Production Rate Research Articles

Enhancing organic matter dissolution and microbial community structure in waste activated sludge using thermal-alkali-rhamnolipid pretreatment: Focus on thermal optimization

This study investigated the impact of pretreatment temperature on the dissolution of organic matter in sludge pretreated with alkaline rhamnolipid and its subsequent effect on the microbial community structure during anaerobic fermentation. The findings revealed that when the pretreatment temperature reached 80 °C, the maximum concentration of SCOD is 5008.89 mg/L, which is 4 times higher than that achieved at room temperature. Three-dimensional fluorescence parallel factor analysis indicated that increasing the pretreatment temperature significantly enhanced the degree of humification of sludge DOM and reduced the ratio of protein-like and fulvic acid in the sludge. The 16S rRNA gene-based analyses revealed that the relative abundance of Bacteroidetes was highest at 80 ℃ (11.14 %), and continued to increase as fermentation time progressed. This study highlights the critical role of temperature in the three-factor pretreatment of sludge, demonstrating that higher pretreatment temperatures not only accelerate the acid production rate during anaerobic fermentation but also enhance overall acid production.

Greenhouse gas emission and denitrification kinetics of woodchip bioreactors treating onsite wastewater

The accurate evaluation of denitrification rate and greenhouse gas (GHG) emission in field-scale woodchip bioreactors for onsite wastewater treatment are problematic due to inevitably varied environmental conditions and underestimated GHG production with limited analysis of dissolved gas in field samples. To address these problems, batch incubation experiments were conducted with controlled conditions to precisely evaluate the denitrification kinetics and N2O and CH4 emission of both gaseous and dissolved phases in fresh (6 months) and aged (5 years) woodchip bioreactors treating onsite wastewater at high (1–3 mg L-1) and no (0 mg L-1) dissolved oxygen (DO) levels. NO3- removal rate decreased from 37.5–119.0 g NO3--N m-3d-1 at no DO to 8.8–16.6 g NO3--N m-3d-1 at high DO (1–3 mg L-1) due to the growth suppression of NO2- reducing microorganisms (37–55 % lower nirS+nirK abundance). However, the presence of high DO increased N2O emission level from 5.6–6.9 mg N2ON m-3 at no DO to 179.5–273.6 mg N2ON m-3) due to the enhanced growth of NO reducing microorganisms (1–7 times higher norB levels) and the decreased abundance of N2O reducing microorganisms (53–75 % lower nosZ abundance). On the other hand, increased DO level negatively correlated with CH4 production (1.0–3.9 g CH4-C m-3d-1) in fresh woodchips, while showed insignificant impact on CH4 production (0.1–1.4 g CH4-C m-3d-1) in aged woodchips. Woodchip age increase (5 years) negatively impacted the NO3- removal rate (75–85 % lower than fresh woodchips) and CH4 production rate (>3 times lower than fresh woodchips), probably due to the reduced biomass density of NO2- reducing microorganisms (52–58 % lower nirS+nirK abundance) and methanogens (95–98 % lower mcrA levels). The incubation results suggested that long hydraulic retention time (>2–5 days) and anaerobic/anoxic condition are preferred for the optimal NO3- removal and low N2O emission potential of woodchip bioreactors treating onsite wastewater.

Synthesis, Characterization of KNb0.99Eu0.01O3 and improved Photo-catalytic H2-Production on Ag/La2NiO4/ KNb0.99Eu0.01O3 hetero-junction

The perovskite KNb0.99Eu0.01O3 prepared by nitrate combustion is applied as a hydrogen photocathode in heterojunction with La2NiO4 under visible light. The XRD pattern confirms the formation of KNb0.99Eu0.01O3 structure with orthorhombic single phase. The SEM images present grains between 0.2 and 0.4 µm while the optical band gap (3.14 eV) is calculated from the diffuse reflectance. Under illumination, the cyclic voltammetry (CV) and the capacitance measurements in Na2SO4 electrolyte show an increased current below ∼ -0.7 V vs. Ag/AgCl and p-type behavior with a conduction band (CB = −1.95 V) cathodically positioned with respect to H2 level, thus leading to H2 photo-production. The hetero-system La2NiO4/KNb0.99Eu0.01O3 shows a much higher activity than KNb0.99Eu0.01O3 where efficient H2-photoevolution occurs with concomitant oxidation of S2O32−, as reducing agent. So, the co-junction of La2NiO4 with KNb0.99Eu0.01O3 facilitates the charge transfer and increases the reaction efficiency. At neutral pH, the H2 evolution rate for the photocatalysts KNb0.99Eu0.01O3 and La2NiO4/ KNb0.99Eu0.01O3 are 11.15 and 57 µmol g−1 min−1; respectively. Further enhancement is observed with Ag-loaded La2NiO4/KNb0.99Eu0.01O3, reaching a maximum hydrogen production rate of 67 µmol g−1 min−1, attributed to the lower overpotential introduced by Ag. These findings highlight the potential of the ternary system Ag/La2NiO /KNb0.99Eu0.01O3 as an efficient photocathode for H2 generation.

When the Going Gets Tough, the Females Get Going: Sex-Specific Physiological Responses to Simultaneous Exposure to Hypoxia and Marine Heatwave Events in a Ubiquitous Copepod.

The existence of sex-specific differences in phenotypic traits is widely recognized. Yet they are often ignored in studies looking at the impact of global changes on marine organisms, particularly within the context of combined drivers that are known to elicit complex interactions. We tested sex-specific physiological responses of the cosmopolitan and ecologically important marine copepod Acartia tonsa exposed to combined hypoxia and marine heatwave (MHW) conditions, both of which individually strongly affect marine ectotherms. Females and males were acutely exposed for 5 days to a combination of either control (18°C) or a high temperature mimicking a MHW (25°C), and normoxia (100% O2 sat.) or mild hypoxia (35% O2 sat.). Life-history traits, as well as sex-specific survival and physiological traits, were measured. Females had overall higher thermal tolerance levels and responded differently than males when exposed to the combined global change drivers investigated. Females also showed lower metabolic thermal sensitivity when compared to males. Additionally, the MHW exerted a dominant effect on the traits investigated, causing a lower survival and higher metabolic rate at 25°C. However, egg production rates appeared unaffected by hypoxia and MHW conditions. Our results showed that MHWs could strongly affect copepods' survival, that combined exposure to hypoxia and MHW exerted an interactive effect only on CTmax, and that sex-specific vulnerability to these global change drivers could have major implications for population dynamics. Our results highlight the importance of considering the differences in the responses of females and males to rapid environmental changes to improve the implementation of climate-smart conservation approaches.

Investigating the impact of nanofluids and exergy metrics for integrated solar-biomass SCO2 power and desalination cycles

Several strategies have emerged for utilizing waste heat across diverse sectors. Yet, integrated systems that merge power generation with freshwater production, especially those leveraging renewable energy, remain relatively unexplored. Addressing this gap, a novel solar biomass-driven system is under development for power generation and desalination facilities. In the suggested system, rather than wasting the energy of a supercritical CO2 power cycle, a bottoming cycle is proposed to augment energy utilization factor (EUF). By integrating humidification-dehumidification, thermal vapor compression, and reverse osmosis (HDH-TVC-RO) with a multi-effect distillation (MED) unit, freshwater production rate is significantly enhanced. The outcomes reveal a freshwater output of 29.36 kg/s, a gained output ratio (GOR) of 17.36, and the EUF of 3.372. Various nanofluids have been assessed for the solar collector and due to superior total exergy efficiency and less corrosion effects, Cu- and carbon-based nanoparticles are recommended. Sensitivity analysis indicates that increasing the pressure ratio of compressors boosts the total GOR. Furthermore, adjustments to both the parameters of pressure of steam fed to HDH-TVC, and the compressor pressure ratio demonstrate a linear effect on EUF behaviour.

A new approach on the management of landfill leachate reverse osmosis concentrate: Solar distillation coupled with struvite recovery and biological treatment

The management of reverse osmosis (RO) concentrate remains a challenging task for operators of Landfill Leachates Treatment Plants. In this article we suggest an integrated treatment scheme for RO concentrate that combines solar distillation, struvite precipitation to reduce ammonia content of the distillate and biological treatment of the supernatant either with mixed cultures of bacteria or with microalgae. Experiments in a pilot-scale solar still, equipped with underfloor heating system, showed that the production rate of the distillate ranged up to 3.17 L/d m2. The distillate was characterized by elevated average concentrations of ammonium nitrogen; 2028 mg/L and 1358 mg/L in the two experiments conducted, respectively. A decreasing trend on concentrations of NH4+-N was noticed during these experiments, while the opposite was observed for COD. Struvite recovery experiments showed that the optimum Mg:NH4:PO3 ratio was that of 2:1:5.8. Under these conditions, the NH4+-N removal reached 88%. Further treatment of the process supernatant into a 4-L hybrid sequencing batch reactor with biocarriers and activated sludge achieved NH4+-N removal higher than 98% in Phases C and D, where 450 and 600 mL of supernatant were added, respectively. Similar removal was also observed in a 2-L bioreactor with microalgae Chlorella sorokiniana when 150 mL of struvite supernatant were added (Phase B) while further increase of the amount of added supernatant to 200 mL resulted to a sharp stop of NH4+-N consumption (Phase C). Calculations for a landfill serving 20,000 inhabitants and a daily RO concentrate production of 6 m3/d showed that the required area for the construction of the solar still was 1893 m2 and the volumes of the hybrid and the microalgae reactor were 54 m3 and 60 m3, respectively. The recovered solid material of struvite process, after characterization for heavy metals and organic micropollutants, could be reused to the fertilizers industry.

Efficient flame retardancy of polypropylene by cobalt ions doped phytate melamine synergized with expandable graphite

Maintaining a delicate balance between flame retardancy and amount of expandable graphite (EG) in flame retardant polypropylene (PP) is still a formidable challenge, primarily due to the lower flame-retardant efficiency of EG. In order to address this concern, a novel cobalt-doped nanosheet flame retardant (PAMA-Co) was fabricated by a hydrothermal method utilizing phytic acid (PA) and melamine (MA), exhibiting a promising potential in constructing synergistic EG flame retardant PP. Significantly, the incorporation of only 7 wt% PAMA-Co/23 wt% EG system raises the limiting oxygen index (LOI) of PP to 27.3% and UL-94 V0 level, which indicates the excellent synergistic flame-retardant efficiency of PAMA-Co. Furthermore, both the peak heat release rate (PHRR) and the peak smoke production rate (PSPR) of PP composites with 7 wt% PAMA-Co/23 wt% EG are substantially reduced, exhibiting an 81.6% lower PHRR and 87.8% PSPR compared to pure PP. The excellent flame-retardant efficiency is attributed to the following mechanisms: Gas-phase dilution, catalytic cross-linking charring effect, and the suppression of the EG "popcorn effect" of PAMA-Co. In summary, this work not only advances an understanding of flame-retardant mechanisms but also offers a practical, green strategy for enhancing the safety and utility of PP in various applications.

Nutritional Value, Phytochemical Properties of Different Parts of Dill (Anethum graveolens L.) and Their Effects on in vitro Digestibility in Ruminants

Introduction: At the interface between man, animal and environment, the use of phytobiotics in agroecology practices has been developed as one of the most effective nutritional strategies for animal performance, health, and well-being. This study aimed to determine the effect of extracts from different parts (leaves, flowers and fruits) of a medicinal and food plant, dill ( Anethum graveolens L.) on in vitro digestibility in small ruminants. Methods: Chemical and parietal composition and antioxidant activity were determined, and nutritional and energy values were predicted. Substrate fermentation was studied using in vitro gas production techniques in sheep and goat intestines. Results: Flowers were rich in secondary metabolites, while fruits were rich in fiber and showed the best antioxidant activity against DPPH (IC50 = 41.71 μg/ml). The studied dill plant parts were digestible and nutritious, mainly fruits, with lower gas production rates compared to leaves and flowers in sheep and goats. The methane gas produced by fermentation was not significant in the leaves of either species. Conclusion: In summary, A. graveolens fruits can be considered a natural source of antioxidants that improve animal nutrition and health. Moreover, A. graveolens leaves can play an ecological role in the environment.

A comparative study of bioenergetic metabolism on mammary epithelial cells from humans and Göttingen Minipigs

Mammary epithelial cells (MECs) of humans (h) and Göttingen Minipigs (mp) were analyzed to compare their ability to perform ATP production by oxidative phosphorylation and glycolysis. The ATP production under basal and stressor situations highlights the same metabolic potential of both primary cell lines. However, quantitively the ATP production rate of hMECs was higher than mpMECs. Conversely, oxidative cell respiration in mpMECs exploits a maximum respiratory capacity to support pathophysiological circumstances or stress conditions that could require an excessive effort of cell metabolism. Since mpMECs primarily utilize an oxidative metabolism similar to hMECs, the metabolic characterization conducted allows us to confirm that mpMECs represent a potential alternative cellular model in the translational medicine approach.

Thermoeconomic modeling of new energy system based on biogas upgrading to multigenerational purpose

The following article outlines an integrated approach toward the valorization of biogas for energy, chilled water, hot water, freshwater, and liquid carbon dioxide production. The suggested system includes a biogas upgrading unit with a biomethane-fueled burner, a Kalian cycle, an LNG regasification process, and a multi-effect desalination unit that can provide CO2, electricity, cooling, and heating. The new ideas in the proposed system include a cryogenic biogas upgrading process that can be used in many industrial settings, the production of liquid carbon dioxide through biogas upgrading, and the use of biomethane in the integrated combustion process. Furthermore, the grey wolf optimization technique is applied in various multi-objective optimization contexts to achieve optimal operating conditions and preferred performance outcomes. In this simulation, the generation of electricity reaches a value of 755 kW. Attached to it is a cooling load of about 5102 kW, with a heating load of 4725 kW, freshwater capacity about 1.33 kg/s, production rate of liquid CO2 at 0.58 kg/s, and natural gas at 3.1 kg/s. Thermodynamic results reveal that the proposed multigeneration performance scheme providently enhances energy and exergy efficiencies up to 59.82 % and 5.74 %, respectively, compared to the condition of a single product. The performed exergy analysis shows that the overall irreversibility of the suggested configuration is equal to 18,047 kW while about 42.6 % of this value is contributed from the heat exchanger E-104. Moreover, the CO2 emission intensity of the process can be kept as 0.35 kg/kWh. Cryogenic separation can obtain about 88 % of CO2 in biogas and turn it into its liquid phase. The performed economic assessment has resulted in the following total cost rate as well as cost per unit exergy: 321.38 $/h and 83.06 $/GJ, respectively. Under optimal conditions, an exergy efficiency of 13.40 % and a net power output of 2034.39 kW are attained.

Disruption of natural disturbance regime decouples habitat and life stage in a keystone species

AbstractAnthropogenic disturbance of stream ecosystems, often chronic in nature, has been studied extensively. However, when disturbance is driven by more than one resource policy over many decades, feedback between habitat evolution and biological adaptation can be disrupted and ecological function affected in unforeseen ways. We analyzed over 100 years of Chinook salmon (Oncorhynchus tshawytscha) length frequency trends associated with fisheries management and changes in available spawning substrate (habitat) linked to flow regulation in a highly altered California river. Over time, salmon lengths generally decreased, fluctuating with exploitation (ocean harvest) and hatchery production rates. Female size reduction, coupled with a degrading and coarsening channel, and perching peripheral habitat related to past mining activity, indicates available spawning substrate may be too large to support the current salmon population. Assuming a salmon can move material ~10% of her body length, length frequency data and current substrate size distribution suggest that increasing salmon sizes to historic distributions could increase available spawning habitat by as much as 13%. Alternatively, decreasing spawning substrate size could support a greater portion of the current population. To test the latter hypothesis and inform future management actions, we monitored two spawning riffles where large and small gravel was placed on top of a cobble. We observed an immediate spawning activity increase that was more pronounced where smaller gravel was deposited. Following a decade of habitat decline, the two sites were both replenished with medium gravel. Elevated spawning use occurred immediately at both sites, commensurate with this intermediate size, further supporting our hypotheses. Sediment coarsening and habitat disconnect below dams, combined with reduced salmon size, indicate the natural spawning process may be decoupled from available habitat below dams in the foreseeable future without continuous intervention. Actively managing salmon population demographics through modified hatchery and size‐selective harvest practices and developing a coarse sediment budget with size‐appropriate material for regulated anadromous rivers could produce immediate benefits for ecosystem services, including salmon populations. However, these management actions will require continued maintenance and informed socio‐ecological goals to remain successful.

Explaining Muon Excess in Cosmic Rays Using the Gluon Condensation Model

Ultrahigh-energy cosmic rays are often characterized indirectly by analyzing the properties of secondary cosmic ray particles produced in the collisions with air nuclei. The particle number N μ of muon and the depth of shower maximum X max after air shower cascade are mostly studied to infer the energy and mass of the incident cosmic rays. Research has shown that there is a significant excess in the observed number of muons arriving at the ground from extensive air showers compared to the simulations using the existing cosmic ray hadronic interaction model. To explain this muon excess phenomenon, a new theoretical model, the gluon condensation model, is introduced in this paper and simulated by using the AIRES engine. We assume that the gluon condensation (GC) effect appears mainly in the first collision of the cascade, leading to a significant increase in the strangeness production, consequently, the production rate of kaons is increased, and n K /n π is greater than the value of the usual hadronic interaction process. In the calculation, the model assumes that only pions and kaons are produced in the GC state. The increase of strange particle yield would mean that the energy transferred from the hadronic cascade to the electromagnetic cascade through π 0 → 2γ decay is reduced. This would in turn increase the number of muons at the ground level due to meson decays. Our model provides a new theoretical possibility to explain the muon excess puzzle.

Photocatalytic H2 production over CoxNi0.85-xSe decorated TiO2 S-scheme heterojunction

The construction of an S-scheme heterojunction facilitates the efficient separation of charges and preserves its high REDOX potential. In this study, a series of CoxNi0.85-xSe(x=0.05,0.1,0.2,0.3and0.4) and TiO2 nanoparticles were both prepared using solvothermal method, and then Co0.3Ni0.55Se was combined with TiO2 to form Co0.3Ni0.55Se/TiO2 heterojunction through a solvent evaporation strategy for efficient photocatalytic H2 production. It found that the H2 production rate of 10 wt%-Co0.3Ni0.55Se/TiO2 composite can reach 10,070.9 µmol∙g−1∙h−1 with TEOA as a sacrificial agent under a simulated sunlight irradiation, which is 307.9, 33.5and 3.3 times higher than those of pure Co0.3Ni0.55Se,TiO2 and 10 wt%-Ni0.85Se/TiO2, respectively. This enhanced performance is primarily attributed to the formation of an S-scheme heterojunction between TiO2 and Co0.3Ni0.55Se, which effectively enhances light absorption capacity and facilitates charge separation and migration during light irradiation processes. Especially, the S-scheme charge separation can retain the active REDOX capacity of electrons in the conduction band of CoxNi0.85-xSe and the holes in the valance band of TiO2, thereby promoting H2 generation. This study demonstrates that CoxNi0.85-xSe serves as a reducing photocatalyst that offers a viable approach for achieving ideal S-scheme heterojunctions.

Sustainable Oily Liquid-Proof Passive Cooling (SOC) Textile for Personal Thermal Management.

Sweat passive-cooling textiles with asymmetric wettabilities on different sides offer an effective and low-energy consumption solution to personal thermal management in extreme thermal environments. However, the sweat-wicking and the cooling abilities decrease when the textile is contaminated by low-surface tension oily liquid fouling. The integration of anti-oily liquid fouling and sweat-wicking abilities on textile involves resolving the contradiction between hydrophilic and oleophobic properties and seeking eco-friendly short-chain fluorides to reduce the surface energy. Herein, a sustainable oily liquid-proof passive cooling (SOC) textile for personal thermal management is proposed. The SOC textile is obtained by applying a fluoride-free hydrophobic coating layer to one side of the high thermal conductive superoleophobic/superhydrophilic basal textile, which is fabricated using eco-friendly short-chain fluoride. The SOC textile preserves the anti-oily liquid fouling property even after 2000 abrasion cycles. Experimental test revealed that the SOC textile exhibits a cooling effect of ≈5°C compared with the cotton textile, and the up to 70% reduction in sweating rate under the constant metabolic heat production rates. The configuration of the SOC textile would inspire the future design of intelligent textiles for personal thermal management, and the proposed strategy have implications for fabrication of eco-friendly oil-water separation materials.

Relationships between flowering behavior and seed yield in mungbean mutants

Flower is the prime sink that produces pods and yield depends on numbers and size of pods in legume crops. Flowering behavior affects the synchrony of pod maturity, which is crucial for efficient harvesing that regulates the yield. Thus, it is essential to study the relationship between flowering behavior and pod yield in mungbean mutants. This experiment was conducted using a Randomized Complete Block Design (RCBD) with three replications at the BINA headquarters physiology pot yard. The aim was to assess the relationship between flowering patterns, flowering duration, and seed yield in ten mungbean mutants/varieties. Results indicated that high-yielding mutant (MM-1) produced more opened flowers (38.0 flowers per plant) and had a longer flowering duration (12 days) compared to low-yielding varieties/mutants (13.1-18.0 flowers per plant and 7-9 days). Additionally, high-yielding varieties exhibited higher flower production rates over time, with peak flower production occurring within 5-8 days, while low-yielding varieties peaked within 3-4 days. High-yielding mungbean mutants/varieties exhibit lower pod set and reproductive efficiency (48.7-55.0%) compared to low-yielding ones (63.2-70.9%), indicating potential for yield improvement in high-yielding genotypes through enhanced pod set. Pod number, a key yield parameter, has a significant positive correlation with flower number (r = 0.56**), while pod number is also dependent on flowers per plant (r = 0.68**). Additionally, seed yield shows a strong positive relationship with the harvest index (r = 0.62**). These findings suggest that future breeding efforts should focus on synchronizing flower production to increase mungbean yield. Bangladesh J. Nuclear Agric, 38(1): 111-117, 2024

A dynamic solvent chamber propagation estimation framework using RNN for warm solvent injection in heterogeneous reservoirs

Warm solvent injection (WSI), injecting low-temperature solvent into formations to reduce the viscosity of heavy oil, is a clean technology for heavy oil production through reducing greenhouse gas emissions and water usage. The success of WSI operation depends on the uniform development and propagation of solvent chambers in reservoirs. However, reservoir heterogeneity stemming from shale barriers plays a detrimental role in the conformance of solvent chamber development and oil production rate. In this work, we developed a novel recurrent neural network (RNN)-based framework with the capability of efficiently tracking and estimating the solvent chamber positions in heterogeneous reservoirs based on only production time-series data. The developed estimation model utilizes the “sequence-to-sequence" mapping methodology to correlate observed production time-series sequence and solvent chamber edge sequence via a long short-term memory (LSTM) algorithm. The trained RNN models exhibit high accuracy, evidenced by the predicted dynamic solvent chamber locations match the corresponding true locations from numerical simulation, with a high coefficient of determination (R2) and a low mean squared error. Specifically, the achieved R2 values exceed 0.98 on both the training and testing data. The developed RNN-based workflow was tested via several cases from both regularly- and irregularly-shaped shale barriers, and the results were promising. The predicted solvent chambers showed strong agreement with those obtained from numerical simulations. The major benefits of this workflow include reducing computational time and saving overall monitoring and tracking costs for conventional techniques. The present work would provide a good demonstration of the capability of practical integration of machine learning methods in solving engineering problems.

Conservative deep neural networks for modeling competition of ribosomes with extended length

We develop a network model that combines several ribosome flow models with extended objects (RFMEO) competing for the finite pool of ribosomes. This alleviates the need to systematically coarse-grain the mRNA molecules. The dynamics of the network is described by a system of non-linear ordinary differential equations. It is shown that the network always converges to a steady state for a fixed number of ribosomes. Our analysis shows that increasing any of the transition rates along an RFMEO increases its output rate and either the output rates of the other RFMEOs all increase or all decrease. Simulations also demonstrate a counterintuitive result that increasing the ribosomal footprint may sometimes lead to an increase in the network production rate. Next, we propose a conservative deep neural network (CDNN) framework to approximate the solution of the network. The proposed loss function also incorporates the term satisfying the first integral property of the network. Point-wise comparison of the solutions by CDNN is in good agreement with the Runge–Kutta based numerical solution. Also, the CDNN framework offers a closed-form solution of the RFMEONP as a function of free parameters, thus allowing evaluation of the solution at any parameter value without again simulating the system.

Investigations of inlet arrangement strategies and particle parameters on thermochemical performance in falling particle solar reactors

The reformation of methane to hydrogen and steam in a falling particle solar reactor (FPSR) is a promising method to use the solar energy, which converts solar energy into chemical energy. FPSR has higher operation temperature, higher pressure bearing capacity and more direct heat energy storage than those of traditional reactor. However, due to the short residence time of the particles, hydrogen production efficiency is reduced. Thus, inlet arrangement strategies and particle catalysts should be carefully designed to improve the thermochemical reaction performance of FPSR. In this contribution, the Eulerian-Eulerian model in CFD program (Fluent 2020 R2) is used to explore the effects of different particle inlet arrangement strategies, non-uniform particle mass flow inlet and particle size on the performance enhancement of methane steam reforming reaction. The results indicate that the two arrangement strategies show different trends in influencing hydrogen production efficiency. Besides, non-uniform particle mass flow rate also has a significant impact on hydrogen production efficiency, with the optimal arrangement conditions increasing the hydrogen production rate by 2.4831 mol/m−3(−|-) s−1. Additionally, smaller particle size demonstrates better hydrogen production efficiency, with a 0.15 mm particle size catalyst showing a 14.02 % improvement in hydrogen production efficiency compared to a 0.75 mm particle size. This contribution can provide a guidance for optimizing the heat and mass transfer performance of the falling particle solar reactor.

ZnO/nZVI nanoparticle-enhanced double-slope U-shaped solar distillation: A thermodynamic investigation of cephalexin adsorption

The increasing need for sustainable methods to remove pharmaceutical contaminants like cephalexin and improve water desalination is critical. This study explores ZnO/nZVI nanoparticles synthesized with Jackfruit peel extracts as eco-friendly, cost-effective adsorbents, enhancing water purification in solar desalination systems. This work used a matte black paint coating within a double slope U-shaped solar distiller (DSUD) in a discontinuous experimental setting to examine potential improvements in solar distillation performance. Activated carbon (AC) and bioactive powdered nanoparticles of ZnO/nZVI (nano zerovalent iron), produced from jackfruit peel extracts (JP) were combined in a synergistic way. The effectiveness of cephalexin removal was assessed taking into account the JPAC solution parameters, reaction duration, ZnO/nZVI concentrations in the nanocomposite dosage, and initial nanocomposite concentration. The best conditions for cephalexin adsorption were found to be pH 5 and reaction time of 50 min, which resulted in high absorption efficiencies of 94.74% (nZVI) and 97.53% (ZnO) at room temperature with a JPAC dose of 2.50 g L⁻1. The efficiency of the eco-friendly adsorbent in getting rid of cephalexin was calculated using “pseudo-second-order kinetics” for nanocomposites, which is consistent with the “Langmuir” isothermal absorption process. The nanocomposites as absorbent materials in solar thermal desalination processes, efficient heat transmission and energy storage have been established. JPAC and the addition of steel balls (S) with a silver hue to the DSUD improved the internal heat transfer mechanisms. Thermodynamic of Gibbs free energy and the Laplacian method (TGL), two thermodynamic concepts, were used to extensively study the temperature dynamics of the DSUD with SJPAC components. For ZnO/JPAC, an exceptional distillate production rate was noted from 8:00 to 18:00, with a noteworthy 4.932 L/m2 output in winter and 5.833 L/m2 per day in summer. Using silver balls, ZnO/JPAC generated significant yields over a 24-h period: 8.957 L/m2 in summer and 7.253 L/m2 in winter, with an ideal energy efficiency of 51.05%. The unique advancements in TGL procedures and their environmental consequences are presented in this paper. The field of thermal energy transduction will advance if silver balls are used in DSUD for the synthesis of JPAC, ZnO/JPAC, and nZVI/JPAC, as supported by the theoretical insights presented here.

Photocarrier behavior and photocatalytic H2O2 synthesis performance of amorphous/crystalline SrTiO3/BiVO4 layered heterostructures

BiVO4 (BVO), as a visible light responsive semiconductor material, has been widely employed in the field of photocatalysis. However, monoclinic BVO is afflicted by a high recombination rate of photogenerated charge carriers and poor charge transport capability, resulting in low charge utilization efficiency. Constructing heterostructures for interface modification of BVO is an effective strategy to improve photocatalytic performance. Herein, amorphous/crystalline SrTiO3/BiVO4 (STO/BVO) layered film nanoheterostructures have been successfully fabricated on the (001) yttrium stabilized zirconia substrate by magnetron sputtering. Under 440 nm monochromatic light irradiation, the H2O2 production rate of the composite film is increased by 1.2 times compared to pure BVO. The type II heterostructure composed of STO and BVO accomplishes selective interface hole transport from BVO to STO, promoting the separation of space charges. Additionally, the interaction between amorphous/crystalline interfaces effectively suppresses the photocorrosion of BVO and strengthens the stability of the film, which is of great significance for studying charge transport behavior and photocatalytic mechanisms.