Effect Of Various Pretreatment Methods Research Articles

Enhancing thermophilic methane production from oil palm empty fruit bunches through various pretreatment methods: A comparative study

This study investigated the effects of various pretreatment methods on the anaerobic digestibility of oil palm empty fruit bunches (EFB) for methane production. Pretreatment methods included weak alkaline (2 % Ca(OH)2), weak acid (2 % acetic acid), acidified palm oil mill effluent (POME), biogas effluent, hydrothermal (180 °C, 190 °C, and 200 °C), and microwave pretreatments. All pretreatment methods enhanced methane yield compared to untreated EFB (189.45 mL-CH4/g-VS), with weak alkaline pretreatment being the most effective (277.11 mL-CH4/g-VS), followed by hydrothermal pretreatment at 180 °C (244.33 mL-CH4/g-VS) and biogas effluent pretreatment (238.32 mL-CH4/g-VS). The enhanced methane yield was attributed to increased cellulose content (45.5 % for weak alkaline pretreatment), reduced hemicellulose (18.0 % for hydrothermal pretreatment at 200 °C), and lignin contents (19.0 % for hydrothermal pretreatment at 200 °C), decreased crystallinity index (40.0 % for hydrothermal pretreatment at 200 °C), and increased surface area. Weak alkaline pretreatment also showed the highest net energy balance (8.73 kJ/g-VS) and a short break-even point (2 years). Microbial community analysis revealed that weak alkaline pretreatment favored the growth of syntrophic acetate-oxidizing bacteria and hydrogenotrophic methanogens, contributing to improved methane yield. This study demonstrates the potential of EFB pretreatment, particularly weak alkaline and biogas effluent pretreatment, for enhancing methane production and sustainable management of palm oil mill waste.

Nondestructive Detection of Corky Disease in Symptomless 'Akizuki' Pears via Raman Spectroscopy.

'Akizuki' pear (Pyrus pyrifolia Nakai) corky disease is a physiological disease that strongly affects the fruit quality of 'Akizuki' pear and its economic value. In this study, Raman spectroscopy was employed to develop an early diagnosis model by integrating support vector machine (SVM), random forest (RF), gradient boosting decision tree (GBDT), extreme gradient boosting (XGBoost), and convolutional neural network (CNN) modeling techniques. The effects of various pretreatment methods and combinations of methods on modeling results were studied. The relative optimal index formula was utilized to identify the SG and SG+WT as the most effective preprocessing methods. Following the optimal preprocessing method, the performance of the majority of the models was markedly enhanced through the process of model reconditioning, among which XGBoost achieved 80% accuracy under SG+WT pretreatment, and F1 and kappa both performed best. The results show that RF, GBDT, and XGBoost are more sensitive to the pretreatment method, whereas SVM and CNN are more dependent on internal parameter tuning. The results of this study indicate that the early detection of Raman spectroscopy represents a novel approach for the nondestructive identification of asymptomatic 'Akizuki' pear corky disease, which is of paramount importance for the realization of large-scale detection across orchards.

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.

Effect of ultrasound, centrifugation, and enzymatic pretreatments on phytochemical properties and membrane fouling during microfiltration of Sohiong (Prunus nepalensis L.) juice.

The study aimed to investigate the effects of various pretreatment methods on sohiong fruit juice during the microfiltration process. The ultrasound, centrifugation, and enzymatic pretreatment processes were used before the microfiltration process of the juice. The highest total phenolic content, anthocyanin content, and antioxidant activity of sohiong fruit juice were observed after enzymatic pretreatment. However, the browning index and color of the sohiong juice deteriorated with enzyme pretreatment. The fouling behavior of the microfiltration process for the pretreated sohiong juice was well explained by the complete pore-blocking model as the coefficient of determination (R 2 ) varied from 0.821 to 0.971. All pretreatment methods significantly (p ≤ 0.05) increased the initial flux of the microfiltration process, and the highest flux was observed for the enzyme pretreated juice. Furthermore, as compared to alternative pretreatments following microfiltration, the enzyme pretreated fruit juice had a high sensory acceptance. The work manifested a way to develop high-quality sohiong fruit juice with a low fouling tendency.

Impacts of Pretreatment Techniques on the Quality of Tuber Flours.

Besides dietary sources of energy, roots and tuber crops can also serve as functional foods and nutraceutical ingredients to be explored in disease risk reduction and wellness. However, they are easily spoiled because of their high moisture contents and enzymatic reactions. Therefore, this review aimed at gathering information on the effects of various pretreatment methods on the quality of tuber crops before converting them into flour. Studies reported by different scholars showed that there were significant differences in physicochemical and functional properties between untreated tuber and the treated tuber samples. The review also highlighted that the chemical treatment methods, particularly sulfite treatment, could increase the lightness value of the flour. In addition, blanching could induce a decrease in protein, ash, and fat. Despite this, blanching pretreatment techniques increased moisture and carbohydrate content. Chemical treatment increases the ash content, which might be responsible for chemical diffusion into the sample. The reviewed results showed that the application of different pretreatments on tuber crops significantly improves many quality characteristics such as color, fiber content, carbohydrate, and the functional properties used for value addition during food product development in the industry. Therefore, application of pretreatment methods particularly chemical treatments could enhance nutritional value, and functional and physical properties of tuber flours.

Effect of Pre-Treatment on the Quality of Smoked Baltic Sprats

Abstract Baltic sprats (Sprattus sprattus balticus) are a good source of protein, vitamins D3, B12, minerals, and unsaturated fats. In response to consumer demand, various types of fish products of stable quality are available all year round. Pre-treatment with brine containing acetic acid, salt (NaCl), and/or granulated CaCl2 in various concentrations and proportions can be used to stabilise quality. The aim of the study was to evaluate the effect of various pre-treatment methods on smoked Baltic sprat sensory and technological parameters. Prior to smoking, fish was treated in a solution of additives in various proportions for 30 min. Untreated sprats were used as a control sample. The use of pre-treatment allowed reduction of the smoking losses; the combination of NaCl and acetic acid resulted in about 26% smoking loss. If no pre-treatment was applied, the drying losses after 24-hour storage were 1.6%, while using the solution of NaCl and CaCl2 it decreased to 0.3%. Both the pre-treatment method and freezing affected fish pH. The pH of smoked fresh sprats was 6.73 and for smoked frozen sprats, it was 6.38. Sensory testing using the Just About Right (JAR) method demonstrated that the use of acetic acid made smoked fish texture firmer.

Combustion behaviour of biochars thermally pretreated via torrefaction, slow pyrolysis, or hydrothermal carbonisation and co-fired with pulverised coal

The combustion characteristics and kinetics of straw biochars thermally pretreated via torrefaction, slow pyrolysis, or hydrothermal carbonisation (HTC) and co-combusted with bituminous coal were examined in this study to explore the effects of various pretreatment methods and blending ratios on the combustion characteristics of biochars to assess potential practical applications. Non-isothermal experiments were performed using a thermogravimetry analyser. The results showed that the thermogravimetric curve of biochar obtained after HTC was similar to that of raw straw, thereby indicating similar combustion characteristics and reactivity. The average reactivity ( R m ) index of hydrochar and straw was 1.648 and 2.082, respectively. By contrast, the biochars produced after torrefaction or pyrolysis were more similar to bituminous coal, with the R m index of 0.696, 0.78 and 0.773, respectively. A positive interaction was observed during the char combustion stage of co-firing, with the activation energy of the blends tending towards the lower side. The catalytic effect of biomass ash was likely the predominant reason for the better interaction of pyrolytic biochar with coal. • Combustion behaviors and kinetic of straw biochars and their co-firing were studied. • Pre-treatments include torrefaction, slow pyrolysis, or hydrothermal carbonisation. • Combustion characteristics and reactivity of hydrochar are close to those of straw. • Combustion of biochar after torrefaction or pyrolysis is similar to bituminous coal. • Positive interaction was observed during the char combustion stage of co-firing.

Wastewater treatment and application in the advanced nanofiltration system

The Aral Sea Region is characterized by being a very demanding consumer of industrial wastewater treatment. We studied the effects of various pretreatment methods on aluminum production. This method can be used as an alternative one in industrial wastewater treatment. The aim of multi-year study is to explore a nanofiltration as a one of the most attractive technologies for this application since nanofiltration membranes can retain ions and small organic molecules from an aqueous solution. But it is also very challenging due to the presence of salts and operating problems such as fouling, salt deposition, etc. Result becomes available thank to experimental set-up based on an ion exchange and a reverse osmosis. Results are also verified by evaluation tests and field applications showing their usage and wastewater conversion efficiency. The technological scheme includes combined water treatment plant using desalination technology and additional block functioning for an aluminum production and a temporary storage. Aluminum is to be produced of the Syr Darya river rich of it with the help of cutting-edge technology of oxide film removal and cartridge packing. This work evaluates the use of aluminum accumulated in the reaction unit by means of aluminum powder plus water module to reduce the pollutant contents of industrial wastewater quickly and effectively. The invention makes it possible to reduce the cost of aluminum by 3-4 times. Energy consumption of the desalination process was also discussed. Extracted aluminum is a superior material for industry. The high activity of aluminum to water is prohibited by a thin layer of aluminum oxide on its surface. The water treatment system with a combined phase purification and desalination may contribute up to 50 per cent to meeting the reduction of energy consumption for end product (aluminum).

Phycoremediation and Biogas Production Potential of Chlorella Vulgaris Grown in Secondarily Treated Wastewater

Present study aims at exploring parallel nutrient removal from secondarily treated wastewater and biogas production potential of Chlorella vulgaris. The observed growth rate (per day) and doubling time (days) of C. vulgaris was 0.36 and 0.44, respectively. C. vulgaris has removed 31 % COD, 40 % PO4-P , 36 % NH4-N and 38 % TKN from secondarily treated wastewater using open raceway pond. The biomass was analyzed for proteins, carbohydrates, Lipids, fibres, TS and VS. The optimum loading rate for maximum biogas yield was found to be 2 g VS/L. Effect of various pre-treatment methods (thermal, chemical, sonication and thermo-chemical) has also been studied. The biomass and biomass extract (before and after pre-treatments) were also analyzed for solubilization of complex compounds. Thermally pre-treated biomass has increased biogas production by 60 % (480 mL/g VS) relative to untreated biomass (350 mL/g VS). This study has successfully demonstrated that microalgal cultivation in wastewater can be easily adopted in currently available wastewater treatment plants without any major modifications of existing available infrastructure.

Method of Aluminum Salts Extraction from Wastewater Using Desalination Technology: Syr Darya River Case Study1The Authors thank the Government of the Russian Federation for its financial support of the Decree No. 860 August, 29 2017

The Aral Sea Region is characterized by being a very demanding consumer of industrial wastewater treatment. We studied the effects of various pretreatment methods on aluminum production. This method can be used as an alternative one in industrial wastewater treatment. The aim of multi-year study is to explore a nanofiltration as a one of the most attractive technologies for this application since nanofiltration membranes can retain ions and small organic molecules from an aqueous solution. But it is also very challenging due to the presence of salts and operating problems such as fouling, salt deposition, etc. Result becomes available thank to experimental set-up based on an ion exchange and a reverse osmosis. Results are also verified by evaluation tests and field applications showing their usage and wastewater conversion efficiency. The technological scheme includes combined water treatment plant using desalination technology and additional block functioning for an aluminum production and a temporary storage. Aluminum is to be produced of the Syr Darya river rich of it with the help of cutting-edge technology of oxide film removal and cartridge packing. This work evaluates the use of aluminum accumulated in the reaction unit by means of aluminum powder plus water module to reduce the pollutant contents of industrial wastewater quickly and effectively. The invention makes it possible to reduce the cost of aluminum by 3-4 times. Energy consumption of the desalination process was also discussed. Extracted aluminum is a superior material for industry. The high activity of aluminum to water is prohibited by a thin layer of aluminum oxide on its surface. The water treatment system with a combined phase purification and desalination may contribute up to 50 per cent to meeting the reduction of energy consumption for end product (aluminum).

Comparison of microwave-assisted zinc chloride hydrate and alkali pretreatments for enhancing eucalyptus enzymatic saccharification

In this work, four kinds of pretreatment methods including microwave-assisted ZnCl2·4H2O or NaOH pretreatment, traditional electrical heating ZnCl2·4H2O or NaOH pretreatment were developed and compared for eucalyptus hydrolysis at 100 °C. The effect of various pretreatment methods on hemicellulose and lignin degradation, and as well as subsequent pretreated solids enzymatic saccharification were completely investigated. The results showed that microwave-assisted ZnCl2·4H2O pretreatment was highly successful for enhancing eucalyptus enzymatic saccharification due to the removal of hemicellulose and the change of cellulose crystal structure. The pretreatment time can be significantly shortened from 90 min to 20 min by using microwave irradiation as a heating manner, which means energy saving. The addition of Tween 80 into enzymatic hydrolysis step could remarkably reduce the cellulase dosage while the glucose yields do not decrease. The highest glucose yield of this work was 35.7 g/100 g raw material, which represented 90.6% glucose in eucalyptus feedstock. It could be concluded that combination of ZnCl2·4H2O and microwave irradiation provided an applicable strategy for enhancing sugars release from eucalyptus.

Effect of Various Pretreatment Methods on Bioethanol Production from Cotton Stalks

Cotton stalks (CS) are considered a good candidate for fuel-ethanol production due to its abundance and high carbohydrate content, but the direct conversion without pretreatment always results in extremely low yields due to the recalcitrant nature of lignocelluloses. The present study was undertaken to investigate the effect of various chemical and physicochemical pretreatment methods, i.e., alkali, microwave-assisted acid, organosolv, hydrothermal treatment, and sequentially organosolv and hydrothermal pretreatment, on chemical composition of CS and subsequent ethanol production applying pre-hydrolysis and simultaneous saccharification and fermentation (PSSF) at high solid loading. The best results in terms of ethanol production were achieved by the sequential combination of organosolv and hydrothermal pretreatment (32.3 g/L, using 15% w/v substrate concentration and 6 h pre-hydrolysis) with an improvement of 32% to 50% in ethanol production compared to the other pretreatments. Extending pre-hydrolysis time to 14 h and increasing substrate concentration to 20% w/v, ethanol production reached 47.0 g/L (corresponding to an ethanol yield of 52%) after 30 h of fermentation.

Effect of various pretreatment methods on sugar and ethanol production from cellulosic water hyacinth

Effects of acid, alkali, ionic liquid (IL), and microwave-alkali pretreatments on cellulosic water hyacinth (WH) were investigated based on the total reducing sugars (TRS) and ethanol production. For the first time, IL pretreatment with (1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]) was used for WH, and the efficiency was compared with the other methods. Cellulase and Saccharomyces cerevisiae were fermented together for 72 h. Based on the results, all pretreatment methods effectively increased the sugar content as well as the ethanol yield. Untreated WH had 25 ± 1.5 mg/g of TRS, which was increased to 157 ± 8.2 mg/g, 95 ± 3.1 mg/g, 51 ± 4.2 mg/g, and 45 ± 2.6 mg/g via alkali, microwave-alkali, acid, and IL pretreatments, respectively. The highest TRS level of 402 mg/g was obtained in 24 h and 6.2 ± 0.4 g/L of ethanol in 48 h of fermentation with the alkali-treated WH. The ethanol production was followed by other treatment methods of WH in the order of microwave-alkali, acid, and IL. The results indicated that the ethanol production from WH was related to the type of pretreatment as well as the TRS production.

Effects of sequential sodium hydroxide Ultrasonication and hot water treatment of rice straw and coconut shell on biogas production

Objectives: This study aims to determine the effects of various pretreatment methods on the biomass properties and biogas yield in the anaerobic co-digestion of agricultural biomass waste co-digested with different biomass feedstocks for power generation applications. Methods: This study was carried out in order to determine the effects of the methane production on the two pre-treatments (3% and 4% w/v NaOH) subjected to sequential NaOH-ultrasonication and Liquid Hot Water treatment for the rice straw and coconut shell feedstocks, which can be used as substrates for the anaerobic co-digestion experiments; using cow manure, digested manures and sewage sludge as inoculant. Findings: Results showed that the methane production increased by 140% and 290% from the pre-treatment of rice straw and coconut shells, respectively. With these, the pre-treated coconut shell subjected to ultrasonication with 3% NaOH and Liquid Hot Water has the best effect among the pre-treatment of biomass feedstocks of rice straw and coconut shell at various NaOH concentrations. Applications: The results of this experiment would give a viable estimate on the possible methane production from codigestion of these resources. The enhancement of the biogas yield was attributed to the improvement of biodegradability of rice straw and coconut shell through the pre-treatments. The changes of chemical compositions, chemical structures, and physical characteristics made rice straw and coconut shell feedstocks become more available and biodegradable and thus were responsible for the enhancement of the biogas yield. These results are contributing to develop a feasible biogas production from rice straw and coconut shell. Keywords: Anaerobic Digestion, Biogas, Cattle Manure, Coconut Shell, Rice Straw, Sewage Sludge

Effect of biomass pretreatment on the product distribution and composition resulting from the hydrothermal liquefaction of short rotation coppice willow

A major challenge for the implementation of hydrothermal liquefaction (HTL) as a continuous process is the formulation of lignocellulosic feedstock, which is prone to phase separation into water and biomass parts when pressurized. One approach to remedy such phase separation is to reduce the dry matter content; however, as this approach is detrimental to process cost efficiency, designing an appropriate pretreatment step to ensure pumpability at high dry matter content is preferable. This paper evaluated the effect of various pretreatment methods on product distribution and composition resulting from the HTL of willow and proposes short rotation coppice as an alternative biomass feedstock for biofuels production. Alkaline–thermal pretreatment, besides making high dry matter pumpable feedstock slurries, also led to an increase in the production of the bio-crude product with an oxygen content lower than 8wt% and a higher concentration of aromatics and phenolic compounds.

The Effect of Various Pretreatment Methods on Oil Palm Empty Fruit Bunch (EFB) and Kenaf Core Fibers for Sugar Production

In this study, oil palm empty fruit bunch (EFB) and kenaf core fibers were converted into sugar for bioethanol production. Results of enzymatic hydrolysis showed that the untreated EFB and kenaf core fibers were hardly to be hydrolysed, in which yielded only 2.6% and 0.4% of reducing sugar (glucose), respectively. In consideration to environmentally friendliness, simple aqueous pre-treatments were carried out prior to hydrolysis aimed to increase sugar production. Based on the results obtained, it was interesting to note that by adopting merely water, acid and alkaline pre-treatments, the total glucose yields were increased to 34.9%, 34.2% and 27.9% for EFB fiber, while 19.3%, 11.7%, and 12.6% for kenaf core fiber, respectively. The results of chemical composition analysis of pre-treated fibers indicated the increase of the sugar production was highly related to the removal of hemicellulose and/or lignin in the fibers. Between the two fibers, pre-treated EFB fiber attained the highest total glucose yield in all the pre-treatments. This revealed that EFB fiber was more viable for sugar production than kenaf core fiber.

Biological hydrogen production by anaerobic digestion of food waste and sewage sludge treated using various pretreatment technologies

The purpose of this study was to enhance the efficiency of anaerobic co-digestion with sewage sludge using pretreatment technologies and food waste. We studied the effects of various pretreatment methods (thermal, chemical, ultrasonic, and their combination) on hydrogen production and the characteristics of volatile fatty acids (VFAs) using sewage sludge alone and a mixture of sewage sludge and food waste. The pretreatment combination of alkalization and ultrasonication performed best, effecting a high solubilization rate and high hydrogen production (13.8mL H2/g VSSconsumed). At a food waste:pretreated sewage sludge ratio of 2:1 in the mixture, the peak hydrogen production value was 5.0L H2/L/d. As the production of hydrogen increased, propionate levels fell but butyrate concentrations rose gradually.

Comparative study on the effect of various pretreatment methods on the enrichment of hydrogen producing bacteria in anaerobic granulated sludge from brewery wastewater

Five pretreatment methods, namely chemical, acid, heat-shock, freezing and thawing, and base, were evaluated for the enrichment of hydrogen-producing bacteria in anaerobic granulated sludge, which will be subsequently used as seed in biological hydrogen production. All the pretreatments showed positive effects towards improving hydrogen (H2) generation by the microbial population with higher hydrogen production yield and COD removal efficiency as compared to control. The granulated sludge pretreated by heat-shock showed maximum accumulated H2 (19.48mLg−1-COD), COD removal efficiency (62%), and biomass concentration (22.5 gL−1).

Effects of various pretreatment methods on mixed microflora to enhance biohydrogen production from corn stover hydrolysate

Five individual pretreatment methods, including three widely-used protocols (heat, acid and base) and two novel attempts (ultrasonic and ultraviolet), were conducted in batch tests to compare their effects on mixed microflora to enhance hydrogen (H 2) production from corn stover hydrolysate. Experimental results indicated that heat and base pretreatments significantly increased H 2 yield with the values of 5.03 and 4.45 mmol H 2/g sugar utilized, respectively, followed by acid pretreatment of 3.21 mmol H 2/g sugar utilized. However, compared with the control (2.70 mmol H 2/g sugar utilized), ultrasonic and ultraviolet pretreatments caused indistinctive effects on H 2 production with the values of 2.92 and 2.87 mmol H 2/g sugar utilized, respectively. The changes of soluble metabolites composition caused by pretreatment were in accordance with H 2-producing behavior. Concretely, more acetate accumulation and less ethanol production were found in pretreated processes, meaning that more reduced nicotinamide adenine dinucleotide (NADH) might be saved and flowed into H 2-producing pathways. PCR-DGGE analysis indicated that the pretreatment led to the enrichment of some species, which appeared in large amounts and even dominated the microbial community. Most of the dominated species were affiliated to Enterobacter spp. and Escherichia spp. As another efficient H 2 producer, Clostridium bifermentan was only found in a large quantity after heat pretreatment. This strain might be mainly responsible for better performance of H 2 production in this case.

Single and combined effect of various pretreatment methods for biohydrogen production from food waste

Four individual pretreatment methods: ultrasonication, heat, acid, and base and three combined pretreatment methods comprising ultrasonication with heat (UH), ultrasonication with acid (UA), and ultrasonication with base (UB) were applied on the food waste. The effect of the seven pretreatment methods on food waste solubilization was first evaluated, and then batch experiments were conducted for biohydrogen production without using extra seed. UB pretreatment achieved the highest increase in soluble chemical oxygen demand (SCOD) and soluble protein of 33% and 40%, respectively. The highest increase in soluble carbohydrate of 31% was observed for UA pretreatment. Among the four individual pretreatment methods, ultrasonic pretreatment produced the highest hydrogen yield (as mL hydrogen per g initial volatile solid) of 97 mL/g VS initial, while the lowest hydrogen yield of 46 mL/g VS initial was observed for base pretreatment. In case of combined pretreatment methods, UA pretreatment had a positive effect on hydrogen production reflected by the highest hydrogen yield of 118 mL/g VS initial. While UH and UB pretreatments had a negative impact on hydrogen yield reducing it from 97 mL/g VS initial for ultrasonic only to 78 mL/g VS initial for UH pretreatment and to 67 mL/g VS initial for UB pretreatment. A hydrogen yield of 42 mL/g VS initial was observed for the untreated food waste. UA had the highest final volatile fatty acids (VFAs) concentrations of 16,900 mg COD/L as well as highest acetate to butyrate (HAc/HBu) molar ratio of 1.87, while base pretreatment had the lowest final VFAs of 9700 mg COD/L and the lowest HAc/HBu ratio of 0.61.