Pretreatment Efficiency Research Articles

Deep eutectic solvent with bifunctional Brønsted-Lewis acids for highly efficient lignocellulose fractionation

Green and low cost deep eutectic solvents (DESs) are promising to replace the solid acids and ionic liquids in biomass fractionation process. To enhance the lignocellulose pretreatment efficiency, an acidic DES that composed of Brønsted acid (ZnCl2) as hydrogen bond acceptor and Lewis acid (lactic acid) as hydrogen bond donator was designed. This bifunctional DES was used for the extraction of lignin from poplar sawdust. Under the optimal pretreatment condition, the ZnCl2-lactic acid DES could recover 95.2 wt% of lignin with a purity of 92.1%. The recovered lignin demonstrated a low polydispersity of 1.67 and small amount of β-aryl-ethers. Moreover, the acidic DES had a good recyclability and reusability. Such performance was attributed to the presence of bifunctional acid sites, which help selectively cleave lignin-carbohydrate complex linkages. The acidity and polarity of Brønsted acid can be modulated by the Lewis acid, thus synergistically promote the lignin extraction and production.

Hydrothermal pretreatment optimization and deep eutectic solvent pretreatment of lignocellulosic biomass: An integrated approach

The combined effect of hydrothermal (HT) and deep eutectic solvent (DES) pretreatment on hemicellulose and lignin removal was studied to enhance cellulose digestibility during saccharification. The operating conditions (water loading and time) for HT pretreatment of sugarcane bagasse (SB) were optimized using response surface methodology (RSM). The SB optimum conditions were applied to other biomass with similar lignin and hemicellulose composition (rice straw (RS) and napier grass (NG)). The HT solids were further subjected to DES pretreatment using ChCl/LA (1:2). The pretreatment efficiency was compared between untreated, HT, ChCl/LA, and HT-ChCl/LA treated solids based on the glucose yield during saccharification. The hemicellulose recovery and delignification were higher in HT-ChCl/LA solids compared to HT and ChCl/LA solids. During saccharification (72 h) of HT- ChCl/LA solids, the glucose yield increased 3.1, 3.4, and 2.9-times for SB, RS, and NG, respectively. Hemicellulose and lignin obtained at different pretreatment stages could benefit the biorefineries.

Industrial scale pilot at Maspalomas I desalination plant demonstrates the efficiency of DuPont™ B-Free™ pretreatment – a new breakthrough solution against biofouling

Industrial scale pilot at Maspalomas I desalination plant demonstrates the efficiency of DuPont™ B-Free™ pretreatment – a new breakthrough solution against biofouling

Methane for Free? How Pressure Affects the Efficiency of Ultrasonic Sewage Sludge Pretreatment

Methane for Free? How Pressure Affects the Efficiency of Ultrasonic Sewage Sludge Pretreatment

Possibility Assessment of Ultrafiltration Membrane Pre-Treatment Efficiency for Brackish Water Reverse Osmosis-Based Wastewater Reuse: Lab and Demonstration

Possibility Assessment of Ultrafiltration Membrane Pre-Treatment Efficiency for Brackish Water Reverse Osmosis-Based Wastewater Reuse: Lab and Demonstration

Levulinic Acid Production from Macroalgae: Production and Promising Potential in Industry

The development of macroalgal biorefinery products as an alternative source of renewable fuels is an opportunity to solve the dependence on fossil fuels. Macroalgae is a potential biomass that can be developed as a raw material for producing platform chemicals such as levulinic acid (LA). In the industrial sector, LA is among the top 12 biomass-derived feedstocks designated by the U.S. Department of Energy as a high-value chemical. Several studies have been conducted on the production of LA from terrestrial-based biomass, however, there is still limited information on its production from macroalgae. The advantages of macroalgae over terrestrial and other biomasses include high carbohydrate and biomass production, less cultivation cost, and low lignin content. Therefore, this study aims to investigate the potential and challenge of producing LA from macroalgae in the industrial sector and determine its advantages and disadvantages compared with terrestrial biomass in LA production. In this study, various literature sources were examined using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) method to identify, screen, and analyze the data of the published paper. Despite its advantages, there are some challenges in making the production of levulinic acid from macroalgae feasible for development at the industrial scale. Some challenges such as sustainability of macroalgae, the efficiency of pretreatment, and hydrolysis technology are often encountered during the production of levulinic acid from macroalgae on an industrial scale.

Simultaneous determination of eight carbamate pesticide residues in tomato, rice, and cabbage by online solid phase extraction/purification-high performance liquid chromatography-tandem mass spectrometry

建立了在线固相萃取/净化-高效液相色谱-串联质谱(online SPE-HPLC-MS/MS)同时测定番茄、大米和圆白菜中8种氨基甲酸酯类农药的分析方法。将番茄5.0 g(不加水)、圆白菜和大米各2.0 g(各加3 mL水),以1000 r/min旋涡1 min,加入2 g氯化钠和10 mL 0.5%(v/v)甲酸乙腈溶液,旋涡均匀后离心,上清液氮吹后用10%(v/v)乙腈水溶液复溶,复溶液使用CAPCELL PAK C18净化柱(50 mm×2.0 mm, 15 μm)进行在线净化,当流动相0.1%(v/v)甲酸水溶液和乙腈的体积比分别为90:10和35:65时,可实现氨基甲酸酯农药的吸附和洗脱。以ACQUITY UPLC CSH C18色谱柱(100 mm×2.1 mm, 1.7 μm)为分析柱,实现8种氨基甲酸酯类农药的分离,以0.1%(v/v)甲酸水溶液和乙腈为流动相进行梯度洗脱,在12.0 min内即可完成分析。在优化条件下,8种氨基甲酸酯类农药在各自线性范围内线性良好,相关系数均大于0.995, LOD和LOQ分别为0.01~0.3 ng/mL和0.05~1.0 ng/mL;在3个加标水平下,8种氨基甲酸酯类农药的加标回收率为73.76%~112.32%,相对标准偏差为1.28%~13.14%(n=6)。通过在线净化的方式,大大提高了前处理效率,只需12 min即可完成净化上样,不需氮吹复溶等步骤,提高了处理效率。该法回收率高,重复性好,具有准确、快速、灵敏、环保等优点,可用于植物性食品中8种氨基甲酸酯类农药的检测。

Lignocellulosic Biomass Pretreatment for Enhanced Bioenergy Recovery: Effect of Lignocelluloses Recalcitrance and Enhancement Strategies

Bioenergy recovery from lignocellulosic (LC) biomass is the beneficial and sustainable approach due to its abundant availability. On the Otherhand, its recalcitrant nature makes the biomass to resist biological hydrolysis and it limits the conversion potential of organics to biomethane. Thus, it is essential to evaluate the association among the recalcitrant nature of LC biomass and its biomethane conversion efficiency. Consequently, this review critically recaps the recalcitrance of LC biomass and its effects on bioenergy recovery, its composition and characteristics. In addition, various enhancement approaches (pretreatments) were conferred as main aspect which plays main role in biomass disintegration and biomethane increment. Based on up -to -date information, elevated energy input and cost necessities of the pretreatments are the main factors that mediates the economic feasibility of the process. The present review apart from spotlighting the pretreatment efficiency, it also focusses on the challenges and limitations of enhancement strategies, energy and technoeconomic feasibility of the various pretreatments of LC biomass.

Improvement of lignocellulosic pretreatment efficiency by combined chemo - Mechanical pretreatment for energy consumption reduction and biofuel production

A pretreatment process is a preliminary stage to alter the recalcitrant structure of lignocellulosic biomass for enhancing its digestibility. An evaluation of the energy consumption and the environmental restrictions of the pretreatment step is required to develop a feasible eco-friendly process for industrial implementation. In this study, a combined alkaline-mechanical fractionation of rice straw for fermentable sugar (FS) production was developed with the objectives of i) evaluating energy efficiency and ii) addressing the sustainability of technology. The maximum fermentable sugar production was 0.54 kg/kg rice straw with an enzymatic hydrolysis efficiency of 97.34%. Furthermore, the results indicated that the pretreatment by 5% NaOH followed by mechanical size reduction provided the highest energy efficiency of 0.35 kg of FS/kWh with 94.44% glucose recovery, which also provided the lowest waste generation of less than 0.1 kg of waste/kg FS. These experimental results suggest that the combined alkaline-mechanical fractionation could effectively increase total FS yields and could be a promising pretreatment technology for an eco-friendly and sustainable pretreatment process integrated into a biorefinery platform.

Polar solvents enhance the efficiency of microwave pre-treatment of woody biomass

Microwave pre-treatment of woody biomass may be the key to unlocking an energy efficient process for the production of renewable chemicals and fuels. Here we investigated the dipolar polarisation mechanism of polar solvents, ranging from dilute aqueous solutions of ethylene glycol, isopropyl alcohol, formaldehyde and water-only, to improve the efficiency of MW pre-treatment of woody biomass. The optimal conditions were 3.7 wt% FA solution for 10 min at 180 °C, where heating rate was accelerated by 50%, saccharification of biomass increased by 56% and stabilised lignin monomers were produced compared to water-only. Autoclave pre-treatment of woody biomass released 3 to 6 times less sugar yield in the presence of water-only and 3.7 wt% FA compared to MW irradiation. Our efficient method can potentially produce three streams of building blocks – cellulose fibres, solvated hemicellulose and stabilised lignin – for transformation into renewable products.

Comparison of Efficacy of Ondansetron Pre-treatment in Alleviating Pain due to Propofol during General Anaesthesia with Placebo

Background: Ondansetron is a 5HT3 receptor blocker and has multifaceted action like sodium channel blocker and µ - opioid agonist. Objective: To compare the efficiency of ondansetron pre-treatment in alleviating pain caused by propofol during induction of general anaesthesia with placebo. Material & Method: In this randomized controlled trail 120 patients of ASA grade I & II undergoing elective surgery were included and divided into two equal groups A & B by using lottery method. Each group comprised of 60 patients. In group A two ml 0.9 % normal saline and in group B, 2 ml ondansetron (4mg) given intravenously. In both groups propofol was given in a dose of 2.5 mg / Kg intravenously. Results: The mean age of patients in group A was 29.95 ± 4.79 year and in group B was 30.30 ± 4.87 year. Majority of patients 67(55.83 %) were between 18 to 30 year of age. Out of 120 patients. 63 (52.50 %) were ASA I & 52 (47.50 %) were ASA II. Efficacy of group A (placebo) was seen in 11 (18.33 %) while in group B (ondansetron) was seen in 56 (93.33 %). Conclusion: Ondansetron pre-treatment in alleviating pain cause by propofol is very effective. Keywords: Pain, ondansetron, propofol, general anaesthesia.

Preparation of Fe3O4@BA-MOF magnetic solid-phase extraction material and its application to the detection of pesticide residues in tea

在茶叶的农药残留检测中,茶多酚及色素具有很强的基质效应,严重影响了色谱检测结果。该文将Fe3O4磁性纳米粒子与硼酸官能化金属有机骨架(BA-MOF)材料相结合,制备出一种对茶多酚等基质具有高效捕获能力的吸附材料Fe3O4@BA-MOF。结合气相色谱-质谱联用技术,建立了一种茶叶样品中农药残留的有效分析方法。通过在金属有机骨架结构中引入硼酸配体,将其作为顺式二醇的识别位点,实现对茶多酚的高效捕获。这种新型材料具有快速磁分离,比表面积高,功能位点丰富等优点。通过傅里叶变换红外光谱、扫描电子显微镜以及X射线粉末衍射仪对制备材料进行了表征。同时对吸附剂的固相吸附条件(溶液pH、吸附剂用量、吸附时间)进行了优化,结果显示,50 mg Fe3O4@BA-MOF吸附材料可在5 min内去除74.58%茶多酚,溶液pH在7.0时效果最佳。利用硼亲和与茶多酚之间的可逆化学反应,通过调节溶液pH,可使Fe3O4@BA-MOF具有循环利用性,经过4次循环使用后仍具有优异的吸附性能。引入Fe3O4磁性纳米粒子,使其在样品前处理过程中表现出快速磁响应特性,提高前处理效率。在茶叶农药残留检测的实际应用中,经过Fe3O4@BA-MOF前处理后,10种农药的平均加标回收率为75.8%~138.6%, RSD为0.5%~18.7%(n=3)。研究结果表明,所制备的Fe3O4@BA-MOF纳米复合材料可以特异性吸附茶多酚基质,在茶叶的农药残留检测中具有净化基质,提高检测效率的功能,适用于茶叶中农药的检测分析。

A comprehensive study of the promoting effect of manganese on white rot fungal treatment for enzymatic hydrolysis of woody and grass lignocellulose

BackgroundThe efficiency of biological systems as an option for pretreating lignocellulosic biomass has to be improved to make the process practical. Fungal treatment with manganese (Mn) addition for improving lignocellulosic biomass fractionation and enzyme accessibility were investigated in this study. The broad-spectrum effect was tested on two different types of feedstocks with three fungal species. Since the physicochemical and structural properties of biomass were the main changes caused by fungal degradation, detailed characterization of biomass structural features was conducted to understand the mechanism of Mn-enhanced biomass saccharification.ResultsThe glucose yields of fungal-treated poplar and wheat straw increased by 2.97- and 5.71-fold, respectively, after Mn addition. Particularly, over 90% of glucose yield was achieved in Mn-assisted Pleurotus ostreatus-treated wheat straw. A comparison study using pyrolysis gas chromatography mass spectrometry (Py-GC/MS) and two-dimensional 1H–13C heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR) spectroscopy was conducted to elucidate the role of Mn addition on fungal disruption of the cross-linked structure of whole plant cell wall. The increased Cα-oxidized products was consistent with the enhanced cleavage of the major β-O-4 ether linkages in poplar and wheat straw lignin or in the wheat straw lignin–carbohydrate complexes (LCCs), which led to the reduced condensation degree in lignin and decreased lignin content in Mn-assisted fungal-treated biomass. The correlation analysis and principal component analysis (PCA) further demonstrated that Mn addition to fungal treatment enhanced bond cleavage in lignin, especially the β-O-4 ether linkage cleavage played the dominant role in removing the biomass recalcitrance and contributing to the glucose yield enhancement. Meanwhile, enhanced deconstruction of LCCs was important in reducing wheat straw recalcitrance. The findings provided not only mechanistic insights into the Mn-enhanced biomass digestibility by fungus, but also a strategy for improving biological pretreatment efficiency of lignocellulose.ConclusionThe mechanism of enhanced saccharification of biomass by Mn-assisted fungal treatment mainly through Cα-oxidative cleavage of β-O-4 ether linkages further led to the decreased condensation degree in lignin, as a result, biomass recalcitrance was significantly reduced by Mn addition.Graphic abstract

Impacts of sewage outbursts on seawater reverse osmosis desalination

Sewage outbursts affect coastal environments as seawater is enriched with nutrients, organic matter and microbes, thus can potentially impair seawater reverse osmosis (SWRO) desalination. In this study, we evaluated how municipal sewage outbursts affect SWRO desalination in a pilot-scale system. To this end, feedwater characteristics (i.e., coastal water), the removal efficiency of organic foulants by a dual-media gravity filter, and cartridge micro-filtration were determined daily for 12 days. Permeate water flux was maintained constant during the study, while trans-membrane pressure (TMP) was automatically adjusted and continuously monitored. The results indicate that sewage outbursts caused an immediate (∼1 d) buildup of phyto/bacterioplankton biomass (up to 10-fold), and enhanced activity (maximal 30-fold) followed by an increase in transparent exopolymer particle (TEP) concentrations. After sewage addition, algal biomass was significantly removed by the pretreatment system (72–90%), while a considerable fraction of the bacterial biomass (42–65%) and TEP (53–65%) passed these procedures. The result was a negative impact on the desalination performance reflected by a significant increase (> 10%) in RO-TMP 7.5 d after the sewage addition. Our results indicate on a direct link between sewage outbursts, pretreatment efficiency, and SWRO desalination. Nevertheless, these findings can lead to new avenues for the development of science-based operational protocols to minimize the deleterious effects of abrupt sewage outbursts on SWRO desalination.

The environmental impacts of citrus residue management in China: A case study in The Three Gorges Reservoir Region.

This study conducted the first life cycle analysis for citrus residue (CR) management systems in China. The results indicated conventional waste treatment systems were not suitable for CR management in China. Although feed system seems to be a favourable option, the uncertainty analysis suggested valorisation system could achieved better performance in global warming, eutrophication and human toxicity. The environmental impacts of valorisation systems were more sensitive to energy consumption. For silage and single cell protein (SCP) system, the environmental impacts could be significantly reduced by improving the energy use efficiency or using more renewable energy. In comparison, although the environmental impacts of biorefinery system were less favourable than SCP and silage systems. The multiple extraction unit had less impact than reported values in other studies. Further research in biorefinery system can focus on increasing the energy efficiency of pre-treatment or reuse of extraction chemicals.

Step washing: A modified pretreatment approach for industrial applications to improve chemical composition of agricultural residues

To improve the efficiency and applicability of the washing pre-treatment for combustion, pyrolysis and gasification, a modified approach was developed in the present study. Two novel washing approaches were tested using wheat straw and empty fruit bunches of oil palm: multiple-step washing with fresh water (SWFW) and wastewater recirculation (SWWR). SWFW showed the high removal of K (<68%), Cl (<99%), S (<80%), N (<58%), and ash (<52%) reducing fouling, slagging, and corrosion propensity of the biomass. Furthermore, with one-third the amount of water used in SWFW, SWWR showed similar to higher efficiency than SWFW with relatively better energy (98%) yields. Industrial-scale pilot testing was also conducted for the validation of the SWWR approach, which showed similar findings as the lab-scale results. The effect of a high washing temperature and pressing on washing efficiency and characterisation of wastewater was also determined. Overall, SWWR with pressing is recommended for industrial applications.

Fabrication of dual responsive imprinted materials of magnetic and solvent and their solvent-regulated binding performance for bisphenol A

Facile and versatile adsorbents with fast separation and tunable adsorption performance based on molecularly imprinting polymers hold significant potential to improve the efficiency of sample pretreatment. In this work, a type of magnetic imprinted materials (SMMIPs) was prepared, using magnetic multi-walled carbon nanotubes (MWNTs@Fe3O4) as carrier, triethylene glycol dimethacrylate as cross-linker, and acryloyl-modified beta-cyclodextrin (β-CD-MA) as functional monomer, which can interact with bisphenol A (BPA) by host–guest interaction. MWNTs@Fe3O4 not only was served as substrates, but also contributed to the immobilization of β-CD-MA/BPA complex on their surface due to hydrogen bonding interaction between pre-assembly complex and carboxyl groups on its surface. Taking advantages of excellent solvent-responsiveness, SMMIPs can easily adsorb templates BPA in water with the adsorption capacity of 13.84 mg/g while desorb the adsorbed BPA in organic solvents (i.e. methanol, acetonitrile, ethanol and isopropanol) without the aid of acid. Significantly, even after reuse in successive four cycles, SMMIPs maintained high adsorption. Under the optimal extraction conditions, the proposed SMMIPs were successfully employed for the determination and separation of trace BPA in environmental waters and orange juice, exhibiting great potential in the determination of BPA in environmental and food samples.

Insight into the deep eutectic solvent pretreatment of oil palm empty fruit bunches: Effects of temperature, empty fruit bunch to solvent ratio, and time

This work aimed to comprehensively examine the pretreatment efficiency of oil palm empty fruit bunches (EFB) using two different types of deep eutectic solvent (DES) mixtures, i.e., choline chloride/imidazole (DES-I) and choline chloride/glycerol (DES-G) in terms of pretreated EFB structural composition and enzymatic hydrolysis. The influence of the pretreatment temperature (55 °C, 90 °C, 125 °C, 160 °C, and 195 °C), EFB to solvent ratio (1:5, 1:10, 1:15, and 1:20), and pretreatment time (2 h, 4 h, and 6 h) on the performance of pretreated EFB and the generated black liquor was examined. The optimal conditions for EFB pretreatment were 160 °C, 1:5 ratio, and 2 h using DES-I solvent, and 160 °C, 1:10 ratio and 4 h using DES-G solvent. The structural carbohydrates of empty fruit bunch pretreated with DES-I, DES-I EFB1 and DES-G, DES-G EFB2 increased to 66.1%, and 64.6%, respectively. The enzymatic hydrolysis of DES-I EFB1 resulted in higher glucan conversion (92.4%) compared to DES-G EFB2, indicating that DES-I solvent was more efficient than DES-G for EFB pretreatment. X-ray diffraction, Fourier transform infrared spectroscopy, and variable-pressure scanning electron microscopy confirmed the removal of lignin and hemicelluloses from EFB during pretreatment and enzymatic hydrolysis.

Evaluation of low-medium temperature pretreatment on the removal efficiency of organic toxic pollutants from pesticide waste salts: Characteristics, regularity, and key factors

A large amount of waste salts (WS) produced during the production of pesticides has posed a great threat to enterprise production and human health. In the study, the regularity and efficiency of low-medium temperature pretreatment of pesticide WS were studied to provide help for the subsequent treatment and recycling of the WS. Eight kinds of WS originating from herbicides, insecticides, and bactericides were studied by thermogravimetric (TG) analyses and tubular furnace simulation experiments. The TG and kinetic results showed that the pretreatment temperatures ranged from 350 °C to 700 °C. The optimal disposal temperature varied for different WS, and oxygen could facilitate the pretreatment of WS. Tubular furnace simulation experiments indicated that the effect of pretreatment depends on the organic toxic pollutants (OTPs) components of the samples rather than the type of pesticide. Dicamba WS had the lowest removal rate of OTPs (58.23%), while triadimefon WS had the highest rate (99.74%). The mean rate of OTPs removal from WS was 80%. The results confirmed that low-medium temperature pretreatment can effectively eliminate most of OTPs in WS and reduce the burden of subsequent management and disposal. This technique can be useful for large-scale waste management in the pesticide industry.

Secretome characterization of the lignocellulose-degrading fungi Pycnoporus sanguineus and Ganoderma resinaceum growing on Panicum prionitis biomass

ABSTRACT C4 grasses are common species in rangelands around the world and represent an attractive option for second-generation biofuel production. Although they display high polysaccharide content and reach great levels of biomass accumulation, there is a major technical issue to be addressed before they can be used for bioethanol industrial production: lignin removal. Concerning this, Pycnoporus and Ganoderma fungal genera have been highlighted due to their ability to hydrolyze lignocellulose in biological pretreatments. Our goals here were to evaluate the pretreatment efficiency using the secretome of species from Pycnoporus and Ganoderma spp. harvested from a glucose-free inductive medium (using a C4 grass) and to identify the fungal enzymatic activities responsible for the lignin degradation and glucose release. Our results show that P. sanguineus secretome exhibits a higher activity of lignocellulolytic enzymes such as cellulases, xylanases, laccases, and manganese peroxidases compared with that from G. resinaceum. Interestingly, zymograms in the presence of 2 M glucose suggest that a β-glucosidase isoform from P. sanguineus could be glucose tolerant. The proteomic approach carried out allowed the identification of 73 and 180 different proteins in G. resinaceum and P. sanguineus secretomes, respectively, which were functionally classified in five main categories and a miscellaneous group. These results open new avenues for future experimental work that lead to a deeper comprehension and a greater application of the mechanisms underlying lignocellulosic biomass degradation.