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This study investigated expired dairy product (EDP) removals in a two-stage system in anaerobic batch reactors co-digested with synthetic domestic wastewater (SDW) to evaluate H 2 and CH 4 production. Acidogenesis was performed in anaerobic batch reactors with 10%, 15%, and 20% EDP (v/v) mixed with SDW, and the effluents were the substrate for methanogenic reactors. During acidogenesis, reactors with 10%, 15%, and 20% EDP achieved 86.8%, 90.1%, and 92.3% carbohydrate removal, producing 1.5, 1.9, and 1.7 mol H₂ per mol carbohydrate removed, respectively. Paraclostridium was the dominant genus (55.7–82.7%) involved in hydrogen, volatile fatty acid (VFA) and alcohol generation. Methanogenesis assays with 10% and 15% EDP achieved high methane yields (323.0 and 225.1 mL CH₄ gVSadd⁻1) and COD removals (91.8% and 94.7%), while 20% EDPs led to inhibition due to VFA accumulation. Methanosaeta was prevalent in high-yield reactors, correlating with effective COD removal. This study highlights the potential for EDP recovery through biogas production. [Display omitted] • Effective co-digestion was achieved with 15% expired dairy products and 85% synthetic domestic wastewater. • Satisfactory carbohydrate removal (86.8–92.3%) was obtained for all assays. • High methane yields (259.2–323.0 mL CH₄ gVSadd⁻1) and COD removals (91.8%–94.7%) were achieved. • Inhibition was observed at higher substrate concentrations due to volatile fatty acid accumulation. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSThe biomethanization of lignocellulosic wastes remains an inefficient and complex process due to lignin structures that hinder the hydrolysis step, therefore, some treatments are required. This work describes the addition of an enriched microbial consortium in the biomethanization of rice straw. The experiment was carried out in lab batch reactors following two strategies: (i) pretreatment of rice straw for 48 h using the enriched microbial consortium (dilution 1:100), and (ii) addition of this enriched microbial consortium (dilution 1:100) directly to the anaerobic reactors (bioaugmentation). The kinetic behavior was described using three models. As a result, the microbial consortium molecular characterization showed 58 different bacterial species, predominantly the Lactobacillaceae family (45.7%), and the Clostridiaceae family (19.1%), which were responsible for the positive effect obtained by bioaugmentation with methane yield increases of 16% (290 LNCH4/kgVS) respect to the control. All kinetic models applied fitted the experimental data for cumulative methane production, although the modified Hill model showed the best fit. Bioaugmentation strategies demonstrate their effectiveness in lignocellulosic biodegradation, but the novelty of this research lies in the application of an enriched microbial consortium obtained by the authors through soil isolation techniques, which are very inexpensive and affordable for developing countries.An enriched microbial consortium developed by using the effective microorganism’s technology and soils isolated was characterized.Rice straw anaerobic digestion was bioaugmented by the addition of the enriched microbial consortium.Bacterial community dynamics during rice straw anaerobic digestion were influenced by pretreatment or bioaugmentation strategies.Bioaugmentation increases the celluloses biomass availability and the methane yield (16%).Specific methanogenic activity and kinetic were influenced by adding the enriched microbial consortium.An enriched microbial consortium developed by using the effective microorganism’s technology and soils isolated was characterized.Rice straw anaerobic digestion was bioaugmented by the addition of the enriched microbial consortium.Bacterial community dynamics during rice straw anaerobic digestion were influenced by pretreatment or bioaugmentation strategies.Bioaugmentation increases the celluloses biomass availability and the methane yield (16%).Specific methanogenic activity and kinetic were influenced by adding the enriched microbial consortium. [ABSTRACT FROM AUTHOR]

AbstractThe study employed batch shake flasks to evaluate the impact of various nitrogen sources, phosphate levels, and sodium acetate (Na-acetate) on the Rhodotorula mucilaginosa growth and metabolite production. Adding Na-acetate to the medium resulted in significant improvements in critical metabolites. In shake flask experiments, this led to a cell dry weight (CDW) of 1.65 ± 0.94 g L−1, with lipids comprising 66.53% of the biomass. While β-carotene and carotenoid were 5.84 ± 0.05 and 37.66 ± 2.13 µg g−1, respectively. Subsequent experiments in a batch reactor with Na-acetate supplementation further improved these metrics. CDW increased to 5.02 ± 0.83 g L−1, and lipid content to 65.73 ± 0.81%. Carotenoid production rose to 40.33 ± 1.84 µg g−1, with β-carotene reaching 17.63 ± 0.32 µg g−1. The most promising results were obtained using a fed-batch bioreactor strategy with Na-acetate. R. mucilaginosa achieved the highest yields across all parameters: 48.36 ± 1.14 µg g−1 of total carotenoids, 21.38 ± 1.14 µg g−1 of β-carotene, and a lipid content of 68.58 ± 1.95%. [ABSTRACT FROM AUTHOR]

Experiments on methylamine (CH3NH2${\rm CH}_3{\rm NH}_2$) decomposition in shock tubes, flow reactors, and batch reactors have been re‐examined to improve the understanding of hydrocarbon/amine interactions and constrain rate constants for CHx${\rm CH}_{ x}$ + NHy${\rm NH}_{ y}$ reactions. In high‐temperature shock tube experiments, the rapid thermal dissociation of CH3NH2${\rm CH}_3{\rm NH}_2$ provides a fairly clean source of CH3${\rm CH}_3$ and NH2${\rm NH}_2$ radicals, allowing an assessment of reactions of CH3${\rm CH}_3$ with NH2${\rm NH}_2$ and NH. At the lower temperatures in batch and flow reactors, CH3NH2${\rm CH}_3{\rm NH}_2$ is mostly consumed by reaction with H to form CH2NH2${\rm CH}_2{\rm NH}_2$ + H2${\rm H}_2$; these results are useful in determining the fate of the CH2NH2${\rm CH}_2{\rm NH}_2$ radical. Interpretation of these data, along with flow reactor data for the CH3NH2${\rm CH}_3{\rm NH}_2$/H system at lower temperature, indicates that at temperatures up to about 1400 K at atmospheric pressure and above 2000 K at 100 atm, the CH3${\rm CH}_3$ + NH2${\rm NH}_2$ reaction forms mainly methylamine. At sufficiently high temperature, H‐abstraction to form CH4${\rm CH}_4$ + NH and addition–elimination to form CH2NH2${\rm CH}_2{\rm NH}_2$ + H become competitive. The CH3${\rm CH}_3$ + NH reaction, with a rate constant close to collision frequency, forms CH2NH${\rm CH}_2{\rm NH}$ + H, also leading into the hydrocarbon amine pool. Thus, methylamine can be expected to be an important intermediate in co‐combustion of natural gas and ammonia, and more work on the chemistry of CH3NH2${\rm CH}_3{\rm NH}_2$ is desirable. [ABSTRACT FROM AUTHOR]

This paper introduces a comprehensive approach to treating industrial laundry wastewater collected from a railway laundry, employing a novel unique sequential combination of coagulation–flocculation, neutralization, ultraviolet (UV)-H2O2 treatment, and biological processes. Typical characterization of laundry wastewater reveals high pH, suspended solids, dissolved organic content, and low biodegradability. The researched treatment sequence involved turbidity reduction (65%) using FeCl3 and cationic polyelectrolyte coagulants followed by pH neutralization (7–8), UV-H2O2 treatment [83% and 23% chemical oxygen demand (COD) and biochemical oxygen demand (BOD) removal, respectively) and aerobic biological treatment (88% and 97% for COD and BOD removal, respectively). During the UV-H2O2 process, when the H2O2 dosage exceeded 30 mg·L−1, inefficiency in COD removal was observed owing to the scavenging of hydroxyl radicals. With the increase in flow rate, the COD removal was reduced nominally. The effluent from the UV-H2O2 process was treated by an aerobic sequential batch reactor, demonstrating high efficacy in removing both BOD and COD. The biokinetics parameters, such as half-saturation coefficient (ks), maximum specific rate of substrate utilization (k), yield coefficient (Y), decay rate (Kd), and maximum specific growth rate (µm) were determined, and they were observed to be 130 mg of COD·L−1, 0.3 day−1, 0.9 mg volatile suspended solids/mg COD, 0.055 day−1, and 0.42 day−1, respectively. Overall, a reduction of approximately 95% of COD and 97% of BOD was attained, rendering the wastewater suitable for safe disposal into inland surface waters. This showcases an effective and sustainable method for treating laundry wastewater. Practical Applications: The present work deals with the characterization and treatment of industrial laundry wastewater. The typical laundry wastewater is mainly characterized by high suspended solids and chemical oxygen demand (COD) due to nonbiodegradable organics. The biodegradability index of the wastewater was very poor (0.15–0.25), which made it difficult to treat by conventional biological processes. Hence, a treatment chain consisting of coagulation–flocculation–sedimentation, neutralization, ultraviolet-H2O2 advanced oxidation process, and sequential batch reactor (SBR) was used. Alum coagulation at high pH, along with the addition of cationic polyelectrolyte, removed the suspended solids to a great extent. Sulfuric acid was found to be the most efficient to neutralize the wastewater after coagulation. In the UV-H2O2 process, the COD of the wastewater was reduced to < 250 mg·L−1, below the discharge standard specified in the Central Pollution Control Board, India guidelines. However, the biochemical oxygen demand (BOD) was much higher compared to the discharge standard. The biodegradability index increased to 0.8, which indicated that nonbiodegradable organics were converted to biodegradable organics. The BOD of the wastewater was reduced to < 30 mg·L−1 through SBR. The proposed wastewater treatment chain led to an overall 95% of COD and 97% of BOD removal. [ABSTRACT FROM AUTHOR]

In the present study, ohmic heating system was developed for the pasteurization of liquid egg white. A batch reactor system was designed with a capacity of 100 ml and operated at varied gradients of voltage (20, 15, 10 V/cm), frequencies (10, 55, 100 Hz), holding times (1, 2.5, 4 min) at two different waveforms (sine and square). The treated liquid egg white was evaluated for validation parameters viz., heating rate, turbidity, soluble protein content, foaming capacity, and foaming stability. The viscosity of ohmically treated egg white was observed by subjecting the egg white to the shear rate ranges from 0.167 to 68 (s−1) where the viscosity decreased as the shear rate increased. The ohmic heating process variables were optimized using the Box-Behnken design and had a significant effect (P < 0.005) on the responses. The optimized parameters 17.93 V/cm voltage gradient, 10 Hz frequency, and 1.6 min holding time for sine waveform resulted in 19.6 °C/min heating rate, 0.01 turbidity, 98.35% soluble protein, 405.68% foaming capacity, and 31.84% foaming stability with the highest desirability of 78% of liquid egg white. The model developed from the dataset of this design can be used for predicting the responses within the limits of process variables. [ABSTRACT FROM AUTHOR]

This paper presents a contrast of two different observation strategies viz a nonlinear observer and a classical extended Luenberger observer applied to a bioreactor system for Bacillus thuringiensis production. The performance of the two observers was evaluated under different conditions, both with and without state perturbations. Firstly, equal initial conditions were considered without the presence of white noise in the measurement of dissolved oxygen concentration in the culture medium. The performance was then analyzed by perturbing the maximum cell growth rate with equal and different initial conditions, and, finally, the performance of the observer with the presence of white noise was evaluated. The proposed observer performed better than the extended Luenberger observer against initial conditions different from the model. The results of this study are of great interest, as they provide insight into the estimation of the state of the dynamics for the B. thuringiensis bioreactor in a batch mode. In addition, these results provide valuable information for future research in the design of observers for B. thuringiensis bioprocessing. [ABSTRACT FROM AUTHOR]

This study investigates the simultaneous separation process using a batch reactor coupled to a cellulose acetate membrane for the enzymatic hydrolysis of residual soybean oil. The membrane was manufactured with 30 s pre‐evaporation time and 1‐mm thickness. Their morphologies and wettability were analyzed. Pichia pastoris lipase was characterized based on temperature and pH and was applied to the hydrolysis of residual soybean oil at 45 °C and pH 7 in batches, with and without simultaneous separation. The results show that the process efficiency with the cellulose acetate membrane resulted in 55.58 % ± 2.78 % free fatty acids in enzymatic hydrolysis, compared with 39.72 % ± 1.99 % without the membrane. The membrane also achieved 100 % oil rejection. [ABSTRACT FROM AUTHOR]

The efficacy of zero-valent iron (ZVI) for the simultaneous nitrification denitrification and phosphorus removal (SNDPR) process is unclear, although it has been shown in numerous studies to help improve nitrate removal in biological wastewater treatment systems. This study investigated the response of the SNDPR process to ZVI addition in an anaerobic/aerobic/anoxic (An/O/A)-sequencing batch reactor (SBR). The results indicated that ZVI addition could promote the removal of phosphorus and total inorganic nitrogen (TIN). The phosphorus removal by ZVI was mainly attributed to iron precipitation due to the in situ oxidation of ZVI by oxygen or nitrate. The TIN removal by ZVI was attributed to the chemical denitrification reaction, which reduces nitrate to nitrite and nitrogen gas. The nanoscale zero-valent iron (nZVI) was more favorable for TIN removal than microscale zero-valent iron (mZVI) in the SNDPR process. The average removal efficiency of PO43−-P and TIN increased from 50.37 ± 7.55% to 99.29 ± 1.24% and 73.15 ± 5.92% to 76.75 ± 5.05% with nZVI addition. The relative abundance of Dechloromonas sp. decreased by 0.65% and that of Nitrospira sp. increased by 3.78% with the addition of ZVI, indicating that ZVI could weaken the activity of polyphosphate-accumulating organisms (PAOs) and promote the activity of nitrite-oxidizing bacteria. These results provide a new and environmentally friendly approach for applying ZVI in SNDPR systems, reducing the dependence on organic carbon sources. [ABSTRACT FROM AUTHOR]

The ring‐rearrangement of 5‐hydroxymethylfurfural (HMF) to 3‐hydroxymethylcyclopentanone (HCPN) was investigated over Ni catalysts supported on different carbon supports and metallic oxides with different structure and acid‐base properties. Their catalytic performance was tested in a batch stirred reactor in aqueous solution at 180 °C and 30 bar of H2. Under these conditions, the HMF hydrogenation proceeds through three possible competitive routes: (i) a non‐water path leading to the total hydrogenation product, 2,5‐di‐hydroxymethyl‐tetrahydrofuran (DHMTHF), and two parallel acid‐catalyzed water‐mediated routes responsible for (ii) ring‐opening and (iii) ring‐rearrangement reaction products. All catalyst systems primarily produced HCPN, but reaction rates and product distribution were influenced by several variables, some of them intensely analyzed in this work. The most proper conditions resulted to be the presence of the medium/strong Lewis's acidity of a Ni/ZrO2 catalyst (initial TOF=5.99 min−1 and 73 % HCPN selectivity) or the Brønsted acidity originated by an oxidized high surface area graphite, Ni/HSAG‐ox (initial TOF=5.92 min−1 and 87 % HCPN selectivity). However, too high density of acidic sites on the catalyst support (Ni/Al2O3) and sulfur impurities from the HMF feedstock led to catalyst deactivation by coke deposition and Ni poisoning, respectively. [ABSTRACT FROM AUTHOR]

This work presents a way to use ethanol and spent coffee grounds (SCG) as feedstocks for biodiesel production to solve ethanol overproduction in Thailand and biodiesel feedstock shortage problems together. Waste coffee oil (SCGO) was ethanolic extracted from SCG; then, ethanol-SCGO mixture was transesterified in supercritical condition without ethanol removal. The ethanolic extraction curves of SCG at a temperature range of 50–70 °C were constructed. Transesterification experiments were studied in a batch reactor and a continuous reactor at various temperatures (275–350 °C) and reaction time (5–40 min) under 15.0 MPa. The molar ratio of ethanol-oil mixture was set at 30:1. The highest ester content of 88.37 ± 3.00 wt% was found in biodiesel obtained at a temperature of 275 °C and a reaction time of 40 min in a batch reactor. Furthermore, excess temperature (< 300 °C) and reaction time (< 20 min) induced thermal degradation and promoted the loss of ethyl linoleate. For continuous reactor, the maximum ester content of 83.38 ± 5.86 wt% was observed at 325 °C and 29.4 min of residence time. Unlike in batch reactors, thermal degradation of ethyl linoleate was not observed in a continuous reactor. The results showed that ethanolic extraction and supercritical transesterification are alternative ways to produce biodiesel from SCG without removing extractant and using catalyst. From a prospective point of view, techno-economic analysis (TEA) and life-cycle assessment (LCA) of invented process should be conducted to ensure profitability and environmental benefits, respectively. [ABSTRACT FROM AUTHOR]

Substantial amounts of expired dairy products (EDP) are generated due to their high perishability. These wastes are rich in organic matter, and their landfill disposal negatively impacts the environment. An alternative to reducing and recovering this waste would be to use it as a substrate in anaerobic digestion (AD) to produce biogas. This study investigated methane (CH4) production using different concentrations of EDP co-digested with synthetic domestic wastewater (SDW). Five anaerobic batch reactors (1000 mL) were assembled with different concentrations of EDP in SDW (500 mL working volume), namely (1) 0%, (2) 5.0%, (3) 7.5%, (4) 10.0%, and (5) 15.0% (v/v). COD removals were 81%, 84%, 80%, 89%, and 14% for assays 1 to 5, respectively. The cumulative CH4 productions were (mL/L) 717, 3354, 5327, 6584, and 1156 for assays 1 to 5, respectively. Assay 5 (15% EDP) was inhibited by volatile fatty acid (VFA) accumulation. However, assays 2, 3, and 4 (with 5.0–10.0% EDP) showed high CH4 yields (mLCH4/gVSadd) of 319, 333, and 317, respectively, demonstrating the feasibility of anaerobic co-digestion of EDP with SDW. In assays 3 and 4, a similar archaeal community structure was observed, dominated by the genera Methanosaeta, Methanolinea, Methanoregula, and Methanobacterium. In assay 2, the archaeal community demonstrated lower dominance due to insufficient substrate adaptation. This study confirms the viability of using EDP in AD systems to generate CH4, suggesting future sustainable applications for this residue. [ABSTRACT FROM AUTHOR]

The impact of sodium dodecyl sulfate (SDS, as model linear anionic surfactant) dosage on overall nitrogen removal performance of anammox reactor alongside its microbial population and sludge properties was investigated. In this study (day 136), an anmmox sequencing batch biofilm reactor was subjected to gradual dosage of SDS from 0 to 20 mg L−1. Intriguingly, results revealed that SDS at ≥7.5 mg L−1 prompted sludge disintegration, evidenced by increased protein and polysaccharide content in the effluent. Nevertheless, reactor's average total nitrogen removal efficiency slightly improved from 83.12% (0 mg L−1) to 86.3% (20 mg L−1). The 16S rRNA gene sequencing revealed that SDS dosing significantly suppressed the unwanted and unavoidable nitrite oxidizing bacteria (NOBs) in the reactor as the abundance of genus Nitrospira declined from 40.68% (day 1) to 19.15% (day 136). The abundance of anammox genus Candidatus Kuenenia significantly improved from 1.86% (day 1) to 40.02% (day 136) as a result of NOB suppression. This study revealed that low concentration of surfactants in wastewater does not affect the anammox bacteria in a biofilm reactor. Furthermore, adding low concentrations of SDS (≥7.5 to 20 mg L−1) to wastewater may effectively suppress notorious NOBs in biofilm‐based anammox systems. [ABSTRACT FROM AUTHOR]

For ammonium removal from wastewater, anammox technologies are among the most efficient and rapidly developing ones. Due to the low growth rate of anammox bacteria and their sensitivity to various inhibitors, technologies using attached biocenosis carriers (ABCs) provide for reliable operation. The goal of the present work was to investigate a new ABC type, ETEK biochips based on a nonwoven fibrous material. The work involved the techniques of materials science (design of a new ABC type) and physical modeling of the anammox process (in a laboratory bioreactor), as well as electron microscopy and molecular profiling of activated sludge communities. Comparison of the ETEK biochips with the ABCs of foamed polyethylene BF33 and Mutag revealed more rapid accumulation (5-fold) of the activated sludge biomass on ETEK biochips upon reactor launching, as well as comparable buoyancy and reactor productivity regarding N removal. The specific rate of nitrogen removal obtained with ETEK biochips considerably exceeded that for foamed polyethylene with a filler: 1.5–3 times higher per chip and 1.5 times higher per activated sludge biomass unit. The studied ABC shared the same issue of floating to the surface due to the active formation of gas (N2). The algorithm for calculating the downward flows in bioreactors with rapidly surfacing ABC is proposed, and a new hydrodynamic type of a bioreactor (with hybrid hydrodynamics) is described, a moving bed–sequencing batch reactor (MB-SBR). [ABSTRACT FROM AUTHOR]

The production of volatile fatty acids (VFAs) through the acidogenic fermentation of wastewater is an emerging technology that requires further research to optimize operational variables for specific substrates. Cassava wastewater, which is a byproduct of the cassava sour starch extraction process, has been minimally studied regarding its potential for VFA production through acidogenic fermentation. Batch reactors were used to evaluate the effects of the substrate-to-microorganism (S/M) ratio and temperature on VFA production from cassava wastewater. The results showed no statistically significant differences between the evaluated S/M ratios. The maximum total VFA concentration observed was 2214.64 mg of acetic acid (HAc)/L (0.32 gCODVFA/gCOD), which was achieved at a S/M ratio of 4 gCOD/gVS. This concentration was predominantly composed of acetic acid (42.7%), followed by butyric acid (30.1%) and propionic acid (24.6%), with a minor quantity of isovaleric acid (2.6%). The statistical analysis for the temperature variable showed significant differences between the evaluated conditions. The maximum concentration of total VFAs was 2650.19 mgHAc/L (0.45 gCODVFA/gCOD) at 34 ± 1 °C, with acetic (40.9%), butyric (29.8%), and propionic (29.3%) acids as primary metabolites. Cassava wastewater shows promise as a potential substrate for VFA production, warranting evaluation in continuous reactors. [ABSTRACT FROM AUTHOR]

Denitrification coupled to methane oxidation (DOM) has been shown to be an appropriate process for wastewater treatment applications, since it can reduce greenhouse gas emissions and nitrogen discharges, making wastewater treatment plants more environmentally sustainable. Study of DOM has focused on laboratory-scale application using membrane biological reactors (MBR) or sequency batch reactors (SBR), which have been shown to be able to retain DOM biomass and therefore appropriate for use with this process. However, it is necessary to expand knowledge of the behavior of this process using other configurations, with a view to scaling up. Therefore, in this study, an upflow fixed bed bioreactor (UFBR) was implemented using plastic carriers such as bioballs and Biochips® to carry out the DOM process under anoxic conditions. The reactor reached stable nitrogen removal conditions after approximately 400 days of continuous operation, forming a biomass composed of denitrifying methane-oxidizing microorganisms where the genus Anaerolinea and Methylocystis predominated. Once the biomass was formed and the DOM process was stabilized, maximum nitrite and nitrate removal rates of 17.6 mgN-NO2−/L-d and 8.9 mgN-NO3−/L-d, respectively, and a removal efficiency of methane up to 77% were obtained. This demonstrates the feasibility of the application of the DOM process under anoxic conditions using fixed bed bioreactors, which is promising for further nitrogen removal from wastewater using a varied reactor configuration easily to scaled-up. Highlights: UFBR properly allowed DOM process under anoxic conditions. Biomass formed by DOM microorganisms, heterotrophic denitrifyers and methanotrophs. Up to 90% removal of nitrite and nitrate after 400 days of operation. [ABSTRACT FROM AUTHOR]

To date, the understanding of various modes of CO2 mass transport remains incomplete, impeding the transfer of catalysts identified in the more accessible electrochemical batch cells to high-performance flow cells. In this work, we demonstrate that the meniscus region formed between the electrode and the convex liquid level due to the electrowetting of the catalyst plays a vital role in the CO2RR in batch cells. CO2RR in the meniscus region in batch cells exhibits similar performance with that in flow cells, and the performance disparity between these two configurations largely disappears when conducting CO2RR primarily in the meniscus region. An assembled double-sided gas diffusion electrode with a gas channel is developed to maximize the meniscus-like region, achieving a CO2RR partial current density of 640 mA/cm2 geo on commercial Cu in the KHCO3 electrolyte. This performance represents the highest CO2RR activity in neutral buffered media. [ABSTRACT FROM AUTHOR]

Enzymatic production of nucleotide sugars on a multigram scale presents a challenge, as only a few processes have been reported for large-scale nucleotide sugar production. They rely primarily on batch synthesis and employ exceptional amounts of enzymes. This study introduces a novel approach for the multigram-scale production of nucleotide sugars with a continuous fed-batch membrane reactor. We successfully synthesized five main nucleotide sugars: UDP-Gal, UDP-GalNAc, UDP-GlcA, GDP-Man, and CMP-Neu5Ac on a multigram scale. Efficient biocatalyst utilization results in high performance, including space-time yield (STY, g*L−1h−1), total turnover number (TTN, g product per g enzyme), and an efficient product formation rate (g/h) suitable for industrially relevant bioprocesses. The established continuous-fed batch reactor system produced up to 8.2 g CMP-Neu5Ac in three consecutive productions in less than 15 h with satisfying TTNs of 91 g Product /g Enzyme. Continuous production of UDP-GlcA over 28 h resulted in a final product amount of 14.8 g and TTN of 493 g P /g E. This process enables the production of nucleotide sugars with stable product formation, requiring minimal technical equipment for multigram quantities of nucleotide sugars at the laboratory scale. Notably, the system exhibited robustness and flexibility, allowing its application to various enzymatic nucleotide sugar synthesis cascades. [Display omitted] • New process for the multi-gram scale production of nucleotide sugars. • Multigram-scale production of five out of the nine main nucleotide sugars. • High TTNs possible in a lab-scale approach. • High throughput of substrates using small quantities of enzyme. • Continuous production over up to 28 h. [ABSTRACT FROM AUTHOR]

The immobilization of suspension catalysts in flexible, fibrillated films offers a promising solution to the mass transfer limitations often encountered in three-phase hydrogenation reactions. This study investigates the catalytic performance and mass transfer properties of fibrillated films in the hydrogenation of nitrobenzene to aniline, comparing them to free-flowing powdered catalysts. Fibrillated films were prepared from Pd/C catalysts with varying thicknesses (100–400 µm), and their performance was evaluated through kinetic studies in both batch reactors and microreactors. The specific activity of the films was significantly influenced by film thickness with thinner films demonstrating lower mass transfer limitations. However, mass transfer limitations were observed in thicker films, prompting the development of alternative film designs, including enhanced macro-porous films and sandwich structures. These modifications successfully minimized diffusion limitations, achieving similar specific activity to the powder catalysts while maintaining the mechanical stability of the films. This work demonstrates the feasibility of using fibrillated films for continuous catalytic processes and highlights their potential for efficient catalyst reuse, avoiding filtration steps and enhancing process sustainability. Furthermore, while PTFE remains indispensable for producing such films due to its mechanical and thermal stability, ongoing research focuses on identifying more environmentally friendly alternatives without compromising performance. [ABSTRACT FROM AUTHOR]

A tandem catalyst system comprised of trifluoromethanesulfonic (triflic acid, HOTf) or hafnium tetratriflate (Hf(OTf)4) and Ru/C in glacial acetic acid (HOAc) as the solvent at 200 °C and ∼ 7 MPa hydrogen pressure in a batch reactor converts penta‐acetyl‐xylitol ((2R,3R,4S)‐pentane‐1,2,3,4,5‐penta‐acetoxy‐pentane) or unprotected xylitol to 3‐acetoxymethylene‐tetrahydrofuran (3‐AMT) in up to 15% yield at full conversion. A comparative analysis by SEM‐EDS and XPS of the fresh commercial Ru/C catalyst versus catalyst reused and recovered after five cycles shows increasing aggregation of ruthenium to larger particles with a concomitant decrease in yield of 3‐AMT to 8%–9% for cycles four and five. 3‐AMT or its hydrolysis product 3‐hydroxymethyl‐tetrahydrofuran (3‐HMT) are valuable synthons for the preparation of agrochemicals, pharmaceuticals, and specialty polyurethanes and polyesters. [ABSTRACT FROM AUTHOR]

The direct conversion of syngas into hydrocarbons, catalyzed by a combination of metal oxide and acidic zeolite, has garnered increasing attention in the scientific community. The remarkable hydrocarbon selectivity achieved in the OX‐ZEO process is a key factor in this growing interest. This process involves two distinct steps: CO activation over the oxide and subsequent C−C coupling within the zeolite pores, connected by an unidentified oxygenate intermediate. In this study, we explored three proposed oxygenates as potential intermediates and compared their conversion within the OX‐ZEO process. Using a bifunctional ZnCr2O4/H‐MOR catalyst in a syngas‐fed batch reactor, we found that methanol (MeOH) and dimethyl ether (DME) produced a hydrocarbon distribution similar to syngas conversion. However, the conversion of acetic acid (AcOH) resulted in a notably distinct range of hydrocarbons, including short olefins not detected with other reagents. Our findings suggest that methanol/DME might serve as active intermediates in the OX‐ZEO process over the ZnCr2O4/H‐MOR catalyst. This study provides a deeper insight into the transformation of proposed intermediates, contributing to the identification of the bridging intermediate that links the two catalytic functions. [ABSTRACT FROM AUTHOR]

Composite filaments are of considerable interest in research due to their exceptional performance characteristics and broad applicability. In this study, highly electrically conductive composite filaments comprising cellulose nanofibrils (CNF) and silver nanowires (AgNWs) are carefully prepared, accompanied by the proposition of an integrated microwave‐microfluidic synthesis method for AgNWs. The proposed reaction system exhibits a remarkable capability for swift AgNW synthesis, with a space‐time yield of 1.2 × 104 g (h·m3)−1, approximately five times superior to that achievable through conventional batch reactor methodologies. The microwave‐assisted microfluidic synthesis of AgNWs introduces a novel aspect to the extensive research on 1D nanomaterials. The design of experiments and multi‐objective Bayesian optimization are integrated iteratively to converge toward the global optimum, aiming to enhance screening efficiency and achieve a balanced outcome by maximizing aspect ratio and minimizing size for AgNWs. The AgNWs synthesized under optimal conditions has a diameter of ≈50.4 nm and an aspect ratio of ≈555. Subsequently, they are integrated into composite filaments with CNF, resulting in electrical conductivity and tensile strength of the composite filaments at values of 8.35 × 105 S m−1 and 186 MPa, respectively, surpassing those reported in existing literature for other analogous materials. [ABSTRACT FROM AUTHOR]

This study explores the impact of initial substrate concentrations on biomass growth, hydrogen production, and acid generation during acidogenic fermentation of a synthetic fruit juice wastewater. Four substrate concentrations, within the range 0.30–2.12 C mol·L−1, were tested using a mixed acidogenic bacterial culture. Batch reactors were employed to conduct the study, and the results were analyzed to determine inhibition effects. The highest hydrogen production (6.1 L H2·substrate C mol−1) and hydrogen percentage in the gas phase (57%) were achieved at a substrate concentration of 0.30 C mol·L−1. Higher substrate concentrations reduced the hydrogen production due to substrate and product inhibition events. The maximum H2 potential production was 4.15 Nm3/m3 reactor at a substrate concentration of 0.91 C mol·L−1. Biomass growth and VFA production followed exponential trends at low substrate concentrations, 0.30 and 0.091 C mol·L−1, while high concentrations resulted in linear trends due to inhibition effects caused by the substrate. The main acids produced were lactic at low concentrations, and acetic when dealing with high concentrations. The highest final acid concentrations were obtained with the highest initial substrate concentration, but their yields were significantly lower due to the substrate and product inhibitions experienced by the biomass. [ABSTRACT FROM AUTHOR]

For multi‐enzymatic cases, the determination of the batch reactor (BR) optimal operating policy often translates into a difficult multi‐objective problem. Exemplification is made here for the enzymatic reduction of D‐fructose to mannitol by using the mannitol dehydrogenase (MDH) enzyme and nicotinamide adenine dinucleotide (NADH) cofactor, with in situ regeneration of NADH at the expense of formate degradation by using the FDH enzyme. This paper presents an original rule to in silico generate the problem solution, by using the Pareto optimal‐front approach with accounting for pairs of competing economic goals and constraints. The optimal BR is then compared to an optimal fed‐BR (FBR), or a series of equal BRs (SeqBR). As proved, the Pareto‐optimal front alternative is an advantageous option, compared to the classical nonlinear programming technique, being simple to apply, by considering pairs of opposite objective functions. In the present case study, the Pareto‐optimal BR operating mode predicts an M‐productivity 1.5x better than those of an optimized FBR, with comparable enzymes consumption. The MDH consumption of this Pareto‐optimal BR is 10x smaller than an optimal SeqBR, and 130x smaller vs. heuristic (sub)optimal BR. [ABSTRACT FROM AUTHOR]

Organic peroxides are widely used chemical additives as polymerization initiators, polyester curing agents, crosslinking agents for polymer materials, and oxidants. The traditional synthesis process within batch reactor has low phase transfer rate, uncontrollable process parameters, large liquid hold-up, leading to low efficiency, poor quality, and high risk. Micro reaction systems have unique advantages for peroxidation process due to their large specific surface area, enhanced mass and heat transfer rates, and high controllability. This article reviews the research progress on the synthesis of organic peroxides in microreactors in the past decade from the perspective of the general and specific challenges lying in the synthesis of organic peroxide acid, peroxyesters, alkyl hydroperoxide, and ketone peroxide. It introduces the commonly used reaction systems, operating parameters, and microreactor types for the synthesis of organic peroxides, discusses the important role and potential problems of microreactors in improving the controllability, efficiency, and safety in peroxidation reaction. Finally, the solutions and future development trends for the improvement of peroxidation in micro-scale are proposed. [ABSTRACT FROM AUTHOR]

In this study, a new sacrificial anode comprised of scrap iron packaged in a polyethylene mesh chamber for Furan-2-carbaldehyde removal using the electrocoagulation (EC) process was fabricated. Therefore, the influences of different operational parameters, such as solution pH, current intensity, initial Furan-2-carbaldehyde concentration, and detention time on the process performance at the batch hydraulic reactor were investigated. Due to the large surface area of the anode, the applied current intensity was low, which led to high efficiency for the Furan-2-carbaldehyde removal (> 97%) at low operating voltage and energy consumption (5.4 kWh/m3). The experimental results corresponded well to the first-order kinetic model. The mineralization values for Furan-2-carbaldehyde using the EC process were 46.5% and 75.5% for total organic carbon (TOC) and chemical oxygen demand (COD), respectively. Moreover, the EC process shows the biodegradability was significantly increased compared to the initial solution after 120 min of reaction time. Based on the LC-MS analysis, the major produced intermediates and the degradation pathway of Furan-2-carbaldehyde were proposed. Consequently, on the contrary plate electrodes, the use of scrap iron as a sacrificial anode increases efficiency and reduces the total required operating costs for energy and electrodes. [ABSTRACT FROM AUTHOR]

A significant and sustainable feedstock for many value added products is levulinic acid, which is basically a short‐chain fatty acid. The current study aims to comprehend how multiple factors affect the hydrothermal reactions that convert glucose to levulinic acid. Glucose can be readily obtained from lignocellulosic biomass and hence it is selected in the work as representative sustainable source. The effect of various operating parameters, including time (0–180 min), temperature (140–180°C), nitrogen pressure (0–25 bar), glucose concentration (3%–10%), agitation speed (100–300 RPM), and acid concentration (2%–6%); use of different salts (NaCl, AlCl3 6H2O, FeCl3); and different acids (HCl, H3PO4, H2SO4) on the reaction progress has been studied in a batch autoclave reactor. It was elucidated that pressure (only nitrogen purge was essential for reaction progress) or salt content changes did not affect sugar conversion significantly. The process was seriously influenced by the presence of acids, mostly in the form of homogeneous catalysts, and the most significant results were obtained for H2SO4. The highest levulinic acid yield (39.7 g/g) at 90 min, with nearly complete sugar conversion, was obtained under the ideal conditions of 160°C, 5% sugar loading, and 5% H2SO4 concentration. The current study indicates that the two primary operating parameters in this conversion process are temperature and time, with higher temperature and lower sugar concentration showing a rising tendency in sugar conversion. Overall, the study establishes a sustainable process for levulinic acid synthesis. [ABSTRACT FROM AUTHOR]

Medium chain‐length polyhydroxyalkanoates (mcl‐PHAs) are efficiently synthesized from fatty acids. It was hypothesized that under non‐axenic conditions, the anti‐microbial properties of fatty acids would reduce growth of microbial competitors and allow Pseudomonas putida LS46 to dominate the population resulting in non‐sterile mcl‐PHA production. Non‐sterile batch and fed‐batch cultures produced similar final mcl‐PHA content, monomer composition, and productivity during 24–27 h cultivations when compared to sterile control cultures for initial octanoic acid concentrations ranging from 5 to 40 mM at an initial pH of 6.5. In the absence of a P. putida inoculum, growth was eventually observed in non‐sterile medium after a lag period of up to 120 h, the length of which was dependent on the octanoic acid concentration. The efficacy of prolonged non‐sterile cultivation was tested using a sequential batch reactor (SBR). After 28 days (672 h), 1.62 g L−1 of total biomass was observed, of which the mcl‐PHA content was 47%. This resulted in a PHA titer of 0.77 g L−1, and a volumetric PHA productivity of 32 mg L−1 h−1. The polymer composition remained stable throughout at 87.0 ± 2.7% C8 monomers, and short‐chain length (scl‐) monomers were not detected. This study is the first of its kind to report that purely mcl‐PHAs were produced after prolonged periods in a non‐sterile environment and demonstrate that medium chain‐length fatty acids exert a strong selective pressure toward organisms that synthesize mcl‐PHA. This suggests an opportunity for mcl‐PHA production in open continuous cultivation, which could reduce both fixed and operating costs. [ABSTRACT FROM AUTHOR]

In order to investigate the enhancement mechanism of modified three-dimensional elastic filler (MTEF) on the nitrogen removal performance of the integrated fixed-film activated sludge (IFAS) process, and to clarify the interactions between competition and synergy between activated sludge and biofilm in the IFAS system, an IFAS reactor (T2) filled with MTEF was employed for the study, while a sequencing batch reactor activated sludge process (SBR) reactor (T1) was utilized for comparison. IFAS and SBR reactors were operated over an extended period at ambient temperature to assess the enhancement of pollutant removal performance with the addition of the filler to investigate the competitive dynamics between activated sludge and biofilm under varying influent water qualities (C/N, N/P, and organic loading), and to analyze the synergistic relationship between activated sludge and biofilm at the microbial level using high-throughput sequencing technology. The results demonstrate that throughout the entire operational phase, reactor T2 exhibited superior pollutant removal efficiency. Compared to reactor T1, reactor T2 achieved an average increase in the removal rates of COD, ammonia nitrogen, and total nitrogen by 13.07%, 12.26%, and 28.96%, respectively. The findings on the competitive dynamics between activated sludge and biofilm indicate that the nitrification volumetric load of the IFAS system is significantly higher than that of a pure activated sludge system, suggesting that the IFAS system possesses enhanced nitrification capabilities. Furthermore, when dealing with wastewater characterized by low C/N ratios and high phosphorus pollution, or under substantial organic loads, the biofilm holds a competitive edge and the IFAS system exhibits improved stability. High-throughput sequencing data reveal that the microbial community structures in activated sludge and biofilm can influence each other, thereby enabling the IFAS system to effectively enrich denitrification-related functional microbial populations. Additionally, the biofilm has a certain enhancing effect on the expression levels of nitrogen metabolism-related functional genes in the activated sludge phase microorganisms, indicating that, in addition to competitive interactions, there is also a synergistic effect between the biofilm and activated sludge. [ABSTRACT FROM AUTHOR]

Precise control of operational parameters in anaerobic digestion reactors is crucial to avoid imbalances that could affect biomethane production and alterations in the microbiota. Restoring the methanogenic microbiota after a failure is essential for recovering methane production, yet no published strategies exist for this recovery. In this study, we restored the methanogenic microbiota in an anaerobic SBR reactor that operates with both biofilm and suspended biomass simultaneously, aiming to treat tequila vinasses. Four strategies were evaluated for restoring the methanogenic microbiota: reducing the initial vinasse concentration, increasing the reaction time (RT), adjusting the carbon/nitrogen (C/N) ratio, and progressively increasing the initial vinasse concentration. Among these, adjusting the C/N ratio emerged as a critical parameter for restoring organic matter removal efficiency and reestablishing methanogenic microbiota. The operational conditions under which the methanogenic activity and microbiota were restored were as follows: Operating the A-SBR with an initial vinasse concentration of 60%, an RT of 168 h, a pH of 6.9 ± 0.2, a temperature of 35 ± 2 °C, and a C/N ratio adjusted to 100/1.9 resulted in stable COD removal efficiency of 93 ± 3% over a year and a high percentage of methanogenic microorganisms in both the suspended microbiota (69%) and biofilm (52%). The normalized methane production (0.332 NL CH4/g CODr) approached the theoretical maximum value (0.35 L CH4/g CODr) after restoring the population and methanogenic activity within the reactor. [ABSTRACT FROM AUTHOR]

We conducted experiments on concurrent labradorite dissolution, calcite precipitation, and clay precipitation in batch reactor systems and tracked reaction processes using multiple isotope tracers. Labradorite was chosen for its role as a major and reactive component in basalt; the experiments thus directly impact our understanding of CO 2 storage in basalt aquifers and enhanced rock weathering. We doped initial solutions with 29Si, 43Ca, and Ca13CO 3 (s). Experiments were conducted at 60 °C and pH ∼ 8.3 for up to 840 h, with isotope ratios in the experimental aqueous solutions measured using MC-ICP-MS. Unidirectional rates of labradorite dissolution near equilibrium were approximately two orders of magnitude slower than far-from-equilibrium rates reported in the literature. Calcite growth occurred near equilibrium and the rates were limited by the labradorite dissolution rates. In the steady state phase, the interplay of these three heterogeneous reactions—labradorite dissolution, calcite growth, and clay precipitation—results in a coupled system that approaches a near-equilibrium state. The system does not reach true equilibrium because labradorite continues to dissolve, albeit at a much slower rate near equilibrium. The overall reaction can be approximated as, Na 0.4 Ca 0.6 Al 1.6 Si 2.4 O 8 + 0.6HCO 3 - + 1·.7H 2 O + 0.4H+ → 0.4Na+ + 0.6CaCO 3(s) + 0.5Al 2 Si 2 O 5 (OH) 4(s) + 0.6Al(OH) 4 - + 1.4SiO 2 o (aq) The experimental results show that using short-term far-from-equilibrium rate constants would lead to an overestimation of feldspar weathering rates at the Earth's surface (e.g., basalt weathering and enhanced rock weathering) and CO 2 mineralization in basalt aquifers. [ABSTRACT FROM AUTHOR]

Expired, non-edible forms of oats which are considered as trash have the potential to enable biodiesel production at larger scale without competing for any requirements. The process of producing biodiesel has been examined step-by-step, begining with the conversion of oat lipids to FAME. Using DME in a batch reactor, the SCE (super critical carbon dioxide extraction) method was used to extract lipids from oats. The fatty acid profile shows the abundance of C18 compounds from lipid extraction. Catalyst used for the biodiesel production was ZnO–Al2O3; in which varied loadings of copper was carried out. Utilizing XRD, FTIR, N2 sorption, TPD, and SEM examination, the catalyst was characterized. A catalyst with an alcohol ratio of 2:10, a flow rate of 4 ml per hour, 300 mg of oats, and 15% of copper-loaded catalyst was found to be the most effective combination for converting lipids into biodiesel while also exhibiting high selectivity and yield. GCMS spectrum indicates the abundance of C18 fractions at 22.34 min with peak area of 53.69%. The kinetic study such as Arrhenius plot for pure biodiesel and biodiesel blend shows that pure biodiesel at constant temperature shows rate maximum. Engine analysis characteristics such as brake power, torque, BTE, CO, and NO emission data demonstrated the performance of pure biodiesel that was obtained in good yield from oat lipid. [ABSTRACT FROM AUTHOR]

Abstract Pharmaceutically active compounds (PACs) are ubiquitous contaminants that can pollute the environment. This study critically analyzes the sorption of PACs to soil materials based on 137 published papers encompassing 106 PACs and 212 soil materials. The batch technique is commonly employed for sorption studies of PACs to soil, but the experimental setups vary in terms of the type and number of PACs, mixing time, solid to liquid (S/L) ratio, solution type, range of initial concentration, and bio-inhibition method. Sorption competition among PACs or between PACs and dissolved organic matter occurs for certain cases. Linear or close to linear behavior was reported for sorption of many PACs to soil, but sorption of some PACs deviates from linearity. The reaction of PACs to soil is fast at the initial stages but slows down as it approaches equilibrium. PACs characteristics, soil properties, and solution attributes intricately influence the sorption process. Zwitterionic PACs exhibit the highest sorption affinity, whereas neutral PACs display increased sensitivity to soil hydrophobicity. The average sorption coefficient (K) ranges from 0.0915 mL/g for anionic sulfonamides to 84725.5 mL/g for zwitterionic norfloxacin. An increase in the molar volume corresponds to heightened sorption for cationic PACs and reduced sorption for anionic PACs. Increasing solubility, soil organic carbon, cation exchange capacity, S/L ratio, and soil surface area while decreasing pH, ionic strength, and temperature result in an increase in K. The values of K determined by the batch technique are higher than their column-determined counterparts, possibly due to variations in the employed residence times between the two systems. Several models have been developed to estimate K of PACs, but they are limited in their applicability to specific PACs and soil types. Future research related to sorption of PACs to soils has been suggested.

Laccase, the selectively lignin degrader, vital to the initiation of lignocellulosic deconstruction was immobilized onto activated agarose beads to increase its reuse potential. Laccase cross-linked beads (~ 3.42 mm) recorded a specific activity of 23 Umg− 1, retaining about 80.43% enzyme activity after 45 days of storage. The immobilization yield and efficiency were 89% and 97% respectively. The equilibrium data fitted the Freundlich equation (R2 = 0.9987) demonstrating multilayer adsorption and the presence of Cu, Fe, and S in the elemental analysis of immobilized beads established effective binding between activated agarose beads and the laccase protein. Characterization studies of the immobilized laccase-treated crop residues revealed significant differences in the lignin polymer after each treatment cycle. An increase in digestibility of 26.21% and 7.62% was observed in paddy and finger millet-treated straws respectively, over the controls corroborating efficient lignin depolymerization. The propitious performance of laccase beads authenticated in the batch enzymatic reactor to treat crop residues paves headway as a sustainable green technology in the deconstruction of crop residues for use as ruminant feed, augmenting productivity. [ABSTRACT FROM AUTHOR]

The results on zirconia-amine bifunctional modification of hierarchically porous silica monoliths for continuous-flow processes ar presented. The study reports the synthesis and properties of the modified porous monoliths and their performance in the tandem process of deacetalization-Knoevenagel condensation reaction. The properties of the materials were studied by thermal analysis, FTIR spectroscopy, XRF and nitrogen adsorption. It was found that both active centres were uniformly distributed along the monolithic cores, and the antagonistic interaction of the acid and base centres was not observed. It was shown that hydrophobicity of the monolith surface has opposite effects on the efficiency of the studied reactions. The overall rate of the tandem process depends on the rate of the condensation reaction. The performance of the bifunctional microreactors was checked and compared with those of cascade-connected monofunctional microreactors and batch reactor. The yield of cyanocinnamate product obtained in both flow systems was ca. 78%; however, pressure drop in the bimodified reactor was only half of that in the cascade. An effective way of water supply to the reaction system has been proposed. The research demonstrates the benefits of using flow-through structured micro-/mesoreactors in tandem reaction processes. [ABSTRACT FROM AUTHOR]

Investigating the self‐sorting behaviour of assemblies with subtle structural differences is a captivating yet challenging endeavour. Herein, we elucidate the unusual self‐sorting behaviour of metallacages with subtle structural differences in batch reactors and microdroplets. Narcissistic self‐sorting of metallacages has been observed for two ligands with identical sizes, shapes, and symmetries, with only minor differences in the substituted groups. In particular, the self‐sorting process in microdroplets occurs within 1 min at room temperature, in stark contrast to batch reactors, which require equilibration for 30 min. To reveal the mechanism of self‐sorting and the role of microdroplets, we conducted a series of experiments and theoretical calculations, including competitive self‐assembly, cage‐to‐cage transformation, control experiments involving model metallacages with larger cavities, noncovalent interaction analysis, and root mean square deviation (RMSD) analysis. This research demonstrates an unusual case of self‐sorting of very similar assemblies and provides a new strategy for facilitating the self‐sorting efficiency of supramolecular systems. [ABSTRACT FROM AUTHOR]

In this work, the pyrolysis process and the characteristics of biochar produced using a bench-scale fixed-bed reactor and a prototype-scale auger reactor were studied. Residual forest biomass (RFB) from acacia, broom, gorse, and giant reed was used as feedstock. Besides information on pyrolysis characteristics of these specific biomass species from the Iberian Peninsula, new knowledge on the understanding of how results from small-scale reactors can be used to predict the behavior of higher-scale and continuous-operation reactors is offered. Batch pyrolysis was carried out using 40 g of biomass sample in a fixed-bed reactor with a heating rate of 20 °C∙min−1, pyrolysis temperature of 450 and 550 °C, and a residence time of 30 min, while for the continuous process it was used a prototype of an auger reactor with continuous operation with a biomass flow rate up to 1 kg/h, with temperatures of 450 and 550 °C, and a solids residence time of 5 min. The biochar yield was in the range of 0.26 to 0.36 kg/kg biomass dry basis, being similar for both types of reactors and slightly lower when using the auger reactor. The proximate analysis of the biochar shows volatile matter in the range 0.10 to 0.27 kg/kg biochar dry basis, fixed carbon in the range 0.65 to 0.84 kg/kg biochar dry basis, and ash in the range 0.04 to 0.08 kg/kg biochar dry basis. The carbon, oxygen, and hydrogen content of the biochar was in the range of 0.71 to 0.81, 0.09 to 0.22, and 0.02 to 0.03 kg/kg biochar dry basis, respectively. The results show that the up-scaling of the reactor and regime of operation does not have an important influence on the yield and characteristics of the biochar produced. The biochar obtained in the two types of reactors has characteristics appropriate for environmental applications, such as an additive to improve soil properties. It is possible to see that the characteristics of the biochar are influenced by the type of biomass and the conditions and parameters of the process; therefore, it is of major importance to control and know of these conditions, especially when considering upscaling scenarios. [ABSTRACT FROM AUTHOR]

Changes in the structure and properties of a microbial community of a sequencing batch reactor (SBR) enriched with phosphate-accumulating microorganisms (PAO) after a pH shift to more acidic values (pH 6.7‒7.1) were studied in. The relative abundance of Ca. Accumulibacter decreased from 43.6 to 13.9%, while abundance of potential PAO belonging to the genera Dechloromonas and Thauera increased. The overall share of PAO changed insignificantly (40‒43%). The share of glycogen-accumulating microorganisms (GAO), the main competitors of PAO, remained low throughout the experiment: abundance of the Competibacter 16S rRNA gene fragments before and after the pH shift was 2‒4%. While decrease in pH resulted in a drop in the amount of phosphates released during the anaerobic phase, the amount of phosphorus in the biomass (15‒17%) remained high, as well as phosphorus removal (92‒94%). [ABSTRACT FROM AUTHOR]

Hydrothermal co-liquefaction (HTCL) is the prominent process for producing bio-products with a higher conversion rate. It is performed at high temperatures and pressure in the presence of water. Earlier, it was mostly conducted in batch reactors, but it has major limitations including operating volume, back mixing, and tedious process for high productivity. With that, the present investigation is performed on designing the screw shaft for the high-pressure HTCL process. The dimensional factors including flight length, pitch, helix angle, and depth were considered to design the optimal screw shaft. Likewise, principal stresses, shear stress, bending stress, bending moment, and total deformation were regarded as inevitable response variables to analyze the internal strength of the shaft. In this regard, the Taguchi approach provides the L9 (34) orthogonal array as an experimental design. Then, the numerical results from the transient structural analysis were analyzed with the assistance of statistical methods such as Grey Relational Grade (GRG), Grey Fuzzy Reasoning Grade, Analysis of Variance (ANOVA), and Taguchi method to find the most influential dimensions for minimizing the response variable. Consequently, the results from both GRG and Taguchi optimization were compared, and selected the most optimum parameters. [ABSTRACT FROM AUTHOR]

Household food waste (HFW), which is rich in organic matter, is a good candidate for producing added-value bio-based chemicals, such as volatile fatty acids (VFAs), by acidogenic fermentation processes. However, the lack of design tools, such as appropriate kinetic models, hinders the implementation of this technology because the results of these processes are affected by operational factors. In this work, VFA production by the acidogenic fermentation of HFW under uncontrolled pH levels (4–5) was studied at thermophilic (55 °C) and mesophilic (35 °C) temperature conditions. Batch reactors were used to digest HFW, and VFA production and the individual acid distributions were measured at different fermentation times from 0 to 624 h. The results showed higher individual and total VFA production at 35 °C and 120 h of fermentation time as a consequence of the competition between the VFA production and decomposition reactions. Acetic and valeric acids were VFAs mainly produced as a result of a high content of proteins in the initial substrate, and a small amount of propionic and butyric acids were present. A simplified kinetic model was successfully developed to represent the complex process of VFA formation from the acidogenic fermentation of HFW. A simple mechanism for the production–decomposition of VFAs, corresponding to a zero-order reaction for the first 48 h and a single consecutive reaction from that time on, was proposed. For both mesophilic and thermophilic conditions, the suggested kinetic model was able to predict the individual and total concentrations of VFAs along the fermentation time. [ABSTRACT FROM AUTHOR]

The co-digestion of agri-food by-products, such as Olive Mill Waste (OMW) and Cattle Manure (CM), is an efficient method for waste management and biogas production. OMW, characterized by a high soluble organic content, low methane yield, and limited biodegradability, contrasts with the easily degradable properties of CM. The synergistic use of these wastes enhances the hydrolytic-acidogenic phase, increasing the availability of Volatile Fatty Acids (VFAs) and thereby boosting biogas production through bacterial fermentation of VFAs. This study introduces a novel mathematical model for mesophilic anaerobic co- digestion of OMW and CM in batch reactors. The uniqueness of the model lies in its ability to balance comprehensiveness with simplicity, implemented in MATLAB, for both precision and user-friendliness. Its focus on crucial factors, such as total VFA and methane generation, sets it apart in the field of anaerobic digestion modeling. The exceptional performance of the model is evidenced by its high accuracy in predicting experimental results, achieving impressive R2 values of 0.96469 and 0.99133 for 50:50 and 75:25 OMW to CM ratios, respectively. These results demonstrated the robustness of the model in simulating key co-digestion parameters across varying substrate compositions. By enhancing the feasibility of numerical computation while maintaining high predictive accuracy, this approach represents a significant advance in biogas production optimization. The practical applicability and accuracy of the model make it a valuable tool for optimizing real-world waste management and renewable energy production processes, potentially leading to improved methane yields and overall biogas production. [ABSTRACT FROM AUTHOR]

Sequential batch reactor is widely used for industrial wastewater treatment. To consider sequential batch reactor for biological treatment of wastewater at a specific site, it is essential to ensure economy and sustainability. An approach for scrutiny of economic aspects may be based upon use of cost functions to compare sequential batch reactor and other technologies. Such approach will enable to conduct prudent analysis and select the most economic treatment scheme for a particular project. In most of published studies, the cost functions for conventional wastewater treatment systems are described with historic or some other data available to the investigators. No detailed engineering exercise related to cost functions for sequential batch reactor is cited in earlier research studies. In this document the novel and appropriate methodology has been presented to develop cost functions based on engineering, estimation and statistical approach to forecast cost for sequential batch reactor based wastewater treatment system. [ABSTRACT FROM AUTHOR]

H2O2 photosynthesis represents an appealing approach for sustainable and decentralized H2O2 production. Unfortunately, current reactions are mostly carried out in laboratory-scale single-phase batch reactors, which have a limited H2O2 production rate (<100 μmol h−1) and cannot operate in an uninterrupted manner. Herein, we propose continuous H2O2 photosynthesis and extraction in a biphasic fluid system. A superhydrophobic covalent organic framework photocatalyst with perfluoroalkyl functionalization is rationally designed and prepared via the Schiff-base reaction. When applied in a home-built biphasic fluid photo-reactor, the superhydrophobicity of our photocatalyst allows its selective dispersion in the oil phase, while formed H2O2 is spontaneously extracted to the water phase. Through optimizing reaction parameters, we achieve continuous H2O2 photosynthesis and extraction with an unprecedented production rate of up to 968 μmol h−1 and tunable H2O2 concentrations from 2.2 to 38.1 mM. As-obtained H2O2 solution could satisfactorily meet the general demands of household disinfection and wastewater treatments. Photocatalytic H2O2 synthesis is often performed in lab-scale batch reactors with low efficiency. Here, the authors report a biphasic fluid system that enables continuous H2O2 synthesis and automatic product extraction, addressing the limitations of traditional methods. [ABSTRACT FROM AUTHOR]

Nitrospira is a common genus of nitrite-oxidising bacteria (NOB) found in wastewater treatment plants (WWTPs). To identify the key factors influencing the composition of NOB communities, research was conducted using both sequencing batch reactor (SBR) and continuous flow reactor under different conditions. High-throughput 16S rRNA gene sequencing revealed that Nitrospira (18.79% in R1 and 25.77% in R3) was the dominant NOB under low dissolved oxygen (DO) and low nitrite (${\rm NO}_2^-$ NO 2 − -N) concentrations, while Nitrobacter (21.26% in R2) was the dominant NOB under high DO and high ${\rm NO}_2^-$ NO 2 − -N concentrations. Flocculent and granule sludge were cultivated with Nitrospira as the dominant genus. Compared to Nitrospira flocculent sludge, Nitrospira granule sludge had higher inhibition threshold concentrations for free ammonia (FA) and free nitrous acid (FNA). It was more likely to resist adverse environmental disturbances. Furthermore, the effects of environmental factors such as temperature, pH, and DO on the activity of Nitrospira granular sludge were also studied. The results showed that the optimum temperature and pH for Nitrospira granular sludge were 36°C and 7.0, respectively. Additionally, Nitrospira granular sludge showed a higher dissolved oxygen half-saturation constant (Ko) of 3.67 ± 0.71 mg/L due to its morphological characteristics. However, the majority of WWTPs conditions do not meet the conditions for the Nitrospira granular sludge. Thus, it can be speculated that future development of aerobic partial nitrification granular sludge may automatically eliminate the influence of Nitrospira. This study provides a theoretical basis for a deeper understanding of Nitrospira and the development of future water treatment processes. [ABSTRACT FROM AUTHOR]

AbstractThis study explores a novel enzymatic pretreatment approach in anaerobic reactors for dairy wastewater, using lipase AY Amano to enhance methane production and modify microbial and archaeal community composition. Batch and semi-batch reactors with a total volume of 2000 mL were used to treat dairy wastewater with initial COD of 2000 and 15,000 mg L−1, respectively. In a new novel approach, the semi-batch reactors underwent a three-phase operation: 30 days of acclimation, 30 days of rest, and 30 days of active operation. Adding lipase (0.05% wv−1) as a pretreatment significantly increased methane yield over the 90 days by 135–138% compared with the control (without enzyme addition). The organic loading rate reached 0.22 g COD day−1 L−1. Furthermore, 30 days after the end of the semi-batch reactor approach (120 days from the start), reusing sludge in batch reactors increased methane yield by 114–122% compared to the control. This increase was linked to the emergence and shift of new methanogenic communities within the sludge. Integrating hydrolytic enzymes into the anaerobic treatment enhances performance and sustainability by fostering methanogen-enriched microbial communities. This is crucial for maximizing methane production but may increase costs, requiring further economic feasibility research. [ABSTRACT FROM AUTHOR]

Pharmaceutically active compounds (PACs) are ubiquitous contaminants that can pollute the environment. This study critically analyzes the sorption of PACs to soil materials based on 137 published papers encompassing 106 PACs and 212 soil materials. The batch technique is commonly employed for sorption studies of PACs to soil, but the experimental setups vary in terms of the type and number of PACs, mixing time, solid to liquid (S/L) ratio, solution type, range of initial concentration, and bio-inhibition method. Sorption competition among PACs or between PACs and dissolved organic matter occurs for certain cases. Linear or close to linear behavior was reported for sorption of many PACs to soil, but sorption of some PACs deviates from linearity. The reaction of PACs to soil is fast at the initial stages but slows down as it approaches equilibrium. PACs characteristics, soil properties, and solution attributes intricately influence the sorption process. Zwitterionic PACs exhibit the highest sorption affinity, whereas neutral PACs display increased sensitivity to soil hydrophobicity. The average sorption coefficient (K) ranges from 0.0915 mL/g for anionic sulfonamides to 84725.5 mL/g for zwitterionic norfloxacin. An increase in the molar volume corresponds to heightened sorption for cationic PACs and reduced sorption for anionic PACs. Increasing solubility, soil organic carbon, cation exchange capacity, S/L ratio, and soil surface area while decreasing pH, ionic strength, and temperature result in an increase in K. The values of K determined by the batch technique are higher than their column-determined counterparts, possibly due to variations in the employed residence times between the two systems. Several models have been developed to estimate K of PACs, but they are limited in their applicability to specific PACs and soil types. Future research related to sorption of PACs to soils has been suggested. [ABSTRACT FROM AUTHOR]

The Pinnick oxidation, due to its tolerance for sensitive functional groups, is widely used in the process of oxidizing α,β-unsaturated aldehydes to corresponding carboxylic acids. The reaction reagents typically include sodium chlorite, buffer salts, and a scavenger. However, the controllability of Pinnick oxidation in the batch reaction process is poor due to the inherent limitations of the reactor's performance. This leads to potential safety risks and necessitates the reaction to proceed slowly under conditions of low temperature and low concentration. In this work, we introduced a new continuous micro-reaction process to intensify the Pinnick oxidation. The water-soluble crotonic acid was selected as a typical object of study. Through the study of reaction parameters and the construction of a micro-reaction system, efficient continuous process was achieved under high-temperature and high-pressure conditions for the first time. Compared to the batch process, the reaction benefited from the superheated condition resulting in a significant acceleration of the reaction rate, efficient gas–liquid interphase mass transfer allowing for effective utilization of the generated chlorine dioxide, and the inherent safety of the microreactor enabling an increase in reaction concentration. In addition, the buffer salts used in the Pinnick oxidation has been successfully replaced by hydrochloric acid and applied to the continuous flow. This work shows the tremendous potential of microreactors in utilizing harsh reaction conditions to achieve process intensification. Article Highlights: A superheated micro-reaction process was introduced into the Pinnick oxidation to achieve efficient and safe preparation of crotonic acid. Efficient gas–liquid interphase mass transfer in microreactor realized effective utilization of the by-product chlorine dioxide. The great replacement of phosphate buffer salts with hydrochloric acid was achieved in continuous flow. [ABSTRACT FROM AUTHOR]

In situ and operando investigation of photocatalysts plays a fundamental role in understanding the processes of active phase formation and the mechanisms of catalytic reactions, which is crucial for the rational design of more efficient materials. Using a custom‐made operando photocatalytic cell, an in situ procedure to follow the formation steps of Pd/TiO2 photocatalyst by synchrotron‐based X‐ray absorption spectroscopy (XAS) is proposed. The procedure resulted in the formation of ∼1 nm Pd particles with a much narrower size distribution and homogeneous spreading over TiO2 support compared with the samples generated in a conventional batch reactor. The combination of in situ XAS spectroscopy with high‐angle annular dark‐field scanning transmission electron microscopy demonstrated the formation of single‐atom Pd(0) sites on TiO2 as the initial step of the photodeposition process. Palladium hydride particles were observed for all investigated samples upon exposure to formic acid solutions. [ABSTRACT FROM AUTHOR]

Tyrosinase, an enzyme involved in browning reactions in plants/crops exposed to mechanical injury, was isolated from the pulp of some different locally available bananas (M. cavendish, M. acuminata, and M. paradisiaca). Tyrosinase from the pulps was extracted, purified, immobilized, and characterized. Thereafter, the potentials of the immobilized tyrosinase in the possible production of l-3,4-dihydroxyphenylalanine (L-DOPA) in an improvised batch reactor was exploited using tyrosine and ascorbate as the substrates. L-DOPA production was monitored via thin-layer chromatography and spectrophotometry (Arnow's method). L-DOPA is a drug that is used in the treatment of Parkinson's disease. Hence, this study exploited a non-chemical route for its synthesis using the tyrosinase obtained from the banana pulps. The purified tyrosinase had an optimum pH and temperature of 6.5 and 7.0, respectively. The molecular weight of the purified tyrosinase was 45 kDa. Quercetin and resorcinol both competitively inhibited the purified tyrosinase from the three cultivars. Immobilized M. cavendish tyrosinase produced the highest concentration (0.60 mM) of L-DOPA after 8 h in an improvised batch reactor. The tyrosinase in the banana pulps serves as a cheap and readily available green route for the possible production of L-DOPA. [ABSTRACT FROM AUTHOR]