Статті в журналах: "Alkaline pre-Treatments"

1

Konn, Jonas, Andrey Pranovich, and Bjarne Holmbom. "Dissolution of fibre material in alkaline pre-treatment and refining of spruce CTMP." Holzforschung 60, no. 1 (January 1, 2006): 32–39. http://dx.doi.org/10.1515/hf.2006.007.

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Abstract The chemistry of chemithermomechanical pulping (CTMP) was assessed by chemical pre-treatment of spruce chips, followed by laboratory-scale refining. Pre-treatments with alkali, sulfite, alkaline sulfite and alkaline peroxide liquors were carried out at 40°C, 60°C and 80°C. The sodium hydroxide dosages were 1% and 2% and the sodium sulfite and hydrogen peroxide dosages were 2%, 4% and 6% on a dry wood basis. Process water samples were taken before and after refining. Alkali consumption in the pre-treatments and the amount and composition of released wood components were determined. A major part of the alkali was consumed in the alkaline and alkaline sulfite pre-treatments. In the alkaline peroxide pre-treatments, however, alkali consumption was considerably lower. Acetic acid was the main wood component released to the process waters in alkaline pre-treatments. Pectins, determined as galacturonic acid and rhamnose by acid methanolysis, were also released to some extent, as well as easily soluble polysaccharides. After fibre separation in refining, more hemicelluloses and pectins were released. There was a significant difference between the degree of demethylation for pectins and the degree of deacetylation for galactoglucomannans after the pre-treatments. The diffusion of chemicals into the secondary wall layers seemed to be slower than the liquor penetration into the porous middle lamella through the pit pores. Up to 10% of the pectins were dissolved in the process waters as a result of depolymerisation and extensive demethylation. The residual amount of pectins in the fibres, however, was determined to be as low as 65–70% of the initial pectin content.

2

Beszédes, Sándor, Zoltán Jákói, Balázs Lemmer, and Cecilia Hodúr. "Enhanced biodegradability of dairy sludge by microwave assisted alkaline and acidic pre-treatments." Review on Agriculture and Rural Development 7, no. 1-2 (November 1, 2019): 92–97. http://dx.doi.org/10.14232/rard.2018.1-2.92-97.

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Considering the rapid, volumetric and selective heating effects of microwaves the microwave assisted chemical methods could provide appropriate alternatives for conventional thermal methods in sludge processing. Microwave irradiation alone is suitable to accelerate the hydrolysis stage of anaerobic decomposition of sludge resulted in accelerated biogas production rate and in higher biogas yield. Alkaline pre-treatments increase the organic matter solubility and suitable for disintegration of sludge particles. In some study are concluded that acidic conditions help the disintegration of waste activated sludge and assist in the solubilisation of carbohydrates and proteins which led to increased higher biogas production, as well. Beside the promising results related to effects of microwave pre-treatments on anaerobic digestion of sludge there are very few reports on the investigation of combined acidic/alkali-microwave pre-treatment method for food industry originated sludge. Hence, our study focused on the examination of the effects of combined microwave-alkali and microwave-acidic pre-treatment on aerobic and anaerobic biodegradability of sludge produced in dairy industry Our experimental results verified, that microwave irradiation with alkaline dosage improve the solubility of organic matters in the pH range of 8-12. But enhancement of disintegration was not correlated linearly with biodegradability. During pre-treatment stage, applying pH over 10, the aerobic biodegradability show decreasing tendency. Applying of acidic condition during microwave irradiation resulted in lower disintegration degree than obtained for microwave-alkaline sludge pre-treatment method. But with microwave assisted acidic pre-treatments a higher aerobic biodegradability could be achieved than with alkaline dosage. In microwave pre-treatments acidic condition was preferable to increase the shorter aerobic biodegradability; the alkaline condition was favourable to intensify the anaerobic digestion process.

3

Louhelainen, Jarmo, Joni Lehto, Teresa Kłosińska, Michał Drożdżek, and Raimo Alén. "Characterization of pre-treatments on wood chips prior to delignification by near infrared spectroscopy." BioResources 12, no. 4 (September 22, 2017): 8378–89. http://dx.doi.org/10.15376/biores.12.4.8378-8389.

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A near infrared (NIR) spectroscopy-based method for predicting yields and lignin contents of differently pre-treated silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips was developed. The approach was to create multivariate calibration models from the NIR data by the partial least squares (PLS) method. Both parameters are important factors when adjusting adequate conditions for pre-treatments either with hot-water (HW) as such and slightly acidified HW (collectively referred to as autohydrolysis) or dilute alkaline aqueous solutions prior to alkaline pulping. Pre-treatment conditions were varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). In the case of alkaline pre-treatments, the NaOH charge was 1% to 8% NaOH on wood dry solids (DS). The yields varied in the range 81.2% to 99.3% (in autohydrolyses) and 83.5% to 97.9% (in alkaline pre-treatments). High correlation coefficients and low prediction errors in relation to conventional yield and lignin content data clearly indicated the suitability of NIR spectroscopy combined with the multivariate modeling as an effective and fast tool for this purpose. This technique also showed promising possibilities for developing practical process control methods to follow such pre-treatments.

4

Rohma, N. A., S. Suhartini, and I. Nurika. "Chemical pre-treatments on oil palm empty fruit bunches: Impacts on characteristics and methane potential." IOP Conference Series: Earth and Environmental Science 924, no. 1 (November 1, 2021): 012071. http://dx.doi.org/10.1088/1755-1315/924/1/012071.

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Abstract Production of biogas from lignocellulosic biomass by anaerobic digestion (AD) has attracted much interest. Oil palm empty fruit bunches (OPEFB), one of lignocellulosic biomass, is highly abundant in Indonesia and has potential as feedstock for bioenergy production such as biogas or methane. Yet, pre-treatments are needed to improve biogas production due to its complex crystalline structures. Chemical pre-treatments with acid or alkaline solution were reported to increase cellulose or highly reduce the lignin content of OPEFB. This study aimed to evaluate the effect of acid and alkaline pre-treatments on the characteristics of OPEFB and methane potential. The acid pre-treatment experimental design was used factor of H2SO4 concentration (1, 1.3, and 1.6 (%v/v)) and NaOH concentration (1.8, 2.8, and 3.8 (%w/v)). Methane potential evaluation was carried out using the biochemical methane potential (BMP) test with the Automatic Methane Potential Test System (AMPTS) II under mesophilic condition (37°C), operated for 28 days. The results showed that both dilute acid and alkaline pre-treatment positively impact altering the characteristics of OPEFB, hence the specific methane potential. Alkaline pre-treatment with NaOH 3.8 (%w/v) gave the highest average SMP value of 0.161 ± 0.005 m3 CH4/kgVSadded.

5

Zemanová, Matilda, Ján Lokaj, Mária Karľová, and Jana Madejová. "Influence of pre-treatment on zirconium based conversion coating on AA2024." Acta Chimica Slovaca 10, no. 2 (October 26, 2017): 101–6. http://dx.doi.org/10.1515/acs-2017-0018.

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AbstractA comparison of the influence of two alloy pre-treatments and temperature treatments on the formation and composition of zirconium based conversion coating on the AA2024 alloy has been performed. The investigation employed mass changes, atomic force microscopy (AFM), XRD dispersive spectroscopy (EDX), infrared spectroscopy (IR) and electrochemical tests by open circuit potential (OCP) measurements. Pre-treatment using only alkaline etching is called alkaline pre-treatment. When alkaline etching is followed by de-oxidization in a phosphoric acid solution the process is called acidic pre-treatment. Conversion coatings were formed in Pragokor BL. IR analysis revealed the formation of a phosphate on the alloy surface. EDX analysis showed Mg dissolution. The Zr content increased with the temperature of the conversion coating formation. Both pre-treatment methods provided a phosphate layer on the alloy surface.

6

Konn, Jonas, Lari Vähäsalo, Andrey Pranovich, and Bjarne Holmbom. "De-esterification and sulfonation in spruce CTMP: Effects on pulp and paper properties." Holzforschung 60, no. 4 (July 1, 2006): 355–64. http://dx.doi.org/10.1515/hf.2006.056.

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Abstract De-esterification and sulfonation reactions, which create new anionic groups in the middle lamella and primary wall layers, are the key chemical reactions in chemithermomechanical pulping. The effects of these reactions on the resulting fibre dimensions, refining energy demand, hand-sheet bulk and strength properties were assessed by laboratory-scale chemical pre-treatments and refining of Norway spruce chips. After pre-treatments with alkaline, sulfite, alkaline sulfite and alkaline peroxide liquors, a Wing defibrator-type batch refiner was used. The refining energy was measured. The degree of alkaline hydrolysis of acetyl and methyl ester groups in galactoglucomannans (GGMs) and pectins, and the degree of lignin sulfonation were determined. Hand-sheets were prepared and their physical properties were tested. The data were subjected to multivariate analysis and the order of significance of the chemical reactions towards pulp and paper properties was estimated. Chemical pre-treatments were found to increase the fibre length and the energy demand considerably. The fibre length and width after refining were strongly influenced by lignin sulfonation and pectin demethylation. GGM deacetylation had little influence on preserving the fibre dimensions in CTMP refining. The bulk, on the other hand, was highly influenced by GGM deacetylation. Peroxide reactions in alkaline peroxide treatments had no effect on the pulp and paper properties.

7

Solár, R., J. Dibdiaková, M. Mamoň, F. Kačík, Z. Rázgová, V. Vacek, J. Sivák, and M. Gaff. "Alkaline and Alkaline/oxidation pre-treatments of spruce wood (Picea abies) – Impact on the quality of kraft pulp." Bioresource Technology 102, no. 2 (January 2011): 1921–27. http://dx.doi.org/10.1016/j.biortech.2010.08.023.

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8

Sun, Runcang, J. Mark Lawther, and W. B. Banks. "Influence of alkaline pre-treatments on the cell wall components of wheat straw." Industrial Crops and Products 4, no. 2 (July 1995): 127–45. http://dx.doi.org/10.1016/0926-6690(95)00025-8.

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9

Fonseca, Alessandra de Souza, Suhara Panthapulakkal, Samir Kumar Konar, Mohini Sain, Lina Bufalinof, Joabel Raabe, Ires Paula de Andrade Miranda, Maria Alice Martins, and Gustavo Henrique Denzin Tonoli. "Improving cellulose nanofibrillation of non-wood fiber using alkaline and bleaching pre-treatments." Industrial Crops and Products 131 (May 2019): 203–12. http://dx.doi.org/10.1016/j.indcrop.2019.01.046.

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10

Afolabi, M. S., W. A. Lamidi, and M. O. Akoroda. "Response of Sweet Potato Storability with Different Pre-storage Treatments at Ambient Temperature." Journal of Agricultural Research and Development 19, no. 1 (April 22, 2021): 10–17. http://dx.doi.org/10.4314/jard.v19i1.2.

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The storage of sweet potato tuberous roots in tropical countries is a major challenge to farmers and retailers due to unfavourable climatic conditions. In this study, the storage performance of sweet potato roots in an ambient condition was investigated over a 12-week duration. The three different pre-storage treatments used were ash, alkaline solution (1.5 mol dm-3) and Siam weed (Chromolaena odorata) extract – to evaluate their effects on weight loss, shrinkage, weevil damage and sprouting. The control comprised tubers with no pre-treatment. It was observed that weight loss increased linearly from the inception of storage while shrinkage became apparent only after two (2) weeks. The percentage shrinkage of the tuber pre-treated with Siam weed increased at decreasing rate from 8 WAP. Treatment of tuber with Siam weed extract provided significantly higher protection against weevil damage (p > 0.05). After this, sprouting was initiated. By the 12th week, the Siam weed (Chromolaena odorata) extract treatment yielded better results. The Siam weed (Chromolaena odorata) treatment also recorded the lowest weight loss of 28% and lowest shrinkage of 2.8%. It also sustained less weevil damage at 33.5% compared with the other treatments. Sprouting was higher in the tuber without pre-storage treatment. The alkaline solution and ash treatments had varied degree of performance for all the indicators. Keywords: Sweet potato storability, Ambient condition, Pre-storage treatment, Chromolaena odorata

11

Guise, G. B., and G. N. Freeland. "6—SHRINK-RESIST TREATMENTS OF WOOL BY EXHAUSTION OF POLYMERS: THE EFFECT OF ALKALINE PRE- AND AFTER-TREATMENTS." Journal of the Textile Institute 77, no. 1 (January 1986): 56–65. http://dx.doi.org/10.1080/00405008608658521.

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12

Ferreira da Silva, Isadora, Luciana Reis Fontinelle Souto, Samuel R. A. Collins, Adam Elliston, José Humberto de Queiroz, and Keith W. Waldron. "Impact of Hot Water and Alkaline Pre-treatments in Cellulosic Ethanol Production from Banana Pseudostem." BioEnergy Research 13, no. 4 (May 4, 2020): 1159–70. http://dx.doi.org/10.1007/s12155-020-10123-w.

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13

Di Girolamo, Giuseppe, Lorenzo Bertin, Lorenzo Capecchi, Claudio Ciavatta, and Lorenzo Barbanti. "Mild alkaline pre-treatments loosen fibre structure enhancing methane production from biomass crops and residues." Biomass and Bioenergy 71 (December 2014): 318–29. http://dx.doi.org/10.1016/j.biombioe.2014.09.025.

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14

Mancuso, Giuseppe, Michela Langone, Gianni Andreottola, and Laura Bruni. "Effects of hydrodynamic cavitation, low-level thermal and low-level alkaline pre-treatments on sludge solubilisation." Ultrasonics Sonochemistry 59 (December 2019): 104750. http://dx.doi.org/10.1016/j.ultsonch.2019.104750.

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15

Kosorn, Wasana, Boonlom Thavornyutikarn, and Wanida Janvikul. "Effects of Surface Treatments of Polycaprolactone Scaffolds on their Properties." Advanced Materials Research 747 (August 2013): 178–81. http://dx.doi.org/10.4028/www.scientific.net/amr.747.178.

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Polycaprolactone (PCL) was surface modified with alkaline hydrolysis by NaOH and/or low pressure oxygen (O2) plasma treatment. The hydrolysis was conducted in two different stages: one was performed prior to PCL scaffold fabrication by a high pressure supercritical CO2 technique; the other was carried out after the fabrication. The resulting hydrolyzed PCL scaffolds, with pore sizes in the range of 150-250 μm, were denoted as pre-HPCL and post-HPCL, respectively. Both non-hydrolyzed and hydrolyzed PCL scaffolds were subsequently subjected to the plasma treatment, to further enhance the hydrophilicity of the scaffolds. The surface morphology, wettability and chemical composition of all PCL scaffolds were analyzed by scanning electron microscopy (SEM), water contact angle measurement, and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the surface of the scaffolds turned from fairly smooth to highly rough after the hydrolysis and plasma treatment, particularly when both treatments were in use. The post-hydrolysis induced more surface roughness, compared to the pre-hydrolysis. In addition, the water contact angles on the scaffolds enormously reduced after the treatments; plasma treatment, however, showed a more prominent effect than the alkaline hydrolysis. Although expressing a zero-degree contact angle, the plasma-treated pre-HPCL scaffold was wetted more readily than the plasma-treated post-HPCL. These were in good agreement with the XPS results; interestingly, the plasma-treated pre-HPCL scaffold exhibited the greatest O/C atomic ratio among the PCL scaffolds. This indicated its highest extent of PCL chain oxidation, a degradation of ester groups into-COOH and-OH groups.

16

Liew, Kang Chiang, Yu Feng Tan, Charles Michael Albert, and Vinodini Raman. "Cross-Laminated Timber and Glulam from Low-Density Paraserianthes falcataria: A Look into Densification and Shear Strength." Forests 13, no. 10 (September 21, 2022): 1540. http://dx.doi.org/10.3390/f13101540.

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The aim of this study was to investigate the shear performance of cross-laminated timber (CLT) and glulam made from densified Paraserianthes falcataria laminas. The densification process involved pre-treatment, compression with heat (105 °C, 6 MPa), and a cooling phase. CLT was manufactured from densified laminas of different thicknesses (24–60 mm), while glulam was produced from densified laminas that underwent pre-treatments of (1) pre-steaming (0–30 min) and (2) alkaline pre-treatment (sodium hydroxide (NaOH) concentrations: 0%–9%). Both CLT and glulam were cut into a pre-determined size before being subjected to a block shear test. The findings showed that the presence of pre-steaming (20 min) exhibited the highest shearing strength value. In contrast, alkaline pre-treatment reduced the shear performance of glulam. Here, 24 mm and 30 mm CLT were found to have the highest shearing strength among the parameters. Pre-steamed laminas showed better wettability, but no statistically significant correlation between the contact angle and shear strength of glulam. The densification process reduced the fiber pore areas of the laminas. The fiber pore areas with a shear strength of glulam, with or without alkaline pre-treatment, revealed a weak correlation. The correlation between fiber pore areas and the shear strength of CLT show no statistical significance. Here, 30 mm CLT with lowest moisture content and highest wood failure percentage exhibited a better bonding performance.

17

Schmitz, Eva, Eva Nordberg Karlsson, and Patrick Adlercreutz. "Ultrasound Assisted Alkaline Pre‐treatment Efficiently Solubilises Hemicellulose from Oat Hulls." Waste and Biomass Valorization 12, no. 10 (March 12, 2021): 5371–81. http://dx.doi.org/10.1007/s12649-021-01406-0.

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AbstractThe establishment of sustainable bioeconomies requires the utilization of new renewable biomaterials. One such material currently seen as a waste product is oat hulls. Oat hulls exhibit a great potential for the production of dietary fibres due to their exceptionally large hemicellulose content (35%). Their recalcitrant structure however requires a suitable pre-treatment method to access and process the hemicellulose. After a screening of various physical, chemical and physico-chemical pre-treatment methods, including autoclaving, ultrasonication, microwave-, deep eutectic solvents-, as well as alkaline treatments, a combined ultrasonication and alkali pre-treatment method was here found to be the most suitable. A factorial design resulted in optimized conditions of 10 min ultrasonication in water, followed by an incubation in 5 M NaOH at 80 ºC for 9 h yielding solubilisation of 72% of all hemicellulose in the hulls. The method was shown to efficiently break the ester bonds between ferulic acid and the hemicellulose main chain, contributing to its solubilisation. Graphic Abstract

18

Vasmara, Ciro, Stefania Galletti, Stefano Cianchetta, and Enrico Ceotto. "Advancements in Giant Reed (Arundo donax L.) Biomass Pre-Treatments for Biogas Production: A Review." Energies 16, no. 2 (January 14, 2023): 949. http://dx.doi.org/10.3390/en16020949.

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Giant reed is a non-food, tall, rhizomatous, spontaneous perennial grass that is widely diffused in warm-temperate environments under different pedo-climatic conditions. In such environments, it is considered one of the most promising energy crops in terms of economic and environmental sustainability, as it can also be cultivated on marginal lands. Owing to its complex and recalcitrant structure due to the lignin content, the use of giant reed as a feedstock for biogas production is limited. Thus, pre-treatment is necessary to improve the methane yield. The objective of this review was to critically present the possible pre-treatment methods to allow the giant reed to be transformed in biogas. Among the studied pre-treatments (i.e., hydrothermal, chemical, and biological), alkaline pre-treatments demonstrated better effectiveness in improving the methane yield. A further opportunity is represented by hybrid pre-treatments (i.e., chemical and enzymatic) to make giant reed biomass suitable for bio-hydrogen production. So far, the studies have been carried out at a laboratory scale; a future challenge to research is to scale up the pre-treatment process to a pilot scale.

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Carballa, M., F. Omil, A. C. Alder, and J. M. Lema. "Comparison between the conventional anaerobic digestion of sewage sludge and its combination with a chemical or thermal pre-treatment concerning the removal of pharmaceuticals and personal care products." Water Science and Technology 53, no. 8 (April 1, 2006): 109–17. http://dx.doi.org/10.2166/wst.2006.241.

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Many novel treatment technologies, usually representing a pre-treatment prior to the biological degradation process, have been developed in order to improve the recycling and reuse of sewage sludge. Among all the methods available, a chemical (alkaline) and a thermal treatment have been considered in this study. The behaviour of 13 substances belonging to different therapeutic classes (musks, tranquillisers, antiepileptic, anti-inflammatories, antibiotics, X-ray contrast media and estrogens) has been studied during the anaerobic digestion of sewage sludge combined with these pre-treatments (advanced operation) in comparison with the conventional process. Two parameters have been analysed: the temperature (mesophilic and thermophilic conditions) and the sludge retention time. While organic matter solubilization was higher with the alkaline process (55–80%), no difference between both pre-treatments was observed concerning volatile solids solubilization (up to 20%). The removal efficiencies of solids and organic matter during anaerobic digestion ranged from 40–70% and 45–75%, respectively. The higher removal efficiencies of pharmaceuticals and personal care products were achieved for the antibiotics, Naproxen and the natural estrogens (>80%). For the other compounds, the values were in the range 20–70%, except for Carbamazepine, which was not removed at any condition tested.

20

Haranghy, Laura, Zoltán Jákói, Cecilia Hodúr, and Sándor Beszédes. "Detection of efficiency of microwave-enhanced sludge treatments by dielectric measurements." Analecta Technica Szegedinensia 15, no. 2 (December 15, 2021): 53–57. http://dx.doi.org/10.14232/analecta.2021.2.53-57.

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Microwave irradiation is a promising pre-treatment method for sludge stabilisation, but there are few studies focusing its effect on organic matter solubility and biodegradability of wastewater and sludge originated from the food industry. In our research, microwave irradiation was applied standalone and in combination with alkaline treatment to enhance the solubilisation and biodegradation of organic matter content of meat industry wastewater and municipal sludge, respectively. The energy efficiency was investigated, as well. Dielectric measurement is a suitable method to detect physicochemical changes, therefore our research work covered the determination of dielectric properties of the investigated materials. Our experimental results have revealed that the lower power and energy intensity microwave-alkaline treatments were the most efficient pre-treatment process from energetically aspects to increase the organic matter solubility and biodegradability of wastewater and sludge. Furthermore, a strong linear correlation was found between the dielectric constant and the indicators of the solubility of organic matter (SCOD/TCOD) and aerobic biodegradability (BOD/COD) in both treated materials, respectively. Our results show that the dielectric measurements can be applied for detection of physicochemical changes, predict the improvement of biodegradability, and considered as a promising method to estimate the efficiency of sludge pre-treatment methods.

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Doymaz, İ. "Effect of Pre-treatments using Potassium Metabisulphide and Alkaline Ethyl Oleate on the Drying Kinetics of Apricots." Biosystems Engineering 89, no. 3 (November 2004): 281–87. http://dx.doi.org/10.1016/j.biosystemseng.2004.07.009.

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22

Rodrigues, Plínio R., Mateus F. L. Araújo, Tamarah L. Rocha, Ronnie Von S. Veloso, Lílian A. Pantoja, and Alexandre S. Santos. "Evaluation of buriti endocarp as lignocellulosic substrate for second generation ethanol production." PeerJ 6 (August 2, 2018): e5275. http://dx.doi.org/10.7717/peerj.5275.

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The production of lignocellulosic ethanol is one of the most promising alternatives to fossil fuels; however, this technology still faces many challenges related to the viability of the lignocellulosic alcohol in the market. In this paper the endocarp of buriti fruit was assessed for ethanol production. The fruit endocarp was characterized physically and chemically. Acid and alkaline pre-treatments were optimized by surface response methodology for removal of hemicellulose and lignin from the biomass. Hemicellulose content was reduced by 88% after acid pretreatment. Alkaline pre-treatment reduced the lignin content in the recovered biomass from 11.8% to 4.2% and increased the concentration of the cellulosic fraction to 88.5%. The pre-treated biomass was saccharified by the action of cellulolytic enzymes and, under optimized conditions, was able to produce 110 g of glucose per L of hydrolyzate. Alcoholic fermentation of the enzymatic hydrolyzate performed by Saccharomyces cerevisiae resulted in a fermented medium with 4.3% ethanol and a yield of product per substrate (YP/S) of 0.33.

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Costa, Stefania, Irene Rugiero, Christian Larenas Uria, Paola Pedrini, and Elena Tamburini. "Lignin Degradation Efficiency of Chemical Pre-Treatments on Banana Rachis Destined to Bioethanol Production." Biomolecules 8, no. 4 (November 9, 2018): 141. http://dx.doi.org/10.3390/biom8040141.

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Valuable biomass conversion processes are highly dependent on the use of effective pretreatments for lignocellulose degradation and enzymes for saccharification. Among the nowadays available treatments, chemical delignification represents a promising alternative to physical-mechanical treatments. Banana is one of the most important fruit crops around the world. After harvesting, it generates large amounts of rachis, a lignocellulosic residue, that could be used for second generation ethanol production, via saccharification and fermentation. In the present study, eight chemical pretreatments for lignin degradation (organosolv based on organic solvents, sodium hypochlorite, hypochlorous acid, hydrogen peroxide, alkaline hydrogen peroxide, and some combinations thereof) have been tested on banana rachis and the effects evaluated in terms of lignin removal, material losses, and chemical composition of pretreated material. Pretreatment based on lignin oxidation have demonstrated to reach the highest delignification yield, also in terms of monosaccharides recovery. In fact, all the delignified samples were then saccharified with enzymes (cellulase and beta-glucosidase) and hydrolysis efficiency was evaluated in terms of final sugars recovery before fermentation. Analysis of Fourier transform infrared spectra (FTIR) has been carried out on treated samples, in order to better understand the structural effects of delignification on lignocellulose. Active chlorine oxidations, hypochlorous acid in particular, were the best effective for lignin removal obtaining in the meanwhile the most promising cellulose-to-glucose conversion.

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Yang, Chung-Wei, and Guan-Kai Wang. "Effect of Hydrothermal (Sr)-Hydroxyapatite Coatings on the Corrosion Resistance and Mg2+ Ion Release to Enhance Osteoblastic Cell Responses of AZ91D Alloy." Materials 13, no. 3 (January 27, 2020): 591. http://dx.doi.org/10.3390/ma13030591.

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The biomedical applications of Mg-based alloys are limited by their rapid corrosion rate in the body fluid. In this study, the hydrothermal synthesis is employed to produce protective bioactive hydroxyapatite coating (HAC) and strontium-substituted hydroxyapatite coating (Sr-HAC) to further enhance the corrosion resistance and in vitro biocompatibility of biodegradable AZ91D Mg alloy in physiological environments. For comparison, the brucite Mg(OH)2 prepared by the alkaline pre-treatment is designated as a control group. Experimental evidences of XRD and XPS analysis confirm that Sr2+ ions can be incorporated into HA crystal structure. It is noted that the hydrothermally synthesized Sr-HAC conversion coating composed of a specific surface topography with the nanoscaled flake-like fine crystallites is constructed on the AZ91D Mg alloy. The hydrophilicity of Mg substrate is effectively enhanced with the decrease in static contact angles after performing alkaline and hydrothermal treatments. Potentiodynamic polarization measurements reveal that the nanostructured Sr-HAC-coated specimens exhibit superior corrosion resistance than HAC and alkaline pre-treated Mg(OH)2. Moreover, immersion tests demonstrate that Sr-HAC provides favorable long-term stability for the Mg alloy with decreasing concentration of released Mg2+ ions in the SBF and the reduced corrosion rate during the immersion length of 30 days. The cells cultured on Sr-HAC specimens exhibit higher viability than those on the alkaline-pre-treated Mg(OH)2 and HAC specimens. The Sr-substituted HA coating with a nanostructured surface topography can help to stimulate the cell viability of osteoblastic cells.

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Yashim, M. M., M. Mohammad, N. Asim, A. Fudholi, and N. H. Abd Kadir. "Characterisation of microfibrils cellulose isolated from oil palm frond using high-intensity ultrasonication." IOP Conference Series: Materials Science and Engineering 1176, no. 1 (August 1, 2021): 012004. http://dx.doi.org/10.1088/1757-899x/1176/1/012004.

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Abstract This study highlighted the utilization of agricultural byproducts as an alternative fiber resource to be used as one of the materials for reinforcement biocomposite. Cellulose was extracted from oil palm frond using the alkaline treatment and successfully isolated into microfibril via the combination of carboxymethylation pre-treatment ultrasonication to get highly crystalline and good thermal stable microfibers. 4% NaOH was used during alkaline treatment and followed by oxidative bleaching with 30% H2O2. Once the extracted cellulose is chemically pre-treated with monochloroacetic acid, it was subjected to 30 minutes ultrasonication treatment to reduce its size. The detailed comparative analysis using SEM, FTIR and TGA was conducted in this work revealed some breakages of intramolecular hydrogen bonds and glycosidic bonds that occurred during the alkaline and bleaching treatment of oil palm biomass. The SEM images showed significant morphology of rigid, organized and highly ordered cellulose fibrils changed into aggregated fibril bundles of microfibrils after ultrasonication. The results from the infrared spectrums revealed that the mild alkaline treatments and oxidative bleaching were able to remove a large fraction of lignin and hemicelluloses to leave a clean cellulose sample. The isolated microfibrils cellulose exhibit good thermal stability as almost 50% of its initial mass remains at a temperature of 300 °C. These findings demonstrate that oil palm fronds can be utilized for biocomposite reinforcement applications.

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Yashim, M. M., M. Mohammad, N. Asim, A. Fudholi, and N. H. Abd Kadir. "Characterisation of microfibrils cellulose isolated from oil palm frond using high-intensity ultrasonication." IOP Conference Series: Materials Science and Engineering 1176, no. 1 (August 1, 2021): 012004. http://dx.doi.org/10.1088/1757-899x/1176/1/012004.

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Abstract This study highlighted the utilization of agricultural byproducts as an alternative fiber resource to be used as one of the materials for reinforcement biocomposite. Cellulose was extracted from oil palm frond using the alkaline treatment and successfully isolated into microfibril via the combination of carboxymethylation pre-treatment ultrasonication to get highly crystalline and good thermal stable microfibers. 4% NaOH was used during alkaline treatment and followed by oxidative bleaching with 30% H2O2. Once the extracted cellulose is chemically pre-treated with monochloroacetic acid, it was subjected to 30 minutes ultrasonication treatment to reduce its size. The detailed comparative analysis using SEM, FTIR and TGA was conducted in this work revealed some breakages of intramolecular hydrogen bonds and glycosidic bonds that occurred during the alkaline and bleaching treatment of oil palm biomass. The SEM images showed significant morphology of rigid, organized and highly ordered cellulose fibrils changed into aggregated fibril bundles of microfibrils after ultrasonication. The results from the infrared spectrums revealed that the mild alkaline treatments and oxidative bleaching were able to remove a large fraction of lignin and hemicelluloses to leave a clean cellulose sample. The isolated microfibrils cellulose exhibit good thermal stability as almost 50% of its initial mass remains at a temperature of 300 °C. These findings demonstrate that oil palm fronds can be utilized for biocomposite reinforcement applications.

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Ying, Lee, R., Al-Amsyar S. Muhammad, Rusli N. Dini, Mohammad M. Rahman, Hasnita C. Harun, and Mat K. "Alkaline pre-treatment of rice hull and coconut hull using Response Surface Methodology." Journal of Tropical Resources and Sustainable Science (JTRSS) 9, no. 1 (August 22, 2021): 70–75. http://dx.doi.org/10.47253/jtrss.v9i1.713.

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In this research, the rice hull and coconut hull from agriculture waste were investigated. The lignin content within the rice and coconut hull were determined before and after pre-treatment. Response Surface Methodology (RSM) used to predict the optimal condition for the treatments and Fourier Transform Infrared (FTIR) to identify the lignin content. The interaction of NaOH concentration, contact time (CT), and sample weight was investigated to optimize the lignin removal percentage (%). The correlation coefficient, R2 for a quadratic model of rice hull lignin removal was 0.8863 while for coconut hull lignin removal in the linear model was 0.7998, as well as the 2FI model was 0.8892. The optimum condition for rice hull lignin removal predicted by RSM were10 M NaOH concentration, 1-hour CT and 0.5 g sample produced 32.45% lignin removal. While for coconut hull lignin removal were 10 M NaOH concentration, 12 hours CT, 0.5 g sample produced 59.47% removal of lignin. Results show that alkaline pre-treated rice hull and coconut hull able to be used to remove higher percentage of lignin.

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Karray, Raida, Manel Hamza, and Sami Sayadi. "Evaluation of ultrasonic, acid, thermo-alkaline and enzymatic pre-treatments on anaerobic digestion of Ulva rigida for biogas production." Bioresource Technology 187 (July 2015): 205–13. http://dx.doi.org/10.1016/j.biortech.2015.03.108.

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López González, Lisbet Mailín, Ileana Pereda Reyes, Julio Pedraza Gárciga, Ernesto L. Barrera, and Osvaldo Romero Romero. "Effects of press- mud pre-treatment on the feasibility of biogas production." Revista Facultad de Ingeniería Universidad de Antioquia, no. 92 (May 23, 2019): 51–59. http://dx.doi.org/10.17533/udea.redin.20190520.

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In this study, an energetic, economic and environmental feasibility for the anaerobic digestion (AD) of press mud previously pretreated with liquid hot water (LHW) or thermo-alkaline (TA) methods were assessed. A typical Cuban sugar mill was selected as ¨Case Study¨. The sugar mill has a potential capacity to process 4600 t d-1of sugar cane and operates 130 days per year. The biogas produced can be used to feed an internal combustion engine to produce electricity and heat. It was assumed that the electricity will be sold to the national electric grid and the heat recovered from the exhaust gases will be used as energy source to supply the thermal demand for press mud pre-treatments. The thermal requirements for pre-treatments (9.4 and 12.1 MWh d-1) were energy sufficient by recovering the heat from the engine exhaust. For the alternatives considered, an improvement of the environmental profile with respect to the reference scenario was obtained. The profitability of methane production also increased for alternatives considering pre-treatment. In general, the economical, energetic and environmental assessment showed the best indicators for the AD of press mud using LHW pre-treatment.

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Brautigan, D. J., P. Rengasamy, and D. J. Chittleborough. "Amelioration of alkaline phytotoxicity by lowering soil pH." Crop and Pasture Science 65, no. 12 (2014): 1278. http://dx.doi.org/10.1071/cp13435.

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Highly alkaline soils (pH >9) may adversely affect agricultural crop productivity. At pH >9.2, aluminium (Al) phytotoxicity may further retard plant development. Most alkaline soils have little alkaline buffering capacity, making it feasible to use acid to lower soil pH to <9.2. Many methods of lowering soil pH have been trialled; however, little research has been done on their relative effectiveness and longevity. Methods trialled in this study as means of lowering soil pH were chemical additives (gypsum), organic additives (glucose, molasses, horse manure, green manure, humus) and leguminous plants. Gypsum was also used in conjunction with plants to determine any synergistic effects of combining treatments. All ameliorants trialled except humus and horse manure proved effective at lowering soil pH to <9.2. The reduction achieved with biological amendments was temporary, with pH returning to pre-amendment levels over the course of the study. Gypsum was most effective amendment for lowering soil pH and sustaining the lowered pH level. The use of plants to lower soil pH, in conjunction with gypsum to sustain the lowered pH, may be an effective and economic method of remediating Al phytotoxicity in alkaline soils.

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İnan, Benan, and Didem Özçimen. "A Comparative Study of Bioprocess Performance for Improvement of Bioethanol Production from Macroalgae." Chemical & biochemical engineering quarterly 33, no. 1 (2019): 133–40. http://dx.doi.org/10.15255/cabeq.2018.1499.

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In the last decade, studies that have focused on biodiesel production from algal biomass have been replaced with bioethanol production from algae, because bioethanol production from algae seems more promising when assessed on economic terms. Most coastal areas are covered with macroalgae, which are considered as a waste, and thus become a great problem for the municipality. Instead of their disposal, they can be alternatively utilized for bioethanol production. In this study, macroalgae located in the coastal regions of the Marmara Sea were collected and utilized for bioethanol production, and effects of the concentration of pre-treatment chemicals, pre-treatment temperature, and pre-treatment time on bioethanol yield were investigated. The highest bioethanol yields for dilute acid and alkaline pre-treatments were obtained under the conditions of 2 N sulfuric acid and 0.15 N potassium hydroxide solutions at the pre-treatment temperature of 100 °C and pre-treatment time of 60 minutes.

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Fagerlund, Annette, Even Heir, Trond Møretrø, and Solveig Langsrud. "Listeria Monocytogenes Biofilm Removal Using Different Commercial Cleaning Agents." Molecules 25, no. 4 (February 12, 2020): 792. http://dx.doi.org/10.3390/molecules25040792.

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Effective cleaning and disinfection (C&D) is pivotal for the control of Listeria monocytogenes in food processing environments. Bacteria in biofilms are protected from biocidal action, and effective strategies for the prevention and removal of biofilms are needed. In this study, different C&D biofilm control strategies on pre-formed L. monocytogenes biofilms on a conveyor belt material were evaluated and compared to the effect of a conventional chlorinated, alkaline cleaner (agent A). Bacterial reductions up to 1.8 log were obtained in biofilms exposed to daily C&D cycles with normal user concentrations of alkaline, acidic, or enzymatic cleaning agents, followed by disinfection using peracetic acid. No significant differences in bactericidal effects between the treatments were observed. Seven-day-old biofilms were more tolerant to C&D than four-day-old biofilms. Attempts to optimize biofilm eradication protocols for four alkaline, two acidic, and one enzymatic cleaning agent, in accordance with the manufacturers’ recommendations, were evaluated. Increased concentrations, the number of subsequent treatments, the exposure times, and the temperatures of the C&D agents provided between 4.0 and >5.5 log reductions in colony forming units (CFU) for seven-day-old L. monocytogenes biofilms. Enhanced protocols of conventional and enzymatic C&D protocols have the potential for improved biofilm control, although further optimizations and evaluations are needed.

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Seppälä, M., T. Paavola, A. Lehtomäki, O. Pakarinen, and J. Rintala. "Biogas from energy crops—optimal pre-treatments and storage, co-digestion and energy balance in boreal conditions." Water Science and Technology 58, no. 9 (November 1, 2008): 1857–63. http://dx.doi.org/10.2166/wst.2008.503.

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The objective of this research was to evaluate the biogas production from crops in boreal conditions, focusing on the optimal pre-treatment and storage methods, co-digestion and energy balance of farm-scale crop based biogas plants. Alkaline treatments offered some potential for improving the methane yield from grass and sugar beet tops. The results show that the CH4 yield of energy crops can be maintained by appropriate ensiling conditions for even after 11 months in ambient conditions. The CH4 yield was best preserved with wet grass mixture without additives. Co-digestion of manure and crops was shown to be feasible with feedstock volatile solids (VS) containing up to 40% of crops. The highest specific methane yields of 268, 229 and 213 l CH4 kg−1 VSadded in co-digestion of cow manure with grass, sugar beet tops and straw, respectively, were obtained during feeding with 30% of crop in the feedstock, corresponding to 85–105% of the total methane potential in the substrates as determined by batch assays. The energy output:input ratio of farm-scale grass silage based biogas plant varied significantly (3.5–8.2) with different assumptions and system boundaries being lowest when using only inorganic fertilizers and highest when half of the heat demand of the system could be covered by metabolic heat.

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Wong, Yi Hang, Eamon Marcus T.-Z. Chew, Pey Yi Toh, and Lee Muei Chng. "Evaluation of Oil Palm Empty Fruit Bunch for Cellulose Production." IOP Conference Series: Earth and Environmental Science 945, no. 1 (December 1, 2021): 012021. http://dx.doi.org/10.1088/1755-1315/945/1/012021.

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Abstract Oil palm empty fruit bunch (OPEFB) with a cellulose content of 39 wt% is a good promise to be an alternative lignocellulosic feedstock for cellulose production through environmentally friendly extraction process. Therefore, this research was aimed to establish an effective cellulose extraction scheme from OPEFB via introduction of ultrasonication in the alkaline pulping stage for process intensification. The process could greatly reduce alkali solvent usage for cellulose extraction, hence alleviating the environmental impact caused by chemical disposal. Firstly, four distinct pre-treatment techniques had been used to pre-treat the OPEFB powder, namely autoclave, organosolv, acid and microwave pre-treatments. Afterwards, the pre-treated samples further underwent ultrasonic-assisted alkali extraction to extract the cellulose content. It was observed that the autoclave pre-treated ultrasonic extract achieved the highest cellulose content of 77.14 wt% at optimum KOH concentration of 0.75 M, ultrasonic amplitude of 30%, duration of 30 min and temperature of 80 °C. Therefore, the introduction of ultrasonication in alkali extraction of cellulose was indeed an effective approach in establishing a green production scheme of cellulose from lignocellulose.

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Comparini, Andrea, Ivan Del Pace, Walter Giurlani, Roberta Emanuele, Margherita Verrucchi, Marco Bonechi, and Massimo Innocenti. "Electroplating on Al6082 Aluminium: A New Green and Sustainable Approach." Coatings 13, no. 1 (December 22, 2022): 13. http://dx.doi.org/10.3390/coatings13010013.

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Aluminium and its alloys are interesting for many applications because they are very light, cheap, and unlimitedly recyclable. Despite being a promising base material for the fashion-jewellery sector, their tendency to form a passivating film makes them difficult to be galvanized, even more when recycled aluminium contains impurities of refractory elements. Indeed, the most common processes for galvanising aluminium are often expensive and not environmentally sustainable because they involve the use of cyanides. In this work we focussed on the pre-treatments and electroplating on Al6082 aluminium which is largely used for fashion-jewellery applications. The objective of the present study was to assess whether Al6082 series aluminium is suitable a as base material for the fashion market; therefore, we investigated the effectiveness of plating pre-treatments and the success of electroless zinc deposition using an innovative alkaline cyanide-free zincate solution. After the electroplating, adhesion between the deposited layers was evaluated both with cross-sectional scanning electron microscope (SEM) analysis as well as with an adhesion evaluation test (ISO2819:2018): no detachments confirmed the positive test outcomes and thereby highlighted that Al6082 can be exploited as base material in the fashion-jewellery market.

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Varlı, Mücahit, Elif Gülin Ertuğral, Zoltán Jákói, Cecilia Hodúr, and Sándor Beszédes. "Intensification of cellulose enzymatic hydrolysis by microwave pretreatment." Analecta Technica Szegedinensia 14, no. 1 (June 8, 2020): 89–99. http://dx.doi.org/10.14232/analecta.2020.1.89-99.

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A significant representative of the third generation of raw materials is waste containing hemicellulose. Agriculture and the food industry generate a great deal of this type of waste, which has many potential opportunities for processing. Our research group investigated the pre-treatments for the enzymatic saccharification of the cellulose content of the two fractions of corn cob meal. Microwave energy communication was performed in both acidic and alkaline media. It was found that the pH of the medium influences the amount of reducing sugars, but to an almost equal extent. The yield is also significantly dependent on the starting material and the concentration of the suspension.

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Mousa, Nibal Kh, Saad H. Khudiar, Iman H. Qatia, Amal Ab Halob, Eman A. Muhsin, Duha B. Mohammed, Shahad Sh Sabbar, Mohammed A. Ayyash, and Ishrak Ab Ahmed. "Cinnamic acid activity against Trichlorfon pesticide toxicity and liver function enzymes in mice." Journal of Biotechnology Research Center 8, no. 3 (September 1, 2014): 52–58. http://dx.doi.org/10.24126/jobrc.2014.8.3.360.

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The study was carried out to determine hepatotoxicity and hepatoprotective effects of cinnamic acid in comparison with vitamin C against the mutagenic pesticide influence of trichlorfon, which is a chemical compound that damages hepatic cells and has mutagenic effects. The effect was studied in mammalian system in mice depended on evaluating the enzymatic activity of three hepatic enzymes: Alanine Transaminase(ALT), Aspartate Transaminase (AST) and Alkaline Phosphate (ALP).Two concentrations of pure cinnamic acid (60,30) mg/body weight were tested to choose the suitable concentration which compared with negative control, positive control and comparative group of Vitamin C. In order to use in the interaction experiments, included two types of treatments pre-trichlorfon and post-trichlorfon in order to determine the mechanisms of the pure cinnamic acid, showed no toxic and hepatotoxicity influence in biological system and it showed highly performance in prevention or reduction in hepatotoxicity of trichlorfon. Cinnamic acid increased the ALT, AST and ALP enzymes with normal levels especially with dose of 30 mg/body weight. The positive effect of cinnamic acid was higher when used as post-trichlorfon treatments and to less extent in pre-trichlorfon treatments, therefore, cinnamic acid can be considered as a cure hepatocytes from acute liver damage also work protective to cardiac, skeletal muscle and placental tissue protective.

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Peršin, Zdenka, Alenka Vesel, Karin Stana Kleinschek, and Miran Mozetič. "Characterisation of surface properties of chemical and plasma treated regenerated cellulose fabric." Textile Research Journal 82, no. 20 (June 26, 2012): 2078–89. http://dx.doi.org/10.1177/0040517512445338.

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The aim of this research work was to study the surface properties and sorption characteristics of differently treated regenerated cellulose fabrics. Surface modifications of viscose, modal and lyocell samples caused by using standard chemical pre-treatment procedures were compared to an alternative activation procedure by applying low pressure oxygen plasma treatment. The elemental chemical composition of the modified fabric surfaces was investigated using X-ray photoelectron spectroscopy (XPS), while hydrophilic/hydrophobic properties were evaluated by determining the water contact angles, as well as thoroughly analysed using Owens–Wendt surface energy (SFE) and surface polarity investigations. Standard chemical and also plasma treatments changed the surface chemistry of cellulose. Bleaching and alkaline treatments increased the surface carboxylic acid content by approximately 4.8% while plasma treatment increased it by approximately 9.7%. As a consequence, higher hydrophilicity arises as proved by water contact angle decrease; i.e. 24% (61°) after standard chemical treatments and 70% (20°) after plasma treatment. Both chemical treatments increase the SFE and polar components, while the reduction of dispersive components was less pronounced. The oxygen activation treatment has the greatest influence on the SFEs of the samples as well as on polarity of the samples.

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Hassan, Nur Syakilla, Khairiah Haji Badri, and Li Shen Lim. "Silica Extraction from Rice Husk by Warm Water Pretreatment." Advanced Materials Research 1087 (February 2015): 309–15. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.309.

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Rice husk (RH) has high content of silica. In this study, the extraction of silica from rice husk while maintaining the organics was carried out by warm water pre-treatment followed by alkaline hydrolysis. RH powder was treated with water at 50oC and 100oC prior to treatment with 1 M of sodium hydroxide (NaOH) aqueous solution at 50oC. The filtrate from the alkaline hydrolysis was then further reacted with 1 M of hydrochloric acid (HCl) for silica extraction. The samples obtained after each stage of the treatments were carefully characterized and their chemical compositions were determined. The morphology of the untreated and treated RH powder was analyzed by Scanning Electron Microscopy (SEM). Estimation on the silica content was made by Energy Dispersive X-ray (EDX). The functional group present in untreated and treated RH were determined by Fourier Transform Infrared Spectroscopy (FTIR). The percentage of silica extracted from ΔH2O/NaOH-RH filtrate was higher (18.9%) than from H2O/NaOH-RH filtrate (12.6%). FTIR spectroscopy data indicated the disappearance of siloxane group when RH was treated with hot water and warm water followed by alkaline hydrolysis. The selected extraction method has successfully recovered silica at high yield but at the same time maintaining the organic compounds in the rice husk.

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Zheng, Jing Wu, Dan Li, Yao Ying, Liang Qiao, Li Qiang Jiang, and Cheng Zhang. "Copper Ultrasonic-Electrodeposition on Zn Alloy in Alkaline Bath Containing 1-Hydroxyethylene-1,1-Diphosphonic Acid." Advanced Materials Research 472-475 (February 2012): 251–55. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.251.

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Zn alloy die casting is easily corroded and porous, so it is hard to obtain the strong adhesion strength between the substrate and the metal coating. In this paper, Cu coatings were prepared by ultrasonic-electrodeposition on Zn alloy in a cyanide-free deposition bath containing a base agent of 1-hydroxyethylene-1, 1-diphosphonic acid (HEDPA). The effect of ultrasound on the electrochemical behavior of bath and the morphology of the coating were investigated by potential sweep and by SEM, respectively. Experimental results indicate that pre-treatments, such as electrolytic degreasing, have a remarkable influence on adhesion strength. Application of ultrasonic increases the limiting current density of cathode and enhances the throwing power of bath. Application of ultrasonic also promotes the formation of network-cross copper coating which enhances the adhesion strength between the substrate and the coating.

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Alino, João Heneique Lima, Jhenifer Aline Bastos, Paula Verônica Remor, Laercio Mantovani Frare, Fábio Orssatto, Felippe Martins Damaceno, and Thiago Edwiges. "Alkaline Pretreatment and Pre-Hydrolysis Using Acidic Biowastes to Increase Methane Production from Sugarcane Bagasse." Methane 1, no. 3 (August 17, 2022): 189–200. http://dx.doi.org/10.3390/methane1030015.

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Sugarcane bagasse (SCB) is the main residue obtained from sugarcane processing, and it has been widely investigated as a strategic renewable energy source. The typical recalcitrant characteristic of SCB requires the use of pretreatments (e.g., chemicals) to increase methane production through anaerobic digestion, which is normally reported to generate toxic effluents and increase operational costs. Based on this, the present study evaluated the efficiency of an inexpensive, alternative, and more sustainable method to improve the biodegradability of SCB and increase methane production by pre-storing it with acidic organic biowastes, such as cheese whey (CW) and fruit and vegetable waste (FVW). Different fresh weight-based proportions of FVW (5:95, 10:90, and 15:85) and CW (10:90, 20:80, and 25:75) were soaked with SBC for 7 days at 25 °C. These treatments were compared with traditional alkaline pretreatment using NaOH at concentrations of 1%, 5%, and 10% (w/v). The best result was obtained with SCB + FVW (5:95), being 520 ± 7 NL CH4 kg VS−1 (27.6% higher than the control) with degradation time (T90) reduced from 13 to 7 days. Pretreatment with SBC + CW resulted in antagonistic effects due to process inhibition, while alkaline pretreatment with NaOH at concentrations of 5% and 10% similarly increased methane yield by 21.2% and 34.1%, respectively. Therefore, pre-storage of SBC with FVW proved to be the best strategy to increase methane production from SCB, while simultaneously avoiding the use of chemical reagents that result in toxic effluents.

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Wetzstein, Hazel Y., and S. Edward Law. "Enhanced Visualization of the Fine Structure of the Stigmatic Surface of Citrus using Pre-fixation Washes." Journal of the American Society for Horticultural Science 137, no. 5 (September 2012): 290–93. http://dx.doi.org/10.21273/jashs.137.5.290.

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Stigma characteristics and morphology can be useful in taxonomic and phylogenetic studies, indicate relationships in stigma function and receptivity, and be valuable in evaluating pollen–stigma interactions. Problematic is that in some taxa, copious stigmatic exudate can obscure the fine structural details of the stigmatic surface. Such is the case for Citrus, which has a wet stigma type on which abundant exudate inundates surface papillae. The components of stigmatic surface compounds are highly heterogeneous and include carbohydrates, proteins, lipids, glycoproteins, and phenolic compounds. This study evaluated the efficacy of several pre-fixation wash treatments on removing surface exudate to visualize the underlying stigmatic surface. Wash treatments included various buffer solutions, surfactants, dilute acids/bases, and solvents. Stigmas prepared using conventional fixation methods in glutaraldehyde had considerable accumulations of reticulate surface deposits with stigmatic cells obscured. Pre-fixation washes containing solvents such as methanol, chloroform, and ethanol left accumulations of incompletely removed exudate and crystalline deposits. Alkaline water washes produced a crust-like deposit on stigma surfaces. Buffer washes left residues of plaque-like deposits with perforated areas. In contrast, excellent removal of stigmatic exudate was obtained with a pre-fixation wash composed of 0.2 M Tris buffer, pH 7.2, containing 0.2% Triton X-100 surfactant and allowed clear imaging of the stigma and surface papillae morphology. A central sinus and radially arranged openings on the stigmatic surface were clearly visible and shown for the first time using scanning electron microscopy (SEM).

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Puițel, Adrian Cătălin, Gabriel Dan Suditu, Elena Niculina Drăgoi, Maricel Danu, Gabriela-Liliana Ailiesei, Cătălin Dumitrel Balan, Daniela-Lucia Chicet, and Mircea Teodor Nechita. "Optimization of Alkaline Extraction of Xylan-Based Hemicelluloses from Wheat Straws: Effects of Microwave, Ultrasound, and Freeze–Thaw Cycles." Polymers 15, no. 4 (February 19, 2023): 1038. http://dx.doi.org/10.3390/polym15041038.

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The alkaline extraction of hemicelluloses from a mixture of three varieties of wheat straw (containing 40.1% cellulose, 20.23% xylan, and 26.2% hemicellulose) was analyzed considering the following complementary pre-treatments: freeze–thaw cycles, microwaves, and ultrasounds. The two cycles freeze–thaw approach was selected based on simplicity and energy savings for further analysis and optimization. Experiments planned with Design Expert were performed. The regression model determined through the response surface methodology based on the severity factor (defined as a function of time and temperature) and alkali concentration as variables was then used to optimize the process in a multi-objective case considering the possibility of further use for pulping. To show the properties and chemical structure of the separated hemicelluloses, several analytical methods were used: high-performance chromatography (HPLC), Fourier-transformed infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H-NMR), thermogravimetry and derivative thermogravimetry analysis (TG, DTG), and scanning electron microscopy (SEM). The verified experimental optimization result indicated the possibility of obtaining hemicelluloses material containing 3.40% glucan, 85.51% xylan, and 7.89% arabinan. The association of hot alkaline extraction with two freeze–thaw cycles allows the partial preservation of the hemicellulose polymeric structure.

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Trakselyte-Rupsiene, Karolina, Grazina Juodeikiene, Darius Cernauskas, Elena Bartkiene, Dovile Klupsaite, Daiva Zadeike, Joana Bendoraitiene, Jonas Damasius, Jonas Ignatavicius, and Sidona Sikorskaite-Gudziuniene. "Integration of Ultrasound into the Development of Plant-Based Protein Hydrolysate and Its Bio-Stimulatory Effect for Growth of Wheat Grain Seedlings In Vivo." Plants 10, no. 7 (June 28, 2021): 1319. http://dx.doi.org/10.3390/plants10071319.

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This study was dedicated to increasing the efficiency of producing plant-based protein hydrolysate using traditional and non-traditional treatments. Low- and high frequency ultrasound (US) at different intensities were applied to corn steep liquor (CSL) at 50 °C for 30 min, and enzymatic hydrolysis was performed using industrially produced alkaline protease. The efficiency of US and enzymatic treatments was characterized by protein solubility (soluble protein (SP) content, hydrolyzed protein (HP) concentration, and free amino acid (FAA) profile) and kinetic parameters: Michaelis–Menten constant (KM) and apparent breakdown rate constant (kA). A significant effect of 37 kHz US pre-treatment for CSL enzymatic hydrolysis was found and resulted in the highest HP concentration (17.5 g/L) using the lowest enzyme concentration (2.1 g/L) and the shortest hydrolysis time (60 min). By using US pre-treatment, on average, a 2.2 times higher FAA content could be achieved compared to traditional hydrolysis. Additionally, results for the kinetic parameters kM and kA confirmed the potential of applying US treatment before hydrolysis. The effect of CSL protein hydrolysate on plant growth was tested in vivo on wheat grain seed germination and resulted in the significant increase in germination parameters compared to the control treatment. These findings indicate that by-products of starch industry could be a promising source for the production of low-cost sustainable biostimulants.

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Hina, K., P. Bishop, M. Camps Arbestain, R. Calvelo-Pereira, J. A. Maciá-Agulló, J. Hindmarsh, J. A. Hanly, F. Macías, and M. J. Hedley. "Producing biochars with enhanced surface activity through alkaline pretreatment of feedstocks." Soil Research 48, no. 7 (2010): 606. http://dx.doi.org/10.1071/sr10015.

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Surface-activated biochars not only represent a useful carbon sink, but can also act as useful filtering materials to extract plant nutrients (e.g. NH4+) from wastes (e.g. animal or municipal waste streams) and added thereafter to soils. Biochars produced by low-temperature pyrolysis of fibrous debarking waste from pine (PI) and eucalyptus (EU) were pre-treated with either diluted (L) or undiluted (S) alkaline tannery waste (L-PI, S-PI, L-EU, S-EU). Biochars produced from untreated feedstock were used as controls. Samples were characterised by FT-IR, solid-state CP MAS 13C NMR, XPS, SEM microphotographs, and BET specific surface area. Elemental composition, carbon recovery, yield, surface charge, and NH4+ sorption/desorption properties were also studied. Carbon recovery was lower in biochars prepared from L-EU and S-EU (43 and 42%, respectively) than in control EU (45%) but these biochars showed greater changes in their chemical characteristics than those made from L-PI and S-PI, which showed minimal decrease in recovered carbon. The specific surface area of the biochars decreased with treatments, although acidic surface groups increased. In subsequent sorption experiments, treated biochars retained more NH4+ from a 40 mg N/L waste stream (e.g. 61% retention in control EU and 83% in S-EU). Desorption was low, especially in treated biochars relative to untreated biochars (0.1–2% v. 14–27%). The results suggest that surface activated biochars can be obtained with negligible impairment to the carbon recovered.

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Hýsek, Štěpán, Jaroslav Čermák, and Martin Lexa. "Influence of Lignocellulosic Waste Pre-Treatment on the Characteristics of Bond Rupture." Sustainability 11, no. 17 (September 2, 2019): 4784. http://dx.doi.org/10.3390/su11174784.

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Post-harvest crop residues are an interesting raw material for the production of composite materials. However, their surface often contains waxy and siliceous substances, which can cause adhesion problems. Therefore, various surface pre-treatment methods have been developed to increase the surface tension of these particles and hence to improve adhesive adhesion. The influence of hydrothermal, chemical, plasma and enzymatic treatment was investigated. The aim of the paper is to evaluate the effect of pre-treatments of post-harvest crop residues on the nature of joint failure and adhesive dispersion on the particles. The evaluation is based on microscopic analysis of particles obtained from the rupture area after internal bonding tests. The nature of bond failure and adhesive dispersion on the particle surface is evaluated. The results show a clear influence of material pre-treatment on the failure bond of the bond and, to a large extent, correlate with the mechanical properties of composites published in previous studies. The most suitable treatment appears to be a plasma treatment at a properly adjusted intensity. Conversely, the unsuitable treatment was alkaline, which, although it increased adhesion, deteriorated the overall mechanical properties. Hydrothermal treatment could be also considered as an industrially suitable method.

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Rebah, Faouzi Ben, Rajeshwar D. Tyagi, Danielle Prévost, and Rao Y. Surampalli. "Wastewater Sludge as a New Medium for Rhizobial Growth." Water Quality Research Journal 37, no. 2 (May 1, 2002): 353–70. http://dx.doi.org/10.2166/wqrj.2002.022.

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Abstract The objective of this study was to demonstrate that municipal and industrial wastewater sludges could be used as a sole raw material to sustain growth of rhizobia. Growth of two different groups of rhizobium (fast growing: Sinorhizobium meliloti, Rhizobium leguminosarum bv viciae; and slow growing: Bradyrhizobium japonicum and Bradyrhizobium elkanii) was tested on primary, secondary and mixed sludges obtained from different wastewater treatment plants. The results obtained in Erlenmeyer flasks indicated that slow- and fast-growing rhizobia grew well in sludge. Generally, the number of cells of rhizobia exceeds 1 × 109 cfu/mL in 72 h. The composition of sludges varies with the sludge type and origin. The sludge composition affected the generation time, cell yield and nodulation index. Higher solids concentration tended to give higher generation time. The high sludge metals concentration did not affect the growth kinetics of rhizobia. However, primary sludge could inhibit cell growth. Acid, alkaline and oxidative pre-treatments increased the primary sludge biodegradability and consequently the cell count of S. meliloti. Pre-treatment of pulp and paper sludge with NaOH enhanced the bacterial cell concentration to a maximum 1 × 1010 cfu/mL. Sludge pre-treatment decreased the generation time and reduced the process time.

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Monetta, Tullio, Anna Carangelo, Francesco Bravaccino, Ciro Sinagra, and Annalisa Acquesta. "The Effect of Hydrofluoric Acid Concentration in Sulfuric Acid-Based Desmutting Solution for Aluminium Alloys." Materials Science Forum 1016 (January 2021): 934–39. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.934.

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The natural oxide layer, which spontaneously covers the surface of aluminium and its alloys, is well adherent to the surface, but it does not show adequate corrosion resistance in many conditions. In order to improve the material anti-corrosion performance, it is necessary to replace the surface oxide by a conversion coating. The first step to do this is to prepare the alloy surface to subsequent treatments. The pre-treatment implemented before the conversion treatment is one of the main factors responsible for the performance of the conversion coating. It involves several phases, including desmutting that encompasses the part immersion in an acid or alkaline solution bath. In this work, the influence of hydrofluoric acid concentration in the desmutting bath's formulation was investigated. The samples surface were characterised by using electrochemical techniques, glow discharge optical emission spectrometry and contact angle measurements.

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Jing, Mingyan, Shusheng Zhao, Anna Rogiewicz, Bogdan A. Slominski, and James D. House. "Effects of phytase supplementation on growth performance, plasma biochemistry, bone mineralisation and phosphorus utilisation in pre-lay pullets fed various levels of phosphorus." Animal Production Science 61, no. 6 (2021): 568. http://dx.doi.org/10.1071/an20265.

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Context Reducing the environmental impact of animal production is becoming a really hot topic, especially with raised concerns over excessive flows of nitrogen and phosphorus (P) to the environment. Aims The present study was conducted to determine the effects of phytase supplementation on growth, plasma biochemistry, bone mineralisation and P utilisation of pre-lay pullets fed varying levels of non-phytate P. Methods A total of 240 Lohmann pullet chicks were randomly allocated to one of six dietary treatments with eight replicate cages (5 birds per cage) per treatment. Six treatments included three phytase-free diets and three diets supplemented with 1000 U/kg phytase; the non-phytate P levels were 2.75–2.50–2.25, 3.75–3.50–3.25 and 4.75–4.50–4.25 g/kg in the former, and 1.75–1.50–1.25, 2.75–2.50–2.25 and 3.75–3.50–3.25 g/kg in the latter, for the age of 0–4, 4–8 and 8–16 weeks respectively. Key results No significant differences were found for growth performance, plasma biochemistry (calcium, P, alkaline phosphatase and albumin) and bone mineralisation among dietary treatments, but P retention (%) was different (P < 0.001). Analysis of planned contrasts showed that phytase supplementation increased phytate P retention (P < 0.001), and improving the utilisation of phytate P tended most efficiently under low P conditions. Total P retention rate was reduced slightly by phytase supplementation (P < 0.05). Conclusions The results indicated that dietary non-phytate P level could possibly be reduced to 1.75, 1.50 and 1.25 g/kg for 0–4, 4–8 and 8–16 weeks of age respectively after phytase supplementation, without compromising pullet growth and performance during the pre-laying period. Implications The results of this study will contribute to decreasing P excretion by poultry and reducing the potential environmental impact with land application of manure.

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Motta, Ellen S., Paulo Thiago Souza-Santos, Tuany R. Cassiano, Flávio J. S. Dantas, Adriano Caldeira-de-Araujo, and José Carlos P. De Mattos. "Endonuclease IV Is the Main Base Excision Repair Enzyme Involved in DNA Damage Induced by UVA Radiation and Stannous Chloride." Journal of Biomedicine and Biotechnology 2010 (2010): 1–9. http://dx.doi.org/10.1155/2010/376218.

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Stannous chloride (SnCl2) and UVA induce DNA lesions through ROS. The aim of this work was to study the toxicity induced by UVA preillumination, followed bySnCl2treatment.E. coliBER mutants were used to identify genes which could play a role in DNA lesion repair generated by these agents. The survival assays showed (i) Thenfomutant was the most sensitive toSnCl2; (ii) lethal synergistic effect was observed after UVA pre-illumination, plusSnCl2incubation, thenfomutant being the most sensitive; (iii) wild type andnfomutants, transformed with pBW21 plasmid (nfo+) had their survival increased following treatments. The alkaline agarose gel electrophoresis assays pointed that (i) UVA induced DNA breaks andfpgmutant was the most sensitive; (ii)SnCl2-induced DNA strand breaks were higher than those from UVA andnfomutant had the slowest repair kinetics; (iii)UVA+SnCl2promoted an increase in DNA breaks thanSnCl2and, again,nfomutant displayed the slowest repair kinetics. In summary, Nfo protectsE. colicells against damage induced bySnCl2andUVA+SnCl2.

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