Influence of High Temperatures on the Mechanical Properties of Wood Bio-Concretes

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.

Development of GHG Emissions Curves for Bio-Concretes Specification: Case Study for Bamboo, Rice Husk, and Wood Shavings Considering the Context of Different Countries

Bio-concretes are receiving special attention in recent research as an alternative for climate change mitigation due to their low carbon footprints. Different bio-based materials can be used, e.g., wood shavings, bamboo, rice husk, and coconut. However, various methodological parameters can influence the carbon footprint of bio-based materials, especially bio-concretes, like biogenic carbon, amount of carbon in dry matter, rotation period of bio-aggregates, and type of cementitious materials. It is important to have easier ways of estimating the carbon footprint of bio-concretes, using parameters and data easily available. This research aims to evaluate the (1) carbon footprint of different mixtures of three bio-concretes (wood bio-concrete - WBC, bamboo bio-concrete - BBC and rice husk bio-concrete - RBC), and the (2) development of GHG emissions curves for bio-concretes specification based on easily available data (such as density, biomass content, and compressive strength). Based on experimental data, the carbon footprint was performed using the Life Cycle Assessment (LCA) methodology. In order to extend the findings of this study, the context of the following four countries was evaluated: Brazil, South Africa, India, and China. In addition, the replacement of Portland cement for Supplementary Cementitious Materials (SCMs) are evaluated hypothetically. The results show that the increase of biomass content in bio-concretes and the replacement of Portland cement by SCMs leads to a radical decrease in life cycle GHG emissions. The percentage of carbon in biomass is a critical factor for reducing the carbon footprint. The WBC was the biomass that performed better for this parameter. The presented GHG emissions curves can be a useful way to estimate the carbon footprint of bio-concretes and can be adapted to other kinds of bio-concretes and countries.

Environmental Performance of Wood Bioconcretes with Different Wood Shavings Treatments

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.

Evaluation of Bacterial Diversity in a Swine Manure Composting System Contaminated With Veterinary Antibiotics (VAs)

The objective of this work was identify microorganisms present in swine effluent composting system, under the contamination by most use veterinary drugs in Brazil. The composting took place for 150 days, where was addition of 200 liters of manure (these 25 liters initially contaminated with 17 antibiotics) in 25 kg of eucalyptus wood shavings. Microorganisms were measured at times (0 until 150 days), and were identified in the V3-V4 regions of the 16S RNAr for Bacteria, by means of next-generation sequencing (NSG). The results showing 7 different Bacteria Phyla and, 70 Bacteria Genus identified (more than 1% significance), in total there were more than 26 phyla and 585 genera of bacteria. The genus Brucella was found during mesophilic and thermophilic phases, this genus, not yet been reported in article involving composting process. These results suggested the potential of adaptation of the bacterial community with antibiotics denoted through the antibiotics.

Synthesis and characterization of biopolyols through biomass liquefaction of wood shavings and their application in the preparation of polyurethane wood composites

The sustainability of production systems in wood processing, wood industry, and wooden waste disposal is an important issue for European industry and society. Proper development of products based on renewable wood resources gives an opportunity to provide materials with long-term environmental, social, and economic sustainability. This study aims to establish a new way of forestry and agricultural waste materials utilization by synthesis of bio-based polyols and manufacturing of polyurethane wood composites (PU-WC). The first part of this paper describes the liquefaction of wood shavings at a temperature of 150 °C for 6 h in three different solvents—glycerol, poly (ethylene glycol) and their mixture in a 1:1 ratio. The second part deals with the synthesis of polyurethane (PU) resins containing 90% of biopolyol. Eight sets of materials with different NCO:OH ratios were obtained in a one-step method using a hydraulic press. These materials were characterized, and the material with the most promising properties was selected for polyurethane wood composites production. Composites with 40%, 50%, 60%, and 70% of wood shavings were obtained. The addition of filler caused an increase in flexural strength, Young`s modulus, hardness, and impact strength. Scanning electron microscopy (SEM) showed good adhesion between the polymer and the filler. The optimum filler content is between 50 and 60% by weight of the composite. The presented study provides a significant step toward a greener alternative for materials produced mainly from non-renewable resources.

Chemical and Microbial Analysis of Bedding Material (Wood Shavings) Treated with Graded Levels of Aluminium Sulphate (Alum)

The study was carried out at the poultry unit of the Department of Animal Science teaching and research farm, Ahmadu Bello University, Zaria to determine the chemical and microbial analysis of poultry litter (wood shavings) treated with graded levels of alum. The alum used was obtained from the Sabon-gari market in Zaria, Kaduna State. The rates of alum application (prior to keeping the birds) was as follows: T1 control (normal wood shavings with no alum), T2 (5% alum by kg weight of wood shavings), T3 (10% alum by kg weight of wood shavings) and T4 (15% alum by kg weight of wood shavings). Five sets of litter samples were obtained fortnightly from each pen from different locations i.e. the four corners and center from which the microbial load, pH, total nitrogen (N), soluble reactive phosphorus, VFA and NH4+ concentration were measured. The result shows significantly (P<0.05) lower pH value in all the alum treated wood shavings groups (5%, 10% and 15% alum treated wood shavings) compared to the control. The result showed that significantly (P<0.05) lower total volatile fatty acid level was obtained in all the alum treated wood shavings groups (5%, 10% and 15% alum treated wood shavings) compared to the control untreated wood shaving group. The results showed a decrease in total bacteria, E. coli and Salmonella spp. load in alum treated wood shavings groups (5%, 10% and 15% alum treated wood shavings) compared to the control, while mould and yeast load was increased in all the alum treated wood shavings groups (5%, 10% and 15% alum treated wood shavings) compared to the control. The study conclude that treating wood shavings with alum can reduce microbial load of the litter, hence improve health and reduce mortality. Treating wood shavings with alum tends reduce the microbial load of the litter.

The influence of particle soaking in acetic acid and NaOH solutions on the quality of sandwich particleboard from raru wood and belangke bamboo

As a composite product, particleboard has disadvantages related to low dimensional stability. The research purpose was to analyze the effect of immersion in acetic acid and NaOH solution on the quality of the particleboard sandwich. Sandwich particleboard (SPb) was made in a size of 25 cm length and 25 cm width. The target thickness and density are 1 cm and 0.75 g/cm3, respectively. The adhesive used was isocyanate adhesive with a content of 7%. First, The particles, which were in the form of wood shavings and bamboo strands, were soaked in a solution of acetic acid and NaOH at various concentrations (0, 1, 2, and 3%). The moisture content of the particles to be made SPb was set at 7%. After evenly mixing the particles (wood shavings and bamboo strands) and the adhesive, the sheet was created. The board sheets were made into three layers, namely 40% face layer in the form of a bamboo strand, 20% core layer in the form of wood shavings, and 40% back layer in the form of the bamboo strand. The next stage was the hot pressing process at 160 °C for 5 min and 30 kg/cm2 pressure. The following process was conditioning the board for seven days. Testing of quality refers to the standard JIS A5908 (2003). The results showed that the immersion of Raru wood particles in acetic acid and NaOH significantly affected the value of density, water absorption, thickness swelling, modulus of elasticity, modulus of rupture, and internal bond. Except for the moisture content on the AA3 and NA2 boards and the internal bond value on the untreated (control) board, all of the panel properties in this study met the standard.

Assessment of lignocellulosic residues from Northern Patagonian Andes (Argentina) for cultivation of Pleurotus ostreatus

This work evaluated mycelial growth rate (Kr) and fruiting of two Pleurotus ostreatus commercial strains (A01, 129) on formulations composed of lignocellulosic residues from farming and agroindustry of Northern Patagonian Andes, and of woody materials from invasive plants. Rosehip fluffs (RF), rosehip woodchips (RWC), southern beech wood shavings (SBWS), wheat straw (WS), and willow woodchips (WWC) were used as base substrates, and brewing bagasse (BB) as an alternative supplement to wheat bran (WB). Kr was higher in WS-WB and WS-BB for both strains. Experiments in fruiting chambers showed biological efficiencies (BEs) above 40% in WS-BB (both strains) and WS-WB (strain 129). Formulations using RWC or WWC gave BEs under 40%, while those composed of SBWS or RF showed lower Kr and contamination by moulds. Medium-scale fruiting experiments using strain A01 showed the highest BEs in WS-BB and RWC-WB. These results suggest that WS is the best substrate for Pleurotus ostreatus culture, although scarce in Northern Patagonian Andes. Nevertheless, WWC and RWC are suggested as alternative substrates, while BB is cheap and abundant, suitable as an alternative supplement to WB.

Hasil Pengujian Proksimasi Dan Gas Buang Pada Briket Campuran Limbah Serutan Kayu, Sekam Padi Dan Bulu Ayam

Biomass energy is one that can be used as an alternative energy as a substitute for fossil fuels and can also be useful for reducing environmental pollution due to increasing waste or waste. The manufacture of briquettes from chicken feather waste, wood shavings and rice husk waste aims to help deal with the problem of waste and use it as an alternative fuel. The making of briquettes is carried out by the process of drying the ingredients, charcoal, milling, sieving, kneading, printing, drying, proximate testing and measuring emissions on the briquettes. In this study, the composition of a mixture of chicken feathers (30%, 40%, 50%), wood shavings and rice husk (35%, 30%, 25%) was treated as well as particle sizes of 30 mesh and 60 mesh. The results of this study indicate that the lowest moisture content is in sample B2 of 4.5%. The lowest levels of volatile matters were in sample A1 of 37.4%. The lowest ash content was found in sample B3 at 10.8%. The highest fixed carbon was found in sample A3 at 45.1%. The highest calorific value (Gross Calorific Value) is found in the B3 sample of 5594 Kcal / Kg. And it has the highest CO, CO2, and HC emissions produced from the briquettes, namely 0.24%, 0.8%, 46 ppm. The properties of briquettes that have met SNI standards are moisture content, calorific value (except for sample A1), and the resulting emissions. And those that have not met SNI standards are the levels of volatile matter, ash content and fixed carbon. The resulting briquette can be used because the calorific value obtained is quiet high, which is above the specified standard of ≥ 5000 Kcal/Kg.

Investigation of Polymer Biofilm Formation on Titanium-Based Anode Surface in Microbial Fuel Cells with Poplar Substrate

Microbial fuel cells (MFCs) have attracted attention by directly converting the bioelectrochemical energy possessed by the organic materials that make up the biomass into electrical energy. In this study, the relationship between the biofilm formed on the titanium-based anode electrode surface, and the chemical composition of the substrate, the energy source of MFC, was investigated. For this, MFCs were made by using poplar wood shavings rich in organic material as the substrate, titanium-based material as the anode electrode, and natural soil as bacterial habitat. Three types of MFCs containing 1%, 10%, and 20% poplar wood shavings by weight were made and named P1-MFC, P2-MFC, and P3-MFC, respectively. According to electrochemical analysis, P3-MFC provided the highest open circuit voltage with 490 mV value, and the highest power density with 5.11 mW/m2 value compared to other MFCs. According to optical microscopy examinations, there were Bacillus and Coccus species of bacteria in the soil structure, and these bacteria also existed around the fiber of poplar wood shavings in MFCs. Scanning electron microscopy (SEM), energy-dispersive spectrum (EDS), and Fourier transform infrared spectroscopy (FTIR) analysis showed that MFCs formed biofilm in the titanium-based anode, and the chemical composition of this biofilm with poplar tree was similar. As a result, due to the catalysis reactions of bacteria, the titanium-based anode electrode surface was coated with polymer biofilm released from poplar wood shavings.