The manufacture of particleboards using mixture of peanut hull (Arachis hypoqaea L.) and European Black pine (Pinus nigra Arnold) wood chips

This research was conducted to investigate the suitability of peanut hull to produce general purpose particleboards. A series of panels were produced using peanut hull and mixture of peanut hull and European Black pine wood chips. Particleboards were manufactured using various hull ratios in the mixture (0%, 25%, 50%, 75% and 100%). Urea formaldehyde adhesive was utilized in board production and boards were produced to target panel's density of 0.7 g/cm3. Panels were tested for some physical (water absorption and thickness swelling), chemical (holocellulose content, lignin content, alcohol-benzene solubility, 1% NaOH solubility, hot water solubility and cold water solubility) and mechanical (modulus of rupture, modulus of elasticity and internal bond) properties. The main observation was that increase in peanut hull in the mixture resulted in a decrease in mechanical and physical properties of produced panels and panel including 25% hull in the mixture solely met the standard required by TS-EN 312 standard. Conclusively, a valuable renewable natural resource, peanut hull could be utilized in panel production while it has been mixed to the wood chips.     

Fire-retardant-treated low-formaldehyde-emission particleboard made from recycled wood-waste

The objective of this study was to manufacture fire-retardant-treated low-formaldehyde-emission particleboard from recycled wood-waste particles using polymeric 4,4'-methylenediphenyl isocyanate (PMDI) and phenol-formaldehyde (PF) resins. The influence of the PMDI/PF ratio (ratio of particles sprayed with PMDI to particles sprayed with PF, w/w) after fire retardant treatment on formaldehyde emissions, mechanical properties, and surface fire resistant performance of the manufactured particleboard was investigated. The experimental results showed that the formaldehyde emissions linearly decreased with an increasing PMDI/PF ratio. Moreover, the bending strength, internal bond strength, and screw holding strength increased with an increasing PMDI/PF ratio. The thickness swelling of the particleboard was improved by using an increasing PMDI/PF ratio. Furthermore, the fire-retardant-treated low-formaldehyde-emission particleboards fabricated in our study could pass the third grade standard of surface fire resistant performance as specified by CNS 6532.     

Contributions of polystyrene to the mechanical properties of blended mixture of old newspaper and wood pulp

Composites from recycled newspaper would result in the effective use of the waste product which is currently burned or land-filled, as well as potential reduction in the cost of manufactured composite. In this work, old newspaper (ONP) together with yellowish wood pulp and waste polystyrene from packaging were used to produce composite. The technique studied in this work is an alternative to the conventional melt compounding and was expected to provide efficient wetting of fibers by the polymer. Polystyrene was grafted with acrylonitrile, ethylmethacrylate and butylmethacrylate, respectively, using benzoyl peroxide as an initiator. The amount of polystyrene to monomer is 1:0.75 and to initiator is 1:1. The grafted copolymers were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Different ratios of waste polystyrene or grafted waste polystyrene were mixed with a blend of old newsprint and wood pulp to form composites. The mechanical properties of these composites as well as water uptake were studied. The tensile properties of the prepared composites did not show essential improvement, except for the modulus of elasticity. Scanning electron microscopy indicate that composites with grafted polystyrene showed more homogeneity than the composite with polystyrene and also than blank, so the grafted polymer is distributed very well improving the mechanical properties of the composites. Strong adhesion between the fiber and grafted polymer was found.     

Lactic acid production from pretreated corn stover with recycled streams

In order to overcome bottlenecks of the high amount of cellulase consumption in lignocellulosic l-Lactic acid (LA) production, a non-sterilized fed-batch simultaneous saccharification and fermentation (SSF) -membrane separation integration process was established in this current work. During the process, residual cellulase that remaining in the waste aqueous solution and solid residuals of corn stover (CS) were recycled and reused in subsequent fermentations. A total 6 rounds of operation were performed. Averagely, LA yield of 0.389 g g⁻¹ (pretreated CS) was achieved, which was 1.20 times higher than that of the conventional process without waste stream recycling. Moreover, the wastewater discharge and the cost of nutrients for fermentation can also hugely decrease. Results indicated that cellulase, wastewater discharge and nutrients consumption of the process reduced by 47.4 %, 73.7 % and 86.1 %, respectively. This study opens a promising way for the reduction of second-generation LA production cost, which could significantly change the economic feasibility of the LA biorefineries.     

Evaluation of the mechanical, physical properties and decay resistance of particleboard made from particles impregnated with Pinus brutia bark extractives

The mechanical, physical properties and decay resistances of particleboard made from particles impregnated with Pinus brutia bark extractives were examined. Properties included were modulus of rupture, modulus of elasticity, internal bond, thickness swelling, and weight loss according to European standards. The results showed that particleboards made from particles impregnated with bark extractives had significantly lower mechanical values than those made from unimpregnated particles. Impregnating wood particles with bark extractives improved the decay resistance and thickness swelling of particleboard. Increasing concentration of the extractives decreased the mechanical properties and improved the thickness swelling and decay resistance of the panels. Particleboards made from 1% P. brutia bark extractives met the specifications for modulus of rupture and internal bond strength for general purposes.     

Use of mycelial waste from the drug industry

It was shown that mycelial waste (MW) from manufacture of riboxin and neomycin was useful as an active filler for press compositions and a raw material for fuels. Addition of MW to a polymer press composition, depending on the amount added, provided a 2-10-fold decrease in the time of gel formation in the mixture and hardening of the products as well as a significant decrease in their shrinkage during the hardening. Optimal physicomechanical properties were achieved when the contents of MW and polymer in the press composition were equal. Pyrolysis of dry MW at a temperature of 450-500 degrees C resulted in formation of a product which was not inferior to the known fuels in its physicochemical properties. The low freezing point of the prepared fuel as compared to that of oil fuels allowed one to recommend it as a low-temperature additive to the fuels lowering their freezing points.     

Enhanced methane and hydrogen production from municipal solid waste and agro-industrial by-products co-digested with crude glycerol

The effects of crude glycerol on the performance of single-stage anaerobic reactors treating different types of organic waste were examined. A reactor treating the organic fraction of municipal solid waste produced 1400 mL CH₄/d before the addition of glycerol and 2094 mL CH₄/d after the addition of glycerol. An enhanced methane production rate was also observed when a 1:4 mixture of olive mill wastewater and slaughterhouse wastewater was supplemented with crude glycerol. Specifically, by adding 1% v/v crude glycerol to the feed, the methane production rate increased from 479 mL/d to 1210 mL/d. The extra glycerol-COD added to the feed did not have a negative effect on the reactor performance in either case. Supplementation of the feed with crude glycerol also had a significant positive effect on anaerobic fermentation reactors. Hydrogen yield was 26 mmole H₂/g VS added and 15 mmole H₂/g VS added in a reactor treating the organic fraction of municipal solid waste and a 1:4 mixture of olive mill and slaughterhouse wastewater. The addition of crude glycerol to the feed enhanced hydrogen yield at 2.9 mmole H₂/g glycerol added and 0.7 mmole H₂/g glycerol added.     

特异腐质霉角质酶-锚定肽融合蛋白的特性及在处理再生纸胶黏物中的应用

随着森林木材资源的减少,废纸回收利用越来越受到人们的重视.然而,废纸回收利用过程中产生的胶黏物会对再生纸的生产造成严重影响.生物法控制胶黏物主要是通过酶断裂胶黏物组分之间的酯键,防止胶黏物的絮凝,具有高效、专一、无污染等优势.角质酶是一种丝氨酸酯酶,可降解胶黏物中的部分成分.相关研究表明,锚定肽tachystatin ...     

High surface area activated carbon prepared from cassava peel by chemical activation

Cassava is one of the most important commodities in Indonesia, an agricultural country. Cassava is one of the primary foods in our country and usually used for traditional food, cake, etc. Cassava peel is an agricultural waste from the food and starch processing industries. In this study, this solid waste was used as the precursor for activated carbon preparation. The preparation process consisted of potassium hydroxide impregnation at different impregnation ratio followed by carbonization at 450-750 degrees C for 1-3 h. The results revealed that activation time gives no significant effect on the pore structure of activated carbon produced, however, the pore characteristic of carbon changes significantly with impregnation ratio and carbonization temperature. The maximum surface area and pore volume were obtained at impregnation ratio 5:2 and carbonization temperature 750 degrees C.     

The physical action of cellulases revealed by a quartz crystal microbalance study using ultrathin cellulose films and pure cellulases

The effects of fungal cellulases on model cellulose films were studied using a high-resolution quartz crystal microbalance (QCM) sensitive to minute changes of the nanometer thick model cellulose films. It was found that endoglucanases not only produce new end groups but also cause a swelling of the cellulose film. The cellobiohydrolases degraded the films quickly, which was detected as a rapid decrease in the remaining amount of cellulose on the QCM crystal. However, changing viscoelastic properties of the films also indicated a softening of the film during the degradation. A defined mixture of selected cellulases caused a significantly higher rate of degradation than only cellobiohydrolases. Cellulase synergism is discussed with the endoglucanase swelling effects and film softening added.     

Efficacy of organic wastes amendment on the establishment and biomass yield of grass species on a degraded Alfisol

Abstract

Deficiencies of organic matter and essential nutrients are important features of derelict/degraded lands; these characteristics have profound effects on the establishment of functional soil-plant systems on such lands. This work reports on the impact of organic wastes amendments on the establishment, growth and biomass yield of grass mixtures grown on a degraded soil. The experimental site was a heavily compacted and eroded land due to excavation (scrapping) of topsoil layer for urban construction activities. Zero, 10 and 20cm layers each of substrates collected from an old (abandoned) municipal refuse and from site affected by long-term surface disposal of livestock litter and topsoil collected under fallow vegetation were applied on soil surface, before the establishment of a mixture of grass species. Substrates collected from old municipal refuse contained high amount of essential nutrients and metals and, on application, produced upward shift in soil pH and electrical conductivity. Nevertheless, these properties neither significantly retarded plant growth nor impaired biomass yield. Plant establishment and biomass yield were comparable under topsoil application and organic waste amended soil and produced significantly higher biomass yield when spread at 20cm layers were made of them. This experimental group also produced superior biomass yield over the unamended control. The agronomic benefits of organic waste incorporation stemmed from improved soil properties in surface horizon and contents of essential nutrients supportive of the establishment and development of plant cover. Nutrient supply is related to soil organic matter status, organic wastes are therefore important to the reconstruction of effective nutrient cycling and the eventual functional soil-plant system on this degraded ecosystem. The goal of these revegetation efforts is to improve soil and plant productivity, plant diversity, conservation of native grasslands and aesthetic.     

玉米秸秆和异Vc钠生产废液固态发酵生产高蛋白饲料研究

以玉米秸秆为原料,以麸皮和异Vc钠生产废液(WEP)为辅料进行生物蛋白饲料固态发酵研究.通过菌种配伍试验,确定了混菌发酵菌种为白地霉、产朊假丝酵母和枯草芽孢杆菌.在此基础上通过单因素优化试验确定了秸秆蛋白饲料的最优发酵条件:以玉米秸秆(5 g)和麸皮(1 g)为基料,4%WEP营养液,固液比1:4(g/mL),初始pH值4.5;以麸皮浸汁作种子培养液,种龄24 h,各菌接种比例为产朊假丝酵母∶白地霉∶枯草芽孢杆菌=3:1:1,接种量2 mL;28℃、静置发酵2 d,在此条件下,秸秆饲料中真蛋白含量为6.21%,比对照提高了23.95%.该研究为秸秆和异Vc钠生产废液的高质化利用提供了新的思路和途径.     

Soft shell resins for solid-phase peptide synthesis.

Soft shell (SS) resins with a lightly or noncross-linked shell layer were prepared by reducing the amount of cross-linking agent, divinylbenzene (DVB), during seed suspension polymerization from polystyrene (PS) resin. These SS resins have a lower swelling volume than that produced by normal cross-linking. Despite its lower swelling, however, SS (10-00) resin, which consists of the 1% DVB-cross-linked core and the noncross-linked surface layer, showed higher efficiency in peptide synthesis compared with 1% DVB-PS resin and other SS resins.     

Possibility of using waste tire composites reinforced with rice straw as construction materials

Agricultural lignocellulosic fiber (rice straw)-waste tire particle composite boards were manufactured for use as insulation boards in construction, using the same method as that used in the wood-based panel industry. The manufacturing parameters were: a specific gravity of 0.8 and a rice straw content (10/90, 20/80 and 30/70 by wt.% of rice straw/waste tire particle). A commercial polyurethane adhesive for rubber was used as the composite binder. The water proof, water absorption and thickness swelling properties of the composite boards were better than those of wood particleboard. Furthermore, the flexibility and flexural properties of the composite boards were superior to those of other wood-based panel products. The composite boards also demonstrated good acoustical insulation, electrical insulation, anti-caustic and anti-rot properties. These boards can be used to prevent impact damage, are easily modifiable and are inexpensive. They are able to be used as a substitute for insulation boards and other flexural materials in construction.     

火龙果果皮中可溶性膳食纤维的提取方法

火龙果(Hylocereus undulatus)果皮可以作为一种优良的膳食纤维来源,且其膳食纤维具有良好的理化性能。为提高火龙果果皮的综合利用水平,该研究以火龙果果皮为原料,首先采用纤维素酶水解法对火龙果果皮中的可溶性膳食纤维进行提取,然后采用单因素试验和响应面法优化酶提取工艺。结果表明,纤维素酶法提取火龙果果皮中可溶性膳食纤维的优化工艺条件为:纤维素酶浓度0.54%,酶解温度50°C,pH5.2。在此条件下,可溶性膳食纤维的提取率可达19.81%;膳食纤维的持水力为31.25 g·g~(–1),溶胀性为29.11 m L·g~(–1)。     

Ethanol production by <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> and <Emphasis Type="Italic">Kluyveromyces marxianus</Emphasis> in the presence of orange-peel oil

Summary Two ethanologenic yeasts, Saccharomyces cerevisiae and Kluyveromyces marxianus, were used to ferment sugar solutions modeling hydrolyzed Valencia orange peel waste at 37°C. Orange stripper oil produced from orange peel was added in various amounts to determine its effect on ethanol production. The minimum peel oil concentration that inhibited ethanol production was determined after 24, 48 and 72 h and the two yeasts were compared to one another in terms of ethanol yield. Minimum inhibitory peel oil concentrations for ethanol production were 0.05% at 24 h, 0.10% at 48 h, and 0.15% at 72 h for both yeasts. S. cerevisiae produced more ethanol than K. marxianus at each time point.     

Particleboard quality characteristics of saline jose tall wheatgrass and chemical treatment effect

The objective of this research was to characterize the qualities (mechanical properties and water resistance) of particleboard made from saline Jose Tall Wheatgrass (JTW), Agropyron elongatum. For the JTW particleboards made with 4% polymeric methane diphenyl diisocyanate (PMDI), the mechanical properties and water resistance improved with the increase of particleboard density from 0.71 to 0.75 g/cm(3). The particleboards with density of 0.74 g/cm(3) had similar mechanical properties of wood-based particleboards, except for lower internal bond strength. Among the particleboards made with particles of different initial moisture contents from 2% to 10%, the particleboard with the particles of 8% initial moisture content had the highest qualities. The pretreatment using NaOH solution to wash the JTW particles reduced the qualities of finished particleboards bonded with both PMDI and urea formaldehyde (UF) resins. Particleboards made with PMDI showed superior qualities than those made with UF, as shown by the measured contact angle results between the adhesives and JTW.     

Some of the properties of flame retardant medium density fiberboard made from rubberwood and recycled containers containing aluminum trihydroxide

The flame retardancy of medium density fiberboard (MDF) made from mixture of rubberwood fibers and recycled old corrugated containers was studied. Aluminum trihydroxide (ATH) was used as a fire retardant additive and mixed with the fibers to manufacture experimental MDF panels using wet process. Phenol formaldehyde (PF) resin in liquid, 2% based on oven dry weight of fibers, was used along with 0%, 10%, 15% and 20% of ATH. The flame retardant test was done using the limiting oxygen index (LOI) test. The other properties investigated include internal bond strength, thickness swelling and water absorption. The results showed that ATH loading increased as the LOI of MDF increased. This demonstrated that ATH could improved the fire retardant property of MDF at sufficient loading. An increase in concentration of ATH showed an increase in the IB values of MDF made without resin. MDF panels made without resin showed a progressive increase in internal bond as the composition of recycled old corrugated containers fiber increased. Addition of resin improved internal bond strength and reduced thickness swelling, and water absorption. Thickness swelling of panel increased as the composition of recycled old corrugated containers fiber increased. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) showed that there is indication of ATH and resin filling the void space in between fibers.     

Application of waste activated bleaching earth containing rapeseed oil on riboflavin production in the culture of Ashbya gossypii

Waste activated bleaching earth (ABE) that contained 40% rapeseed oil and was discharged by an oil refinery plant, was used for riboflavin production in a culture of Ashbya gossypii. When 125 g/L waste ABE that contained 50 g/L rapeseed oil was added into the culture, the riboflavin concentration was 1.12 g/L, which was almost 1.6-fold as high as that of pure rapeseed oil. However, in waste ABE concentration higher than 125 g/L, the produced riboflavin concentration decreased, which was due to the difficulty in mixing due to the presence of a high amount of solid material in the culture. The surface of the waste ABE was smooth without a hitch, because of being covered with rapeseed oil. However, after the culture, the surface of the waste ABE seemed like that of new one, and the oil content was nearly zero grams per liter. The waste ABE, oily clay, and its black color gradually fade and yellow little by little, and finally the waste ABE changed to yellow powder. Of the riboflavin produced during the culture, 70% was adsorbed in the oil free waste ABE. With diluted alkali solution, extraction only two times yielded 90% recovery of riboflavin adsorbed in the waste ABE. The waste ABE containing waste vegetable oil was suitable for raw material for production of the value-added useful bioproducts, which might be a good model for reuse of the waste resource.     

The balance of nitrogen and composition of proteins inPleurotus ostreatus grown on natural substrates

The balance of nitrogen and nitrogen compounds in Pleurotus ostreatus, cultivated on waste materials, corn straw and maize residues, was investigated. The results show that this organism has a considerable ability to fix atmospheric nitrogen, fixing 312 g of total nitrogen per 100 kg dry weight. When recalculating with respect to a decrease of the substrate during growth of the organism a value of 9.7 mg per 1 g of the decrease in material is obtained. Fruiting bodies, as well as the produced substrate contain 17-19 amino acids. In the produced substrate the content of the protein nitrogen represents only 30% of the total. It can concluded that Pleurotus ostreatus yields a suitable raw material in the food industry and possibly also a fodder based on the basis of solid, cellulose-containing wastes.