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The main purpose of this paper was to investigate the effects of hot water pre-extraction (HWP) on the refining energy consumption and the brightness of bamboo alkaline peroxide mechanical pulp (APMP). It was found that compared with un-extraction, the refining energy consumption dropped by about one-third after HWP. The reduction of energy consumption was proved through enhancing the channel of water and chemicals into inferior fiber based on the surface characterization of bamboo. Scanning electron microscope (SEM) images showed that the HWP made the fibers' structure loose and porous. Both pore volume and specific surface area were increased significantly after HWP, by 260.00% and 1804.76%, respectively. A decrease in pulp brightness was mainly due to the formation of new chromophore groups during the HWP process. The results of 13C nuclear magnetic resonance spectroscopy (13C-NMR) illustrated that some structures of milled wood lignin (MWL), such as guaiacyl, etherificated guaiacyl, and aromatic units, were increased during the HWP process. However, some lignin-links units of α-O-4, β-O-4, and some carbohydrate structures such as xylan, α- and β-glucose, and β-and β-mannose in lignin-carbohydrate complex (LCC) were evidently degraded. Additionally, most of the lignin and LCC were degraded under the simulative conditions of HWP bamboo. Furthermore, the analysis of UV spectrophotometry indicated that HWP was conductive to the generation of chromophore groups such as conjugated carbonyl, catechol, and o-benzoquinone.

espanolSe evaluaron cuatro pretratamientos del Buchon de Agua (Eichhornia crassipes) para su transformacion en azucares y etanol. El Buchon de Agua es una planta acuatica de rapido crecimiento que representa un serio problema de invasiones por lo que se propone su transformacion en etanol, teniendo en cuenta la inminente escasez de combustibles fosiles a nivel mundial. En esta seleccion preliminar el Buchon de Agua exhibio caracteristicas constitutivas de tipo quimico, que lo convierten en una materia prima promisoria para produccion de etanol, obteniendose, rendimientos de 17,15 g/l, 18,10 g/l, 17,73 g/l y 4,53 g/l con los pretratamientos remojo con amoniaco, delignificacion alcalina, pretratamiento con acido diluido y peroxido alcalino, respectivamente. Finalmente, se seleccionaron los pretratamientos con acido diluido y delignificacion alcalina para ser utilizados con mayor profundidad mediante la aplicacion de un diseno experimental, obteniendose un rendimiento de etanol de 190,35 l/ton biomasa seca alimentada para el pretratamiento acido diluido y 197,33 l/ton biomasa seca alimentada para el pretratamiento delignificacion alcalina, a partir de la fraccion solida. EnglishWater Hyacynth (Eichhornia crassipes) is a fast growing aquatic plant that represents a serious problem of invasion, so its transformation into ethanol is proposed as a solution, taking into account the imminent scarcity of fossil fuels worldwide and the panorama of opportunity that is lived in the world due to the legislation on biofuels. For this, four different pretreatments were evaluated taking into account production of sugars and final ethanol yield to select the most promising. In this preliminary selection, the Water Hyacinth exhibited chemical type compositional characteristics that make it a promising raw material for ethanol production, obtaining yields of 17.15 g/l, 18.10 g/l, 17.73 g/l and 4,53 g/l with the pretreatments aqueous ammonia soaking, alkaline delignification, pretreatment with diluted acid and alkaline peroxide, respectively. Finally, the pretreatments with diluted acid and alkaline delignification were selected to be studied more deeply through the application of an experimental design, obtaining an ethanol yield (better design conditions). 190.35 l/ton dry biomass fed to the diluted acid pretreatment and 197.33 l/ton dry biomass fed to the alkaline delignification pretreatment, from the solid fraction.

The effect of pretreatments by hydrothermolysis (180 °C; 15 min) and alkaline delignification (NaOH 5M; H2O2 1%; 24 h) in citrus peel waste (CPW) was evaluated, as well as the effect on H2, organic acids and alcohols production, in addition to characterization of the microbial community involved in fermentation. Batch reactors at 37 °C were operated with 3 gTVS/L of CPW with allochthonous consortium (UASB reactor sludge; 2 gTVS/L) and autochthonous of CPW (1.5 gTVS/L) as inocula. H2 production was higher in reactors with in natura CPW (13.31 mmol/L) compared to hydrothermolysis (8.19 mmol/L) and alkaline delignification (7.27 mmol/L). The acetogenic pathway was predominant in the in natura CPW (4,355 mg/L acetic acid). The most abundant genera in the in natura CPW and after hydrothermolysis were Clostridium (18.97 and 12.90%, respectively) and Ruminiclostridium (16.65 and 1.04%, respectively) commonly related to cellulolytic bacteria and/or H2 production.

Bangladesh is a densely populated agricultural country. As the allocated forestland for pulpwood production is very limited and a substantial amount of crops residues are generated each year, the latter can substitute pulpwood. But it is hard to use crops residues as pulping raw materials in a conventional pulping process due to its high content of silica and fines. It was observed that formic acid (FA) pulping process can overcome these limitations. In this context, fourteen residues of crops produced in Bangladesh were evaluated by FA pulping with varying FA charge for 4 h at the boiling temperature followed by peroxyformic acid (PFA) treatment under constant conditions. It was observed that pulp yield and delignification degree decreased with FA charge. Also, PFA treatment further reduced the kappa number of pulps. Final pulp yields were 39–51% with the kappa number of 12–28 depending on crops residues. Holocellulose and α-cellulose content in crops residues were positively correlated (R2 = 0.95) with pulp yield at 0% level of significance. Pulps were bleached by alkaline peroxide bleaching and brightness reached to about 80% with acceptable papermaking properties.

In this study, a poplar high-yield pulp [preconditioning refiner alkaline peroxide mechanical pulp (P-RC APMP)] was used to produce lignin-containing cellulose nanofibril (LCCNF) dispersions throug...

In recent years, the biological activity of polysaccharides and their derivatives has been widely studied. However, in addition to the natural polysaccharides directly extracted from plants and animals, there are rich polysaccharides in the pulping waste liquor that have not been fully utilized. The extracted polysaccharide from eucalyptus Alkaline Peroxide Mechanical Pulping (APMP) waste liquor was used as a raw material. For the production of carboxymethyl polysaccharide, the effects of temperature (T), the amount of alkali (NaOH) and the amount of etherifying agent (ClCH2COOH) on the degree of substitution (DS) were investigated, the optimal preparation conditions are: reaction time 2 h, temperature 75 °C, and the molar ratio of polysaccharide, NaOH and ClCH2COOH is 1:1:2, the highest DS is 1.47; FT-IR, NMR and GPC were used to characterize the structure and Molecular weight, the results show that the polysaccharide of APMP waste liquor is rich in xylan, and it was proved that the carboxymethyl substitution was successful and the positions of the substituent group were determined. The characterization and biological activity research of xylan polysaccharide (XP) and carboxymethyl xylan polysaccharide (CMXP), such as antioxidation, moisture absorption/retention, bacteriostatic action and cytotoxicity were discussed. CMXP shows better effects compared with XP.

Conversion and reuse of furfural residues are of great significance as the furfural residues are pollution-carrying biomass waste resources. However, the furfural residues must be pretreated to remove the lignin so as to improve the conversion efficiency. Here, we firstly reported an efficient pretreatment method which integrated uses ionic liquid and alkaline peroxide and found the synergic effect of them on the pretreatment of furfural residues. The pretreatment using [Bmim]Cl and NaOH/H2O2 shows the highest lignin elimination efficiency of 75.09%, which is 1.95 times of that [Bmim]Cl and 1.55 times of that NaOH/H2O2, respectively. The highest yield of reducing sugars is 50.4%. The pretreatment synergistic effect is attributed to the swelling property of the ionic liquid and the delignification of the alkaline peroxide. The effect of ionic liquids structures on pretreatments was also researched and the ionic liquids with Cl and short branched chain are superior for the lignin removal. This article gives an alternative technique for the pretreatment and conversion of furfural residues.

A double pretreatment was developed to improve the efficiency of enzymatic hydrolysis and to increase the sugars production from palm fibre in batch and fed-batch systems. After alkaline peroxide pretreatment using NaOH-H2O2 solution, rigid structure of palm fibre was broken and partial of the hemicelluloses and lignin were removed. Compared with cellulase Accellerase® 1500, when using the conjunction of Accellerase® 1500 and Optimash BG, the conversion ratio increased from 35.9% to 45.0% and the reducing sugar yield increased from 245 mg/g substrate to 307 mg/g substrate. To further increase the hydrolysis efficiency, double pretreatment with NaOH-H2O2 solution was used to treat the hydrolysized residues. Then, the hydrolysis ratio reached 93% and reducing sugar yield was 752 mg/g substrate. Fed-batch enzymatic hydrolysis was carried out with 7% (w/v) solids loading and 0.3 mL/g substrate. Then, 7% solids were fed consecutively at 12 h, 24 h, 36 h and 48 h. After 144 h, the final concentration of reducing sugar reached 214.0 g/L and total biomass conversion ratio was 75.23%. Keywords: Cellulase, Palm fibre, Reducing sugar, Lignin, Alkaline peroxide pretreatment

There are a few chemical solutions used for prosthetic cleaning and they have different antimicrobial effects on denture materials. The aim of this study is to evaluate the efficacy of various chemical solutions used in prosthetic cleaning. For this purpose, 40 specimens of polymethylmethacrylate (PMMA-Meliodent, HeraeusKulzer, Hanau, Germany), which is the most commonly used material in conventional prostheses, and 40 specimens of Deflex (Nuxen SRL, Ayacucho 1053 3-A, Cap. Fed. Buenos Aires, Argentina), which is polyamide-containing semi-flexible acrylic, were molded using a template at the laboratory of Dentistry Faculty. Leveling began with abrasive burs and Stones followed by the sanding with medium and thin discs. Surface preparation was done using wet pumice and felt followed by polishing with gypsum-alcohol and rotary soft brush. The evaluated three solutions are Corega cleaning tablets containing alkaline peroxide, 0.2% chlorhexidine gluconate (CG) and 1% sodium hypochlorite (NaOCl). Distilled water was used as the control group. When both groups of polymers were evaluated in respect to the Candida growth after they were kept in liquid containing NaOCl, Corega, and CG, it was observed that only the acrylics that were kept in Corega revealed Candida growth. It was concluded that Corega could not sufficiently inhibit the growth of Candida albicans which is the one of the most common microorganisms in the oral flora of pediatric and elderly patients. NaOCl and CG can be used safely and effectively for denture cleaning.

Cada material lignocelulósico es un nuevo terreno por explorar, por tanto, la caracterización físico-química de estos materiales es un paso fundamental para el proceso de biotransformación. Se determinó la composición lignocelulósica del bagazo de sorgo dulce, encontrándose valores cercanos a los valores reportados en la literatura. Se estudiaron las tecnologías de pretratamiento, explosión con vapor, hidrólisis ácida suave, deslignificación alcalina, remojo con NH3, pretratamiento con amoniaco AFEX, ozonólisis y peróxido alcalino; encontrándose que la deslignificación alcalina con NaOH es la mejor opción para pretratar este sustrato. Se disminuyó el contenido de lignina en un 52% y se obtuvo una productividad a etanol de 0,87 g/L h, lo cual equivale a un rendimiento de 114 L de etanol/Ton bagazo de sorgo dulce seco pretratado.

Background: One of the acrylic resins properties is the water absorption that affect on the hardness changes of the acry/ic resins. This /aboratory experiments studied disinfectant Alkaline peroxide and celery (Apium graveolens L.) extract 75% effect on the hardness changes of acry/ic denture base resins materia/. Purpose: This study aims to determine the effect of immersion denture cleanser alkalin peroxide and celery (Apium graveolens L.) extract 75% of the hardness acrylic resin.Methods: The study a pure experimental study with posttest-only with control group design. The study was conducted by immersing heat cured acrylic samples of 30 mm of diameter and 5 mm of thickness in alkaline peroxide, ce/ery (Apium graveo/ens L.) extract 75% and aquades for 5 and 15 days. An Vickers Microhardness Testing Machine using the Vickers indentation technique with (50 gr load for 10s) were used for the hardness changes observationResults: The statistical test used One-way ANOVA and Bonferroni with 0.05 significance degree /eve/. The average va/ue of acry/ic hardness in a/ka/ine peroxide and celery extract 5 days 15.01 VHN and 15.37 VHN, 15 days 13.77 VHN and 14.07 VHN.Conclusion: The resu/t showed no significant difference hardness of acry/ic resins denture base plate after immersion in Alkaline peroxide and celery (Apium graveolens L.) extract 75% for 5 and 15 days.

http://dx.doi.org/10.7584/ktappi.2016.48.1.100Journal of Korea TAPPIVol. 48. No. 1, 2016, 100-110pISSN (Print): 0253-3200Printed in Korea • 경상대학교 농업생명과학대학 환경재료과학과/임산공학과(Dept. of Env. Material Sci., IALS, Gyeonsang National Uni-versity, 660-701, Korea)† 교신저자(Corresponding Author): E-mail: jameskim@gnu.ac.kr Alkaline Peroxide Mechanical Pulping (APMP) of Pinus densiflora harvested from domestic mountains was explored. APMP contributes to various advantages including pulp quality, elimination of the need for a bleaching process, and energy savings. Sequential treat-ment of impregnation of bleaching chemicals and refining not only overcome the concern of alkaline darkening of wood chips during chemical impregnation, but it also brightens the chips to the desired brightness levels suitable for writing and printing papers. APMP pulping from Pinus densiflora was greatly influenced by the dosage levels of hydrogen peroxide and sodium hydroxide. Alkaline peroxide treatment was carried out by applying one of three levels of hydrogen peroxide (1.5, 3, and 4.5% based on the oven-dried weight of the wood chips) and one of three levels of sodium hydroxide (1.5, 3, and 4.5% based on the oven-dried weight of the wood chips). Other chemicals including a peroxide stabi-lizers and metal chelation were constantly added for all treatments. Chemical treatment with a liquor-to-wood ration of 9:1 was carried out in a laboratory digestor. Compared to BTMP, APMP pulping displayed outstanding characteristics including the less require-ment of refining energy, the better improvement of tensile strength, the more reduction of shives, and the greater increase of pulp brightness. In particular, when 4.5% of hy-drogen peroxide with impregnation during 90 minutes was used, the brightness of APMP reached 64.9% ISO. Even though bulk of APMP was decreased with the increase of sodium hydroxide, a better and improved balance could be achieved between optical and strength properties. The spent liquor obtained from the discharge of the impregnation process at

This study investigated the performance of recycled polypropylene (RPP)/peanut shell powder (PSP) composites with untreated PSP and treated PSP with alkaline peroxide. The RPP/PSP and RPP/PSP-H2O2 composites were prepared by melt mixing and compression molding at different PSP loadings (10 wt.% to 40 wt.%). The samples were characterized by processing properties, tensile properties, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and water absorption behavior. The treated PSP enhanced the stabilization torque, tensile strength, elongation at break, tensile modulus, and water absorption of RPP/PSP-H2O2 composites. FTIR spectra and SEM showed that the elimination of lignin content strongly influenced the fractured surface and chemical characteristics of the RPP/PSP-H2O2 composites.

Primary refined coarse softwood thermomechanical pulp was treated with alkaline peroxide prior to low-consistency (LC) refining. The effects of the pre-treatments on pulp quality, refinability, and electrical energy consumption were assessed. Four pre-treatments were conducted with alkali charges of 2.5 and 6% and peroxide charges of 3 and 4%. The pulps were refined to specific energies up to 600 kWh/t by multiple passes through an LC refiner at intensities of 90 and 150 kWh/t. It was found that alkaline peroxide treatments increased tear strength and protected the fibre from cutting, especially during high intensity refining below a specific energy of 300 kWh/t. Treatment with 6% NaOH and 4% or 3% H2O2 led to lower brightness gains and scattering coefficients but increased the tensile strength index by 31%, potentially lowering the total electrical energy required to achieve strong pulp. The enhancement of tensile strength caused by the highly alkaline peroxide mostly resulted from increased bonding, which was attributable to acid group generation rather than the promotion of further fibrillation during LC refining.

Residual melanins have been detected in multimillion-year-old animal body fossils, however, confident identification and characterization of these natural pigments remain challenging due to loss of chemical signatures during diagenesis. Here, we simulate this post-burial process through artificial maturation experiments using three synthetic and one natural eumelanin exposed to mild (100 &deg, C/100 bar) and harsh (250 &deg, C/200 bar) environmental conditions, followed by chemical analysis employing alkaline hydrogen peroxide oxidation (AHPO) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Our results show that AHPO is sensitive to changes in the melanin molecular structure already during mild heat and pressure treatment (resulting, e.g., in increased C-C cross-linking), whereas harsh maturation leads to extensive loss of eumelanin-specific chemical markers. In contrast, negative-ion ToF-SIMS spectra are considerably less affected by mild maturation conditions, and eumelanin-specific features remain even after harsh treatment. Detailed analysis of ToF-SIMS spectra acquired prior to experimental treatment revealed significant differences between the investigated eumelanins. However, systematic spectral changes upon maturation reduced these dissimilarities, indicating that intense heat and pressure treatment leads to the formation of a common, partially degraded, eumelanin molecular structure. Our findings elucidate the complementary nature of AHPO and ToF-SIMS during chemical characterization of eumelanin traces in fossilized organismal remains.

The pyrolysis behaviors of the three major organic components of eucalyptus alkaline peroxide mechanical pulping (APMP) spent liquor including alkali lignin (AL), lignin-carbohydrate complexes (LCC), and polysaccharide (PLS) were studied with emphasis on the effect and contributions of components on the overall pyrolysates of APMP spent liquor solid (ASLS). Profound differences on product properties from each component pyrolysis were illustrated. The results indicated that the bio-oil during ASLS pyrolysis was mainly attributed to AL, while the bio-gas and char were mostly affected by PLS. Small molecule hydrocarbons released during ASLS pyrolysis mainly came from AL and LCC, and CO and CO2 mainly produced from PLS. As for bio-oils, AL generated the largest proportion of monomeric phenols and aromatic hydrocarbons (AHs), while PLS and LCC mainly contributed to the production of ketones, furans and acids. The correlation shown here is of interest for further studies on pulping spent liquor grading utilization.

Lignocellulose materials, essentially consisting of lignin, cellulose and hemicelluloses, are abundant sources of fermentable sugars. The bast fiber of Crotalaria juncea (Sunn hemp), a native cover crop of India, was used as feedstock for this study. The primary objective of this study was to add value to the waste C. juncea bast fiber. The same was achieved by pretreating the waste fiber using alkaline peroxide solution at various process conditions. The optimal process condition for alkaline peroxide pretreatment was identified for the fiber to pretreatment solution (S/S) ratio of 1/40 at 50°C for 5h with respect to all response variables (lignin removal, hemicellulose recovery, recovery of solid pretreated material, and crystallinity of lignocellulose). Three-way ANOVA results revealed that S/S ratio had no significant effect; whereas, both temperature and time, and the combination of parameters, exhibited significant effect on response variables. The characteristic peaks associated with lignin and cellulose demonstrated a higher amount of lignin removal and increased cellulose content with elevated treatment time. Autoclave assisted pretreatment proved to be inefficient due to removal of lower amount of lignin in addition to higher hemicellulose degradation. On the other hand, pretreatment using ultrasound was found to be most effective in removing lignin, liberating hemicelluloses along with diminition in cellulose crystallinity.

The present research work presents the study of cost effective cellulose fibers as sorbent for the U(VI) removal from nuclear wastewaters. Alkali-treated cellulose fibers (ATCFs) were extracted from alkaline peroxide mechanical pulp board by using CH3COOH and NaOH treatment. Sorption capability was ascertained by conducting batch experiments. The kinetic sorption of U(VI) on ATCFs could be described by the pseudo-second-order rate equation well. The results demonstrated that the sorption of U(VI) to ATCFs was strongly dependent of pH and weakly dependent of ionic strength. U(VI) sorption on ATCFs was mainly dominated by the outer-sphere complexation.

To reduce the refining energy consumption of chemi-mechanical pulping, treatment with NaOH-thiourea-urea aqueous solution was studied in this work. By means of single-factor experiments, the effects of alkali dosage, soaking time, and freezing time were evaluated. It was found that the optimal conditions were an alkali dosage of 8%, soaking time of 45 min, and freezing time of 105 min. The results revealed that refining energy consumption could be reduced by approximately 40% under optimal conditions compared with that of alkaline peroxide mechanical pulp, while other pulping or paper-making properties were similar. There were no significant effects on the structure of the functional groups, the crystalline region of the pulp, or the whole structure of the treated wood chips. However, damage to single wood fibers on the chips treated in NaOH-thiourea-urea aqueous solution was more obvious.

Chemiluminescent acridinium dimethylphenyl esters are highly sensitive labels that are widely used in automated assays for clinical diagnostics. Light emission from these labels and their conjugates is triggered by treatment with alkaline peroxide. In the current study, we provide a comprehensive examination of how polarity of the N-alkyl group in acridinium dimethylphenyl esters and their protein conjugates affect their properties. We describe a new synthetic strategy for the manipulation of the N-sulfopropyl group in acridinium esters which facilitates the attachment a structurally simple sulfobetaine zwitterion to the acridinium nitrogen. Our studies are the first and most detailed to date and they indicate that N-alkyl groups containing charge-neutral sulfobetaines in acridinium dimethylphenyl esters as exemplified by the labels 3 and 6 offer significant advantages over commonly used N-sulfopropyl groups. These include faster emission kinetics, improved chemiluminescence stability and lower non-specific binding to magnetic microparticles with different surfaces. Acridinium ester 3 is a particularly attractive new label because it contains a structurally simple N-alkyl group with a sulfobetaine zwitterion and its synthesis is relatively straightforward from the corresponding N-(3-chloropropyl) substituted acridinium ester precursor.

Four fiber fractions from poplar alkaline peroxide mechanical pulping, performed with refiner-chemical preconditioning (P-RC APMP), were used to estimate inter-fiber bonding capacity. The relationship between fiber characteristics and inter-fiber bonding capacities was investigated. The surface lignin content of the long fiber fraction was slightly lower than that of the short fiber fraction. Atomic force microscopy (AFM) images showed that the fiber surfaces were heterogeneous (i.e., different cell wall layers were exposed along the fiber surface). The fiber fractions that had lower surface lignin content had higher bonding capacities. Furthermore, modified PFI beating was used to peel the surface of the fibers. After the peeling treatment, the fiber surface charge increased remarkably, while the surface lignin concentration decreased considerably. The lignin and charge on the fiber surface are the two key factors for estimating the inter-fiber bonding capacities.

Fall leaves are biodegraded and composted naturally in forests but they are wastes for urban areas. Moreover, they are widely available cellulose sources but have limited applications. Alkaline peroxide treatment of bioresources is one of the most widely studied clean methods for both delignification and hemicellulose removal but there is no study about application of that method on fall leaves at room temperature. In this study, the effect of alkaline peroxide treatment of fall leaves at room temperature on hemicellulose recovery and cellulose delignification were investigated. Fall leaves (FL) were treated with 0.3-3.0 M NaOH + 0-3 M H2O2 at room temperature. Hemicellulose recovery and cellulose delignification values were analyzed. Hemicellulose recovery and cellulose delignification increased and yield decreased by increasing NaOH and H2O2 concentrations. Hemicellulose recovery and cellulose delignification reached to the maximum levels, 99.5% and 81.6% respectively, at 3M NaOH + 3M H2O2 treatment condition. The end products were confirmed by analytically, spectrally and morphologically. Wasted fall leaves were turned into useful hemicellulose and cellulose products by using clean alkaline peroxide treatment at room temperature. The products can be further processed by known methods into other industrial products.

Pretreatment of biomass is expected to improve the pulp properties and facilitate the main components in the raw materials to be better used. In this work, the refining energy consumption and properties of the poplar chemithermomechanical pulp (CTMP) from different autohydrolysis pretreatment intensities of wood chips were investigated, and the pulp bleaching ability was also studied. The results showed that the CTMP with autohydrolysis pretreatment at a severity factor of 3.47 could have a 26% energy reduction in pressurized refining, a 60% energy saving in PFI refining, and 44% and 46% increases in tensile and tear indices, respectively. Autohydrolysis pretreatment prior to pulping could result in CTMP with a higher water retention value, higher fines content, better strength properties, lower shives content, and lower bulk and ISO brightness after PFI refining. The brightness of CTMP can be improved by alkaline peroxide bleaching.

Aerobic activated sludge was more appropriate for APMP(Alkaline Peroxide Mechanical Pulp) effluent treatment than anaerobic processes because the high content of toxic wood extractives in the effluent. In this article, Eucalyptus APMP effluent was treated with activated sludge and the process conditions was optimized. The optimized conditions were: the initial pH value was 6.0, SV30of activated sludge was 35%, and loading volume of flask was 150ml (250ml flask), cultured shakily for 3 days at 35°Cand 150rpm. The removal of COD was 66.75%, from 4181mg/l to 1390mg/l, and the color of the effluent and treated water were 2541C.U. and 1557C.U. under the optimized conditions, respectively. In most cases, the color of treated wastewater was increased compared with the initial effluent, but the removal of COD was significant.

To improve ethanol productivity with few inhibitors generated, a novel process of combined alkaline peroxide (AP) pretreatment and semi-simultaneous saccharification and fermentation (SSSF) was developed in this work. Pretreatment with 10% (g H2O2/g wood) H2O2 at 160°C for 2h followed by SSSF was found to be the optimal combination with remarkably increased ethanol yield. The proposed process resulted in 63.1% of ethanol yield, which was about five times more than that of the untreated sample that was processed using conventional simultaneous saccharification and fermentation (SSF). The efficient conversion was ascribed to the high delignification efficiency (64.9%) of AP pretreatment, which led to incompact structure and generation of fewer inhibitors during SSSF (c. 6g/L of lactic acid) than SSF (c. 10 g/L of lactic acid). This combined approach was proved to be an effective method for the promotion of the bioconversion of lignocellulosic materials.

The layer-by-layer deposition technique was adopted in this paper to improve the physical strength properties of alkaline peroxide mechanical pulp (APMP). The cationic starch (CS), anionic polyacryamide (APAM) and cationic polyacryamide (CPAM) were chosen and used to build-up polyelectrolyte multilayers on surface of APMP fibers. The improvements of physical strength of pulp through adsorption of different polyelectrolyte onto fibers were discussed and compared. The results showed that when the APMP fibers were treated with CPAM, the breaking length and burst index were 53% and 83% respectively, higher than that of untreated pulp. The optimal treatment conditions are 60 mgCPAM/g pulp, 1.5% pulp concentration and 9min treatment time. The pulp deposited by CPAM-APAM polyelectrolyte multilayer gave a highest physical strength compared with pulp with other multilayer deposition such as CS-APAM. At the whole beating degree range investigated in this paper, the CPAM-APAM deposition on fiber surface can improve the physical strength properties significantly, especially when the beating degree is at 40oSR. In addition, the improvement of physical strength can be remained even after pulp refining.

To convert bleached softwood paper grade pulp into dissolving pulp for viscose application, two stages of treatments consisting of enzymatic treatment and alkaline peroxide treatment were investigated. It was found that high reactivity (about 80%) of pulp could be achieved by endoglucanases (EG)-rich industrial cellulase treatment, and the alpha-cellulose content as well as the viscosity of enzymatically treated pulp can be further adjusted by the alkaline peroxide treatment with certain dosages of NaOH and H2O2 to finally meet the quality requirements of dissolving pulp. The resulting pulp with 68.7% of reactivity, 92.1% of alpha-cellulose content, and 506.9 mL/g of pulp viscosity could be obtained after the two stages of treatments. The appropriate dosage of EG-rich cellulase was 300 IU/g bone dry pulp in the stage of enzymatic treatment, while the suitable dosages of NaOH and H2O2 were 9 wt% and 1 wt%, respectively, in the stage of alkaline peroxide treatment. (C) 2013 Elsevier B.V. All rights reserved.

Lignocellulosic biomass has great potential as a low-cost source of fermentable sugar for the production of biofuels and high value organic acids. One potential biomass is oil palm empty fruit bunch, since it has high cellulose and hemicellulose content. However, its lignin content can hinder the access of cellulose and hemicellulose during the hydrolysis process. Therefore, an effective pretreatment for the delignification of lignocellulose biomass should be considered to reduce the lignin content. In this study, delignification of oil palm empty fruit bunch using peracetic acid and alkaline peroxide solution combined with the ultrasound method is investigated as a novel combination method of biomass pretreatment. The effect of pretreatment time was observed by using a peracetic acid solution for 1, 3, 5, 7 and 9 hours, followed by an alkaline peroxide solution for 4, 6, 8 and 10 hours. Based on the results, the best delignification was achieved by pretreatment using peracetic acid pretreatment for 3 hours, followed by alkaline peroxide pretreatment for 10 hours. Both pretreatments were assisted by the ultrasound method. The results show hemicellulose, cellulose and lignin content of 14.13%, 77.27% and 8.6% respectively. The lignin content was reduced by 68.73% and the cellulose content increased by 121.85%, relative to the untreated EFB. This result was considered as the best pretreatment, since the pretreatment time was shorter and high cellulose content together with low lignin content was achieved, which will improve the hydrolysis process.

Background To evaluate the effect of denture cleansers with and without fatigue stress on the retention of the locator attachments. Materials and methods Three dummy implants of length (13 mm) and a diameter of 4.2 mm with their locator abutments were embedded into three acrylic resin blocks. Seventy pink locator attachments were divided into three groups: 10 for group I, 30 for each group II and group III. Group I exposed to 600 cycles of insertion and removal equivalent to 6 months use, group II and group III was subdivided into three subgroups, A, B, C according to the type of cleaner which was soaked in water, chlorhexidine gluconate 2% and alkaline peroxide solution for a period equivalent to 6 months. Group III was soaked in water, chlorhexidine gluconate 2% and alkaline peroxide solution, then exposed to 600 cycles of insertion and removal. The pink locator was tested for load to dislodgment on universal testing machine with a load cell of 5 kN at a crosshead speed of two in/min. Retention of locator attachments were statistically analyzed using Mann–Whitney test. Difference of mean values between more than two groups was tested by Friedman χ2-test. Results Group I: The retention of pink locator attachments was significantly decreased after 600 cycles of insertion and removal P = 0.005. Group II: The retentive value for attachment soaked in chlorhexidine gluconate 2% and that soaked in alkaline peroxide solution was significantly lower than that soaked in water (P = 0.001). Group III: the locator soaked in water and chlorhexidine gluconate 2% and alkaline peroxide solution was significantly affected after 600 cycles of insertion and removal. Conclusion Chlorhexidine gluconate 2% and alkaline peroxide solution has significant decrease the retention of pink locator attachment. Fatigue has significant effect on the retention of locator attachment either with or without the use of denture cleansers.

Oxalic acid (OA), formed as an oxidation product in alkaline peroxide bleaching (P) of mechanical pulps, can form a sparingly soluble salt with calcium and cause severe scale deposit problems. The focus of this work was the question how much OA is formed from the different components of spruce (Picea abies (L.) Karst.), i.e., from cellulose, lignin, hemicelluloses, extractives, and bark, during the P-stage of bleaching. Isolated wood components and monosaccharides typical for spruce hemicelluloses and pectins were treated with chemicals of P-stage for 90 min at 73°C, and the released OA was analyzed by ion chromatography. Most OA was formed from galacturonic and glucuronic acids, xylans, and lignin. Taking into account the content of these substances in spruce wood, lignin can be regarded as the major source of oxalate. Untreated spruce bark was found to contain substantial amounts of oxalate, and an additional amount of oxalate was formed in the P-stage. It is evident that effective debarking is essential, not only for pulp brightness, but also for the control of calcium oxalate formation.

Pulp from the oil palm empty fruit bunches (EFB) was extracted via Alkaline Peroxide Pulping (APP). The pulping process was conducted through three main steps; dewaxing of EFB, impregnation of alkaline peroxide (AP) into EFB and refining of biomass to finally produce the pulp. The varying peroxide levels and number of impregnation stages were found to affect the refining energy consumption and the properties of the resultant pulp and paper. Diagnosis by electron microscopic imaging revealed a strong correlation between paper properties development and paper surface morphologies. By multiplying the stages of the low alkaline peroxide level (2:2.5% AP) impregnation, refining energy could be reduced by 30% while improving brightness and paper mechanical properties. Higher alkaline peroxide level (4:5% AP) could reduce the refining energy by 50% while still improving brightness. Beyond these AP levels (8:10% AP), refining energy could be reduced by 67% by increasing the number of impregnation stages, with positive effects on brightness and paper mechanical properties. The findings suggest that increasing the AP impregnation stages had exposed more active sites to react with AP. The enhanced AP accessibility to EFB structures facilitated mechanical fibrillation of EFB vascular bundles through the refining process. The proper synergy between AP and the adopted mechanical refining was the factor that triggered the liberation of nanocells from EFB biomass and this had ultimately improved paper properties.

In this paper the two-stage method of enzyme-mild acidic hydrolysis was adopted to isolate lignin from the APMP(Alkaline Peroxide Mechanical Pulp),then the isolated lignin was treated with a laccase-mediator system(LMS).The phosphor magnetic resonance spectrum (31P-NMR) measurements and Infrared spectral analysis technology were chosen to analyze the structural changes of LMS-treated APMP residual lignin.

In this paper, the poplar Alkaline Peroxide Mechanical Pulp (APMP) pulping wastewater was treated by the SBR. The pulping wastewater was from the processes of washing, soaking and defibrination. The COD of the pulping wastewater was 5671 mg/L and the BOD was 1862 mg/L. The B/C (biological oxygen demand/chemical oxygen demand) ratio of the pulping wastewater was 0.32, which indicated that the wastewater was suitable to be treated by biological methods. SBR technology was used to treat the pulping wastewater. After a series of experiments, the best conditions for the pulping wastewater was achieved as follows: time 6hrs, original pH about 8. Under these conditions the removal ratio of COD can reach 81.4% and that of BOD can reach 91.5%;but the removal ratio of the TSS and the Chromaticity were low, the removal ratio of TSS only reach 31.8%.

The study is aiming at the finding of optimal pulping conditions for the alkaline peroxide mechanical pulping process applied to larch in terms of brightness (% ISO) and tensile strength (TS). Based on three variables, the Box-Behnken experimental design was applied to determine the effects of the first-stage and second-stage dosages of H2O2 and the impregnation temperature on % ISO and TS. The equations based on the quadratic regression analysis were developed, which describe the response behaviors as the simultaneous functions of the selected independent variables. The best brightness achieved was 75.4% ISO under the following conditions: first-stage H2O2 3.5%, second-stage H2O2 3.54%, and impregnation temperature 81.4°C. The best TS (37.2 N·m g-1) was found under the following conditions: first-stage H2O2 2.4%, second-stage H2O2 3.9%, and impregnation temperature 90°C.

High-yield pulp (HYP) has various fractions, and they not only play an important role in the papermaking process but also affect paper properties. Hence, it is necessary to clarify the impact of different HYP fractions on paper formation and properties. In this study, the characteristics of poplar preconditioning followed by refining chemical treatment alkaline peroxide mechanical pulp fractions were determined, and their effects on paper formation and paper properties were investigated. The results show that the HYP fiber is not as flexible as the bleached wheat straw pulp fiber. Compared with the HYP long-fiber fraction, the short-fiber fraction can improve the formation index more favorably. It was also found that the long-fiber fraction can maintain the strength properties, while having a negligible effect on the light-scattering coefficient; on the contrary, the short-fiber fraction can improve the light-scattering coefficient effectively but reduces the strength properties.

Preconditioning Refiner Chemic Alkaline Peroxide Mechanical Pulp (PRC-APMP) is one of the most currently used high yield pulps in China. During the bleaching of PRC-APMP, hydrogen peroxide is a commonly used bleaching agent. In order to improve the bleaching efficiency of PRC-APMP, urea was used as an activator in peroxide bleaching of aspen PRC-APMP. The results showed that the brightness of the urea-based bleached pulp higher than that without urea addition at the same hydrogen peroxide dosage. The physical properties such as the breaking length, tear index and fiber length of the bleached pulp were comparable to those without urea addition in peroxide bleaching.

Amaç: Bu çalışmanın amacı; protez temizleyici solüsyonların ısı ile polimerize olan akrilik rezinin mikrosertliği üzerine etkisini incelemektir. Gereç ve Yöntem: 50 akrilik rezinörnek (15 mm × 15 mm × 3 mm) hazırlandı. Örnekler rastgele dağıtılarak,sıralanan solüsyonlara göre gruplara ayrıldı:% 0.2 klorheksidin glukonat, %0.5 sodyum hipoklorit (NaOCl), %1 NaOCl,alkalin peroksit tablet solüsyonu (n=10). Kontrol grubu örnekler distile sudabekletildi. Solüsyonlarda bir daldırma 20-dakika olarak belirlendi. Her birörneğin Vickers sertlik değeri mikrosertlik cihazı ile daldırma öncesi ve 720daldırma sonrası ölçülerek karşılaştırıldı.Veriler SPSS 15.0 programına taşınarak eşleştirilmiş örneklemler t-testi,tek yönlü varyans analizi ve Tukey HSD testi ile gruplar arası karşılaştırmalaryapıldı (p< 0.05).Bulgular: Bulgular alkalin peroksit tablet solüsyonunun akrilik rezinin mikrosertliğinde istatistiksel olarak anlamlı azalmaya yol açtığını göstermiştir. Çalışmada test edilen diğer solüsyonlar akrilik rezinin mikrosertliği üzerinde anlamlı bir etkiye neden olmamıştır. Sonuç: Alkalin peroksit tablet solüsyonu hariç distile su, %0.2 klorheksidin glukonat, % 0.5 NaOCl ve %1 NaOCl solüsyonları günde 20 dakika kullanımı taklit eden 720 kullanım periyodunda ısı ile polimerize olan akrilik rezinin mikrosertliğini anlamlı olarak etkilememiştir Anahtar kelimeler: Diş protezi, Protez temizleyicileri, Sağlamlık testleri, Akrilik rezinler EFFECT OF DENTURE CLEANSING SOLUTIONS ON MICROHARDNESS OF A HEAT-CURE ACRYLIC RESINAim:The aim of this study was to investigate the influence of denture cleansing solutions on micro hardness of a heat-cure acrylic resin.Materials and Methods: Fifty specimens (15mm × 15 mm × 3 mm) were prepared with a heat-cure acrylic resin. Specimens wererandomly distributed into groups and immersed in the following solutions: 0.5%sodium hypochlorite (NaOCl), 1% NaOCl, alkaline peroxide tablet solution and,0.2% chlorhexidine gluconate. The control group was immersed in distilledwater. An immersion was detected 20-minute for all solutions. The microhardnessvalue of each specimen was obtained using the microhardness testing machinerecording the Vickers hardness number before the beginning of the immersioncycles and after completion of 720 immersion cycles and compared. Data wereimported to SPSS 15.0 software and were analyzed by paired t-test and One-WayANOVA and Tukey HSD test were used for comparison among groups (p< 0.05).Results: The results show that alkaline peroxide tablet solution caused the statistically significant reduction of the microhardness of the acrylic resin. Other solutions tested in this study did not cause a significant effect on the microhardness of the acrylic resin.Conclusions:It was concluded that immersion in distilled water, chlorhexidine gluconate, 0.5% NaOCl and, 1% NaOCl solutions, simulating 720 days of 20 min daily soaking did not cause clinically significant adverse effects on the microhardness of the heat-polymerized acrylic resin, except for the alkaline peroxide tablet solutions.Keywords: Dental Prostheses, Denture Cleansers,Hardness Tests, Acrylic Resins

In this chapter the literature on the alkaline hydrogen peroxide (AHP) pretreatment of biomass is reviewed. The review focuses on parameters that influence the efficiency of biomass decomposition aimed at further production of biofuels. The optimal process conditions of the AHP method are discussed. Many examples are given for the application of this pretreatment method to various kinds of biomass. The mechanism of delignification by the AHP treatment is discussed, and the newest proposal for the process kinetics is given. The direction of further investigations of the AHP pretreatment are suggested.

The origin and kinetic changes of carboxyl groups in aspen chemithermomechanical pulp (CTMP) fibres during alkaline peroxide bleaching were evaluated. The results showed that the major contributors of carboxyl groups in aspen CTMP fibres were the 4-O-methylglucuronic acid, galacturonic acid and the carboxyl groups in oxidized lignin. Alkaline peroxide bleaching could increase the total carboxyl groups, surface charge and dissolved anionic substances. However, the excess degradation by superfluous hydroxide and peroxide could result in the reduction of carboxyl groups in fibres because of the production and dissolution of low-molar-mass substances. The total carboxyl groups from polysaccharides in fibres remained constant, and the increase of carboxyl groups in fibres should result from the carboxyl groups newly formed by the lignin oxidation during peroxide bleaching. Alkaline peroxide bleaching could also result in the removal of a large part of extractives and a small fraction of lignin on the fibre surface.

Xylan, galactoglucomannan, arabinogalactan and hemicelluloses with different molecular weights were prepared from wood and then used as wet-end additives and surface sizing agents in papermaking. The results showed that xylan, galactoglucomannan and arabinogalactan all had obvious paper-strengthening effect. As wet-end additives, galactoglucomannan had the best effects, followed by xylan and then arabinogalactan. As surface sizing agents coordinating with starch, xylan showed the best sizing effect (paper-strengthening effect and water resistance), followed by galactoglucomannan. The effects were both greater than that of starch alone. Furthermore, hemicelluloses with higher molecular weights had more significant effects. The results could provide some reference for the use of hemicelluloses in nature and papermaking waste liquor to improve paper physical strength. Although hemicelluloses in APMP (alkaline peroxide mechanical pulp) waste liquor was degraded to a certain degree, it also showed good paper-strengthening effects. Starch as an important papermaking additives comes mainly from food. The hemicelluloses, especially in the high-yield-pulp waste-liquor, can replace starch in papermaking to some extent, which might be beneficial from economic, energy and food standpoints.

A steam pretreatment method with low severity and post pretreatment with alkaline peroxide were investigated in this study with respect to the factors affecting delignification efficiency of Lespedeza Stalks. In alkaline peroxide procedure, four factors were compared to evaluate the lignin removal: substrate concentration (w/w), the ratio of peroxide to substrate (w/w), temperature and time. The remaining lignin of fractions from Lespedeza stalks steam pretreated at low severity was apparently reduced by post treatment with 1 g H2O2/g substrate at the substrate concentration of 1.67% under 60°C for 72h. Scanning electron microscopy images show that the samples with alkaline peroxide treatment have the smoother surface because of the elimination of lignin droplets and the fiber bundles individualized.

Comparisons were studied for untreated and pretreated bagasse with dilute alkaline peroxide and steam for bioethanol production by simultaneous saccharification and fermentation (SSF) process in a continuous stirred batch bioreactor using fungi Fusarium oxysporum. The optimum parameters for bioethanol fermentation were: time, 48 h; pH, 6.0; temperature, 50°C; stirring speed, 35 rpm; and bagasse loading, 35 g/L. Maximum concentrations of bioethanol at optimum fermentation process parameters were 18.73 g/L, 19.69 g/L and 20.45 g/L for untreated, steam and dilute alkaline peroxide pretreated bagasse, respectively. Maximum yields of bioethanol were 0.706 g/g, 0.734 g/g and 0.764 g/g of bagasse at optimum parameters for untreated, steam and dilute alkaline peroxide pretreated bagasse, respectively. The sp. growth rate (µ) of fungi Fusarium oxysporum was determined at 5.91 s−1, 6.25 s−1 and 7.11 s−1 and maximum sp. growth rate (µmax) was calculated at 11.81 s−1, 12.50 s−1 and 14.22 s−1 for untreated, s...

This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate)-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min), 0.5% sodium hypochlorite (10 min) or distilled water (control; 15 min). After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL). Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p < 0.001), and it could be observed by SEM. However, no significant difference (p > 0.05) was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001). Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

Wool is commonly treated with alkaline protease enzyme to improve handle and shrink resistance. The limitations associated with the usage of this enzyme on wool are excessive weight and strength losses and pH sensitive enzyme activity, etc. Wool is generally stable if processed in acidic conditions rather than alkaline conditions. This study explores the possibility of using acid protease enzyme to improve handle and shrink resistance of wool. The acid protease enzyme is applied on acid and alkaline peroxide bleached wool fabrics using optimized process parameters, and the results are compared with alkaline protease enzyme treated wool fabric. The acid protease treated fabrics show 30% higher softness than alkaline protease treated fabrics with 72% and 62% lower weight and strength losses, respectively. The alkaline peroxide bleaching prior to acid protease treatment provides 100% and 67% higher whiteness and shrinkage resistance, respectively, to wool than the acid peroxide bleaching. The action of the e...

In the conventional preconditioning followed by refiner chemical treatment, alkaline peroxide mechanical pulping (P-RC APMP) process, sodium hydroxide (NaOH) is used as the alkali source. In this s...

In this study, the structural modification of Siam weed (Chromolaena odorata) was performed using NaOH–H2O2- and Ca(OH)2–H2O2-based oxidative pretreatment for the enzymatic conversion of the biomass to a biocommodity, reducing sugar (RS). Pretreatment of raw sample was evaluated at temperatures of 60°C, 70°C, 80°C, 90°C for different time intervals of 3, 6, 9, 12 h in alkaline medium (NaOH or Ca(OH)2). The effects of pretreatment time and temperature were considered in obtaining the optimum conditions. The optimum conditions for NaOH–H2O2 was obtained at 70°C and 3 h with a maximum cellulose content of 44.29%(w/w), lignin content reduced to 21.09% from the initial raw value of 24.2%. Pretreatment with Ca(OH)2–H2O2 resulted in the optimum conditions obtained to be 70°C for 3 h with a cellulose content of 47.18%. Enzymatic hydrolysis on the pretreated biomass at the optimum conditions showed NaOH–H2O2-treated sample yielded 424.35 mg equivalent glucose/g biomass of RS while Ca(OH)2–H2O2-treated sample yielded 335.81 mg equivalent glucose/g biomass of RS. The untreated raw sample yielded 68.75 mg equivalent glucose/g biomass of RS. Consequently, NaOH–H2O2 pretreatment displayed a higher efficiency than Ca(OH)2–H2O2 pretreatment. Stereomicroscopic and scanning electron microscopic imaging of the treated and untreated samples revealed morphological disruptions brought about by the treatments.