Fibrolytic rumen bacteria of camel and sheep and their applications in the bioconversion of barley straw to soluble sugars for biofuel production

Lignocellulosic biomass such as barley straw is a renewable and sustainable alternative to traditional feeds and could be used as bioenergy sources; however, low hydrolysis rate reduces the fermentation efficiency. Understanding the degradation and colonization of barley straw by rumen bacteria is the key step to improve the utilization of barley straw in animal feeding or biofuel production. This study evaluated the hydrolysis of barley straw as a result of the inoculation by rumen fluid of camel and sheep. Ground barley straw was incubated anaerobically with rumen inocula from three fistulated camels (FC) and three fistulated sheep (FR) for a period of 72 h. The source of rumen inoculum did not affect the disappearance of dry matter (DMD), neutral detergent fiber (NDFD). Group FR showed higher production of glucose, xylose, and gas; while higher ethanol production was associated with cellulosic hydrolysates obtained from FC group. The diversity and structure of bacterial communities attached to barley straw was investigated by Illumina Mi-Seq sequencing of V4-V5 region of 16S rRNA genes. The bacterial community was dominated by phylum Firmicutes and Bacteroidetes. The dominant genera were RC9_gut_group, Ruminococcus, Saccharofermentans, Butyrivibrio, Succiniclasticum, Selenomonas, and Streptococcus, indicating the important role of these genera in lignocellulose fermentation in the rumen. Group FR showed higher RC9_gut_group and group FC revealed higher Ruminococcus, Saccharofermentans, and Butyrivibrio. Higher enzymes activities (cellulase and xylanase) were associated with group FC. Thus, bacterial communities in camel and sheep have a great potential to improve the utilization lignocellulosic material in animal feeding and the production of biofuel and enzymes.

Chlorine Corrosion in a Low-Power Boiler Fired with Agricultural Biomass

The selection of appropriate heat-resistant materials which are at the same time resistant to atmospheres rich in chlorine and its compounds is one of the most important current construction problems in steel boiler elements when using biomass fuels of agricultural origin. In the research presented here, an area was identified in the furnace of a 10 kW boiler where there was a potential risk of chlorine corrosion. This zone was determined based on numerical analysis of the combustion process; it is the zone with the highest temperatures and where the gas atmosphere conducive to the formation of chlorine corrosion centers. Subsequently, tests were carried out in the process environment of the combustion chamber of a 10 kW boiler (the fuel was barley straw) by placing samples of eight construction materials in a numerically-designated zone. These included samples of steel (coal boiler St41K, heat-resistant H25T and H24JS, and heat-resistant valve 50H21G9N4) as well as intermetallic materials based on phases (FeAl, Fe3Al, NiAl, and Ni3Al). The samples remained in the atmosphere of the boiler furnace for 1152 h at a temperature of 750–900 °C. After this time, the surfaces of the samples were subjected to SEM microscopy and scanning analysis. The results showed that the St41K boiler steel was not suitable for operation under the assumed conditions, and that a thick layer of complex corrosion products was visible on its surface. The least amount of corrosion damage was observed for the samples of 50H21G9N4 steel and intermetallic materials.

Evaluating the Potential for Smoke from Stubble Burning to Taint Grapes and Wine

It has been well established that bushfire/wildfire smoke can taint grapes (and therefore wine), depending on the timing and duration of exposure, but the risk of smoke contamination from stubble burning (a practice employed by some grain growers to prepare farmland for sowing) has not yet been established. This study exposed excised bunches of grapes to smoke from combustion of barley straw and pea stubble windrows to investigate the potential for stubble burning to elicit smoke taint. Increased levels of volatile phenols (i.e., chemical markers of smoke taint) were detected in grapes exposed to barley straw smoke (relative to control grapes), with smoke density and the duration of smoke exposure influencing grape volatile phenols. However, the sensory panel did not perceive wine made from grapes exposed to low-density smoke to be tainted, despite the presence of low levels of syringol providing compositional evidence of smoke exposure. During the pea stubble burn, grapes positioned amongst the burning windrows or on the edge of the pea paddock were exposed to smoke for ~15–20 and 30–45 min, respectively, but this only resulted in 1 µg/kg differences in the cresol and/or syringol concentrations of smoke-affected grapes (and 1 µg/L differences for wine), relative to controls. A small, but significant increase in the intensity of smoke aroma and burnt rubber flavor of wine made from the grapes positioned amongst the burning pea stubble windrows provided the only sensory evidence of any smoke taint. As such, had vineyards been located immediately downwind from the pea stubble burn, it is unlikely that there would have been any smoke contamination of unharvested grapes.

INFLUENCE OF DIFFERENT PREPARATS ON PRODUCTIVITY AND QUALITATIVE INDICATORS OF SPRING BARLEY

In this study we analyzed the influence of the pre-sowing treatment of spring barley seeds with the biological preparat Rizoagrin and the micronutrient fertilizer Tenso Cocktail against the background of the mineral fertilizer diammofosk on the germination of seeds, the quality of the grain yield and biomass of barley straw, the structure of the crop, the chemical composition of grain and straw under the conditions of the Republic of Tatarstan on gray forest soil. It was found that the use of Rhizoagrin and Tenso Cocktail in combination with diammophos increases the grain yield up to 4.05 t / ha, which is 117 % more than the control. We noted an increase in the productivity of plants, the number of ears, grain per ear and the weight of 1000 grains in relation to the control in the same variant. The fourth option has the highest indicators in terms of nitrogen content in grain and straw – by 5.40 and 8.62% more than in the control. In the second variant, the nitrogen content in the grain is 3.24 % higher than the control, and in the straw – by 5.17 %. In the third variant, the nitrogen content in grain and straw is 2.70 and 6.89 % higher than the control. In terms of the phosphorus content in grain and straw, the increase in the third and fourth variants is at the same level – 3.06 and 5.26 % in relation to the control. The second option does not have an increase in the phosphorus content. There was a decrease in the content of potassium in grain and straw in all variants compared to the control. In the fourth variant, the potassium content in grain is lower than the control by 8.45 %, in straw – by 5.69 %. In the second variant, the potassium content in the grain is lower in comparison with the control by 4.22 %, in the third variant – by 1.40 %. In straw, the potassium content in the second and third variants is reduced by 1.62 %.

Effects of biochar and barley straw application on the rice productivity and greenhouse gas emissions of paddy field

To improve the agricultural environment, utilization of biochar and organic materials from paddy fields gaining importance. This is because the long-term use of inorganic fertilizers aggravates the soil environment, and also because rice paddy is a major source of CH4 and N2O emissions during rice cultivation which involves continuous flooding. Recently, the application of organic materials and biochar to the soil has received increasing attention due to their potential benefits related to soil quality, crop growth, and greenhouse gas emission. This study examines the influence of biochar and straw treatments on rice growth, soil physicochemical properties, and global warming potential in the paddy field. Five treatments were applied for the study: control (Cn), inorganic fertilizer (IF), barley straw biochar (BC), barley straw (BS), and BC + BS. Soil quality after rice harvesting improved in the BC treated group. The yield components of rice were also improved in the BC + BS, compared to other treatments. These effects resulted in increased rice yield and uptake of nutrient contents in the BC + BS treatment. Total fluxes of CH4 and N2O relative to global warming significantly decreased by 37.3% and 65.2% in the BC + BS group than in the IF treatment, respectively. Consequentially, a cropping system with BC and BS is an effective strategy to improve rice productivity and soil quality and also reduce GHG emissions from paddy fields, thereby alleviating global warming.

Pretreatment of Lignocellulosic Biomass with 1-Ethyl-3-methylimidazolium Acetate for Its Eventual Valorization by Anaerobic Digestion

This study assessed the breakdown of lignocellulosic biomass (LB) with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]) as a pretreatment to increase the methane yield. The pretreatment was conducted for wheat straw (WS), barley straw (BS), and grape stem (GS) at 120 °C for 120 min, using several LB to [Emim][Ac] ratios (1:1, 1:3, and 1:5 w/w). Pretreatment significantly disrupted the lignocellulose matrix of each biomass into soluble sugars. GS showed the highest sugar yield, which was followed by WS, while BS was slightly hydrolyzed (175.3 ± 2.3, 158.2 ± 5.2, and 51.1 ± 3.1 mg glucose g–1 biomass, respectively). Likewise, the pretreatment significantly reduced the cellulose crystallinity index (CrI) of the resulting solid fractions of GS and WS by 15% and 9%, respectively, but slightly affected the CrI of BS (5%). Thus, BMP tests were only carried out for raw and hydrothermally and [Emim][Ac] (1:5) pretreated GS and WS. The untreated GS and WS showed similar methane yields to those achieved for the solid fraction obtained after pretreatment with an LB to [Emim][Ac] ratio of 1:5 (219 ± 10 and 368 ± 1 mL CH4 g–1 VS, respectively). The methane production of the solid plus liquid fraction obtained after IL pretreatment increased by 1.61- and 1.34-fold compared to the raw GS and WS, respectively.

Soil-cement blocks: a sustainable alternative for the reuse of industrial solid waste

This study aimed to analyze potential industrial solid waste that can be added to soil-cement blocks. A narrative literature review was conducted in the Scopus academic database, using as the search criteria keywords related to the topic, such as soil-cement, building materials, soil-cement blocks, soil-cement bricks, physical and mechanical properties, solid waste, life cycle analysis, and civil construction. A variety of industrial solid waste that can be incorporated into soil-cement blocks was observed, such as waste rock, sludge from water treatment plants, wood sawdust, polyethylene terephthalate fibers (PET), vegetable fibers from loofah, hemp fibers, rice husks, brachiaria grass, poultry eggshells, sugar cane bagasse, wheat and barley straw, welding slag, foundry sand, waste from quartzite mining, construction, and demolition, mechanical turning, pulp industry grains, and steel mill co-products. Among the investigated wastes, those that improved the physical and mechanical properties of the soil-cement blocks were grains from the cellulose industry, rice husks, Brachiaria grass, steel by-products with granulated soil-cement blocks and blast furnace slag. The waste that produced no satisfactory results was sludge from a water treatment plant, sugarcane bagasse, and vegetable loofah. Through this research, it was possible to verify that the behavior of soil-cement blocks is influenced by several factors in their manufacture, mainly regarding the type and percentage of incorporated waste. However, it is important to be concerned with its application in waste blocks so as not to increase the environmental impacts in the long term.

Torrefaction and Pelleting of Wheat and Barley Straw for Biofuel and Energy Applications

Microwave (MW)-assisted torrefaction and pelleting could enhance biomass fuel properties and energy applications. Plastic wastes are considered as a replacement source binder in pellets to minimize their effect on the environment as pollutants. High-density polyethylene (HDPE), an extractable plastic from recycling waste, was investigated as a binder for torrefied wheat and barley straw pellets. Fuel pellet characteristics, such as durability, density, tensile strength, and water absorption, were used to evaluate the pellets produced from a single pelleting test. The results showed that the addition of HDPE as a binder significantly increased the pellet quality in terms of density (686.12–982.93 kg/m3), tensile strength (3.68 and 4.53 MPa) for wheat and barley straw, and reduced ash content of the pellet from 10.34 to 4.59% for barley straw pellet and 10.66 to 3.88% for wheat straw pellets. The higher heating value (HHV) increased with increasing biochar mix and HDPE binder blend. The highest HHV value observed for barley straw was 28.34 MJ/kg, while wheat straw was 29.78 MJ/kg. The study further indicated that MW torrefaction of biomass-biochar mix with HDPE binder reduced the moisture adsorption of wheat and barley straw pellets, which can significantly improve their storage capability in humid locations. The moisture uptake ratio for MW-torrefied barley straw pellets was 0.10–0.25 and wheat straw pellets 0.11–0.25 against a moisture uptake ratio of 1.0 for untreated biomass. MW torrefaction of wheat and barley straw with biochar and HDPE binder addition during pelleting is a promising technique to improve biomass fuel pellet properties.