Seawater Solutions Research Articles

Moderately Reconstructed Ternary Metal Nitride Nanoparticles for Highly Efficient and Robust Freshwater and Seawater Oxidation under Industrial Current Density

Transition metal nitrides (TMNs) electrocatalysts experience rapid performance degradation during oxygen evolution reaction (OER) due to severe and irreversible electrochemical reconstruction, impeding their practical application in electrochemical water splitting. To address this issue, ternary metal (Ni, Fe, Cr) nitride nanoparticles on spongy nitrogen‐doped disordered carbon skeleton electrocatalyst (NFCN/C) is synthesized using a novel one‐pot pyrolysis of eutectic mixture method. The ionomer‐free NFCN/C electrode, which undergoes moderate electrochemical reconstruction, demonstrates high OER performance in both alkaline freshwater and seawater solutions, achieving a current density of 250 mA cm−2 with low overpotentials of 349 and 364 mV, respectively. The NFCN/C anode with Pt/C cathode delivers 10 mA cm−2 at a low cell voltage of 1.49 V and exhibits long‐term durability of 450 h at 500 mA cm−2. In situ Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS), along with pre‐ and post‐characterizations, elucidate that both high electrocatalytic activity and robustness of NFCN/C for OER stem from the proposed intrinsic strategy integrating physical and electronic structures. This work paves the way for designing highly efficient and robust TMNs electrocatalysts with moderate electrochemical reconstruction for industrial freshwater and seawater electrolysis.

Гострий риноcинусит у дитячому віці - нове вирішення старої проблеми

Acute inflammation of the mucous membrane of the nose and paranasal sinuses (acute rhinosinusitis (ARS)) is a fairly common pathology in pediatrics and otorhinolaryngology. The aim of the research was to improve the effectiveness of treatment children with ARS by introducing a combination complex of natural plant extracts "Sinudafen" and effervescent isotonic seawater solution "Sparklin" and to investigate the effect of the proposed complex treatment on the frequency of repeated ARS. Materials and methods. The study was conducted between February and December 2023 in two independent centers. The study included 98 patients with signs of ARS. The Main group - 67 patients who received "Sinudafen" and "Sparklin" for 10-14 days, symptomatic and/or etiotropic therapy if necessary. The Control group - 31 patients who received standard therapy. The results. The examination carried out on the 14th day showed that, compared to standard treatment, the patients of the Main group had a statistically significantly lower risk of maintaining such local symptoms of ARS (edema of the mucous membrane and mucous secretions from the nose). With the faster rates of recovery of children in the Main group, the pharmacological load on patients decreased significantly. The use of "Sinudafen" and "Sparklin" in comparison reduced the need to prescribe antibacterial and antiseptic drugs in the acute period. Better clinical dynamics was accompanied by a reduction in the length of hospitalization, the use of "Sinudafen" + "Sparklin" increased the chances of reducing the duration of the acute period within ≤4 days. Conclusions. The use of "Sinudafen" and "Sparklin" complex in the treatment of children with ARS allows for a 3.8-fold increase in the chances of recovery within ≤4 days. The proposed complex treatment reduces the need for antibiotics/anesthetics by 15.8 times and reduces the risk of repeated episodes of ARS by 18.2 times during the 6-month follow-up period. The use of "Sinudafen" with "Sparklin" is characterized by good tolerability, absence of side effects, high adherence, and also reduces the cost of treatment of one episode of ARS by 50%. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Unraveling the Impact of Ethylenediaminetetraacetic Acid Chelating Agents on the Oil Recovery Processes: An Insight into Its Role in Fluid-Fluid and Rock-Fluid Interactions.

In recent years, chelating agents have garnered increasing attention due to their unique capabilities in addressing challenges associated with chemically enhanced oil recovery materials. Most previous studies have primarily focused on examining the influence of chelating agents on rock-fluid interactions. However, their effects on fluid-fluid interactions, specifically on interfacial tension (IFT) characteristics under various conditions, remain relatively unknown. This study investigates the effect of crucial reservoir parameters on the performance of ethylenediaminetetraacetic acid (EDTA) chelating agents in the IFT between crude oil and brine. Furthermore, the study evaluated the impact of varying concentrations of this agent on rock wettability alteration, zeta potential, and spontaneous imbibition. The results illustrated that introducing EDTA at high concentration into seawater (SW) solution reduced the IFT by 85%. Additionally, while higher pH levels contributed to IFT reduction due to increased hydroxyl ions, excessive salinity levels resulted in elevated IFT. Raising the temperature from 30 to 75 °C further decreased the IFT, changing the IFT for optimal EDTA concentration from 20.43 to 2.56 mN/m (∼88% reduction). The changes in zeta potential and contact angle measurements indicated that solutions of 5 and 7 wt % EDTA shifted rock wettability from oil-wet to strongly water-wet, resulting in the wettability alteration index of 1.01 and 1.02, respectively. Inductively coupled plasma analysis, on the other hand, revealed substantial chelation of metal ions from both the solution and rock when EDTA was added to the rock/SW system. This resulted in a significant increase in Ca2+ ions and a decrease in Mg2+ ions, attributed to the multi-ion exchange phenomenon.

An Experimental study on steam explosion of multiple droplets in different chemical solutions

Motivated by the interest in steam explosion in chemical solutions and seawater, a series of tests were carried out in the MISTEE facility at KTH to investigate steam explosion characteristics as multiple molten droplets of tin were falling through a coolant pool containing deionized water, boric acid solution, neutral solution of boric acid and sodium phosphate, and seawater, separately. The experimental results revealed distinct and complex characteristics of steam explosion of multiple droplets, which were not observed in previous single-droplet steam explosion experiments. The tin melt samples of 5 g and 20 g were employed to formulate different numbers of multiple droplets. In the test with 5 g melt, steam explosion was more energetic at a deeper explosion location − a similar trend found in the single-droplet steam explosion test with 1 g melt. However, the test of 20 g melt did not show a clear trend in a wide range of explosion depth. The peak pressure and impulse increased with increasing mass of melt sample. The steam explosion occurred more closely to the coolant pool surfaces in the seawater and chemical solutions than in deionized water. Steam explosion intensity was significantly reduced in a neutral solution containing 1.2 wt.% boric acid and sodium phosphate. The influence of the chemical solutions on steam explosion was diminishing in the tests with multiple droplets.

Mechanical behavior of glass fiber‐reinforced hollow glass particles filled epoxy composites under moisture environment

AbstractThe utilization of hollow glass particle‐filled fiber‐reinforced composites in marine applications necessitates a proper understanding of their behavior when exposed to moisture environments. In this study, the glass fiber‐reinforced composites reinforced with 0%–30% volume fraction of glass microspheres were fabricated and immersed in seawater and distilled water conditions for monotonic tensile and flexural testing. The degradation mechanisms were analyzed by dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FT‐IR), and scanning electron microscopy (SEM). Moisture absorption results showed an increasing trend with the inclusion of glass microspheres. A decline in glass transition temperature and storage modulus was observed as a result of moisture absorption. The tensile results of the specimens exhibited a decrease of 13% and 9% in distilled water and seawater solution, respectively when compared with unaged samples, respectively. The flexural results of the aged composite specimens demonstrated a reduction of 24% and 11% in distilled water and seawater solution, respectively when compared with unaged samples. The findings also show that the influence of moisture on the modulus is less pronounced compared to its effect on strength under both environmental conditions. The micrograph results revealed a notable deterioration of the glass microsphere and the fiber/matrix interface in the moist environment.Highlights Water absorption increases with the addition of glass microspheres. Microsphere degradation and fiber/matrix debonding are the governing mechanism. Retained 89% of tensile strength of their initial properties after exposed in sea water. Increase in microsphere contents decreases the tensile and flexural strength.

Mechanical Properties Characterization of Glass/Carbon Fiber Hybrid Multilayer Composite under Environmental Aging Condition

Metallic components in boating industry are being replaced with carbon fiber composites due to their light weight, excellent mechanical properties, and corrosion resistance. However, the carbon fiber cost has obstructed the substitution. Hybridization is suggested to merge carbon and glass fibers in cost-effective composites while maintaining the desired engineering properties. This study experimentally examines the impact of hybridization and seawater aging on the mechanical properties of glass and carbon fibers hybrid composites. A range of composites ([C]6, [CGC]s, [C]3[G]3, [GCG]s, and [G]6) are fabricated and aged in simulated seawater solution before their tensile, flexural, impact, and hardness properties are examined. The results revealed degradation in properties due to the ageing, the degree of degradation is influenced by the s hybridization configuration. The [G]6 sample shows the highest tensile strength reduction of 30% compared to 20% for the [C]6. The remaining samples exhibit reduction percentages falling between these two extremes. A similar behavior is observed in the flexural test, though the extremes values are smaller, 10.2%, and 12.5%. The impact and hardness tests showed an inverse relationship between the glass fiber content and impact strength degradation due to aging, while they exhibited a linear correlation for hardness degradation due to ageing.

Клінічне значення деблокади носового дихання в дітей грудного і раннього віку на тлі гострих респіраторних вірусних інфекцій: переваги ізотонічного розчину морської води

Acute respiratory viral infections (ARVI) are an urgent problem in young children, which is due to their significant prevalence, they have a constant tendency to increase and occupy the first places in the structure of infectious diseases. Damage to the mucous membranes of the upper respiratory tract in children with ARVI lead to numerous problems that require adequate replacement of the main functions of the child’s body, which determined the relevance of our study. Purpose - to analyze the effectiveness of the use of isotonic dilution of sea water (Pshyk Mini medicine) for irrigation therapy in nasal congestion in infants and young children caused by acute respiratory infections. Materials and methods. A comprehensive examination of 100 infants and young children with influenza and other ARVI was conducted in the infectious diseases department of the Chernivtsi Regional Children’s Clinical Hospital. The children were randomly divided into 2 clinical groups: the Group I included 55 children (average age - 1.09±0.3 years, the proportion of boys - 58.1%), who, as part of complex standard therapy, received nasal irrigation using 2-3 drops of Pshyk mini medicine in each nostril 3 times/day. The Group II included 45 patients (average age - 1.15±0.2 years (p>0.05), the proportion of boys - 59.1% (p>0.05)), in whom isotonic sodium chloride solution was used for the purpose of the nasal sanitation. Results. The conducted studies showed that starting from the 3-4th day of hospitalization, a statistically significant decrease in catarrhal manifestations and the severity of nasal obstruction was noted in patients of the Group I who received Pshyk Mini in complex treatment. In particular, in relation to the results of the Group II, in the children of the Group I, on the 4th day of inpatient treatment, the chances of reducing the severity of catarrhal manifestations (estimated ≤2 points) increased: the absolute risk increase - 53.0%, the relative risk increase - 67.9% (95% CI: 57.8-76.9) with the minimum number of patients who need to be treated to obtain a positive result - 1.5. We also established that compared to the representatives of the Group II, children of the Group I had almost a 4-fold increase in the chances of restoring tolerance to feeding (estimation of feeding difficulties ≤2 points): attributive risk - 30.5%, relative risk - 1.6 (95% CI: 0.6-4.8), odds ratio - 3.9 (95% CI: 1.2-12.3). Conclusions. For the purpose of unblocking of nasal breathing in infants and children of early age at the background of acute respiratory viral infections, the use of an isotonic solution of sea water (Pshyk Mini medicine) has a number of significant advantages compared to the use of an isotonic solution of sodium chloride for this purpose. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Effect of Rebar Harsh Storage Conditions on the Flexural Behavior of Glass FRP Concrete

Nowadays, fiber-reinforced polymer (FRP) has become a widely accepted alternative reinforcement to steel bars in concrete members due to its many sustainability traits, as represented by its high strength-to-weight ratio, corrosion resistance, non-conductive properties, and electromagnet neutrality. However, FRP bar exposure for an extended period of time to harsh environmental conditions and chemicals can have an adverse effect on their mechanical properties. In this investigation, glass FRP bars were exposed to indoor controlled temperature, outdoor direct sunlight, outdoor shade, seawater, and alkaline solution for six months prior to using them as reinforcement in concrete flexural members. This research involves the fabrication and testing of five pairs of 3 m-long concrete beams with 200 mm by 300 mm cross-sections embedded in the tension zone with the exposed GFRP bars. The 10 beams were instrumented with strain gauges and tested following a four-point loading scheme using a hydraulic jack attached to a rigid steel frame. Crack width records from the tests showed the inferior serviceability of the beams that contained rebars stored in an outdoor environment relative to the control beams. GFRP bar exposure to an alkaline solution or outdoor direct sunlight slightly affected the cracking and ultimate moment capacities, reducing them by 5% and 3% in terms of the same parameters as the controlled indoor exposure, respectively. The influence of GFRP bar exposure to open-air shade or sunlight decreased the pre-cracking stiffness by 25% and flexural ductility by 10–20% when compared with the control specimens. The predicted ultimate flexural strength using the ACI 440 provisions gave comparable results to the experimentally obtained values. A simple mathematical equation that envelops the moment–deflection relationship for GFRP over-reinforced concrete beams and only requires information about initial cracking and ultimate flexural conditions is proposed.

Built-in electric field drives n-n heterojunction toward enhanced electrochemical freshwater and seawater oxidation

Optimizing the electron cloud density on the catalyst surface is the key to achieving fast kinetics for oxygen evolution reaction (OER). Here, a n-n Fe2P/NiCoP core/shell with strong built-in electric field (BEF) is successfully constructed to enable efficient local charge redistribution at heterointerface and contribute to extraordinary OER performance. Remarkably, the optimized Fe2P/NiCoP catalyst only requires the overpotentials of 272 and 291 mV to achieve a current density of 10 mA·cm−2 in 1 M KOH and alkaline seawater solutions, along with superb electrochemical stability over 140 h and 120 h, respectively. Detailed experimental and theoretical studies demonstrate that the well-designed BEF at the heterointerface of Fe2P/NiCoP n-n heterojunction can accelerate the charge transfer and enhance the conductivity. In addition, the self-propelled electron transfer across the n-n interface can prompt localized charge redistribution at the interface region, leading to enhanced adsorption of OH– and thus significantly boosting the kinetics of OER. This research paves a new avenue for the fabrication of heterostructured catalysts with BEF and optimized interfacial electron cloud for the enhanced OER.

Iron-based heterojunction activate strong metal-support interaction enabling hydrogen evolution reaction at ampere-level current density in seawater

Exploring Ru-based materials with strong metal-support interaction (SMSI) is a promising method to develop superb activity and long-term durability electrocatalysts for hydrogen evolution reaction (HER). Herein, a heterojunction substrates strategy is proposed to stimulate the intrinsic activity of Ru nanoparticles loading on FeTeO (Ru/FeTeO) by activating the strong metal-heterojunction substrate interaction (SMHSI). Density functional theory (DFT) and in-situ tests uncover that FeTeO heterojunction substrates can further boost the HER activity by modulating the electronic structure and H adsorption energy. Consequently, the as-prepared Ru/FeTeO possesses outstanding HER activity with low overpotentials of 244 and 311 mV to drive 1.0 and 3.0 A cm−2 current densities in 1.0 M KOH seawater solution, respectively, and displays a long-term stability more than 150 h. This work supplies an effective way to stimulate the intrinsic activity of precious metals.

Removal of Crystal Violet Dye from Aqueous Solutions through Adsorption onto Activated Carbon Fabrics

The removal of contaminants from aqueous solutions by adsorption onto carbonaceous materials has attracted increasing interest in recent years. In this study, pristine and oxidized activated carbon (AC) fabrics with different surface textures and porosity characteristics were used for the removal of crystal violet (CV) dye from aqueous solutions. Batch adsorption experiments were performed to investigate the CV adsorption performance of the AC fabrics in terms of contact time, temperature, adsorbate concentration and adsorbent amount. Evaluation of the thermodynamic parameters and the adsorption performance of the AC fabrics in ground water and sea water solutions were also carried out. Langmuir isotherm model, pseudo first and pseudo second order kinetics models were utilized to analyze and fit the adsorption data. The introduction of oxygen-based functional groups on the surface of AC fabrics was carried out through a nitric acid treatment. This oxidation process resulted in a significant reduction in the surface area and pore volume, along with a small increase in the average pore size and a significant enhancement in the CV adsorption capacity, indicating that the dye molecules are mainly adsorbed on the external surface of the carbon fabrics. The herein evaluated 428 mg/g adsorption capacity at 55 °C for the oxidized non-woven AC fabric is one of the highest adsorption capacity values reported in the literature for CV removal using AC materials. Thermodynamic studies showed that the adsorption occurs spontaneously and is an endothermic and entropy-driven reaction. Furthermore, pristine and oxidized non-woven AC fabrics displayed more than 90% CV uptake from sea water samples, underlining the great potential these fabrics possess for the removal of dyes from natural/multicomponent waters.

Tensile strength retention of glass fibre-reinforced stirrups subjected to aggressive solutions: effect of environmental condition, stirrup shape and stirrup diameter

The aim of this study was to examine how the tensile strength of glass fibre reinforced polymer stirrups is affected by different types of solutions, including alkaline, seawater, tap water, and acidic solutions. The study involved the production and testing of 260 stirrups in two different shapes (L and U) with diameters of 6 and 8 mm. The stirrups were immersed in different solutions for a period of 9 months at different temperatures (25, 40, and 60 °C). The findings indicated that the alkaline solution was the most aggressive environment, resulting in a maximum reduction of 92% in tensile strength after 9 months at 60 °C. Seawater and acidic solutions were the second and third most aggressive environments, causing maximum tensile strength reductions of 34 and 22% respectively, after 9 months at 60 °C. On the other hand, tap water was found to be the least aggressive environment, causing a maximum tensile strength reduction of 20% after 9 months at 60 °C. Furthermore, the study observed that the L-shaped stirrups exhibited slightly superior performance compared to the U-shaped stirrups. However, the diameter of the stirrups was found to be a negligible factor.

In-situ pH monitoring of pre-notched X80 pipeline steel using an all-solid-state Pt/RuOx ultra-micro pH sensor

In the notch microenvironment caused by the stress corrosion of pipeline steel, the local pH value changes mediated by anodic-cathodic corrosion reactions played an important role in comprehending the local corrosion behavior. To address this issue, a radius 5 µm all-solid-state Pt/RuOx ultra-micro pH sensor was developed using cyclic voltammetry deposition method, which was combined with scanning electrochemical microscopy (SECM) to achieve in-situ monitoring the local pH distribution and evolution of the pre-notched X80 pipeline steel. The micro-sensor demonstrates a near Nernstian slope of −60.0 ± 3 mV/pH within the pH value range of 2.00–12.00, accompanied by an exceptionally rapid response time of 200 ms. Moreover, it exhibits high accuracy, strong long-term monitoring ability and remarkable resistance to the interference of common ions in seawater and ferrous ions generated by the corrosion of pipeline steel. Through monitoring the local pH distribution in simulated seawater solution at the notch of X80 pipeline steel, it was found that obvious pH alkalization occurs first on both the surface and inside of the notch, followed by gradual acidification, and this phenomenon is more obvious at the front of the notch. Combined with other characterization methods, a possible corrosion reaction mechanism at the notch of stress corrosion was proposed.

Hetero MOF‐On‐MOF of Ni‐BDC/NH2‐MIL‐88B(Fe) Enables Efficient Electrochemical Seawater Oxidation

AbstractSeawater electrolysis is a sustainable technology for producing hydrogen that would neither cause global freshwater shortages nor create carbon emissions. However, this technology is severely hampered by the insufficient stability and the competition from the chlorine evolution reaction (ClER) in actual application. Herein, a metal–organic framework (MOF)‐on‐MOF heterojunction (Ni‐BDC/NH2‐MIL‐88B(Fe)) denoted as (Ni‐BDC/NM88B(Fe)) is synthesized as an effective oxygen evolution reaction (OER) electrocatalyst for high‐performance seawater electrolysis, which exhibits a long stability of 200 h and low overpotentials of 232 and 299 mV at 100 mA cm−2 in alkaline freshwater and seawater solution, respectively. The exceptional performance is attributed to the rapid self‐reconstruction of Ni‐BDC/NM88B(Fe) to produce NiFeOOH protective layer, thereby avoiding ClER‐induced dissolution. Moreover, the interface interaction between Ni‐BDC and NM88B(Fe) could form the Ni─O─Fe bonds in Ni‐BDC/NM88B(Fe) to promote the electron transfer and lower the energy barrier of the rate‐determining step, thereby accelerating the OER. These electrochemical properties make it intriguing candidate as an efficient electrocatalyst for practical alkaline seawater electrolysis.

The analysis of electrode material efficiency in hydrogen production through electrolysis from seawater solution

The analysis of electrode material efficiency in hydrogen production through electrolysis from seawater solution

Functionalization of seaweed bloom-derived Ulvan using response surface methodology with application in flocculation of oil-in-water pollution

Utilizing macroalgal waste biomass for pollution management is a highly efficient method for addressing the environmental difficulties associated with its disposal. To accomplish this, we have attempted to synthesize a graft copolymer by combining ulvan, a sulfated polysaccharide isolated from seaweed, with acrylates. A one-pot synthesis method using UV-initiated graft polymerization with V-50 as the photoinitiator resulted in the production of a distinctive, high-performance, and eco-friendly flocculant, Ulvan-g-Poly (acrylamide-co-acrylic acid) referred as P(U_AAm_AAc). The synthesis was optimized using the CCD-RSM approach, employing molecular weight and inherent viscosity as indicators to optimize the parameters. The structural and physio-chemical properties of the synthesized P(U_AAm_AAc) were characterized utilizing XRD, ATR-FTIR, ζ-potential, and H1 NMR spectroscopy. The flocculation performance of P(U_AAm_AAc) was further examined for the removal of oils from samples with high neem oil in urea solution and low crude oil in seawater. By employing a coagulant-flocculant combination of poly-aluminium chloride (PAC) and P(U_AAm_AAc), it was noted that more than 94% of oil was effectively eliminated in both samples. Optimization of the dosage of P(U_AAm_AAc) resulted in enhanced turbidity reduction and improved dewatering efficiency of the filter cake generated following flocculation. An evaluation of performance was conducted using the commercial flocculant APAM, where synthesized P(U_AAm_AAc) demonstrated similar results. In conclusion, the findings of this research highlight the potential of P(U_AAm_AAc) as a sustainable alternative to commercial flocculants with multifaceted solution to coastal waste management, paving the way for a cleaner and healthier marine ecosystem to mitigate oil emulsion pollution.

Unveiling the potential of forward osmosis desalination: Multi-objective optimization for peak efficiency

Forward osmosis (FO) has emerged as a promising technology with diverse applications. While recent advancements in FO have primarily focused on developing efficient membranes and draw solutes, studies on process optimization remain scarce. This work aims at identifying optimal operating conditions to use FO in seawater and brackish water desalination. Central Composite Design was conducted to investigate the effects of draw solution concentration, temperature, and flow rate on water flux (Jw), reverse solute flux (RSF), and specific cost index (Isc) responses. Response Surface Methodology analysis was performed to identify factors influencing responses. The desirability function was used to determine the best-input variables. The optimum operating conditions for the FO process are found at a flow rate of 0.6 L/min, a temperature of 32.9 °C, and a concentration of 1.79 mol/l, with corresponding values for water flux, RSF and Isc of 18.16 L/m2h and 41.03 g/m2h and 0.274, respectively. These results were experimentally validated. Experiments were also performed using seawater and brackish water feed solutions.

Effect of seawater on bond performance between BFRP bars and seawater sea-sand concrete

This paper investigates the bond behaviors of BFRP bars with seawater sea-sand concrete (SSC) under seawater conditions. Eighteen experimental cases were established by considering BFRP bar's surface, seawater temperature, and the duration of specimen exposure in seawater as study factors. The BPE and CMR analytical models were calibrated utilizing the test results. Additionally, the bond strength was predicted utilizing the guidelines proposed in FIB Bulletin (40), and the anchorage lengths of deep-ribbed and sand-coated BFRP bars were calibrated. The findings illustrated that all specimens experienced interlaminar shear failure of the bars after immersion in seawater. Although deep-ribbed BFRP bars exhibited the highest initial bond strength, they exhibited greater degradation in the seawater immersion environment. Following 120 days in a 40 °C seawater solution, the bond strength of deep-ribbed BFRP bars was 5.4%, 20.6% lower than that of shallow-ribbed and sand-coated BFRP bars, respectively. The correlation coefficients between the BPE and CMR models and the experimental data were mostly above 0.95. Predicted 50-year results showed that sand-coated BFRP bars would retain between 62.6% and 88.7% bond strength in various conditions. In moisture-saturated environments at different temperatures, it is recommended that the anchorage length for deep-ribbed BFRP bars should range from 32 to 51 times the bar diameter. For sand-coated BFRP bars, the recommended anchorage length is 20 times the bar diameter.

A Sandwich Structure Ag/MgFe2O4-Deposited Surface Carbonized Wood for Integrated Solar Steam Generation and Photoreduction of Cr(VI).

The severe deterioration of the marine ecosystem significantly negatively impacts the performance of solar-driven steam generation (SSG) and the quality of the obtained freshwater. Herein, a bifunctional Ag/MgFe2O4@SCW reactor with a sandwich structure is designed for efficient SSG and Cr(VI) reduction, which is constructed via in situ deposit Ag nanoparticles (NPs) and MgFe2O4 onto surface carbonized wood (SCW). Owing to the advanced sandwich structure and strong interfacial interactions between each component, an ultra-high evaporation rate of 1.55kg m-2 h-1 and the efficiency of 88.6% are achieved using Ag/MgFe2O4@SCW under 1 sun. The system exhibits the long-term evaporation performance in the simulated sewage and strong acid/base solutions along with water-harvesting capacity in outdoor solar desalination. The quality of distilled water after desalination of actual seawater and NaCl solutions with different concentrations meets the WHO-recommended drinkable water standards. Furthermore, Ag/MgFe2O4@SCW shows outstanding antibacterial property, self-desalting capacity, as well as reusability and structure stability. Most importantly, the fast carrier separation endows Ag/MgFe2O4@SCW with superior photocatalytic activity and Cr(VI) photoreduction of up to 96.1% after 180min of illumination. The bifunctional Ag/MgFe2O4@SCW reactor provides an advanced synergistic mechanism for improving SSG and photocatalytic performance, while being promising for solar-powered production of clean water.

CO2 nanobubbles as a novel kinetic promoter in hydrate-based desalination

The use of CO2 nanobubbles (NBs) was investigated as a sustainable kinetic promoter of gas hydrate formation in hydrate-based desalination (HBD) that does not require any separation steps from the recovered water. Stable CO2 NBs (8.07 ± 0.21× 107 bubbles/mL with 103.15 ± 2.47 nm mean radius and −6.35 ± 1.17 mV zeta potential) were generated and tested in HBD experiments conducted at 274.15 K and 3.58 MPa. The colloidal stability of CO2 NBs increased under pressure: their concentration increased and their size decreased. Low concentrations of dissolved chloride salts reduced the size of CO2 NBs, while high concentrations increased the likelihood of NBs' agglomeration. The induction time for CO2 hydrate formation in the presence of CO2 NBs was reduced by 86.04 %. The desalination results confirmed that CO2 NBs played a significant role in accelerating the process based on the memory effect mechanism. In the presence of CO2 NBs, water recovery reached 68.85 ± 1.82 % and 63.37 ± 2.76 % with an ion removal efficiency of 41.35 ± 6.16 and 40–50 % in a single-stage HBD process for 0.5 M NaCl and synthesized seawater solutions, respectively. These findings could unlock the potential for the further development of HBD of natural saline solutions as well as its deployment in near-zero liquid discharge industrial processes.