Peroxide Pretreatment Research Articles

Evaluating the efficiency of the enhanced ultrasonic–assisted hydrogen peroxide degradation of low–rank coal biogenic gas

ABSTRACT The efficiency of biogas formation from low-rank coal was improved through ultrasonic-assisted hydrogen peroxide degradation. We investigated various aspects of this process, including the mass of the small-molecule organic matter, changes in the composition of biogas components in three systems, and alterations in the microscopic morphology of coal before and after biogas formation. Our analytical methods included UV-vis spectrophotometry, drainage gas collection method, gas chromatography, infrared spectroscopy, and scanning electron microscopy. Optimal pretreatment conditions were identified with an ultrasonic power of 400 W, a reaction time of 90 min, and a reaction temperature of 60°C. The biogenic methanogenic cycle was delineated into three stages, with the raw coal and filtrate systems exhibiting fast and slow gas production stages during the first and second stages, respectively. In contrast, the residual coal system displayed slow and fast gas production stages during these stages. Methane yields were measured at 270.72 μmol g−1 (raw coal), 303.50 μmol g−1 (residual coal), and 293.43 μmol g−1 (filtrate). Pretreated coal exhibited biomethane yields (residual coal and filtrate) approximately 120% higher than untreated raw coal. Notably, the gas-forming potential of the filtrate should not be underestimated. Ultrasonic-assisted hydrogen peroxide pretreatment disrupted the macromolecular reticulation structure within the raw coal, resulting in the opening of a portion of the aromatic ring structure. This innovative approach offers a novel strategy for augmenting biomethane production from low-rank coal and furnishes a scientific foundation for advancing industrial applications.

Artificial neural network modeling to predict the efficiency of phosphoric acid-hydrogen peroxide pretreatment of wheat straw

Phosphoric acid-hydrogen peroxide (PHP) pretreatment is an effective method to obtain a cellulose-enriched fraction from biomass. In this study, artificial neural network (ANN) was used to predict PHP pretreatment efficiency of cellulose content (C-C), cellulose recovery (C-Ry), hemicellulose removal (H-Rl), and lignin removal (L-Rl) under various conditions of pretreatment time (t), temperature (T), H3PO4 concentration (Cp), and H2O2 concentration (Ch). The final optimized topology structure of the ANN models had 1 hidden layers with 9 neurons for C-C and 10 neurons for C-Ry, 10 neurons for H-Rl, and 12 neurons for L-Rl. The actual testing data fit the predicted data with R2 values ranging from 0.8070 to 0.9989. The relative importance (RI) revealed that Cp and Ch were significant factors influencing the efficiency of PHP pretreatment with total RI values ranging from 12% to 62.6%. However, their weights for the three components of biomass were different. The value of T dominated hemicellulose removal effectiveness with an RI value of 78.6%, while t did not seem to be a main factor dominating PHP pretreatment efficiency. The results of this study provide insights into the convenient development and optimization of biomass pretreatment from ANN modeling perspectives.

Novel pretreatment with hydrogen peroxide enhanced microwave biochar for heavy metals adsorption: Characterization and adsorption performance

Hydrogen peroxide (HP) was used to pretreat wheat straw (WS) for microwave biochar production at 100–600 W, the physicochemical properties of pretreated WS and biochar products as well as heavy metals adsorption performance were investigated. Results showed that HP enhanced specific surface area (SSA) and pore volume (PV) of WS, and the largest SSA (190.35 m2 g−1) and PV (0.1493 cm3 g−1) of biochar were obtained at microwave powers of 600 W (HPWS600) and 500 W (HPWS500), respectively. HPWS500 showed maximum adsorption capacities, which were 57.56, 190.21, and 65.16 mg g−1 for Cd2+, Pb2+, and Cu2+, respectively. Solution pH values and cation concentrations exhibited significant effects on adsorption capacities of biochar. The pseudo-second-order kinetic and Langmuir isotherm models fitted better for metal adsorption process. The FTIR results suggested that chemisorption mechanisms including precipitation with carbonate and complexation with oxygen-containing functional groups might be predominant adsorption mechanisms. These results suggest that HP pretreatment has excellent potential for biochar production.

Effective cellulose isolation from torch ginger stem by alkaline hydrogen peroxide – Peracetic acid system

Efficient and eco-friendly isolation of cellulose from non-woody plants is paramount. This study aimed to isolate cellulose from torch ginger stem (Etlingera elatior) (TGS) waste efficiently by alkaline hydrogen peroxide pre-treatment and subsequently by peracetic acid treatment (AHP-PAA) under autoclave conditions (121 °C/0.1 MPa). A complete randomized design with three factors—AHP concentration (0, 16, and 33 % (v/v) H2O2 in 5 % (w/v) NaOH), PAA concentration (PAA to water ratio of 0.36, 1.14, and 4.00 (v/v)), and pre-treatment time (30, 60, and 90 min)—was used to investigate changes in yield and fiber’s chemical components. The results showed that TGS is a potential non-wood cellulose source with a high S/G ratio (3.016) and low SiO2 (4.2 %). Analysis of variance exhibited that the AHP and PAA concentration affected lignin-related parameters, but pre-treatment time influenced only carbohydrate-related parameters. The optimum isolation condition resulted in 47.78 % pulp yield with 64.78 % α-cellulose, 34.06 % hemicellulose, 0.15 % lignin, and 71.8 % crystallinity in 90 min of reaction time. Massive liberation of individual fibers from bundles, single peak on thermal degradation, removal of lignin-related functional groups and some metal oxide also supported the effectiveness of the AHP-PAA method to isolate TGS cellulose through prehydrolysis, chromophore group deactivation, and delignification reactions.

A waste-free biorefinery pathway to the valorisation of Chinese hickory shell through alkaline hydrogen peroxide pretreatment

Efficiently harnessing the intrinsic value of lignocellulose requires the integration of multifarious capacities within a zero-waste biorefinery. Chinese hickory shell, a food industry byproduct, remains largely untapped. Unleashing their full potential as a valuable biomass resource has become an urgent challenge. This study utilises the alkaline hydrogen peroxide pretreatment for Chinese hickory shell, exploring the effect of H2O2 dosage, alkali concentration, and temperature on lignocellulosic fractionation. Under optimal conditions, nearly complete removal of lignin and hemicelluloses is achieved, with cellulose enzymatic hydrolysis up to 98.1%, surpassing the original material by over 15-fold. Simultaneously, hemicelluloses transformed into high-value organic acids, yielding 33.5%. Notably, fractionated lignin is abundant in aryl ether linkages after AHP, facilitating subsequent transformation into aromatic chemicals. Through AHP, efficient fractionation of Chinese hickory shell is achieved, yielding fermentable glucose, organic acids, and lignin enriched with high aryl ether content. This research emphasises the pivotal role of comprehensive Chinese hickory shell utilisation in elevating the revenue of zero-waste biorefinery, sparking the production of valuable products from biomass waste streams, and further contributing to establishing resource-efficient biorefineries.

Optimization of Alkaline Hydrogen Peroxide Pretreatment and Enzymatic Hydrolysis of Wheat Straw for Enhancing Sugar Yields

Optimization of alkaline hydrogen peroxide (AHP) pretreatment and enzymatic hydrolysis of wheat straw (WS) was carried out to enhance fermentable sugar yields with the use of glucose and xylose yields from the pretreated WS as responses. In the first step, variables including temperature, hydrogen peroxide concentration and time during pretreatment were detected to have significant effects on the sugar yields. The results indicate that maximal sugar yields could be obtained while the WS was pretreated using 71 g/L hydrogen peroxide solution with 200 g/L of solid loading at 50 °C for 7.6 h. The corresponding cellulose recovery, hemicellulose recovery and lignin removal were 97.5%, 84.3% and 75.0%, respectively. In the second step, enzymatic hydrolysis of the pretreated WS was optimized. The results show that the reaction time, enzyme loading and biomass loading during enzymatic hydrolysis also had significant effects on the sugar yields. The final maximum yields of glucose (552.7 mg/gds (mg/g dry substrate)) and xylose (223.6 mg/gds) could be obtained while enzymatic hydrolysis was carried out at 50 °C for 37.0 h using 10.8 FPU/gds (filter paper activity unit per gram dry substrate) of enzyme loading, 88 g/L of biomass loading and 0.3% (w/v) of Tween-80. The corresponding cellulose conversion and hemicellulose conversion were 94.0% and 83.5%, respectively.

Evaluating Options to Increase the Efficacy of Biocontrol Agents for the Management of Pantoea spp. Under Field Conditions.

Center rot of onion is caused by a complex of plant pathogenic Pantoea species, which can lead to significant yield losses in the field and during storage. Conventional growers use foliar protectants such as a mixture of copper bactericides and an ethylene-bis-dithiocarbamate (EBDC) fungicide to manage the disease; however, organic growers have limited management options besides copper-protectants. Biocontrol agents (BCAs) provide an alternative; however, their efficacy could be compromised due in part to their inability to colonize the foliage. We hypothesized that pretreatment with peroxide (OxiDate 2.0: a.i., hydrogen peroxide and peroxyacetic acid) enhances the colonizing ability of the subsequently applied BCAs, leading to effective center rot management. Field trials were conducted in 2020 and 2021 to assess the efficacy of peroxide, BCAs (Serenade ASO: Bacillus subtilis and BlightBan: Pseudomonas fluorescens), and an insecticide program (tank mix of spinosad and neem oil) to manage center rot. We observed no significant difference in foliar area under the disease progress curve (AUDPC) between the peroxide pretreated P. fluorescens plots and only P. fluorescens-treated plots in 2020 and 2021. Peroxide pretreatment before B. subtilis application significantly reduced the foliar AUDPC as compared with the stand-alone B. subtilis treatment in 2020; however, no such difference was observed in 2021. Similarly, peroxide pretreatment before either of the BCAs did not seem to reduce the incidence of bulb rot as compared with the stand-alone BCA treatment in any of the trials (2020 and 2021). Additionally, our foliar microbiome study showed comparatively higher P. fluorescens retention on peroxide pretreated onion foliage; however, at the end of the growing season, P. fluorescens was drastically reduced and was virtually nonexistent (<0.002% of the total reads). Overall, the pretreatment with peroxide had a limited effect in improving the foliar colonizing ability of BCAs and consequently a limited effect in managing center rot.

Enhancing acidogenic fermentation of waste activated sludge via urea hydrogen peroxide pretreatment: Performance and mechanisms

Improving the anaerobic treatment performance of waste activated sludge (WAS) to achieve resource recovery is an indispensable requirement to reduce carbon emissions, minimize and stabilize biosolids. In this study, a novel strategy by using urea hydrogen peroxide (UHP) to enhance SCFAs production through accelerating WAS disintegration, degrading recalcitrant substances and alleviating competitive suppression of methanogens. The SCFAs production and acetate proportion rose from 436.9 mg COD/L and 31.3% to 3102.6 mg COD/L and 54.1%, respectively, when UHP grew from 0 to 80 mg/g TSS. Mechanism investigation revealed that OH, O2 and urea were the major contributors to accelerate WAS disintegration with the sequence of OH>O2 > urea. Function microbes related to acidification and genes associated with acetate production ([EC:2.3.1.8] and [EC:2.7.2.1]) were upregulated while genes encoding propionic acid production ([EC:6.4.1.3] and [EC:6.2.1.1]) were downregulated. These results raised the application prospects of UHP in WAS resource utilization.

Repercussion of extracellular polymeric removal by low-temperature calcium peroxide pretreatment on bacterial fragmentation for enhancing biohydrogen production

This study envisioned attaining the percipience of effective biohydrogen production from paper mill waste-activated sludge through low-temperature calcium peroxide-mediated bacterial pretreatment (TCP-BP). Floc dissociation with limited cell destruction was attained at a calcium peroxide dosage of 0.05 g/g suspended solids (SS) at 70 °C temperature. This TCP-BP method improves bacterial fragmentation, and very high SS solubilization was achieved at 42 h, with the solubilization and solid reduction of 18.6% and 14.1%, respectively. BP-only pretreatment shows lower solubilization efficiency of 9.4% than TCP-BP pretreatment due to the presence of flocs, which inhibit the enzymatic action during bacterial fragmentation. A biohydrogen test shows a high biohydrogen potential of 94.1 mL H2/gCOD for the TCP-BP sample, which is higher than that of the BP-only and control samples. According to the findings, low-temperature calcium peroxide-mediated bacterial fragmentation is validated to be an efficient process for sludge degradation and biohydrogen production.

Enhancement of biomethane production by huminite-enriched lignite pretreated with hydrogen peroxide

In situ bioconversion of low rank coal to natural gas is an attractive approach to reduce greenhouse gas emissions and utilize underexploited coal recourses. Hydrogen peroxide pretreatment followed by microbial conversion of coal to methane proved effective. However, what maceral component is more susceptible to solubilization and microbial conversion remains elusive. In this study, the dissolution of huminite-enriched Shengli lignite by hydrogen peroxide and its effects on the subsequent methane production by a microbial assemblage were investigated. The huminite was enriched and separated by a combination of hand-picking and floating-sink (isopycnic centrifugation) separation and treated with hydrogen peroxide. Both solid and liquid fractions of the treated coal were subjected to microbial conversion. Various analyses including Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography/Mass Spectrometry (GC/MS), High-Performance Liquid Chromatography (HPLC), Gel Permeation Chromatography (GPC), and DNA sequencing were conducted for both solid and liquid fractions as well as samples after biomethanation. The study demonstrated unequivocally that the enrichment of huminite can improve solubilization and methane production, and that huminite is more accessible and biodegradable compared to other macerals. Microbial analysis revealed that the dominance of methanogens was associated with huminite. Overall, this study provides insight into the bioconversion of lignite to natural gas and suggests that huminite plays a crucial role in this process.

SACARIFICACIÓN ENZIMÁTICA DE BAGAZO DE CAÑA DE AZÚCAR PRETRATADO CON PEROXIDO DE HIDROGENO PARA LA PRODUCCIÓN DE BIOETANOL

&lt;p&gt;&lt;strong&gt;Background.&lt;/strong&gt; Sugarcane (&lt;em&gt;Saccharum officinarum&lt;/em&gt; L.) is one of the main crops in Mexico; during the harvest 2021-2022, 54.6 million tons of raw milled sugarcane were industrialized, ranking sixth in production worldwide. However, during processing, several products and co-products are generated, including sugarcane bagasse, that is used to produce electricity by combustion, converting nearly 25% of its weight into greenhouse gases and generating environmental problems. For this reason, it is necessary to design processes aligned with the axes of sustainable development (environmental, social and economic) to promote valorization and diversification. &lt;strong&gt;Objective&lt;/strong&gt;. To determine the effect of two pretreatments on the enzymatic saccharification of sugarcane bagasse for its subsequent conversion to bioethanol. &lt;strong&gt;Methodology.&lt;/strong&gt; The production of enzymatic extracts by solid state fermentation (SSF) was carried out using sugarcane bagasse as support-substrate and autochthonous fungal strains as inoculum. For the enzymatic saccharification the sugarcane bagasse was pretreated with hydrogen peroxide and microwaves, for the hydrogen peroxide pretreatment the variables time (1, 3 and 6 h), ratio mL of peroxide per gram of bagasse (16. 6:1, 33.3:1 and 100:1), temperature (26, 50 and 70°C) and peroxide concentration (1, 3 and 5%); and for microwave pretreatment the variables microwave power (p30, p50 and p80) and time (5 and 10 min) were evaluated. For the enzymatic saccharification, enzymatic extracts produced by SSF and bagasse pretreated with hydrogen peroxide were used. Finally, fermentable sugars obtained from the enzymatic saccharification of sugarcane bagasse were used as a unique carbon source in alcoholic fermentation system. &lt;strong&gt;Results.&lt;/strong&gt; The SSF results showed the presence of cellulase (2 U/g) and xylanase (61 U/g) activity. On the other hand, the results of pretreatment of sugarcane bagasse with hydrogen peroxide indicated that the best conditions were 100 mL of 3% hydrogen peroxide per gram of sugarcane bagasse at 50°C, while the best conditions of microwave pretreatment were 50p for 5 minutes. The enzymatic saccharification of sugarcane bagasse showed a maximum yield of reducing sugars when the sugarcane bagasse was pretreated with hydrogen peroxide, obtaining 0.41 g/g. Finally, the maximum ethanol concentration (4.32 g/L) was obtained after 48 hours of fermentation with commercial &lt;em&gt;Saccharomyces cerevisae&lt;/em&gt;. &lt;strong&gt;Implications.&lt;/strong&gt; The sugar agroindustry in Mexico is limited to the production of sucrose and ethanol, being necessary a sustainable productive diversification. &lt;strong&gt;Conclusions.&lt;/strong&gt; The isolation of autochthonous fungal strains allowed the production of cellulases and xylanases by solid fermentation with adequate specificity to hydrolyze/saccharify pretreated sugarcane bagasse and its subsequent conversion to ethanol.&lt;/p&gt;

Insights into the capability of the lignocellulolytic enzymes of Penicilliumparvum 4-14 to saccharify corn bran after alkaline hydrogen peroxide pretreatment

BackgroundCorn bran is a major agro-industrial byproduct from corn starch processing. It contains abundant arabinoxylan that can be converted into value-added chemicals via biotechnology. Corn bran arabinoxylan (CBAX) is one of the most recalcitrant xylans for enzymatic degradation due to its particular heterogeneous nature. The present study aimed to investigate the capability of the filamentous fungus Penicilliumparvum 4-14 to enzymatically saccharify CBAX and reveal the fungal carbohydrate-active enzyme (CAZyme) repertoire by genome sequencing and secretome analysis.ResultsCBAX1 and CBAX2 with different branching degrees, together with corn bran residue (CBR) were generated from corn bran after alkaline hydrogen peroxide (AHP) pretreatment and graded ethanol precipitation. The protein blends E_CBAX1, E_CBAX2, and E_CBR were produced by the fungus grown on CBAX1, CBAX2, or CBR, respectively. Under the optimal conditions, E_CBAX1 released more than 80% xylose and arabinose from CBAX1 and CBAX2. Almost complete saccharification of the arabinoxylans was achieved by combining E_CBAX1 and a commercial enzyme cocktail Cellic®CTec3. Approximately 89% glucose, 64% xylose, and 64% arabinose were liberated from CBR by E_CBR. The combination of E_CBR with Cellic®CTec3 enhanced the saccharification of CBR, with conversion ratios of 97% for glucose, 81% for xylose, and 76% for arabinose. A total of 376 CAZymes including plentiful lignocellulolytic enzymes were predicted in P.parvum based on the fungal genomic sequence (25.8 Mb). Proteomic analysis indicated that the expression of CAZymes in P.parvum varied between CBAX1 and CBR, and the fungus produced complete cellulases, numerous hemicellulases, as well as high levels of glycosidases under the culture conditions.ConclusionsThis investigation disclosed the CAZyme repertoire of P.parvum at the genomic and proteomic levels, and elaborated on the promising potential of fungal lignocellulolytic enzymes upon saccharification of corn bran biomass after AHP pretreatment.

Utilization of residual fatty acids in matter organic non-glycerol from a soy biodiesel plant in filaments used for 3D printing

Matter organic non-glycerol (MONG) is a considerable waste output (20%−25% of crude glycerol) typically landfilled by soy biodiesel plants. In this work, soy MONG was characterized for potential use as a copolymer to produce filaments for 3D printing with an intent to add value and redirect it from landfills. As a copolymer, MONG was evaluated to reduce the synthetic polymer content of the natural fiber composites (NFC). Even though the general thermal behavior of the MONG was compared to that of a thermoplastic polymer in composite applications, it is dependent on the composition of the MONG, which is a variable depending on plant discharge waste. In order to improve the thermal stability of MONG, we evaluated two pretreatments (acid and acid + peroxide). The acid + peroxide pretreatment resulted in a stabilized paste with decreased soap content, increased crystallinity, low molecular weight small chain fatty acids, and a stable blend as a copolymer with a thermoplastic polymer. This treatment increased formic acid (17.53%) in MONG, along with hydrogen peroxide, led to epoxidation exhibited by the increased concentration of oxirane (5.6%) evaluating treated MONG as a copolymer in polymer processing and 3D printing.

The impact of alkaline/hydrogen peroxide pretreatment on hydrogen and methane production from biomasses of different origin: The case of willow sawdust and date palm fibers

The present study focuses on the use of two different agricultural residues of lignocellulosic origin, i.e. willow sawdust (WS) and date palm fibers (DPF), as substrates for batch methane and hydrogen production. Prior to use for biofuels production, the substrates were pretreated using dilute solutions of sodium hydroxide, hydrogen peroxide or combinations of the above. The results showed that in almost all cases the pretreatment enhanced biofuels production, leading to remarkably high yields compared with the untreated substrates. Specifically, WS optimal yields were 200.40 ± 13.49 L CH4/kg of raw TS (94% increase) and 102.43 ± 12.25 L H2 per kg of raw TS (345% increase) and they were observed after the addition of the mixture of the two chemical agents for 24 h at 80 °C. Also, DPF optimal yields were 211.55 ± 16.18 L CH4/kg raw TS (62% increase) and 110.50 ± 7.97 L H2/kg of raw TS (310% increase) while they were achieved when hydrogen peroxide was added to the substrate first for 24 h at 80 °C and then sodium hydroxide for another 24 h at 80 °C.

Enhanced volatile fatty acid production from waste activated sludge by urea hydrogen peroxide: performance and mechanisms.

Anaerobic acidogenesis of waste activated sludge (WAS) presents significant potential for resource recovery and waste treatment. However, the slow hydrolysis of WAS limits the efficiency of this approach. In this study, we applied urea hydrogen peroxide (UHP) pretreatment to enhance WAS hydrolysis and investigated the effects of operating parameters on volatile fatty acid (VFA) production and the associated mechanisms. Results demonstrated that UHP significantly improved WAS hydrolysis and VFA production, with a three-fold increase in soluble chemical oxygen demand (SCOD) compared to the control group. UHP dosage emerged as the most critical factor for VFA production, with the maximum VFA concentration increasing from 1127.6 to 8800.9 mg COD per L as UHP dosage ranged from 0 to 6 mmol g-1 VSS (Volatile suspended solids). At an optimal UHP dosage of 4 mmol g-1 VSS, both the unit oxidant promotion efficiency (ΔVFAs/ΔUHP) and the maximum VFA concentration reached relatively high levels, at 35.3 mg COD per mmol and 7527.3 mg COD per L, respectively. UHP pretreatment generated alkaline conditions, H2O2, ·OH and free ammonia, which collectively disrupted the extracellular polymeric substances (EPS) structure, transforming unextractable EPS into extractable forms and promoting the release of organic matter during both the pretreatment and fermentation stages. Excitation-emission matrix (EEM) analysis revealed that UHP increased the concentration of easily utilizable organic matter, providing more substrates for acidogenic bacteria and enhancing VFA production. Furthermore, weak alkaline conditions and high free ammonia concentrations in the UHP group facilitated VFA accumulation by preventing rapid acidification and suppressing methanogen activity. This study offers valuable insights into the potential of UHP pretreatment for enhancing WAS hydrolysis and VFA production, with promising applications in wastewater treatment and resource recovery.

Hydrogen peroxide pretreatment assisted phytoremediation of sodium dodecyl sulfate by Juncus acutus L

BackgroundSodium Dodecyl Sulfate (SDS) an anionic surfactant pollutant has emerged as a serious hazard to the aquatic and terrestrial environment. Due to physical and chemical methodological difficulties for SDS removal, phytoremediation techniques are efficient alternative strategies to tackle such adversities. Juncus acutus L. (J. acutus) is a pioneer wetland species that has been recently exploited for phytoremediation purposes. To our knowledge, the role of exogenous hydrogen peroxide (H2O2), in improving the phytoextraction of SDS has not been examined yet. In this study, pretreatment foliar spray of H2O2 (15 mM) combined with two levels of SDS (50 and 100 ppm) in water culture was evaluated to remove SDS contamination and add value to the phytoremediation process.ResultsThe outcomes revealed that J. acutus has considerable translocation and bioaccumulation abilities for SDS and can be utilized as an appropriate hyperaccumulator in SDS-contaminated sites. However, the involvement of H2O2 extended phytoremediation capacity and successive removal of SDS. H2O2 significantly assisted in increasing SDS remediation via more accumulation in J. acutus tissues by 29.9 and 112.4% and decreasing SDS concentration in culture media by 33.3 and 27.3% at 50 and 100 ppm SDS, respectively. Bioaccumulation factor (BCF) increased by 13.8 and 13.2%, while translocation factor (TCF) positively maximized by 82.4 and 76.2% by H2O2 application at 50 and 100 ppm SDS, respectively. H2O2 pretreatment could drive the decline in biochemical attributes in SDS-affected plants by modulating stress tolerance indices, pigments, water relations, proline content, enzymatic activities, and further, reduced oxidative stress in terms of electrolyte leakage, cellular H2O2, malondialdehyde (MDA) accumulation.ConclusionsH2O2 could play a potential role in maximizing phytoremediation capacity of SDS by J. acutus in polluted sites.

Efficient fractionation and targeted valorization of industrial xylose residue by synergistic and mild alkaline deep eutectic solvent‑hydrogen peroxide pretreatment

Achieving efficient fractionation and tailored downstream high value-added applications of bulk industrial waste biomass could guarantee the sustainability of biorefinery strategies. A synergistic and mild alkaline deep eutectic solvent‑hydrogen peroxide (DES-HP) pretreatment was designed in this study to significantly reduce pretreatment costs while achieving efficient fractionation of industrial xylose residues for preparing high antioxidative lignin and high enzymatic digestion of cellulose substrates for subsequent bioenergy and biochemicals production. The results demonstrated that this DES-HP pretreatment had admirable biomass deconstruction ability and the obtained DES-HP lignin displayed well-preserved structures and excellent antioxidative properties, which facilitated downstream catalytic degradation as well as the production of lignin-based materials and chemicals. Under the optimal condition (60 °C, 2 h, 10 FPU/g), the fermentable glucose yield of the DES-HP pretreated substrate could achieve 95.89%. In conclusion, this synergistic DES-HP is an ideal pretreatment strategy for the current tailored biorefinery scenario of industrial lignocellulosic biomass.

Utilizing rice straw and sugarcane bagasse as low-cost feedstocks towards sustainable production of succinic acid

Succinic acid (SA) has been produced from rice straw (RS) and sugarcane bagasse (SB) as low-cost feedstocks in this study through sequential peracetic acid (PA) and alkaline peroxide (AP) pretreatment assisted by ultrasound and pre-hydrolysis followed by simultaneous saccharification and fermentation (PSSF). The effect of yeast extract (YE) concentration, inoculum concentration, and biomass type on SA production was investigated. The results showed that SA production from RS and SB was significantly affected by the YE concentration. Final concentration and yield of SA produced were significantly increased along with the increasing of YE concentration. Moreover, inoculum concentration significantly affected the SA production from SB. Higher inoculum concentration led to higher SA production. On the other hand, SA production from RS was not significantly affected by the inoculum concentration. Using RS as the feedstock, the highest SA production was achieved on the medium containing 15 g/L YE with 5 % v/v inoculum, obtaining SA concentration and yield of 3.64 ± 0.1 g/L and 0.18 ± 0.05 g/g biomass, respectively. Meanwhile, the highest SA production from SB was acquired on the medium containing 10 g/L YE with 7.5 % v/v inoculum, resulting SA concentration and yield of 5.1 ± 0.1 g/L and 0.25 ± 0.05 g/g biomass, respectively. This study suggested that RS and SB are potential to be used as low-cost feedstocks for sustainable and environmentally friendly SA production through ultrasonic-assisted PA and AP pretreatment and PSSF.

Effects of modified biochars on the shifts of short-chain fatty acid profile, iron reduction, and bacterial community in paddy soil.

Biochar is well known as an effective means for soil amendment, and modification on biochar with different methods could improve the benefits for environmental remediation. In this study, two modified biochars were generated with nitric acid (NBC) and hydrogen peroxide (OBC) pretreatment, and a control biochar was produced after washing with deionized water (WBC). The dynamics of short-chain fatty acids (SCFAs), iron concentration and bacterial community in rice paddy soil amended with different biochars or without adding biochar (CK) were studied during 70 days of anaerobic incubation. Compared to CK treatment, the accumulation of SCFAs was largely inhibited by the amendment of biochars. Besides, OBC and WBC increased the accumulation of Fe(II) at the initial stage of incubation. Via 16S rRNA gene sequencing, modified biochars caused significant response of bacterial community in comparison to WBC at Day 0-1, and three biochars favored bacterial α-diversity in the paddy soil at the end of the incubation. Interestingly, positive and negative correlations between NBC and several bacteria taxa (e.g. Geobacter, Fonticella and Clostridium) were observed. The study revealed that modified biochars had significant effects on the shifts of SCFAs, Fe(III) reduction and bacterial diversity, which provides fundamental information for future application of modified biochars in rice cropping ecosystem.

Testing the effect of oxidizing pre-treatments on amino acids in benthic and planktic foraminifera tests

Amino acid racemization (AAR) is a geochronological method that uses the ratio of D- to L-configurations in optically active amino acids from carbonate fossils to determine the time elapsed since the death of an organism. Although AAR techniques have been widely applied to foraminiferal tests, there have been limited dedicated assessments of the potential of isolating a bleach-resistant, intra-crystalline fraction of proteins to improve the reliability of AAR in this biomineral system. In this study, we evaluate the effect of two oxidative pre-treatments (hydrogen peroxide and bleach) on amino acid concentrations and D/L values in sub-modern benthic foraminifers ( Ammonia spp. and Haynesina germanica ) and well-preserved mid Holocene and mid Pleistocene planktic foraminifers ( Pulleniatina obliquiloculata , Globorotalia truncatulinoides , and Globorotalia tumida ). The oxidative pre-treatments successfully reduced the amino acid content of the foraminiferal tests to a residual fraction, and with the exception of Ammonia spp., neither pre-treatment substantially affected the relative proportion of individual amino acids. The bleaching pre-treatment does not consistently alter D/L values when compared to peroxide pre-treatment, but it does tend to reduce the subsample variability in D/L values, albeit only to a small degree in an inconsistent fashion. Therefore, we recommend that a relatively weak oxidative pre-treatment with 3% hydrogen peroxide is sufficient for foraminifera-based AAR applications. • Intra-crystalline fraction of amino acids in foraminiferal tests was isolated using oxidative pre-treatments • Difference in concentration between the inter- and intra-crystalline fractions of amino acids decreases with increased sample age • No consistent improvement in intra-sample variability when foraminiferal tests are treated with bleach • Pretreating foraminiferal tests with peroxide rather than bleach is recommended