaluate the influence of high temperatures on the mechanical properties of wood bio-concretes. The mixtures were produced with wood shavings volumetric fractions of 40, 50 and 60% and cementitious matrix composed of a combination of cement, fly ash and metakaolin. Uniaxial compression tests and scanning electron microscopy (SEM) were performed, with bio-concrete at age of 28 days, at room temperature (reference) and after exposure to temperatures of 100, 150, 200 and 250 °C. The density and compressive strength of the bio-concrete gradually decreased with increasing biomass content. Up to 200 °C, reductions in strength and densities less than 19% and 13%, respectively, were observed. At 250 °C, reductions of compressive strength reached 87%. Analysis performed by SEM showed an increase in the number of cracks in the wood-cementitious matrix interface and wood degradation by increasing the temperature.


2019 ◽  
Vol 11 (5) ◽  
pp. 1322 ◽  
Author(s):  
Mohit Vij ◽  
Amitabh Upadhya ◽  
Anu Vij ◽  
Manoj Kumar

This study explores the residents’ perceptions of economic, socio-cultural and environmental impacts of a mega-event (World Expo 2020) to be held in Dubai, as well as their level of inclination to participate in the event. The event organizers announced a requirement of thirty thousand volunteers to assist them in successfully organizing the mega event. Such events could prove to be landmarks in destination brand building and may lead to an increase in the number of tourists. The purpose of the study is to gauge the level of understanding about the event impacts within the resident population and their willingness to get involved in event organization. Priory studies of perceptions about the economic, cultural and environmental impacts of a mega-event, are well-nigh non-existent, especially for World Expositions. This study explores residents’ perception to get a fair idea of how they get involved in a mega event that will surely have profound impacts on the destination. Drawing on stakeholder theory and triple bottom line (TBL) model, the study uses primary data collected from more than two hundred fifty residents of the region, through a structured questionnaire. The data analysis follows a descriptive design supported by SEM and path analysis. Major findings indicate favorable and promising responses from the residents, and brings forth the scope to improve the level of involvement of the residents to make the event a success.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zoi G. Ralli ◽  
Stavroula J. Pantazopoulou

PurposeImportant differentiating attributes in the procedures used, the characteristic mineral composition of the binders, and the implications these have on the final long term stability and physico-mechanical performance of the concretes produced are identified and discussed, with the intent to improve transparency and clarity in the field of geopolymer concrete technologies.Design/methodology/approachThis state-of-the-art review covers the area of geopolymer concrete, a class of sustainable construction materials that use a variety of alternative powders in lieu of cement for composing concrete, most being a combination of industrial by-products and natural resources rich in specific required minerals. It explores extensively the available essential materials for geopolymer concrete and provides a deeper understanding of its underlying chemical mechanisms.FindingsThis is a state-of-the-art review introducing the essential characteristics of alternative powders used in geopolymer binders and the effectiveness these have on material performance.Practical implicationsWith the increase of need for alternative cementitious materials, identifying and understanding the critical material components and the effect they may have on the performance of the resulting mixes in fresh as well as hardened state become a critical requirement to for short- and long-term quality control (e.g. flash setting, efflorescence, etc.).Originality/valueThe topic explored is significant in the field of sustainable concrete technologies where there are several parallel but distinct material technologies being developed, such as geopolymer concrete and alkali-activated concrete. Behavioral aspects and results are not directly transferable between the two fields of cementitious materials development, and these differences are explored and detailed in the present study.


2018 ◽  
Vol 772 ◽  
pp. 13-17 ◽  
Author(s):  
Wapoon Tappanawatch ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet

Cellulose nanocrystals (CNC) were extracted from corn cob and synthesized by alkaline treatment using 3 wt% sodium hydroxide (NaOH). Acid hydrolysis with 64 wt% sulfuric acid (H2SO4) at different reaction times (30, 45, 60 min) was performed to obtain CNC solutions. CNC was evaluated as a reinforcing agent in natural rubber (NR) at CNC loadings from 1-5 wt%. Gamma-ray radiation was used as vulcanization method and varied at 10 and 20 kGy. The tensile modulus and tensile strength of NR vulcanizates increased with addition of CNC and contents. In addition, radiation by gamma ray impacts the mechanical performance, where CNC/NR composites vulcanized with higher dose of radiation of 20 KGy were found to have the higher values in tensile strength, elongation at break, and modulus than with 10 KGy. Moreover, the tensile strength and elongation at break of the composites after aging were found to slightly increase due to post-curing during the aging process.


Author(s):  
Daniele Landi ◽  
Leonardo Postacchini ◽  
Paolo Cicconi ◽  
Filippo E. Ciarapica ◽  
Michele Germani

In industrialized countries, packaging waste is one of the major issues to deal with, representing around 35% of the total municipal solid waste yearly generated. Therefore, an analysis and an environmental assessment of packaging systems are necessary. This paper aims at analyzing and comparing the environmental performances of two different packaging for domestic hoods. It shows how, through a packaging redesign, it is possible to obtain a reduction of the environmental impacts. This study has been performed in accordance with the international standards ISO 14040/14044, by using attributional Life Cycle Assessment (LCA) from Cradle to Gate. The functional unit has been defined as the packaging of a single household hood. Primary data have been provided by a household hood manufacturer, while secondary data have been obtained from the Ecoinvent database. LCA software SimaPro 8.5 has been used to carry out the life cycle assessment, and ReCiPe method has been chosen for the life cycle impact assessment (LCIA) stage. The results have shown the new packaging model being able to cut down the environmental impacts of approximately 30%. These outcomes may be used by household manufacturers to improve performances and design solutions of their different packaging.


2019 ◽  
Vol 24 ◽  
pp. 25-36 ◽  
Author(s):  
Hamada Shoukry

Cement manufacturing, which is partially responsible for environmental and health risks as well as the greenhouse gas emissions, is a binder industry that needs energy and raw material. To decrease the needing, this study develops nano-modified eco-friendly cementitious composites including industrial solid wastes and/or by-products. For this purpose, ordinary Portland cement (OPC) was partially replaced with 70 wt% of fly ash (FA), Nano metakaolin (NMK) was incorporated at a rate of 2, 4, 6, 8, 10, 12 and 14 % as partial replacement by weight of FA to take advantage of the great role of nano materials in improving the mechanical and physical properties of cement based materials. Compressive strength, flexural strength, and capillary water absorption coefficient have been studied at 28 days of curing according to the international ASTM standards. Differential scanning calorimeter (DSC) was used to study the phase composition/decomposition. The microstructure characteristics of the hardened samples were investigated by scanning electron microscope (SEM) equipped with energy dispersive analytical x-ray unit (EDAX). The results revealed that the partial replacement of cement by 70% of FA has reduced both compressive and flexural strengths by about 45% in addition; the water absorption has been increased by about 175% as compared to the OPC. The replacement of FA by different amounts of NMK compensate for the loss in strength by about 75%. Furthermore, NMK has considerably improved the microstructure and reduced the water absorption by 86%. The study concluded that, it is possible to substitute 70% of the weight of the cement in the production of eco-friendly cementitious composites with improved mechanical performance attaining 88% of the corresponding performance of the hydrated OPC. The developed composites can be considered as green binders and recommended for various applications in construction industry.


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