Pure Water Research Articles

Oil sands process-affected water composition effect on Henry's law constants for polycyclic aromatic compounds: Theory and experiment

Oil sands process-affected water (OSPW) is a source of atmospheric emission for polycyclic aromatic compounds (PACs), compounds known to have toxic effects on humans. Estimating emissions and assessing the chemical fate of PACs requires measured or predicted physical-chemical properties such as Henry's law constants (H), that can be used to predict chemical transfer into the atmosphere. OSPW is a complex water-based mixture that is highly variable in composition and nature and contains both organic and inorganic ions. This study uses COSMO-RS solvation theory to estimate and compare Henry's law constants for a set of PACs in both water and theoretically modelled OSPW, to assess the expected deviation that occurs from pure water H values due to the ionic content within OSPW. Experimental measurements of Henry's law constants for PACs in pure water and OSPW using EVA-coated passive dosing and sampler beads were also made in support of our theoretical predictions. For the theory work, OSPW composition data for the Athabasca oil sands in Alberta were used to model a simulated OSPW environment with realistic sodium, chloride, fluoride, sulfate, potassium, bicarbonate, and naphthenic acid concentrations. Theory results indicate that the combined presence of these ions at OSPW concentrations has a negligible effect on H values, causing on average a 3% or 0.014 log unit deviation. By comparison, temperature has a much larger influence on H values, with estimations showing an average 0.20 log unit increase for a 5 °C increase in temperature. The experimental results demonstrate that Henry's law constants can be accurately and precisely measured with this technique in pure water but with less precision in OSPW. Nevertheless, the experimental results support the conclusion that Henry's law constants for OSPW can be accurately estimated assuming a pure water phase.

Comparative predictive analysis using ANN and RCA for experimental investigation on branched and conventional micro heat pipe

The demand for compact, high-performance electronic devices rises, making thermal management in limited space crucial. This study presents a novel branched micro heat pipe (MHP) to solve this pressing problem. This novel method improves thermal performance for small-scale electronic cooling applications, surpassing conventional cooling methods. Innovative design has branched condenser of 12.7 mm evaporator, 24.6 mm adiabatic section and 12.7 mm condenser, each, compared to conventional MHP of identical size. Investigation encompasses a study of various parameters including working fluids, wettability characteristics, fill ratio, heat input, and cross-sectional geometries. The significant improvement in thermal performance by applying a hydrophobic surface treatment to the condenser section, increasing capillary force and condensate transport. Ammonia and de-ionized water excel thermal performance at lower and higher applied heat input (Qh), respectively. At higher Qh (>2 W), ammonia and toluene in the conventional MHP experience faster drying compared to the branched MHP, especially for lower fill ratio (0.6 FR). The branched MHP outperforms the conventional MHP, showing improved fluid circulation and performance, for fill ratios ranging from 0.65 to 0.4 and effectively transporting maximum heat flux in range of 10–14.4 W/cm2 with square mono-grooved MHP exhibits inferior performance compared to the trapezoidal and triangular mono-grooved. To provide a framework for future studies, we establish an artificial neural network (ANN) and statistical prediction model of thermal performance using the non-dimensional Kutateladze number (Ku), showcasing a robust correlation with experimental results and demonstrating only a minor deviation of ± 3 %.

Performance analysis of an Active Magnetic Regenerative system using Al2O3 nanofluids

This study investigates the utilization of Al2O3 nanofluids in an Active Magnetic Regenerative (AMR) system, focusing on varying nanoparticle concentrations from 0.01 to 1.0%. Numerical modelling is used to analyze the effects of nanoparticle incorporation on system efficiency and cooling performance. Al2O3 nanoparticles are found to significantly increase the thermal conductivity, density, and viscosity of the base fluid while reducing specific heat capacity. Comparative analysis reveals that Al2O3 nanofluids outperform pure water in terms of cooling performance, achieving a lower final temperature and a higher temperature span after 60 min of operation. Moreover, the study highlights that cooling capacity and pumping work increase with higher nanoparticle concentrations, with a notable improvement of 64.95% in cooling capacity and 39.31% in pumping work for the 1.0% Al2O3 nanofluid compared to water. The Coefficient of Performance (COP) of the AMR system peaks at an optimal nanoparticle concentration of 0.2%, reaching 3.88, before declining due to increased pumping power requirements.

Seawater submersion for cylindrical lithium-ion batteries thermal runaway prevention

Lithium-ion batteries (LIBs) are currently used in various electric vehicles, including electric boats. To assess the risk of fire due to thermal runaway of the LIB during the operation of ferries, seawater can be used as a cooling fluid for the LIB to prevent thermal runaway as it is abundant. However, the seawater could corrode the electrodes of the battery, which would lead to toxic wastewater. Prevention of thermal runaway of lithium-ion batteries by submersion in seawater needs to be investigated to clarify the corrosion that could lead to toxic wastewater. In this study, fully charged, pristine 18650 NMC Li-ion cells were submerged in synthetic seawater (SSW) to investigate the corrosion effect compared to deionized (DI) water. The results showed that SSW induced rapid voltage discharge, leading to corrosion on the electrodes and toxic effluents, while DI water maintained the stability of the cells and did not cause any corrosion effect. In addition, the prevention of thermal runaway was investigated by exposing fully charged LIB to extreme overheating conditions. The liquid submersion system was activated by rapid voltage drop monitoring to evaluate its effectiveness in preventing thermal runaway (TR). The investigation of TR prevention by SSW submersion showed that the TR process can be effectively prevented. In addition, no corrosion effect was observed during submersion in SSW as the battery voltage was not applied. This study shows that seawater can be used to prevent TR in LIB and does not cause environmental problems comparable to water.

A novel fuel cell cathode hybrid intake structure design and control for integrated hydrogen energy utilization system

The typical Integrated Hydrogen Energy Utilization System (IHEUS) does not recycle oxygen. For maximizing the system's efficiency, this study proposes a method for recycling byproduct oxygen in a Fuel Cell (FC) hybrid cathode intake structure and its control. By introducing the pure oxygen produced as a byproduct of hydrogen production into the FC, a hybrid cathode intake structure is formed with the air branch. To control this structure, models of the oxygen and air branch, and the FC stack are established. Subsequently, using BiLSTM network to learn historical data and extract relevant features, the output power demand of the FC system is predicted. Based on the prediction results, the required gas flow is calculated, and a fuzzy PID control strategy is employed to adjust the opening of the solenoid valve to change the gas flow to meet the demand. Finally, comparative studies show that our FC system, operating in a pure oxygen state, outperforms conventional air intake design: heat production increases by 13 %, electric efficiency improves by 20 %, and pure water savings reach 65.57 %. The air compressor witnesses a substantial 37.63 % reduction in power consumption, contributing to an overall energy efficiency increase of 8.92 % for the IHEUS.

Degradation of sodium dodecyl benzene sulfonate in aqueous solution by electron beam radiation and changes in surfactant micelle property

In this study, we investigated the degradation of surfactant sodium dodecyl benzene sulfonate (SDBS) in aqueous solution using electron beam radiation. The removal efficiency of SDBS approached nearly 100%, achieving a COD removal rate of 7–20% with an absorbed dose of 5.0 kGy. Upon irradiation, several notable changes in SDBS micelles were observed. The absolute value of zeta potential and the average diameter size decreased. SEM observations revealed that the clustered aggregates of SDBS micelles fragmented into irregular filamentous pieces. Moreover, the interfacial tension increased remarkably and approached the level of pure water at 2.5 kGy for SDBS in a pure water solution and 5.0 kGy for SDBS in a brine water solution. The foaming power disappeared for SDBS in pure water and decreased to 20 mm for SDBS in brine water at 10 kGy. The defoaming rate of SDBS solution increased incrementally from an initial range of 1–2 mm/min to 3.0–5.6 mm/min at 5.0 kGy. In summary, when SDBS is decomposed, new system is created with new properties. Electron beam radiation offers a clean and sustainable approach to degrade SDBS in wastewater.

Titania and zirconia ceramic nanofiltration membrane fabrication by coating method on mullite and mullite-alumina microfiltration supports for industrial wastewater treatment

Industrial wastewater treatment increasingly relies on membrane separation, with ceramic membranes offering many advantages such as thermal stability and pH resistance. The resistance of ceramic membranes to extreme pH conditions indicates their ability to maintain structure and performance when exposed to highly acidic or alkaline environments. A high-permeability ceramic nanofiltration membrane was developed, boasting excellent rejection rates through a multilayer asymmetric design. Initially, two tubular porous supports, mullite and mullite-alumina, with a weight percent of 50, were fabricated using the extrusion method. Subsequently, a colloidal sol of titania (TiO2) and titania-zirconia (TiO2- ZrO2) was prepared via the sol–gel method and coated on the ceramic supports using the dip-coating method. After analyzing the membrane microstructure using SEM, XRD, and BET, the efficiency of the membranes in treating synthetic oily wastewater was evaluated. The results underscore the significant impact of the Donnan exclusion mechanism on the rejection of nanofiltration (NF) membranes. An increase in pressure led to a rise in rejection rates up to 7 bars. The Chemical Oxygen Demand (COD) rejection for mullite-titania zirconia (MTZ) and mullite-alumina-titania zirconia (MATZ) membranes was 98.65 % and 98 %, respectively. The pure water permeability test results for mullite and mullite-alumina supports, as well as MTZ and MATZ membranes, were recorded as 254, 382, 70, and 89 L bar-1m-2h−1, respectively.

Polysulfone membranes decorated with Fe–Mn binary oxide nanoparticles and polydopamine for enhanced arsenate/arsenite adsorptive removal

Arsenic contamination of water is a global environmental concern, and membrane technology combined with nanotechnology contributes to more efficient removal of arsenic. In this study, Fe–Mn oxide (FM), Polydopamine (PDA), and PDA-modified FM (PFM) were incorporated into polysulfone (PSF) to prepare adsorption membranes (PFMP) for arsenic removal. The prepared nanoparticles and membranes were characterized using TEM, SEM, FTIR, TGA, contact angle, and pure water flux. The introduction of particles enhanced the hydrophilicity of the membranes and significantly enhanced the pure water flux of the membranes. Adsorption experiments indicated that the PFMP membrane exhibited the best arsenic removal performance, with maximum adsorption capacities for As(III) and As(V) were 11.57 mg/g and 12.39 mg/g, respectively. The Langmuir model fitted the adsorption isotherms well, and the kinetics followed the pseudo-second-order model. The filtration experiment revealed that the PFMP membrane was capable of reducing As(III) solution (915 L/m2) and As(V) solution (1075 L/m2) from a concentration of 100 μg/L to the safe limit of As (＜10 μg/L). The As-loaded membrane was regenerated using NaOH solution (pH = 11), and the filtration experiment was repeated. FTIR and XPS demonstrated that the mechanism of the reaction between the membrane and arsenic was ligand exchange, where the arsenic ions were bonded to the oxygen ions to form Mn–O–As and Fe–O–As.

Ultra-sensitive optimized one-dimensional phononic crystal as a fluidic sensor to enhance the measurement of acetic acid concentration

The current investigation theoretically presents a one-dimensional phononic crystal (PnC) as a fluidic sensor. The sensor under consideration aims to distinguish the concentration of acetic acid. The primary configuration of the proposed sensor is constructed with lead, epoxy, and a defect layer in the middle of the structure, that is filled with acetic acid (vinegar). As a result of the rise in density and decline in the speed of sound at a 100% concentration of acetic acid in comparison to pure water, the peak frequency of the output has shifted towards lower frequencies. Given that the maximum permissible concentration of acetic acid in water for vinegar is above 30%, sensor simulations were conducted within the concentration range of 25–35% with a step size of 1%. Interestingly, the sensitivity of the sensor exhibits a polynomial change in response to the concentration of acetic acid. Consequently, the highest level of sensitivity, which corresponds to the lowest concentration of vinegar, is recorded as 48.44 × 106 (Hz). The proposed system exhibits a remarkable value of the quality factor of 2802.91. Furthermore, the optimal figure of merit (FOM) is achieved when the concentration is at its lowest, with a value of 94.00. Furthermore, the temperature effects are taken into account for a wide range between 10 and\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{and}$$\\end{document} 60 °C. A pronouncing sensitivity is obtained for all temperatures changes and the highest one reached the value of 1.57 × 106 (Hz/°C) at a temperature of 25 °C. Considering the present circumstances, the suggested sensor configuration has the potential to cater to a diverse array of other fluids, specifically their concentration and temperature, thereby offering a broad scope of applications.

Preparation of ultra-high permeability dual-layer Al2O3 hollow fiber supports for zeolite membrane fabrication

Four-channel dual-layer Al2O3 hollow fiber with ultra-high permeability and mechanical strength was prepared by co-extrusion and co-sintering technique for the first time and used as support for NaA zeolite membranes fabrication. The macroporous inner layer of the Al2O3 hollow fiber, composed by large Al2O3 particle, gives supports the high permeability and mechanical strength, while the thin out layer, composed by small particles, provides an even and smooth surface for zeolite membrane growth. By using SiO2 as the sintering aid, the sintering temperature of the inner layer was reduced and match with that of the outer layer. The effects of SiO2 adding amount, sintering temperature, Al2O3 particle size and their content on the structure and properties of the prepared hollow fiber were investigated systematically. At a sintering temperature of 1520 °C, a dual-layer hollow fiber with surface pore size of 0.38 μm and fracture load of 24.52 N, exhibits pure water flux as high as 22.23 m3 m 2 h−1 bar−1. The NaA membrane prepared on this support achieved a flux of 14.14 kg m−2 h−1 and a separation factor >10,000 in pervaporation separation of EtOH/H2O solution (90 wt%, 75 °C). This work provides an efficient and low-cost way to prepare ceramic hollow fiber support for high-performance zeolite membrane fabrication.

Establishment of a UPLC-MS method for quantitative analysis of tryptophan-kynurenine metabolism in IBS-D model rats

Background and Aims Abnormalities in tryptophan (TRP) metabolism induce abdominal pain and intestinal motility disorders. The study of TRP metabolism in diarrhea-predominant-irritable bowel syndrome (IBS-D) is important for the prevention, diagnosis, and treatment of this disease. In this study, a rapid and reliable ultra performance liquid chromatography-mass spectrometry (UPLC-MS) method was established to quantify tryptophan-kynurenine (TRP-Kyn) metabolism in the colon of a rat model with IBS-D. Methods The proteins were precipitated by methanol, chromatographically separated on a Welch Ultimate® Polar RP column with a gradient elution for 12 min, and detected by high-resolution tandem mass spectrometry. Pure water were used as an alternative mechanism for standard calibration, and the stable structural analog 2-Cl-Phe was used as an internal standard. Results Within a certain range, the r of TRP, kynurenine (Kyn) and quinolinic acid (QA), kynurenic acid (KA) are greater than 0.99, were found to be accurate and precise. The metabolism of TRP was significantly up-regulated along the Kyn pathway in the IBS-D model rats and normalized after treatment with pivacurium bromide. Conclusion This study investigates the mechanisms of IBS-D gastrointestinal dysfunction from the perspective of colonic TRP metabolism, and also provides new directions for the diagnosis and therapeutic approach of this disease.

Revealing the Effects of Zinc Sulphate Treatment on Melatonin Synthesis and Regulatory Gene Expression in Germinating Hull-Less Barley through Transcriptomic Analysis.

This study investigated the transcriptomic mechanisms underlying melatonin accumulation and the enhancement of salt tolerance in hull-less barley seeds subjected to zinc sulphate stress. Following zinc sulphate treatment, hull-less barley seeds demonstrated increased melatonin accumulation and improved salt tolerance. Through transcriptome analysis, the study compared gene expression alterations in seeds (using the first letter of seed, this group is marked as 'S'), seeds treated with pure water (as the control group, is marked as 'C'), and germinated seeds exposed to varying concentrations of zinc sulphate (0.2 mM and 0.8 mM, the first letter of zinc sulphate, 'Z', is used to mark groups 'Z1' and 'Z2'). The analysis revealed that 8176, 759, and 622 differentially expressed genes (DEGs) were identified in the three comparison groups S.vs.C, C.vs.Z1, and C.vs.Z2, respectively. Most of the DEGs were closely associated with biological processes, including oxidative-stress response, secondary metabolite biosynthesis, and plant hormone signaling. Notably, zinc sulphate stress influenced the expression levels of Tryptophan decarboxylase 1 (TDC1), Acetylserotonin O-methyltransferase 1 (ASMT1), and Serotonin N-acetyltransferase 2 (SNAT2), which are key genes involved in melatonin synthesis. Furthermore, the expression changes of genes such as Probable WRKY transcription factor 75 (WRKY75) and Ethylene-responsive transcription factor ERF13 (EFR13) exhibited a strong correlation with fluctuations in melatonin content. These findings contribute to our understanding of the mechanisms underlying melatonin enrichment in response to zinc sulphate stress.

Multifunctional Design of Catalysts for Seawater Electrolysis for Hydrogen Production.

Direct seawater electrolysis is a promising technology within the carbon-neutral energy framework, leveraging renewable resources such as solar, tidal, and wind energy to generate hydrogen and oxygen without competing with the demand for pure water. High-selectivity, high-efficiency, and corrosion-resistant multifunctional electrocatalysts are essential for practical applications, yet producing stable and efficient catalysts under harsh conditions remains a significant challenge. This review systematically summarizes recent advancements in advanced electrocatalysts for seawater splitting, focusing on their multifunctional designs for selectivity and chlorine corrosion resistance. We analyze the fundamental principles and mechanisms of seawater electrocatalytic reactions, discuss the challenges, and provide a detailed overview of the progress in nanostructures, alloys, multi-metallic systems, atomic dispersion, interface engineering, and functional modifications. Continuous research and innovation aim to develop efficient, eco-friendly seawater electrolysis systems, promoting hydrogen energy application, addressing efficiency and stability challenges, reducing costs, and achieving commercial viability.

A robust COF membrane on polyethylene support via ethanol-assisted self-assembly of COF nanosheets for efficient desalination

Fabrication of high-rejection covalent organic framework (COF) membranes for desalination remains a significant challenge, due to processing limitations and substrate mismatches. Herein, we report an ethanol-assisted self-assembly strategy for preparing high-rejection COF membranes from anionic TpPa-SO3Na COF (SCOF) nanosheets. This method promotes SCOF dispersion in ethanol with high aspect-ratio structures and elimination of interlayer charge, thus facilitating the formation of defect-free SCOF membranes (COFMs). Furthermore, polyvinyl alcohol (PVA) was used to modify commercial polyethylene (PE) supports ensuring compatibility with the high-rejection SCOF layers. The hydrophilic PVA@PE support with appropriate surface pore induces the SCOF nanosheets to form a complete stacking structure. The resultant COFM (MEtOH) exhibit an impressive Na2SO4 rejection rate of 98.83 % and a pure water flux of 4.35 L m−2 h−1, demonstrate exceptional rejection stability under elevated pressure, acidic or alkaline conditions, and high salt concentrations. The superior desalination performance of the COFMs surpasses the most reported 2D desalination membranes.

Unveiling intricate foam behaviors and dynamic instabilities in a two-phase natural circulation loop with seawater

The use of seawater as an alternative emergency coolant in a nuclear power plant presents great potential to enhance the nuclear safety. The present study investigates the dynamic instabilities during the startup experiments of a natural circulation loop with seawater through synchronization of two-phase flow visualization and measurements of transient fluid flow parameters. The results reveal that in seawater the pressure drop oscillations (PDO) with nature of low-frequency pulse-type loop flow occurs at the modified heat flux of 531.56–654.80 kW/m2. On the other hand, the density wave oscillations (DWO) characterized by high-frequency oscillatory flow prevails at higher modified heat flux of 654.80–1844.46 kW/m2. For the loop with seawater, the flow patterns in the riser may evolve from dispersed bubbly flow, foam flow, foam and short slug flow due to the flashing effects, and foam and long slug flow periodically. The image analysis reveals that the foam fraction may decline from 75% to 52.2%, while the flow pattern transforms from the stage II (foam and cape bubbly flow) to III (foam and long slug flow). On the other hand, the flow pattern may evolve from bubbly flow, cap bubbly flow, turbulent slug flow, and long slug flow in de-ionized water. For DWO, the oscillatory frequency is found to be inlet temperature dependent. Interestingly, both fluids demonstrate identical frequencies of 0.06 Hz, 0.14 Hz, and 0.09 Hz, respectively, corresponding to the inlet temperature range of 40–52 °C, 52–65 °C, and 65–75 °C, despite significantly different evolution of two-phase flow patterns. Indeed, the density wave travels at the same speed through the loop operating at the same power for both seawater and de-ionized water, as the buoyancy force is the primary driving force for the present study. These findings contribute significantly to the better understanding of related industrial processes using seawater as the working fluid.

A low-cost salt-tolerant solar evaporator prepared from graphite in spent LIBs for high efficiency seawater desalination

Interfacial photothermal evaporation technology has been greatly promoted due to the increasing demand for sustainable energy around the world. but the development of low cost and durable efficient evaporators remained challenging. In this paper, a polyurethane sponge-loaded chitosan/reconstructed graphite-based evaporator (PCRE) was successfully designed by freeze-drying technique using recycled graphite from spent lithium batteries. The PCRE demonstrated strong hydrophilic properties and exhibited a light absorption rate of 96.06 %. Under the irradiation of 1 light intensity, the photothermal conversion efficiency of PCRE can reach 91.9 %, and the evaporation rate reaches 3.85 kg m-2h−1. Thanks to the large number of hydrophilic groups in PCRE and its excellent pore structure, the enthalpy of evaporation of water inside PCRE (1.2970 kJ g−1) is much lower than that of pure water (2.4417 kJ g−1). Moreover, PCRE can effectively avoid the problem of salt deposition, and its evaporation rate can still be maintained at 3.0 kg m-2h−1 in the treatment of high-concentration brine (25 wt.%), and in long-term evaporation experiments, PCRE has demonstrated highly efficient and stable desalination performance and removal capability for real seawater and organic wastewater. Based on the excellent evaporation performance, simple preparation and low cost of this evaporator, this study provides a new idea for waste recycling in the application of interfacial photothermal evaporation.

Effect of Nixtamalization on Aflatoxins, Functional and Acceptability of Maize from Mulindi, Rwanda

Rwanda relies highly on maize for human food as well as for animal feed and industrial uses. However, high temperature and wet climate conditions in Rwanda favor the growth of fungi that may lead to mycotoxin contamination in maize and subsequent degradation of its quality. Therefore, this study aimed to assess the effect of nixtamalization on the aflatoxins, the functional and acceptability of maize grains from Mulindi, Rwanda. The maize samples were collected from the Mulindi market in Rwanda; representative samples were collected by the guidelines for sampling food for mycotoxin determination. Subsequently, the treated maize samples were dry-milled to produce fine flour, and the flour obtained was analyzed for swelling capacity, water absorption capacity, water solubility, acceptability, and aflatoxins, which were quantified by the HPLC method. The HPLC results showed that the highest total aflatoxin level in maize grains was 44.99 ppb. Cooking maize in water and calcium hydroxide of 1% resulted in a reduction of aflatoxin with degradation percentages of 25% and 88%, respectively. However, in all treatments, aflatoxins B1 and B2 were less reduced compared to aflatoxins G1 and G2. Cooking maize in pure water showed the lowest reduction of aflatoxin compared to the other treatments. However, cooking maize in water with 1% calcium hydroxide decreased aflatoxin to a higher percentage. Cooking maize in lime enhanced the swelling capacity, water absorption capacity, and water solubility of maize, as well as its acceptability. However, the nixtamalization process was observed to reduce aflatoxins levels in maize and improve the functional properties of maize, and therefore, its application could be encouraged for safe products in the market.

Improving the scour-resistance performance of for offshore wind turbines: Experimental and computational fluid dynamics studies on macro and micro characteristics

To enhance the resistance to local scour around offshore wind turbine monopiles, 15 mixtures were designed based on Response Surface Methodology (RSM). Cement content, sodium silicate content, and rubber powder content were selected as independent variables. After determining their flowability, the compressive strength and shear strength were measured after curing in pure water and artificial seawater for 3 days, 7 days, 14 days, and 28 days. Experimental results indicate significant improvement in the mechanical properties of the modified soil, including increased Unconfined Compressive Strength (UCS), internal friction angle, and cohesion. The optimal mix ratio is identified as CSR40–10–15, consisting of 40 % cement, 10 % sodium silicate, and 15 % rubber powder. The strength variation mechanism is elucidated from both macroscopic and microscopic perspectives. Finally, numerical simulations using Computational Fluid Dynamics (CFD) software validate the scour resistance performance based on the optimal mix ratio of flowable solidified soil, offering a new approach for local scour protection around offshore wind turbine monopile.

Efficient carbon dioxide capture using biodegradable surfactants in form of clathrate hydrate: New eco-friendly approach

CO2 hydrate formation kinetics are relatively slow, hindering large-scale implementation for carbon capture and storage. Amino acids have been widely investigated as green promoters for CO2 hydrate formation due to their potential in the CO2 uptake capacity. However, there is still a limited number of studies focusing on the application of biosurfactants for CO2 hydrate formation. In this study, four biodegradable surfactants (BSs), derived from castor oil, were investigated as efficient promoters for CO2 hydrate formation. BSs provided the highest promotion efficiency, enhancing CO2 uptake by 10 times and achieving a 50.19 % conversion degree compared to 6.45 % in pure water. An important characteristic of BSs is their high biodegradability, as demonstrated by a BOD/COD ratio of 52.2 % after 28 days. The combination of promotion power, non-foaming properties, and biodegradability makes BSs unique candidates for addressing the challenges associated with CO2 capture and storage using hydrate-based sequestration strategies.

Natural redox mediator anthraquinone aloe-emodin facilitated the in-situ mineralized γ-FeO(OH) membrane for the removal of tannic acid through photocatalytic-PMS activation

The growing utilization of Traditional Chinese Medicine (TCM) has resulted in an increase in wastewater. Herein, a new kind of organic-inorganic redox mediator membrane by immobilizing γ-FeO(OH) and aloe-emodin(AE) with the characteristic large π-conjugation anthraquinone structure on PVDF membrane was innovatively achieved. AE exhibiting both electron deficiency and redox activity possesses a co-catalyst role in degradation of tannic acid (TA), aiding in the separation of charge carriers through the sequential hydrogenation and dehydrogenation of AE. The removal rates of TA were 92.8 % in the tannic acid solution and 60.3 % in the simulated rhubarb wastewater by the AE-γ-FeO(OH) membrane under PMS+Vis conditions in 45 min. Also, they show a higher recovery of pure water flux and owning good fouling performance. Overall, this current work presents a novel approach for the design and preparation of organic-inorganic photocatalytic composite membrane using readily available natural products for the purification TCM wastewater.