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This study focuses on the mineral carbonation to capture CO2 using an alkaline industrial waste, the grits, formed during the kraft pulp production process. An indirect mineral carbonation route was adopted, composed by two steps: first the extraction of calcium from the grits and second the precipitation of calcium carbonate. Firstly, four solvents were analyzed (HNO3, CH3COOH, NaOH and NH4Cl). Only HNO3 and CH3COOH have shown significant extraction efficiencies of 79.4 and 73.2 %, respectively, after 2 h at 30 °C. Kinetic tests demonstrated that equilibrium conditions are reached after 60 min. Since the nitric acid is a corrosive acid and with high associated costs, the acetic acid was selected for the dissolution of grits and extraction of calcium. The optimal conditions determined were an acetic acid concentration of 2 M, solid/liquid ratio of 30 g/L and temperature of 45 °C with an efficiency approximately of 77 %. In the second step, carbonation experiments were performed contacting the Ca-rich liquor, obtained from the extraction step, with a flux of pure CO2 gaseous in a stainless inox reactor. The optimal conditions determined were 30 °C and 30 bar, reaching a carbonation efficiency of 74 %, corresponding a CO2 sequestration capacity of 460 kg CO2/ton of grits.

Paper mulberry (Broussonetia papyrifera) is widely ensiled to feed sheep in southwestern China, as unconventional woody forage. Feeding lambs with paper mulberry silage (PMS) may improve certain feeding characteristics, thereby affecting the growth performance and meat quality. The aim of this study is to investigate the effects of four diets of PMS on growth performance, rumen microbial composition, and muscle fatty acids profile in Hu lambs. The results showed that 30% and 40% PMS increased the dry matter intake and average daily gain of Hu lambs compared to the control group. PMS30 and PMS40 increased the content of C24:1, and PMS40 increased the content of C20:5n-3. The content of microbial protein (MCP) was higher in PMS40 than in others, but PMS30 and PMS40 reduced the total volatile fatty acid in rumen. PMS30 significantly increased the ratio of acetic acid to propionic acid. The abundance of ruminal Christensenellaceae_R-7_group and norank_f_Eubacterium_coprostanoligenes_group was significantly higher in PMS30 and PMS40 groups. Moreover, Christensenellaceae_R-7_group had a significant positive correlation with n3-polyunsaturated fatty acid. PMS40 might lead to a relatively high content of unsaturated fatty acids in longissimus dorsi muscle by increasing the relative abundance of Christensenellaceae_R-7_group in rumen.

Samples of papers artificially (2 to 60 days) and naturally (10, 45, and 56 years) aged were studied by the Py-GC/MS method to identify decomposition products. Possible reaction scenarios for cellulose degradation were developed. One of the degradation products is acetic acid, which can (auto)catalyze the cleavage of cellulose β(1→4)-glycosidic bonds of cellulose polymer chains. However, during 20 s of Py-GC/MS analysis, temperatures of up to 300 °C did not significantly increase or modify the formation of decomposition products of paper components. At 300 °C, the amount of several cellulose decomposition products increased regularly depending on the number of days of artificial aging and natural aging, demonstrated mainly by the generation of 2-furancarboxaldehyde, 5-hydroxymethylfurfural, and levoglucosan and its consecutive dehydration products. No correlation between the amount of lignin decomposition products and the time of aging was found when the pyrolysis was performed at 300 °C and 500 °C. Compounds present in the products of decomposition at 500 °C bear the imprint of the chemical composition of the sampled paper. Pyrograms taken at 300 °C using the Py-GC/MS method can give additional information on the changes in the chemical structure of paper during natural or artificial aging, mainly about the cleavage of β(1→4)-glycosidic bonds during aging.

Bacterial Cellulose (BC) production from Fermented Rice Noodle Wastewater (FRNW) was fermented by Komagataeibacter sp. PAP1. In order to increase the production of BC, the FRNW-based medium was prepared and optimized for the cultivation of this bacterium. The optimized FRNW-based medium was composed of 5 % (w/v) mannitol, 0.1 % (w/v) beef extract, 0.5 % (v/v) ethanol, 1 % (v/v) acetic acid, pH 7.0 which were incubated at 30 °C for 10 days. Under these conditions, BC yielded 11.76 ± 0.34 g/L higher (4.40 fold) than the standard Hestrin-Schramm (HS) medium. The study on growth and BC production by Komagataeibacter sp. PAP1 in optimized culture condition showed that BC production by Komagataeibacter sp. PAP1 was growth-associated. The bacterial cell of Komagataeibacter sp. PAP1 increased exponentially from the 3rd to 5th day. The BC paper sheets produced using the obtained BC pellicle from an optimized FRNW-based medium gave higher mechanical strength than those from standard HS medium. This study reveals the use of FRNW as a substrate for BC production. The results indicated that FRNW, which is more environmentally friendly, can be used as an alternative low-cost substrate for BC production.

The delignification of horse grass (HG) was carried out using methanol and water (organosolv pulping); varying the cooking conditions at 30min, 60min and 90min with ratios: 1:1, 1:2 and 1:3, Methanol-water, cooked in autoclave at 1050C. The pulp obtained were selected and macerated in equal volume of glacial acetic acid (ethanoic acid) and hydrogen peroxide (1:1) at a temperature 1000C, to investigate the fiber length; fiber diameter; lumen with their derived indices and paper strength properties was determined according to TAPPI standard methods, T 494 om-96. The best fiber length of 3.21mm, tear index 31.43 mN.m2/g, tensile index 97.79Nm/g and bulk index 5.15 kPa.m2/g was obtained at 1:3 methanol: H2O at 105°C with cooking time of 60 min. Therefore, it was established that high quality papers of different grades can be produced from horse grass with acceptable strength properties using low concentration of methanol/water pulping with moderate time at boiling temperature. The research concluded that methanol-water was excellently good for pulping of horse grass fibers. The above results showed that horse grass is a good alternative sources of fibers to produce pulp and paper.

The objective of this paper is to study the deterioration of impregnated kraft papers immersed in dielectric liquids under the chemical stress conditions by furan analysis according to ASTM D5837 and IEC 61198. Mineral oil and natural ester (FR3) were liquid used in this study. Kraft paper samples, 3 pieces per each case study, are prepared in rectangle shape with 25.4 ± 0.5 millimeters (1.00 ± 0.02 inches) wide and approximately 254 millimeters (10.0 inches) long according to the ASTM D828 standard. The paper and liquid insulation are heated to dehydrate at 80 °C for 12 hours with 200 mbar pressure, and then they are filled in 200 milliliter bottles and heated with 5 different temperatures being 60 °C, 80 °C, 100 °C, 120 °C and 140 °C respectively. In the case of 120 °C and 140 °C are only conducted with FR3 due to its thermal characteristics. After that, 98% concentration of acetic acid of 2 quantities, 0.04 and 0.08 milliliters, and oxygen (O2) at 1 psi for 1,200 ml, are used for the chemical aging process for 9 days of the test samples before being tested to find furanic compounds. According to the test result, it can be concluded that all 4 factors, temperature, acetic volume, oxygen and moisture, effect on generated furanic compounds of aging paper insulation.

Aims A paper by Araújo et al. (2018) claims that a variety of compounds present in pyroligneous acid (guaiacol, phenols and furfural) are responsible for the observed antimicrobial activity. We show, on the other hand, that the low pH due to acetic acid present in pyroligneous acid is the real cause of the activity. Methods and Results Pyroligneous acid (PA) was synthesized according to a previous method (Medeiros et al. 2019) with its inhibition activity tested on Escherichia coli and Staphylococcus aureus via the agar diffusion method. The activity of acetic acid at different concentrations was also evaluated for comparison. As expected, crude PA (pH 3.0) and acetic acid produced inhibition halos whose diameters varied according to their employed concentration. However, any PA inhibitory activity completely vanished upon neutralization (pH 7.0), a behaviour also observed for neutralized acetic acid. Conclusions The claim that guaiacol, phenols and furfural are responsible for any inhibitory activity is unsubstantiated. The authors should have neutralized the pyroligneous acid if any activity was to be discovered. Significance and Impact of Study To increase awareness that interfering species may play a detrimental role on the interpretation of results. In this case, the action of acetic acid is vastly more important for the inhibitory activity than any other compound present in PA.

The thermophilic anaerobic co-digestion of food waste and paper waste was successfully operated with a 0% to 70% fraction of paper waste. The variation of functional microbial community was investigated by 16S rRNA gene analysis. The results indicated that the hydrolyzing bacterial community changed from carbohydrate/protein-degrading bacteria to cellulose-degrading bacteria when the paper waste ratio was higher than 50%. Significant changes in the taxon responsible for cellulose degradation were found depending on the paper waste fraction. Cellulose-degrading bacteria outcompeted lactic acid bacteria in the degradation of monosaccharide, resulting in a decline in the proportion of lactic acid bacteria and the absence of an accumulation of lactic acid. At high paper waste ratios, because the cellulose-degrading bacteria, such as Defluviitoga tunisiensis, were more likely to degrade monosaccharides directly to acetate and hydrogen rather than to propionate and butyrate, the abundance of syntrophs was reduced. The variation of those bacteria with high H2-producing ability significantly influenced the proportion of hydrogenotrophic archaea. The change in the microbial community as the paper waste fraction increased was illustrated with regard to anaerobic degradation steps.

The overwhelming majority of library and archival collections are kept in storage. Paper collections themselves are a source of formic acid and acetic acid within the storage room. This paper investigates the concentration of both organic acids in three storage facilities during summer and winter as well as their temperature-related off-gassing from six paper samples in a laboratory set-up. The study reveals a basic pattern in the formation of formic and acetic acid which was notably higher in summer than in winter at all three storage sites. The temperature dependent changes of formic acid and acetic acid level during the seasons correspond to the changes in off-gassing from the six paper samples determined at laboratory conditions. The study indicates that reducing the temperature in storage facilities of libraries and archival collections will reduce the off-gassing of organic acids from paper and by this their concentration in air.

Paper degradation products dissolved in the oil are used as chemical markers for predicting the power transformers lifespan in paper-oil systems. For a compound to be useful as a solid insulation marker, it must be derived exclusively from insulating paper, must be thermally and chemically stable over time, and must have known migration behavior and paper/oil partitioning at different temperatures. Methanol was considered to be potentially useful as marker. The stability of methanol in the presence of organic acids formed by degradation of insulating oil and paper was evaluated in detail, using FTIR and Gas Chromatography Mass Spectrography (GC/MS), in samples of fresh mineral insulating oil (MIO) and high-acidity MIO removed from a transformer in the field, to which formic and acetic acid and methanol were added. The samples were subjected to thermal aging and the results showed that the main problem in using methanol as a marker for paper degradation was its high volatility, apart some possible esterification with low molecular mass acids formed with of paper and /or oil degradation.

Povarov multicomponent reaction (MCR) is an acid-catalyzed process that uses three distinct classes of reactants. i. e. an aldehyde, aniline, and activated alkene. We employ paper spray ionization mass spectrometry (PS-MS) as a convenient platform for investigating the on-surface Povarov reaction using the following suitable prototype starting reactants: the tag-charged aldehyde 1, 4-bromoaniline, 2,3-dihydrofuran, and formic acid. The PS(+)-MS revealed, besides the formation of the Povarov product (a tetrahydroquinoline compound), the transitional imine. Moreover, the oxonium intermediate was also detected as the water and formic acid adducts. Other alkenes (2,3-dihydropyran and styrene), acid catalysts (acetic acid and p-sulfonic acid calix[4]arene), and aldehydes (4-nitrobenzaldehyde, 4-anisaldehyde, 4-methoxycinnamaldehyde, citronellal, and valeraldehyde) were employed to verify the reaction generality. We observed that styrene (an unactivated alkene), p-sulfonic acid calix [4] arene (an acid with a non-nucleophilic conjugated base), and aromatic aldehydes (4-nitrobenzaldehyde and 4-anisaldehyde) showed lower reactivity than the other reactants. In conclusion, an exciting possibility emerges as PS-MS can be widely employed to investigate similar on-surface organic reactions to verify the connections between the on-surface and condensed phase processes.

The purpose of this study is to find the optimum conditions, including the type and concentration of solvent, and the solid/liquid ratio, for the extraction of calcium from Paper Sludge Ash (PSA). Solvents with different properties are divided into the following three groups to conduct the calcium extraction experiments: acid (acetic acid and hydrochloric acid), ammonium salt (ammonium chloride and ammonium acetate), and other (sodium citrate and water). The maximum efficiency of calcium extraction using acid is 54% at a concentration of 0.7 M and solid/liquid ratio of 1:25, while ammonium salt and sodium citrate extract calcium up to 30% and 28%, respectively, at a concentration of 0.3 M and solid/liquid ratio of 1:50.

Herein, a simple, green, and novel paper-based headspace-thin film microextraction in combination with smartphone-based on-cell detection was introduced. Sulfite was selected as a model compound to study the performance of the method. The method was based on converting sulfite to SO2 by acidification of the sample solution. A piece of cellulose paper impregnated with Fe(III), 1,10-phenanthroline, and acetate buffer (pH = 5.5) was used for headspace-thin film microextraction. The sulfur dioxide adsorbed on the thin film reduced Fe(III) to Fe(II). The red color complex formed between Fe(II) and 1,10-phenanthroline was on-cell detected by a smartphone. The effect of various parameters on the method sensitivity was investigated. The method had three individual linear ranges (0.1–1.0, 1–50, and 50–700 µg L−1) with a detection limit of 0.04 µg L−1. The method provided a simple and green assay for the determination of sulfite in food samples. Recoveries were higher than 94% with the relative standard deviations lower than 4.8%. Expensive and complicated facilities were not required in the method.

Thermophilic Clostridium thermocellum (CEL), Clostridium clariflavum (CLA) and Moorella thermoacetica (C. thermoaceticum, ACE) in co-culture were used to directly ferment paper sludge. The triculture system could greatly solubilize cellulose as well as hemicellulose and fermented them into acetic acid. Various microbial inoculum ratios were explored in 0.5-L fermenter and it was found that CEL to CLA to ACE inoculation volume ratio of 1:1:1 provided the highest product concentration and best efficiency. Scale-up to 5.0-L was carried out and resulted into 86.2% carbon conversion efficiency of all saccharides in paper sludge to acetic acid and 90.5% to total products. Such high efficiencies reached without pretreatment and without addition of expensive enzymes consist of a breakthrough towards cost-performant biorefinery. In addition, this work contributes to the yet limited knowledge on the combination of pure anaerobic bacterial cultures.

Dimethylaminocinnamaldehyde was re-evaluated as a wet contact reagent for the treatment of latent fingermarks on porous substrates. A new formulation (consisting of 0.028 g p-dimethylaminocinnamaldehyde, 0.84 mL glacial acetic acid, 6.2 mL ethyl acetate and 0.993 L 40-60 °C petroleum spirits) provides quick, sensitive and robust luminescent ridge detail within 3 h of treatment on both plain and thermal paper. Comparisons to existing formulations indicate improved visualisation and/or a more efficient process.

This study describes the use of a smartphone for monitoring acid–base titrations on wax printed paper microzones. An array of twelve microzones of 5 mm diameter each was wax printed on filter paper. The analytical performance of the proposed devices was explored with acid–base titrations examples, where jaboticaba peel extract was used as a natural pH indicator. The color intensity was captured using a smartphone and analyzed through a free App named Photometrix®. Before titrations, color intensity versus pH was calibrated to be used as a reference in titrations as (i) strong acid versus strong base; (ii) strong base versus strong acid; and (iii) weak acid versus strong base. In all examples, images were obtained after the addition of each aliquot of titrant solutions. The obtained titration curves showed the same behavior as the conventional titration curves. After evaluating the feasibility of the proposed methodology, the concentration level of acetic acid was obtained in three vinegar samples. Although the obtained values ranged from 5% to 8% compared to the concentrations on the conventional method, the proposed methodology presented high analytical reliability. The calculated concentrations of acetic acid in three samples ranged from 3.87% to 3.93%, and the proposed methodology did not significantly differ from classic acid–base titration at a confidence level of 95%. The acid–base titration on paper-based devices is outstanding, since any titration can be completed within 5 min using 20 µL volumes. Besides, the use of a smartphone to capture images followed by analysis in a free app offers simplicity to all users. The proposed methodology arises as a new strand to be exploited in the diffusion of the analytical chemistry education field as well as an alternative for quantitative analysis with extremely simplified instrumentation.

The aim of this study was to assess the changes in chemical and physical properties of selected paper documents, dating from the 18th century to the present date. Paper documents from the 18th, 19th, and 21st centuries had a pH ranging from slightly acidic to alkaline values, whereas paper documents from the 20th century were more acidic. The contents of mannose, glucose, holocellulose, and lignin were significantly correlated with the pH of the paper. High contents of both carboxylic acids (acetic and formic) and the most durable monosaccharide (glucose) were found in the oldest examined paper documents originating from the 18th and 19th centuries. The lowest percentage of brightness was found in paper documents originating from 1920 and 1923. The lowest breaking length was associated with papers originating from 1920.

The understanding of the migration of mercury from packaging materials to food stuffs is the prerequisite for the development of food safety regulations. In this article, the migration of mercury from food paper-plastic packaging containers to four food stimulants under different migrated temperatures is studied. The results show that the mobility and the maximum migration volume of mercury increase at certain temperatures when the migration time is extended. It is also noted that the time to reach equilibrium is reduced as the temperature increases. Meanwhile, different solvents appear various different while the rates of migration are 3% acetic acid >10% ethanol >20% ethanol >50% ethanol. But they show the same trend at the different temperatures. Our data suggest that different solvents, temperatures, and food stimulants affect the migration rates, and ameliorate those conditions will reduce migration and promote food quality.

Paper making requires raw materials with high cellulose and hemicellulose content. The alternative materials that can be used in the paper making are sugarcane bagasse and banana midrib. The paper production method used in this study is acetosolve which involves acetic acid as an organic solvent. The objectives of this research are to figure out the acetic acid concentration in delignification process and the ratio between sugarcane bagasse and banana midrib that produce pulp with the highest yield, cellulose and kappa number. In this research, there are some variables, the first is the levels of acetic acid concentration in delignification process, which are 70%, 75%, 80%, 85%, 90%, the second is the ratio between sugarcane bagasse and banana midrib, which are 20:0, 18:2, 16:4, 14:6, 12:8, 10:10. The results show that the best pulping conditions are found to be 80% acetic acid concentration with 12:8 (w/w) ratio between sugarcane bagasse and banana midrib, and also 1:20 (w/v) ratio between raw material and solution of acetic acid at two hours cooking duration. The highest yield of pulp in acetosolve process was 63.1%, and its characteristics are 84.67% of cellulose and 10.44 kappa number.

Volatile organic compounds (VOCs) can have a strong effect on cellulose degradation, contributing in decreasing the lifetime expectancy of the paper materials, widely employed in the field of conservation. In this work, we investigated several industrial and homemade Japanese papers, as well as fibers, evaluating VOCs emission by using solid-phase micro extraction coupled with gas chromatography–mass spectrometry (SPME-GC/MS). Acetic acid and 1-butanol were highly detected in industrial and homemade papers rather than fibers, suggesting that the emission of these compounds is influenced by the production process more than by the raw material itself. Conversely, N-N dimethyl formammide was peculiar of industrial processes. Ketones, aldehydes and heavier alcohols were preferentially emitted by fibers and homemade papers. The higher emission of furfural from fibers rather than on papers place new questions about the use of this compound to evaluate the degradation state of the paper material that should be carefully evaluated.

Changes in mechanical and optical properties of the duplicated beeswax-treated and non-treated Hanji volumes during artificial aging were examined, and the VOCs emitted from the samples were analyzed using a GC/MS. In results, the decrease in mechanical and optical properties of the beeswax-treated volume during aging was approximately 2.5 times higher than that of non-treated volume. The quality and quantity of the VOCs emitted from the beeswax-treated volume were also greater than those from the non-treated volume. Especially, the amount of acetic acid from beeswax-treated volume after 90 days of aging was 20 times greater than that of non-treated volume.

Aging of a power transformer&rsquo, s insulation system produces carboxylic acids. These acids&mdash, acetic, formic and levulinic&mdash, are absorbed by the paper insulating material, thus accelerating the degradation of the whole insulation system. In this contribution, the effect of these acids on the aging of oil-impregnated paper insulation used in power transformer is reported. A laboratory aging experiment considering different concentrations of these three acids was performed to assess their effect on the insulation system&rsquo, s degradation. Each acid was individually mixed with virgin oil, and a mixture of acids was also blended with oil. The paper&rsquo, s degradation was assessed by the degree of polymerization (DPv). It was found that the DPv of paper aged with formic acid decreased much faster in comparison to the other acids.

Everyday, tons of food wastes are thrown to the environment constantly by people in the cities, which contain many beneficial substances. One of these beneficial wastes of unknown value is eggshells. Although the eggshells are considered negligible and not valuable material, however, the many researches that dealt with this substance proved its high potential to turn into many useful substances such as a catalyst in biodiesel preparation or as a media for adsorption of heavy metals and dyes or soil fertilizer and others. The current study highlighted the benefit possibility of white chicken eggshells (WCES) from another side, considering it as a raw material for preparing acetone one of the most important industrial solvents. The results obtained showed that this worthless raw material has a high effectiveness for acetone production by containing 94.519% by weight of calcium carbonate. The process of converting WCES to acetone was carried out in two steps, the first one were producing calcium acetate by treating it with glacial acetic acid in a batch mode reaction unit at room temperature and agitation speed, acid % excess and contact time of 200 rpm, 20% and 2 h respectively. Whereas, the next step involved conducting the process of thermal decomposition of the prepared calcium acetate at 380 °C to produce acetone in a stainless steel reactor. The results of testing the samples by the gas chromatography (GC) showed that the maximum yield of acetone is 96.395%. With these experimental results, this study presents a new idea in food waste management as one of the solid waste types by utilizing it in a useful manner to produce important materials in an economical, beneficial and environmentally friendly way, reaching to the concept of zero residue level (ZRL).

A high performance liquid chromatography with fluorescence detection (HPLC-FLD) method was developed for the simultaneous determination of formaldehyde and acetaldehyde in packaging paper by dansylhydrazine (DNSH) derivatization. The samples were extracted by derivatization reagent for 30 min, and derived for 24 h. After purifying treatment with a PSA/C18 cartridge, a Diamonsil® C18 column (150 mm×4.6 mm, 5 μ m) was used as stationary phase for separation, the mixtures of acetic acid aqueous solution (pH 2.55)-acetonitrile were used as mobile phases by gradient elution, and the excitation and emission wavelengths were 330 nm and 484 nm, respectively. The results showed that the recoveries of formaldehyde and acetaldehyde spiked in the samples were 81.64%-106.78%, and the relative standard deviations (RSDs) were 2.02%-5.53% (n=5). The limits of detection of formaldehyde and acetaldehyde were 19.2 μ g/kg and 20.7 μ g/kg, respectively. The limits of quantification of formaldehyde and acetaldehyde were 63.9 μ g/kg and 69.1 μ g/kg, respectively. The method is simple, sensitive and reproducible. It provides a basic approach for the determination of trace formaldehyde and acetaldehyde.

Paper chromatography (PC) is a highly flexible, fast, and efficient separation method. In this study, a chromatographic paper with a chiral separation function was investigated and a paper chromatographic method for chiral separation was developed. Single-factor experiments and orthogonal tests were used to determine the optimal oxidation conditions for filter paper. The optimal conditions were that sodium periodate 4% (mass percentage), pH 2 buffer solution, reaction temperature 45℃, and reaction time 4 h. Under the optimal conditions, the aldehyde group content of a dialdehyde-based filter paper was 57.93% (amount of substance percentage). A paper-based chiral separation material was synthesized by a microwave-assisted Schiff-base reaction of the oxidized filter paper with L-glutamic acid. The developing solvent for separating racemic tartaric acid using this chiral filter paper consisted of 100 mL of n-butanol, 50 mL of 50%(v/v) acetic acid, and 0.1000 g of bromophenol blue. The rate of flow (Rf) values of L-tartaric acid and D-tartaric acid were 0.52 and 0.40, respectively. This method does not require large-scale equipment to perform the chiral separation and it is therefore suitable for general teaching, research, and industrial applications.

The microbial conversion of pentoses to ethanol is one of the major drawbacks that limits the complete use of lignocellulosic sugars. In this study, we compared the yeast species Spathaspora arborariae, Spathaspora passalidarum, and Sheffersomyces stipitis regarding their potential use for xylose fermentation. Herein, we evaluated the effects of xylose concentration, presence of glucose, and temperature on ethanol production. The inhibitory effects of furfural, hydroxymethylfurfural (HMF), acetic acid, and ethanol were also determined. The highest ethanol yield (0.44 g/g) and productivity (1.02 g/L.h) were obtained using Sp. passalidarum grown in 100 g/L xylose at 32 °C. The rate of xylose consumption was reduced in the presence of glucose for the species tested. Hydroxymethylfurfural did not inhibit the growth of yeasts, whereas furfural extended their lag phase. Acetic acid inhibited the growth and fermentation of all yeasts. Furthermore, we showed that these xylose-fermenting yeasts do not produce ethanol concentrations greater than 4% (v/v), probably due to the inhibitory effects of ethanol on yeast physiology. Our data confirm that among the studied yeasts, Sp. passalidarum is the most promising for xylose fermentation, and the low tolerance to ethanol is an important aspect to be improved to increase its performance for second-generation (2G) ethanol production. Our molecular data showed that this yeast failed to induce the expression of some classical genes involved in ethanol tolerance. These findings suggest that Sp. passalidarum may have not activated a proper response to the stress, impacting its ability to overcome the negative effects of ethanol on the cells. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-022-00693-6.

Biomass, as renewable energy source, is of importance to investigate to extend the conversion yield by microorganism. Because of lignocellulosic structure, biomass must be pretreated with a process, frequently inorganic acid has to be used with a problem of hazardous byproducts. Organic acid pretreatment is an efficient alternative to be investigated. Sugar beet pulp, as an agro-industrial residue of microorganism, can be utilized by pretreatment, which is usually a costly process. Pretreatment with organic acids creates a great opportunity to convert the process into more economic and effective. Moreover, pressure conditions significantly increase the yield of biodegradable sugar content. In this study, different organic acids of maleic, fumaric, oxalic, and acetic acid pretreatment was investigated to pretreatment of sugar beet pulp, which came vast amount from factories, under pressure and non-pressure conditions via Box–Behnken method to estimate optimum point of acid ratio (1, 3, 5%), time (10, 27.5, 45 min), and solid ratio factors (3, 6.5, 10%) for highest degradation. Results were also evaluated economically. As a result of the experiments, it was observed that acetic acid gave the best result with 409.16 g/L total sugar concentration than the other organic acids. The highest TS concentration of maleic, oxalic, and fumaric acid were 97.26, 97.85, and 91.37 g/L, respectively, under pressure. According to economical evaluation, owing to lower market price and highest TS formation yield, pretreatment cost of acetic acid pretreatment was found averagely 1.51 $/gTS under pressure conditions. Supplementary Information The online version contains supplementary material available at 10.1007/s10163-021-01276-7.

Paper production has been identified with industries that destroy forests (deforestation). Utilizing alternative wood substitute raw materials, such as pineapple leaves can be one solution to the problem. Pineapple plants can produce more than 70 leaves with cellulose content in the leaves which reaches 69.5-71.5%, so it has the potential to be used as raw material for paper. The organosolv process was chosen as a pulp manufacturing process because it produces high purity in the byproducts (lignin and hemicellulose), high pulp yield, easy recovery of black liquor and no sulfur element, making it safer for the environment. This study aims to determine the most influential factors in the organosolv pulping process with a factorial experimental design method 23. Variables used include solvent types (ethanol and acetic acid), pulp cooking time (60 minutes and 110 minutes) and types of leaf dryness (wet leaves) and dried leaves). From the results of the analysis, the most influential factor in the organosolv pulping process is the type of solvent (ethanol). Optimal operating conditions were obtained for solvent ethanol, cooking time of 60 minutes with wet leaves, where cellulose content was 96.31% and lignin content decreased by 17.80% in dry pulp.

This study designed to optimize the operating parameters of the Fenton process in removing acetic acid from food processing using Response Surface Methodology module in the Design of Expert for sustainable water reuse. Optimum operating conditions needed for the highest removal efficiency of 95.2% and 84.7% for color and chemical oxygen demand respectively were found to be at hydrogen peroxide concentration of 0.004 mol/L, ferrous iron concentration of 0.02 mol/L, initial pH of 3.45, and reaction time of 149.08 min for color. While, chemical oxygen demand had a maximum of around 84.7% removal efficiency that could be obtained at a hydrogen peroxide concentration of 0.014 mol/L, ferrous iron concentration of 0.051 mol/L, initial pH of 2.04, and reaction time of 144.58 min. The results showed that the Fenton process via Response Surface Methodology, at a certain level, may be used as a useful technology for pre- and post-treatment of wastewater from food processing for water scarcity as reclaimed water.

Cellulose acetate CA was produced from paper wastes by acetylation reactions with glacial acetic acid, concentrated H 2 SO 4 , and acetic anhydride. The degree of substitution (DS) values can be controlled by the acetylation time leading to biodegradable cellulose derivatives, which a necessary characteristic is considering environmental and economic aspects. Different acetylation times were analyzed in this work, to study the variation in the quality and degree of substitution (DS) of the cellulose acetate produced. Characterization by using H-NMR, 13C-NMR spectroscopy, X-Ray and SEM revealed a high degree of substitution (DS). The purity of CA is shown by solubility test.

Acetic acid acidolysis had so far been performed as a green technology to produce high value-added xylo-oligosaccharide from lignocellulosic residues while around 30% inert xylan-constitute is still retained. For improving economic and environmental benefits, a cascade temperature-arising technical strategy was designed and developed for the co-production of xylo-oligosaccharide and enzymatic-hydrolyzed glucose by a continuous two-step acidolysis mode with the recyclable acetic acid catalyst. The combined process was optimized by uniform design experiments and temperature plays the key factor for xylo-oligosaccharide yield and xylose-chemicals degradation. We obtained respectively 63.41% and 61.44% xylo-oligosaccharide yield from corncob and wheat straw during continuous two-step acidolysis with acetic acid recycling operation at 140 °C and 190 °C, which increased by 52.03% and 76.55% than the one-step process. Meanwhile, the corresponding enzymatic hydrolysis yield was increased to 100% and 98.2%. In short, the two-step cascade temperature-rising acidolysis technology can maximize the utilization of hemicellulose and cellulose constitutes and fully explore the value-added utilization of lignocellulosic biomass. The cascade temperature-arising technical strategy does therefore demonstrate something for the more efficient and green utilization of lignocellulosic biomass.

Graphic abstract Three diazoles namely 5-methyl-1,3,4-oxadiazole -2(3H)-thione, 5-methyl-1,3,4-thiadiazol-2(3H)-thione and 4-amino-5-methyl-2H-1,2,4-triazole-3-thiol were synthesized from acetic acid or ethyl acetate. Seco-acyclo-N-nucleoside analogous was synthesized by condensation of 1,3-benzylidine-glyceryl-2-tosylate with the three diazoles. Structural proof was based upon IR, 1H-NMR, 13C-NMR spectroscopy and MS measurements. The tendency to form complex between 1,3,4-oxadiazole and 1,3,4-thiadiazoles and Pb(II) and Hg(II) ions was achieved, and their structures were assigned by observing some changes in physical properties such as, MP, coloration, Rf (TLC), IR and UV spectroscopy. Most compounds were tested in vitro against Gram-positive and Gram-negative bacteria and showed variable activity. Hg2+ complexes of oxadiazole and thiadiazole derivatives exhibited appreciable antibacterial effect at lower MIC, compatible to the reference vancomycin. Similarly, oxadiazole-nucleoside exhibited high effect on Gram-positive bacteria. Supplementary Information The online version contains supplementary material available at 10.1007/s13738-021-02358-x.

Urgency of the research. Expansion of the raw material base of the pulp and paper industry of Ukraine takes place through the use of alternative types of vegetable raw materials, namely wheat straw, and the improvement of environmentally friendly oxidative-organosolvent technology for the production of straw pulp. Target setting. Methods for the delignification of vegetable raw materials using the oxidant – hydrogen peroxide – are currently available. The disadvantage of these methods is the high consumption of the oxidant, which constitutes 90 % by weight of absolutely dry raw material that significantly increases the cost of technical cellulose. Therefore, it is necessary to improve the technological parameters of the delignification process of wheat straw with hydrogen peroxide in acetic acid. Actual scientific researches and issues analysis. Recent open-access publications have been reviewed, including literature on oxidative-organosolvent delignification methods of plant material using peroxoacids. Uninvestigated parts of general matters defining. Investigation of technological parameters of oxidative-organosolvent delignification for the reduction of oxidant consumption and determination of optimal values of temperature and duration of the delignification process of wheat straw with the mixture of hydrogen peroxide in acetic acid. The research objective. Investigation of straw pulp production method in order to reduce the consumption of cooking reagents while increasing the physical- mechanical properties and yield of the target product. The statement of basic materials. A method of obtaining straw pulp from wheat straw shreddings in acetic acid media with the hydrogen peroxide consumption 50 % by weight of absolutely dry raw material was investigated. The content of the main components in the raw vegetable material was determined. The effect of the delignification conditions, namely the temperature and cooking duration, on the yield of the fibrous semi-finished product, the content of residual lignin and the content of cellulose was studied. It was shown that the increase of temperature from 70 °C to 90 °C and duration of vegetable raw materials processing from 60 to 180 min lead to the decrease in yield by 28 %, the content of residual lignin by 6.5 %, while the cellulose content in the fibrous semi-finished product increased by 21 %. Calculated regression equations adequately described the experimental data and could be used as a mathematical model of the delignification process of wheat straw by hydrogen peroxide in acetic acid media. Optimal values of technological parameters of the wheat straw cooking process were determined using the method of multicriterion optimization of the delignification conditions. Conclusions. Calculated regression equations adequately described the production process of straw cellulose by hydrogen peroxide delignification in acetic acid. Established optimal technological parameters provided obtaining a final product with high quality indicators (yield 78.2%, residual lignin content 3.6%, cellulose content 65.4%, breaking length – 6200 m, punching resistance 210 kPa, tearing resistance – 425 mN, folding endurance 625 n.d.b.).

This study investigated the continuous biohydrogen production in an anaerobic inner cycle biohydrogen production (AICHP) reactor fed with synthetic molasses wastewater as the model substrate under mesophilic conditions (37 ± 1 °C). The hydraulic retention times (HRTs) were set as 6.12, 4.90, 4.08, 3.50, and 3.06 h. Both maximum hydrogen production rate (HPR) (8.08 ± 0.48 L/L/d) and maximum granule formation were achieved at the HRT of 3.50 h. Acetic acid and butyric acid were the dominant metabolites in all tested HRTs throughout the experiment. Microbial community analysis showed that shortening the HRT promoted hydrogen production. This was mainly achieved by enhancing the growth of acetogenic bacteria in the AICHP reactor, rather than the growth of hydrogen-producing bacteria.

Green roofs are a key measure used to alleviate the urban heat island effect and reduce stagnant water from urban runoff. However, the expensive substrate material and high construction cost restrict the large-scale application of green roofs. Wheat straw (WS) contains abundant nutrients needed for plant growth; however, burning this straw waste causes severe environmental pollution. In this study, six pretreatment methods, including mixed, soaked, hydrothermal, ultrasonic, microwave, and steam explosion, and three liquid media, including deionized water, acetic acid, and wood vinegar, were used to treat WS to improve its properties and decrease its environmental pollution effects. The results showed that, compared to other treatments, physical methods (microwave, ultrasonic) used in conjunction with wood vinegar could effectively break down the particle structure of WS and increase porosity. Most of the crystallinities were reduced by 1.45–6.66% compared to WS when using these methods, and the absolute values of the surface zeta potential were reduced by 4.224.67 mV. Additionally, the contents of macromolecular lignocellulose, which is difficult to decompose, were reduced by 3.6613.75%. Compared with the use of deionized water or acetic acid, wood vinegar reduced the compressive force of the WS substrates and the energy consumption of compression. Hydrophilic groups such as hydroxyl were introduced into the WS to increase the water absorption rate. Overall, the microwave-assisted wood vinegar pretreatment was an effective method for improving the WS properties for use as a potential alternative substrate material in green roof construction.

Prevention of struvite formation at wastewater treatment plants (WWTPs) is currently possible using several approaches. However, failure of these measures and subsequent spontaneous struvite formation may lead to serious operational problems. A similar problem occurred at a municipal WWTP with enhanced phosphorus removal and anaerobic sludge digestion, where spontaneous struvite precipitation caused clogging of the pipes with digested sludge. For direct struvite dissolution in the sludge pipes, organic and inorganic acidic solutions were investigated. It was shown that using solutions of pH

This paper reports the synthesis, analgesic activity, acute toxicity and histopathological (HP) assessment of four new compounds from oxazol-5(4H)-ones class that contain in their molecule a diarylsulfone moiety. The new 2-(4-(4-bromophenylsulfonyl)phenyl)-4-arylidene-oxazol-5(4H)-ones were obtained by reaction of 2-(4-(4-bromophenyl-sulfonyl)benzamido)acetic acid intermediate with aromatic aldehydes (benzaldehyde, 4-methoxy, 4-nitro or 4-bromobenzaldehyde), in acetic anhydride and in the presence of anhydrous sodium acetate. The new compounds have been characterized by spectral techniques, such as: Fourier-transform infrared spectroscopy (FT-IR), mass spectrometry (MS), proton nuclear magnetic resonance (1H-NMR) and by elemental analysis. The acute toxicity of the new oxazol-5(4H)-ones in mice was assessed through "acute toxic class" method, according to Organization for Economic Co-operation and Development (OECD) Guidelines. The HP assessment of some preserved organs collected from mice has been performed. The analgesic activity of all new synthesized compounds was carried out with two pharmacological tests: the writhing test and the hot plate test. In order to predict the binding affinities of the synthesized oxazol-5(4H)-ones derivatives against molecular targets involved in pain and inflammation, molecular docking simulations were performed. The results of the writhing test indicated that the most active compound was the oxazolone that contains in the molecule a methoxy group. The acute oral toxicity study revealed no lethal effect of new compounds. The HP assessment of the preserved organs collected from mice did not indicate any cytohistopathological aspects that can be linked to any inflammatory, neoplastic or cytotoxic process, demonstrating the low toxicity of new compounds.

Extensive utilization of the synthetic dyes in various industries is leading to water and soil contamination and ultimately impacting the humans. A research study was conducted for investigating the biodecolorization and biotransformation of Mordant Black 11 dye. For this purpose, potential of biofilm forming bacteria Klebsiella pneumoniae MB398 isolated from effluent outlets of Tops Food Industry, Hattar, Pakistan, was assessed to decolorize and transform Mordant Black 11 dye. Bacterial strain MB398 exhibited the capability of growing optimally at acidic pH (pH 6.0). Klebsiella pneumoniae MB398 efficiently decolorized Mordant Black 11 dye (64.55%) in aerobic environment at pH 6.0 and 37 °C over 24 h, which further increased to 75.35% over a period of 72 h of incubation. Strain MB398 also exhibited the capability of decolorizing Mordant Black 11 dye in the presence of cadmium (63.71%), chromium (61.78%), and copper (61.50%), respectively. UV-VIS spectrophotometric analysis, FTIR, and HPLC spectra were also indicative of biotransformation of dye molecules by Klebsiella pneumoniae MB398. GC-MS analysis of Mordant Black 11 dye revealed formation of 9 novel and unique metabolites including phenol,2,4-bis(1,1-dimethylethyl); 9-eicosene, (E); ethanol,2,2-(2-propenyloxy); acetic acid, benzene; 1-naphthol; methyl formate; valeraldehyde,2,4-dimethyl; and 7-hexadecene (Z). A possible metabolic pathway depicting the biotransformation of Mordant Black 11 dye by Klebsiella pneumoniae MB398 was projected. Findings of the current research study strongly suggest application of Klebsiella pneumoniae MB398 for developing large scale bioremediation strategies for the abatement of synthetic dyes to retain environmental sustainability in bioeconomic way. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-021-00470-x.

The massive consumption of fossil energy forces people to find new sources of energy. Syngas fermentation has become a hot research field as its high potential in renewable energy production and sustainable development. In this study, trophic anaerobic acetogen Morella thermoacetica was successfully immobilized by calcium alginate embedding method. The ability of the immobilized cells on production of acetic acid through syngas fermentation was compared in both airlift and bubble column bioreactors. The bubble column bioreactor was selected as the better type of bioreactor. The production of acetic acid reached 32.3 g·L−1 in bubble column bioreactor with a space–time yield of 2.13 g·L−1·d−1. The immobilized acetogen could be efficiently reused without significant lag period, even if exposed to air for a short time. A semi-continuous syngas fermentation was performed using immobilized cells, with an average space–time acetic acid yield of 3.20 g·L−1·d−1. After 30 days of fermentation, no significant decrease of the acetic acid production rate was observed.

Research background. Despite the great properties of bacterial cellulose, its manufacture is still limited due to difficulties in large-scale production. These problems are mainly related to low production yields and high overall costs of the conventional culture media normally used. To surpass these problems, it is necessary to identify new cheap and sustainable carbon sources. Thus, this work aims to isolate and select a high cellulose-producing Komagataeibacter strain from vinegar industry, and study its potential for bacterial cellulose synthesis in an industrial soybean co-product, known as soybean molasses, used as fermentation medium. Experimental approach. One isolated strain was able to produce high amount of cellulose in the standard Hestrin-Schramm medium, so we tested its ability to produce this biopolymer in a soybean molasses medium. The characteristics and properties of the produced bacterial cellulose membranes were analyzed by thermogravimetric analysis, X-ray diffraction, infrared spectroscopy, water-holding capacity and rehydration ratio. Genetic analysis of the selected strain served to determine its genus and species. Results and conclusions. An isolated strain that produced the highest amount of cellulose in Hestrin-Schramm medium (3.7 g/L) was genetically identified as Komagataeibacter intermedius V-05. This strain produced 10.0 g/L of cellulose in soybean molasses medium. Membranes from both substrates had similar chemical structure, crystallinity and thermal degradation. Soybean molasses proved to be a suitable alternative medium for biosynthesis of cellulose in comparison with the standard medium. In addition to providing higher production yield, the membranes showed great structural characteristics, similar to those obtained from standard medium. Novelty and scientific contribution. In this research, we have isolated and identified a Komagataeibacter strain which exhibits a high capacity for cellulose production in soybean molasses. The isolation and selection of strains with high capacity for microbial metabolite production is important for decreasing bioprocess costs. Furthermore, as there is a necessity today to find cheaper carbon sources to obtain microbial products at a lower cost, soybean molasses represents an interesting alternative medium to produce bacterial cellulose for its industrial application., Pozadina istraživanja. Usprkos izvrsnim svojstvima bakterijske celuloze, njezina je proizvodnja još uvijek ograničena zbog poteškoća u provođenju proizvodnje na veliko, uglavnom zbog niskog prinosa i visokih troškova uzgoja u uobičajeno korištenim podlogama. Da bi se ti problemi zaobišli, potrebno je pronaći nove jeftine i održive izvore ugljika. Stoga je svrha ovoga rada bila tijekom postupka proizvodnje octa izolirati i odabrati soj bakterije Komagataeibacter koji može proizvesti velike količine celuloze, te ispitati njegovu sposobnost sinteze bakterijske celuloze u podlozi od sojine melase, jednom od nusproizvoda industrijskog uzgoja soje. Eksperimentalni pristup. Jedan je od izoliranih sojeva proizveo veliku količinu celuloze u standardnoj Hestrin-Schramm podlozi, pa smo ispitali može li proizvesti taj biopolimer i u podlozi od sojine melase. Glavne značajke i svojstva dobivene bakterijske celuloze ispitane su termogravimetrijskom analizom, rentgenskom difrakcijom, infracrvenom spektroskopijom, te mjerenjem sposobnosti vezanja vode i stupnja rehidracije. Genetičkom su analizom određeni rod i vrsta izoliranog soja bakterije. Rezultati i zaključci. Soj bakterije koji je proizveo najviše celuloze u Hestrin-Schramm podlozi (3,7 g/L) genetičkom je analizom identificiran kao Komagataeibacter intermedius V-05. U podlozi sa sojinom melasom taj je soj proizveo 10,0 g/L celuloze. Celulozne membrane dobivene uzgojem bakterije u obje podloge imale su sličnu kemijsku strukturu, podjednako svojstvo kristaliničnosti i sličnu toplinsku stabilnost. Sojina melasa pokazala se kao dobra alternativna standardnoj podlozi za biosintezu celuloze. Osim što je pomoću nje dobiven veći prinos celuloze, struktura dobivenih membrana bila je izuzetno dobra, slična membranama dobivenim uzgojem u standardnoj podlozi. Novina i znanstveni doprinos. U ovom smo radu izolirali i identificirali soj bakterije Komagataeibacter koji može uspješno proizvesti celulozu u podlozi od sojine melase. Izolacija i odabir sojeva koji mogu proizvesti velike količine mikrobnih metabolita vrlo su važni za smanjenje troškova bioprocesa. Uz to, budući da je u današnje vrijeme neophodno pronaći ekonomičnije izvore ugljika za jeftiniju proizvodnju mikrobnih proizvoda, sojina melasa predstavlja zanimljivu alternativu uobičajenoj podlozi za industrijsku proizvodnju bakterijske celuloze.

In the present work, the biomass known as the malt bagasse, a by-product of the brewing industry, was studied as a biosorbent of acetic acid, in order to evaluate its potential use as an ion exchanger in effluent treatment systems. The process is based on the phenomenon of biosorption, an interface phenomenon, which is the natural accumulation of a solute on the surface of a solid. The studied phenomenon is that of acetic acid adsorption in malt bagasse biomass. In the present work, the influence test of the biomass quantity was carried out, and it was verified that 40 g/L is the ideal concentration of malt bagasse in the acetic acid adsorption process. A kinetic study was also carried out, where a contact time of 20 minutes was defined to reach the balance between the solid/liquid phase. In the identification of the pseudo-second order kinetic model, it was the one that best fitted the experimental data, and based on the intra-particle diffusion model, it was found that more than one step comprises the biosorption mechanism, with intra-particle diffusion being limiting step. Based on this information, the chemical equilibrium test of the solid/liquid phase was performed using the mathematical models of Langmuir and Freundlich, thus presenting, for the malt bagasse, a maximum acetic acid adsorption capacity of approximately 30 mg/g. Where experimental data best fit the Langmuir isotherm. The results show a significant potential for the malt bagasse to remove organic acid in effluents.

Microtubule dynamics are crucial for multiple cell functions, and cancer cells are particularly sensitive to microtubule-modulating agents. Here, we describe the design and synthesis of a series of (Z)-2-(5-benzylidene-4-oxo-2-thioxothiazolidin-3-yl)-N-phenylacetamide derivatives and evaluation of their microtubule-modulating and anticancer activities in vitro. Proliferation assays identified I20 as the most potent of the antiproliferative compounds, with 50% inhibitory concentrations ranging from 7.0 to 20.3 µM with A549, PC-3, and HepG2 human cancer cell lines. Compound I20 also disrupted cancer A549 cell migration in a concentration-dependent manner. Immunofluorescence microscopy, transmission electron microscopy, and tubulin polymerisation assays suggested that compound I20 promoted protofilament assembly. In support of this possibility, computational docking studies revealed a strong interaction between compound I20 and tubulin Arg β369, which is also the binding site for the anticancer drug Taxol. Our results suggest that (Z)-2-(5-benzylidene-4-oxo-2-thioxothiazolidin-3-yl)-N-phenylacetamide derivatives could have utility for the development of microtubule-stabilising therapeutic agents., Graphical abstract

The objective of the present study was to evaluate the influence of the carbon/phosphorus (C/P) ratio (300–1100) on hydrogen production and the control of homoacetogenesis in four anaerobic fluidized bed reactors with fixed carbon/nitrogen ratios of 100, 150, 200, and 250. The reactors were fed glucose (5000 mg L−1) at the hydraulic retention time (HRT) of 8 h. Low production of acetic acid attributed to homoacetogenesis was observed in all reactors (

The pyrolysis of coffee husks and coffee parchment at 350 and 500°C was considered as the first stage of gasification by the two-stage thermal conversion of biomass into synthesis gas. The yields and compositions of pyrolysis products at the selected temperatures were determined. It was found that a significant amount of acetic acid was formed in the aqueous phase of the pyrogenic liquid to significantly complicate the use of an aqueous layer for the subsequent gasification. The possibility of practical implementation of the pyrolysis of waste coffee products as an independent process or the first stage of conversion into synthesis gas was noted.

International audience; Anaerobic digestion allows renewable energy to be produced through the degradation of bio-waste. The process, which is of economic and ecological interest, is implemented industrially in concrete digesters. Bio-waste is a complex medium with a composition that can vary in time and space. It contains several chemical compounds, including volatile fatty acids, ammonium, and CO2, which are aggressive towards concrete and compromise its durability. The individual effects of the different compounds on concrete are significantly different. To move toward a better design of concrete intended for the building of biogas digesters, this paper aims to understand the mechanisms and intensity of alteration associated with the different components of biowaste and their contribution to the total deterioration. Ordinary Portland cement pastes were immersed for 16 weeks in six synthetic solutions made of the three metabolites, taken alone or in mixes. The mass variations of the specimens, the pH, and the concentration of the chemical elements in solution were monitored over time. The microstructural, chemical and mineralogical changes of the samples were analysed by scanning electron microscopy, electron probe micro-analysis and X-Ray diffraction analyses and showed phenomena of dissolution, leaching and carbonation. The results show that the acetic acid solution was the most aggressive, in accordance with its pH value, and had a predominant effect in mixed solutions, whereas sodium bicarbonate solution induced carbonation and showed a protective effect. Interestingly, despite its reputed high aggressiveness, ammonium nitrate did not have a major impact in mixed solutions.

Based on a 19th century method, the process known as mordançage has been used to dramatically alter black and white photographs since the 1960s. Mordançage subjects a fully developed photograph to a series of wet chemical reactions, beginning with an acidic copper(II) chloride and hydrogen peroxide bleaching solution. Different types of photographic paper, time in mordançage solution, and the concentration of hydrogen peroxide, copper(II) chloride, and acetic acid are all variables that influence the degree of emulsion lift and corresponding veils observed. We conducted experiments to explore these variables and analyzed processed prints using ImageJ to measure changes in pixel intensity and SEM-EDS for compositional analysis. Fiber-based and cotton rag papers resulted in more emulsion lift than resin-coated paper, and increased time in the mordançage solution had similar results. Quantitative analysis of the bleaching solution reveals how the process variables affect the formation of veils, and a process scheme is presented. This work provides insight into the chemical transformations involved in this artistic process.

In the present study, Ginkgo biloba leaves were extracted with methanol 80% and fractionated by sequential extraction with petroleum ether (Fr-l), ethyl ether (Fr-II) and ethyl acetate (Fr-III) separately. Fraction III was co-chromatographed after hydrolyzed with 7% sulphuric acid with 3 solvent systems. Paper chromatography on Whatman cellulose chromatography papers 3 CHR with benzene, acetic acid and water (125: 72: 3) as mobile phase enabled good separation of quercetin at 0.6 RF and kaempferol at 0.78 RF. In the present study, quercetin and kaempferol were isolated from Ginkgo biloba leaves grown in Egypt and characterized by various spectral studies. The ethanolic extract of Ginkgo biloba leaves was subjected to high-performance liquid chromatography analysis for the identification of major phenolics and flavonoids. Eleven components were detected. Most flavonoids in Ginkgo biloba leaves are the derivatives of quercetin, and kaempferol. The results were obtained from UV and FTIR indicated for the molecular structure of quercetin and kaempferol. The mass spectrum of kaempferol and quercetin was observed at m/z 286.8 and 302.9, respectively. The results of the present study established the presence of biologically active phytochemicals in the Ginkgo biloba leaves. The results also suggested that the Ginkgo biloba leaves extract contain significant amounts of quercetin and kaempferol. Thus, it may be concluded that the Ginkgo biloba leaves have great potential for producing healthy and highly nutritive products.

The decomposition of lignocellulose in nature, as well as when used as feedstock in industrial settings, takes place in a dynamic system of biotic and abiotic reactions. In the present study, the impact of abiotic reactions during the storage of pretreated lignocellulose on the efficiency of subsequent saccharification was investigated. Abiotic decarboxylation was higher in steam-pretreated wheat straw (SWS, up till 1.5% CO2) than in dilute-acid-catalysed steam-pretreated forestry residue (SFR, up till 3.2% CO2) which could be due to higher iron content in SFR and there was no significant CO2 production in warm-water-washed slurries. Unwashed slurries rapidly consumed O2 during incubation at 50 °C; the behaviour was more dependent on storage conditions in case of SWS than SFR slurries. There was a pH drop in the slurries which did not correlate with acetic acid release. Storage of SWS under aerobic conditions led to oxidation of the substrate and reduced the extent of enzymatic saccharification by Cellic® CTec3. Catalase had no effect on the fractional conversion of the aerobically stored substrate, suggesting that the lower fractional conversion was due to reduced activity of the lytic polysaccharide monooxygenase component during saccharification. The fractional conversion of SFR was low in all cases, and cellulose hydrolysis ceased before the first sampling point. This was possibly due to excessive pretreatment of the forest residues. The conditions at which pretreated lignocellulose are stored after pretreatment significantly influenced the extent and kind of abiotic reactions that take place during storage. This in turn influenced the efficiency of subsequent saccharification. Pretreated substrates for laboratory testing must, therefore, be stored in a manner that minimizes abiotic oxidation to ensure that the properties of the substrate resemble those in an industrial setting, where pretreated lignocellulose is fed almost directly into the saccharification vessel.

The objective of this study was to examine the effect of supplementing goat diets with avocado pulp and oil, with respective ether extract (EE) contents of 14 and 6% (dry matter [DM] basis), on the intakes of DM and nutrients and on the rumen fermentation parameters of pH, ammonia (N-NH3), and volatile fatty acids (VFA). Non-pregnant, non-lactating, rumen-cannulated Saanen goats with an average weight of 66.6±4.6 kg were distributed into two 3 × 3 Latin squares. Concentrate DM intake (g/day) was higher in the animals that consumed the diet with pulp than in the goats fed the control and oil treatments. However, this higher concentrate intake was not sufficient to influence total diet DM intake or the intakes of crude protein, EE, mineral matter, neutral detergent fiber, acid detergent fiber, and total digestible nutrients (TDN). All evaluated rumen parameters were influenced by collection time, except N-NH3, which was influenced by the diets, with lower concentrations obtained with the pulp diet in relation to the control and oil treatments, yet within the limits considered normal to maximize DM intake and digestion. The pulp diet provided a lower butyric acid content than control at the collection times of two and eight hours after the meal, which was attributed to the proportional reduction of roughage in relation to concentrate. Diets with 6% EE do not influence intake or rumen parameters in non-pregnant, non-lactating goats. However, diets with 14% EE (DM basis) induce a reduction in the proportional intake of roughage in relation to concentrate and in the butyric acid and N-NH3 contents in the goat rumen.