Chemical Pretreatment Methods Research Articles

Effects of chemical pre-treatment methods combined with electron beam irradiation on the quality of “Edor” longan

Using electron beam (EB) radiation as a quarantine treatment when exporting fresh fruit is a development trend in the world. In this study, the effect of EB irradiation treatment in the quarantine dose (400 to 1000 Gy) on the quality of export "Edor" longan was investigated. Investigation of chemical pre - treatments measure combined with EB irradiation to decrease pericarp browning of longan has also been carried out. “Edor” longan were treated by SO2 fumigation or dipping in 1,5 N HCl solution for 20 min after EB irradiation at low quarantine dose (400 Gy). Untreated and non-irradiated fruits were used as control. That all were then stored assumed commercial conditions (25-26°C). The results showed that the treated samples delayed a decrease in the total phenolic content and had lower pericarp browning than control. In addition, the treated samples were no significantly difference in terms of weight loss, TSS, total acid content, vitamin C, ... compared with the control. In particular, the treated samples had delayed the degree of damage level due to rotting when extending shelf life up to 22 days compared the control (12 days). Therefore, the method of combining SO2 fumigation treatment with EB irradiation (400 Gy) can be used for quarantine treatment of export "Edor" longan; and treatment with 1,5 N HCl solution can be considered to replace the traditional SO2 fumigation method.

Phosphogypsum-based building materials: Resource utilization, development, and limitation

Phosphogypsum (PG) is a major industrial waste emitted during phosphate production. Facing the environmentally risky challenges posed by PG emissions and stockpiles, a review of the state of PG resource utilization in civil engineering and searching for new ways to utilize PG to improve the utilization rate are necessary. Therefore, this paper compared the chemical composition and pretreatment methods of PG from different sources and outlined the application of PG-based building materials, including gypsum products, cement-based materials, and road materials. It was found that there are differences in the chemical composition and physical properties of PG due to differences in phosphate mines and production processes, which affected the way it was pretreated and applied. Currently, thermal treatment and synergistic treatment by various means are effective methods for cleaning PG, and future treatment processes should be developed to highly efficient, and low cost. PG-based building materials positively contribute to recovering PG and promoting resource recycling, but environmental safety and long-term stability need to be explored. In addition, the importance, limitations, and development trends of applying PG-based building materials were discussed. Future research focuses on solid waste-based cementitious and mineralized materials to inform harmless, high-value and large-scale utilization of PG.

Investigating chemical pre-treatment methods: Valorization of wheat straw to enhance polyhydroxyalkanoate (PHA) production with novel isolate Bacillus paranthracis RSKS-3

Wheat is a crucial food crop worldwide, generating straw upon post-harvest. The straw is often burned to enhance soil fertility, leading to massive air pollution. In this study, wheat straw was investigated for the production of Polyhydroxyalkanoate (PHA) using the novel isolate Bacillus paranthracis RSKS-3. The wheat straw was pulverized and valorized with different acids (2 % and 4 % H2SO4, acetic acid, and hydrochloric acid) and alkalis (2 % and 4 % NaOH, calcium carbonate, and potassium hydroxide). The validation of carbohydrates was done using the Molisch test by analyzing purple-ring production and the DNS test which concluded 4 % H2SO4 as an effective treatment with a maximal sugar yield of 5.04 mg/mL at P < 0.05. The bioconversion efficiency of the extract to PHA resulted in 0.87 g/L by Bacillus paranthracis RSKS-3, later characterized by Ultraviolet (UV)-spectroscopy and FT-IR assessment. The findings of the research offer a potential strategy to mitigate airborne pollutants that result from smouldering wheat straw, thereby contributing significant improvements to sustainable development.

Effect of Pretreatment and Drying on the Nutritional and Functional Quality of Raisins Produced with Seedless Purple Grapes.

Raisins, known for their delicious taste and high nutritional value, are among the most widely consumed dried fruits globally. The natural waxy layer on the surface of grapes impedes water migration, making pretreatment necessary before drying. This study evaluated the effects of various pretreatment methods on the nutritional and functional quality of seedless purple raisins. By using non-pretreated dry seedless purple raisins as a control, the impact of physical and chemical pretreatment methods on the nutritional and functional qualities of seedless purple raisins was assessed through the analysis of nutrient content, phenolic compounds, and antioxidant activity. Our results demonstrate that physical pretreatment significantly increases the levels of vitamin C, fructose, glucose, total acid, total phenolics, total flavonoids, total anthocyanins, and antioxidant activity compared to chemical pretreatment and the control group. The correlation analysis revealed that phenolic substances were closely linked to antioxidant capacity. Additionally, phenolic compounds, including resveratrol, ferulic acid, chlorogenic acid, ethyl coumarate, and cinnamic acid, were more abundant following physical pretreatment. The OPLS-DA model effectively differentiated the three groups of processed samples, showing that different pretreatments significantly affect the nutritional and functional quality of seedless purple raisins. These findings suggest that physical pretreatment offers considerable potential for improving the drying quality of seedless purple raisins.

A Study on the Potentiality of Bioethanol Production from Selected Weed Species of the Asteraceae Family

&#x0D; &#x0D; &#x0D; Increasing population growth, industrialization, and the harmful impacts of fossil fuel burning on the environment fascinated the researchers to find a low-cost, environmentally friendly alternative substitute. A potential substitute feedstock for the synthesis of second-generation bioethanol is the lignocellulosic biomass from invasive weedy plants. The aim of this study was to determine the potential of bioethanol production from two weedy plant species using physical, chemical, and physiochemical pretreatment methods, as well as to optimize the pretreatment and culture conditions to obtain a higher reducing sugar amount and ethanol yield. The collected invasive weedy plants, Chromolaena odorata and Tridax procumbens, were cleaned, then pretreated with different acids and bases (4% v/v) at 121oC for 15 min. Then the filtrate was incubated with Saccharomyces cerevisiae (baker‘s yeast) in the peptone yeast extract and nutrient medium (PYN) at room temperature, the pH was maintained at 5.0. T. procumbens plant substrate with the performic acid pretreatment agent produced a significant amount (0.2%) of ethanol, and further studies were conducted with the same substrate and the pretreatment agent. The conditions were optimized successively by changing one factor at a time while keeping the other variables constant. Several important hydrolysis factors were studied for the optimization, including performic acid concentration (0.2–5%), hydrolysis time (10–60 min), fermentation time (24–120 h), inoculum concentration (1.25–7.5 g/100 ml), and rotation speed (50–250 rpm). The maximum ethanol yield of 0.47% was observed at 0.6% performic acid concentration, 30 min of hydrolysis time, 48 h of fermentation time, 5 g/100 ml of inoculum concentration, and 100 rpm rotation speed with T. procumbens using S. cerevisiae.&#x0D; Keywords: Bioethanol, Lignocellulosic biomass, Acid hydrolysis, Saccharomyces cerevisiae&#x0D; &#x0D; &#x0D;

14C PREPARATION PROTOCOLS FOR ARCHAEOLOGICAL SAMPLES AT THE LMC14, SACLAY, FRANCE

ABSTRACT The Laboratoire de Mesure du Carbone 14 (LMC14) has operated a radiocarbon dating laboratory for almost twenty years with ARTEMIS, the Accelerator Mass Spectrometer (AMS) based on a NEC 9SDH-2 Pelletron tandem accelerator. A first status report describing the chemical pretreatment methods was published in 2017 (Dumoulin et al. 2017). This article summarizes updates of the routine procedures and presents new protocols. The quality checks in place at the LMC14 and results obtained for the GIRI international inter-comparison are reported. New protocols developed by the laboratory over the last five years are described with the preparation of iron, lead white, cellulose, calcium oxalate, and mortar. This report also provides a summary of practical information for sample preparation and can help the laboratory users who provide samples and publish results to better understand all the work behind a 14C dating.

Investigation of silver nanoparticles embedded in extracted gelatins from camel, bovine, and fish bones for possible use in radiation dosimetry

Abstract Gelatins from camel, bovine, and fish bones were successfully extracted by using chemical pretreatment and heating methods. The bones were demineralized for 3 days at ambient temperature using hydrochloric acid solutions (0.5–1 M), and the collagen was partially hydrolyzed by preheating in distilled water at 75–80°C for 3 h, followed by extraction temperature at 90°C for 1 h. Free-standing films of gelatin entrained with silver nanoparticles (Gel/AgNPs) at low concentrations (1.25, 2.5, and 5 mM) were synthesized as radiation dosimeters. A high-energy ultrasonic homogenizer was used to dissolve the gelatin in distilled water and to disperse the AgNPs in the gelatin. The nanocomposites’ morphology and crystallinity were investigated using scanning electron microscopy (SEM), optical absorption, and Fourier transform infrared (FTIR) spectroscopies. Dose enhancement was assessed using X-ray irradiations with beam energies below and above silver K-edge. The beam was configured by setting the X-ray generator at 15, 25.5, and 35 kV potential and a beam current of 1 mA. An X-ray detector is used to detect the number of electrons after passing through Gel/AgNPs samples. The use of AgNPs embedded in gelatin caused the enhancement of X-ray radiation absorption, and the highest percentage of linearity for the dosimeter was found to be 90% in the optical range of 395 nm to 425 nm. The preliminary results demonstrated that Gel/AgNPs material may be used in radiation dosimetry for low-energy radiotherapy sources.

Production of Sugar from Cassava Peel using Different Chemical Pre-treatment

Cassava peel has been a notable agricultural waste material to researchers because of its potential to produce sugar, a valuable product in the food, agricultural, and cosmetic industries. The peels constitute lignin, hemicellulose, and cellulose, also known as lignocellulosic biomass. Cassava peels must undergo a pre-treatment method to separate the lignocellulosic material effectively. This study aims to investigate the optimal chemical pre-treatment methods and optimal pre-treatment concentration to produce sugar from cassava peel. Cassava peels were pre-treated with sodium hydroxide, sulphuric acid, and methanol with a catalyst (organosolv). Then, enzymatic hydrolysis was performed using cellulase to hydrolyze cellulose to glucose. The glucose yield is quantified using Dinitrosalicylic Acid Assay and a portable blood glucometer. The results showed that pre-treatment using sodium hydroxide at a concentration of 0.05 M at 121°C for 15 minutes gave the highest glucose yield of 4.53±1.20 mg/ml. Glucose produced from 0.05 M sulphuric acid (H2SO4) and 0.2 M organosolv sodium methoxide (MeOH+NaOAc) were 3.55±0.68 mg/ml and 3.29±0.93 mg/ml, respectively. Statistical analysis showed that the effect of different pre-treatment methods and pre-treatment concentrations had a significant glucose yield (P&lt;0.05). Similarly, there was a significant difference (P&lt;0.05) in the glucose yield under different pre-treatment concentrations. Further study on mechanical-assisted chemical pre-treatment methods is recommended.

Anaerobic Digestion of Lignocellulosic Biomass: Substrate Characteristics (Challenge) and Innovation

Modern society is characterised by its outstanding capacity to generate waste. Lignocellulosic biomass is most abundant in nature and is biorenewable and contains energy sources formed via biological photosynthesis from the available atmospheric carbon dioxide, water, and sunlight. It is composed of cellulose, hemicellulose, and lignin, constituting a complex polymer. The traditional disposal of these types of waste is associated with several environmental and public health effects; however, they could be harnessed to produce several value-added products and clean energy. Moreover, the increase in population and industrialisation have caused current energy resources to be continuously exploited, resulting in the depletion of global fuel reservoirs. The overexploitation of resources has caused negative environmental effects such as climate change, exacerbating global greenhouse gas emissions. In the quest to meet the world’s future energy needs and adequate management of these types of waste, the anaerobic digestion of lignocellulosic biomass has remained the focus, attracting great interest as a sustainable alternative to fossil carbon resources. However, substrate characteristics offer recalcitrance to the process, which negatively impacts the methane yield. Nevertheless, the biodigestibility of these substrates can be enhanced through chemical, physical, and biological pretreatment methods, leading to improvement in biogas yields. Furthermore, the co-digestion of these substrates with other types and adding specific nutrients as trace elements or inoculum will help to adjust substrate characteristics to a level appropriate for efficient anaerobic digestion and increased biogas yield.

Enhancement of methane yield of Arachis hypogea shells using chemical pretreatment techniques

Anaerobic digestion of lignocellulose feedstocks requires a lengthy period, and the process's efficiency is always low without catalysis. Therefore, this study investigated the influence of chemical pretreatment methods on the methane yield of Arachis hypogea shells using H2SO4 and NaOH. The pretreated substrates were digested in a lab-batch digester for 30 days at mesophilic temperature (37 °C). The optimum methane yield of 205.22 ml/gVSadded was recorded at 0.5% (v.v-1) H2SO4 for 15 min, while 3% (w/w) NaOH treatment for 15 min released the optimum methane yield of 256.78 ml/gVSadded.

Review on the Pre-treatment Advancements of Biogas Production Barriers

Biogas production is a promising renewable energy source that can reduce greenhouse gas emissions and improve environmental health. Substrate pre-treatment methods, including physical, chemical, and biological methods can increase biogas yields and reduce operational costs. This review assessed the advancements in substrate pre-treatment methods for biogas production, while exploring potential benefits and drawbacks of various techniques. Physical pre-treatment methods, such as chopping, grinding, steam explosion, and high-pressure homogenization, have been found to increase biogas yield despite requiring high energy consumption and expensive equipment. Chemical pre-treatment methods involving acid and alkaline hydrolysis have been effective, but can be costly and generate hazardous wastes. The biological pre-treatment methods utilized microorganisms or enzymes, have advantages of higher biogas yields, shorter process time, and eco-friendliness. Future research can focus on developing more efficient and targeted pre-treatment methods using nanotechnology and genetic engineering, optimizing existing methods, and combining multiple pre-treatment methods to enhance efficiency. Improving pre-treatment methods can lead to benefits such as increased biogas production, reduced costs, and improved waste management practices.

A new evaluation system of iron bioavailability in seaweed

In marine ecosystems, the avid binding of iron (Fe) to organic ligands influences Fe bioavailability in seaweed. This study aimed to elucidate Fe's biological availability to seaweed and develop a simple and rapid bioassay method as a new evaluation system. Undaria pinnatifida was used as a model seaweed species and the actual seaweed samples were collected using the 0.5 m × 0.5 m quadrat from the Mashike Bay area of Hokkaido, Japan. Chlorophyll fluorescence measurements were utilized as an index to evaluate the biological -effectiveness of Fe and compared with the results of culture tests based on growth. The effect of Fe content on media, pre-culture, concentrations and types of chelating and reducing agents in clearing solutions, cleaning time, Fe removal effect, and resistance to seaweed were systematically optimized to obtain the maximum efficacy of the washing solution. A bioassay was developed to evaluate the Fe environment by combining chlorophyll fluorescence measurements. The findings suggest that the tolerance of seaweeds to the wash solution is strongly influenced by the concentrations of the chelating and reducing agents than their types. Washing with 0.02 M Ti-Citrate/EDTA solution for 80 s was the most effective in terms of maximum Fe removal with minimum cell damage. The application of pre-culture and chemical pre-treatment methods under Fe deficiency to the culture strain confirmed the maximum reproducibility in the culture test. Finally, the developed method was applied to actual seaweed samples and was found to be applicable to many seaweed species. However, the method was less robust for some seaweed species and depended on the seaweed growth stage.

Effect of chemical, physical, and biological pre-treatment of food wastes on bio-hydrogen production by dark anaerobic fermentation under mesophilic conditions

ABSTRACT With an overall aim of utilizing lignocellulosic food waste as feedstock for anaerobic fermentation and optimizing the reaction for improving energy output, a two-stage anaerobic dark fermentation reactor was set up. This study discusses the evaluation of different pre-treatment methods used to pre-treat the food waste before using it as a substrate for anaerobic fermentation. Five different techniques from physical, chemical, and biological pre-treatment methods, namely, autoclaving, acid pre-treatment, alkali pre-treatment, aeration, and fungal pre-treatment were used for pre-treatment of the substrate. The analysis was also evaluated by the multilevel categoric factorial design of the experiment model. The experiment found that all five pre-treatments improved the hydrogen and methane yield from the reaction. More precisely, fungal pre-treatment shows an almost 3.8-fold improvement in hydrogen yield compared to control conditions and a 1.7-fold increase in methane yield compared to control. The statistical analysis showed that the reaction time duration (day) has a more significant impact on the results than the pre-treatment technique. The model’s F-Values of 24.14 for hydrogen yield and 44.34 for methane yield indicate substantially. However, the actual hydrogen and methane yields are in good accord with the DOE predicted results.

Effect of pretreatment on Typha biomass for biogas production

Plant biomass as an alternative energy source serves as a viable option for improving sustainable development and reducing greenhouse gas emissions. However, the tight bonding within its constituents may hinder anaerobic digestion, thus, requires pretreatment to break down the complex polysaccharide structure into simpler disaccharide and monosaccharide sugars to facilitate digestion and enhance the production of biogas. The research determined the effect physical and chemical pre-treatment methods of Typha biomass for biogas production. Characteristics determined include; carbonnitrogen (C-N) ratio for Typha biomass, temperature, pH, total solids (TS) and volatile solids (VS) of slurry formed by mixing the biomass with cow-dung in ratio 1:1. The volume of biogas produced was determined by water displacement method using an anaerobic digester while the mass balance approach was used to estimate the biogas yield from the TS/VS lost. Results indicated 31.6 C-N ratio; pH of 6.7; Temperature of 32.4OC and TS of 11.3%, which falls within suitable ranges reported for biogas production. The volume of biogas produced was 180 cm3, 235cm3 and 118cm3 for control, physical and chemical pre-treated samples respectively. Similarly, the biogas yield was 21mg/l, 15mg/l and 48mg/l for control, physical and chemical pre-treatment respectively. Hence the findings revealed physical pre-treatment as the best pretreatment method for biogas generation from Typha biomass in relation to chemical pretreatment and untreated Typha biomass.

Instant catapult steam explosion: An efficient preprocessing step for the robust and cost-effective chemical pretreatment of lignocellulosic biomass

The biorefinery based on lignocellulosic biomass requires an efficient preprocessing step to address problems regarding with the high cost of biomass transportation and the low cost-effectiveness of subsequent chemical pretreatment . In this study, the instant catapult steam explosion (ICSE) was investigated as an alternative preprocessing method to treat corn stalk feedstocks , and compared with conventional milling preprocessing. Besides reducing the particle size, ICSE can modify the microstructure and improve enzymatic degradability of the corn stalks as well. These preprocessed feedstocks were further pretreated by moderate chemical pretreatment methods, including dilute acid, dilute alkali, acid and alkali, organosolv, and ionic liquid. The ICSE-treated feedstocks showed 3-fold to 7-fold increase in enzymatic saccharification when compared with milled and untreated feedstocks. Meanwhile, its energy consumption only accounted for 5%–20% of the milling process, thereby resulting in an 80%–85% of energy savings. Therefore, the ICSE-based preprocessing can potentially be integrated with the supply chain of lignocellulosic biomass and enhance the economic efficiency of biorefinery. • Instant catapult steam explosion (ICSE) as a preprocess is superior to milling for the downward chemical pretreatment. • ICSE, modifying lignocellulose's structure and composition, prompts the chemical pretreatment and subsequent enzymatic hydrolysis. • The energy consumption of ICSE is significantly lower than the traditional milling process. • ICSE facility can be adopted by the regional biomass preprocessing center to improve the cost-effectiveness of biorefinery.

Microalgae and Cyanobacteria Biomass Pretreatment Methods: A Comparative Analysis of Chemical and Thermochemical Pretreatment Methods Aimed at Methane Production

Anaerobic digestion of microalgae and cyanobacteria was first proposed as a destination for algal biomass accumulated on stabilization ponds since it could not be disposed of directly in the environment. Now, the versatility of algal biomass makes them a suitable candidate to produce biofuels and other biomolecules in biorefineries. Anaerobic digestion of biomass is advantageous because it does not require the extraction of specific cellular constituents or drying of the biomass. Nevertheless, challenges remain regarding biomass concentration and their resistant cell walls, which are factors that could hamper methane yield. Many pretreatment methods, including chemical and thermochemical, have been proposed to break down the complex polymers present on the cell wall into smaller molecules. Unfortunately, the relationship between biomass solubilization and methane yield is not well defined. This article intends to review the anaerobic digestion of algal biomass and the role of chemical and thermochemical pretreatments in enhancing methane production. Several pretreatment conditions selected from the scientific literature were compared to verify which conditions actually improve methane yield. The severity of the selected pretreatments was also assessed using the combined severity factor. Results suggest that thermochemical pretreatment in less severe conditions is the most efficient, leading to a greater increase in methane yield. Only enzymatic pretreatments and some thermal pretreatments result in a positive energy balance. The large-scale implementation of pretreatment methods requires technological innovations to reduce energy consumption and its integration with other processes in wastewater treatment plants.

Physical, chemical, and bio-pretreatments on microbial gas production in Baode Block coal.

Currently, the exploitation of Baode Block as a biogenic coal-bed gas field has been in the later stage of stable production; hence, exploration and activation of microbial gas production are of great practical significance for the enhancement and stabilization of block production. Pretreatment is the key process to improve anaerobic biodegradation performance and increase yield and production rate of gas. In this study, we examine physical, chemical, and biological pretreatment methods and compare their effectiveness toward microbial gas production in the coal seam. The obtained results indicate that: (1) grinding can enhance contact between the coal sample and bacteria liquid, and coal powder has greater gas-producing performance than the coal lump. (2) Chemical pretreatment of coal samples using acid and base can enhance gas production capacity. NaOH treatment has better gas-producing performance than HCl treatment, and the activity of microbial flora is higher after treatment. (3) Biological pretreatment can greatly enhance the microbial degradation of coal bed. The highest gas yield after white rot fungus pretreatment is 11.65 m3/t, and gas production cycle is shorter than before. This may be due to the white rot fungus effectively degrading macromolecules and, therefore, shortening the duration of methanogenic hydrolysis, which provides more organic matter for methanogens to decompose. During production, in addition to selecting a proper pretreatment method, the treatment cost and balance between energy input of pretreatment and gas energy output must also be considered. The joint pretreatment between different reagents and treatment methods is a possible solution to the problem and a current research trend to realize the large-scale degradation of coal. The simulated microbial methane production of coal seam is feasible for Baode Block in Ordos, where coal samples in this block have great gas-producing potential after treatment, and provides good references for further in-field tests.

Fiber Degradation and Sugars Production of Cotton Stalk by Different Chemical Pretreatment Methods

Cotton stalk can be used as a reinforcement material for biocomposite production and it can be evaluated for biofuel production. The aim of this research is to investigate the effect of different chemical pretreatments on sugar production and fiber production from cotton stalks. For this purpose, thermal assisted alkaline pretreatment, microwave pretreatment with sulfuric acid, and hydrochloric acid pretreatments were performed by varying temperature, reaction time, and concentration. The results were compared according to total sugar amount and cellulose content. The highest amount of total sugar of thermal assisted alkaline pretreatment was 9.98 g/L, microwave pretreatment was 84.80 g/L, and hydrochloric acid pretreatment was 36.58 g/L. Also, the highest amount of cellulose of thermal assisted alkaline, microwave, and hydrochloric acid pretreatment were 64.12%, 62.54%, and 64.12%, respectively. Thus, while microwave pretreatment was the most effective method for total sugar, both alkaline and hydrochloric acid pretreatment had the same highest result for cellulose.

Influence of Combined Mechanical, Chemical, and Thermal Pretreatment Methods and Concentration Control on Biomethane Production from Opuntia ficus-indica Waste

Influence of Combined Mechanical, Chemical, and Thermal Pretreatment Methods and Concentration Control on Biomethane Production from Opuntia ficus-indica Waste

Combining biological and chemical methods to disassemble of cellulose from corn straw for the preparation of porous carbons with enhanced adsorption performance

In this study, we used a combination of chemical and biological pretreatment methods to extract cellulose from corn straw with a relative content of 92.40%. The adsorption performance and mechanism of the prepared porous carbon were investigated using synthetic dye malachite green (MG) and antibiotic tetracycline hydrochloride (TC) as adsorption models. The kinetic studies suggested that the adsorption followed the pseudo-second-order model and Bangham model. The Freundlich isotherm model fitted the adsorption data best for both MG and TC. The thermodynamic studies showed that the adsorption of MG and TC by adsorbents were spontaneous and endothermic in nature. In addition, the adsorption performance was maintained at 50% of the original value after five cycles. More importantly, this method not only improved the adsorption performance of prepared porous carbon materials but also provides a reference for the application of other lignocellulosic materials for cellulose extraction.