Concentration Of Solution Research Articles

An Electrically Small Patch Antenna Sensor for Salt Concentration Measurement of NaCl Solution.

In this paper, a complementary split-ring resonator (CSRR)-based patch antenna is proposed as a microwave sensor to measure the salt concentration of NaCl solution. The microwave sensor consists of an RF-4 substrate, where a small copper disc is attached on the top as the radiator, a larger copper disc integrated with two CSRRs is attached on the bottom side as the finite ground plane, and a coaxial feeding port is introduced at the ground plane center. During salt concentration sensing, only the top disc is immersed into NaCl solution. The results indicate that the proposed microwave sensor can measure salt concentrations ranging from 5‱ to 35‱ with a maximum sensitivity of 0.367 (kHz/(mg/L)). The proposed microwave sensor is low-cost, low-profile, electrically small, lightweight, and easy to fabricate, and it also can be applied to other solutions' concentration sensing.

Optimization of Electroless Plating Solution Parameter for Coating PETG Electrode with Copper using Design of Experiment (DOE)

In the study, an attempt was made to electrolessly plate copper onto PETG plastics that aren't conductors. Three manipulating factors, i.e. volume of copper sulphate and sulphuric acid (A), volume of sulphuric acid (B), and mass of copper sulphate (C), were selected and carried out using Taguchi method with three levels to examine their interactions and effects on the responses, including plating thickness, and electrical resistance. The Design Expert 13 software creates a total of nine runs with a single centre point. Three days were spent submerging every electroplated sample part in a different bath solution concentration. The resistance of the metalized PETG component was measured in the meantime using a digital multi-meter. The Cu-deposited PETG was analysed and measured using scanning electron microscopy (SEM). The ideal situation was identified as having 10 possibilities for achieving the goal, based on interaction effects. According to the results of the experiment, run number 3 provides the ideal solution parameter for copper deposition metallization. For the lowest electrical resistance of 0.64 ohm and the highest plating thickness value of 211.49 m, these runs yield the best ideal results. Because each factor reacts to a response individually, the Analysis of Variance (ANOVA) demonstrates that there are little interactions between the factors and responses. The lowest electrical resistance and highest plating thickness values are obtained with the best chemical composition parameter choices.

Cassava, corn, wheat, and sweet potato native starches: A promising biopolymer in the production of capsules by electrospraying.

Native starches have a high potential for producing capsules by electrospraying despite still being little explored as biopolymeric material. Thus, the present study aimed to investigate the electrospraying capacity of native starches from different sources (cassava, corn, wheat, and sweet potato). The concentration of starch in the polymer solutions was varied from 3% to 10% (w/v) to investigate the impact of both starch source and concentration on the electrospraying process. The study also aimed to deepen scientific knowledge of the behavior of these starches during the process and the characteristics of the resulting capsules. The characterization of the polymeric solutions was carried out regarding rheology and electrical conductivity and the capsules were evaluated by production yield, morphology, size distribution, thermal properties, and crystallinity. Higher viscosities were observed for polymeric solutions obtained from sweet potato starch, compared to other starches at the same polymer concentrations. The increase in starch concentration in polymeric solutions reduced their electrical conductivity, except for corn starch. The production yield of cassava and sweet potato starch capsules was not affected by the polymer concentration in the polymeric solutions, while for corn and wheat starches, there was a reduction in yield as the concentration increased. All starches were able to form capsules. Capsules produced with 7% corn starch showed a more homogeneous size distribution. The electrosprayed starches showed elevated melting temperatures and enthalpies. The capsules produced had an amorphous structure. The starches evaluated in this study proved to be excellent biopolymers for producing capsules by electrospraying, demonstrating possible future uses as encapsulating materials.

Effect of concentration of aqueous alcohol solution and layer thickness on free convection due to local heating

This paper investigates the effect of point heating, ethyl alcohol concentration, and layer thickness on the convective behavior of the solution. Laser heating enhances heat and mass transfer at low energy costs. For the first time, the research determines boundaries of the transition to the chaotic behavior of the velocity field at a change in several parameters: the initial alcohol concentration and the initial thickness of the liquid layer. Simple estimated ratios are obtained to determine the critical value of the Bond number in a binary solution. The solution behavior is predominantly influenced by the solute Rayleigh and Marangoni numbers. A small alcohol concentration (about 10%) is shown to have a stabilizing effect on the velocity field. In the course of evolution, several flow patterns change sequentially, which is associated with changes in the gradient of surface tension, solution concentration and layer thickness with evaporation time.

Gold Nanoparticles Decoration of Zinc Oxide Nanowalls on Flexible Substrates

Metal oxide nanostructures decorated with noble metal nanoparticles are hybrid structures with a special interface that combines the unique properties of those two materials. Noble metal nanoparticles exhibit useful catalytic properties, and they can be functionalized with biomaterials. In this work, we use gold nanoparticles that can be functionalized using thiolated molecules bound to the metal surface. Zinc oxide nano-walls (NWs) are a high surface-to-volume ratio wide-bandgap semiconductor nanostructures that, due to their biocompatibility and non-toxicity characteristics, can be used in biosensing applications that involve contact with tissues and cells. ZnO nano-walls can be deposited from aqueous solutions at low temperatures, both on rigid and flexible substrates, using a simple and low-cost process that can be upscaled to high-volume production. In this work, we study the nucleation and growth of the ZnO nano-walls and we describe the gold nanoparticles decoration at three different schemes of surface functionalization. Among these schemes, we found that the process where ZnO nano-walls were deposited on polyimide substrates followed by activation using a self-assembled monolayer, resulted in a decoration with uniform size and distribution of gold nano-particles. That process was studied as a function of the growth temperature, solution concentration, and time. The morphology of the ZnO nano-walls was studied by Scanning Electron microscope imaging and the crystal structure was studied by X-ray diffraction.

Functionalisation of the Aluminium Surface by CuCl2 Chemical Etching and Perfluoro Silane Grafting: Enhanced Corrosion Protection and Improved Anti-Icing Behaviour

This study aimed to prepare a facile hierarchical aluminium surface using a two-step process consisting of chemical etching in selected concentrations of CuCl2 solution and surface grafting through immersion in an ethanol solution containing 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane. The goal was to achieve superhydrophobic characteristics on the aluminium surface, including enhanced corrosion resistance, efficient self-cleaning ability, and improved anti-icing performance. The surface characterisation of the untreated aluminium and treated in CuCl2 solutions of different concentrations was performed using contact profilometry, optical tensiometry, and scanning electron microscopy coupled with energy dispersive spectroscopy to determine the surface topography, wettability, morphology, and surface composition. The corrosion properties were evaluated using potentiodynamic measurements in simulated acid rain solution and salt-spray test according to ASTM B117-22. In addition, self-cleaning and anti-icing tests were performed on superhydrophobic surfaces prepared under optimal conditions. The results showed that the nano-/micro-structured etched aluminium surface with an optimal 0.5 M concentration of CuCl2 grafted with a perfluoroalkyl silane film achieved superhydrophobic characteristics, with water droplets exhibiting efficient corrosion protection, self-cleaning ability, and improved anti-icing performance with decreased ice nucleation temperature and up to 545% increased freezing delay.

Thiol-functionalized conductive Co-MOF and its derivatives S-doped Co(OH)2 nanoflowers for high-performance supercapacitors

The low conductivity of many traditional metal–organic-framework (MOF)-based electrode limits their developments in the field of electrochemical energy storage and still of great challenge. The controllable preparation of various kinds of nanomaterials using thiol-functionalized MOF shows great prospects. In this work, a thiol-functionalized metal–organic framework sheet structure (Co-MOF/NF) on nickel foam was successfully prepared by in situ interfacial growth synthesis, which was transformed into its derivatives S-doped β-Co(OH)2 nanoflowers Co-x/NF (x = 1, 2 and 6) in different concentrations of KOH solutions through ion etching/exchange reaction. The pristine thiol-functionalized Co-MOF/NF and its derivatives Co-x/NF (x = 1, 2 and 6) nanoflower-like arrays could be used as positive electrode materials for effective supercapacitors. Among them, the transformation of the nanoflower-like Co-1/NF electrode exhibits excellent electrochemical properties with high areal capacitance (1925 ± 23 mF/cm2 at 1 mA/cm2), good rate performance, excellent conductivity and decent cycling stability. The Co-1//AC ASC device provides a high energy density of 0.176 mWh/cm2 (92.6 Wh/kg) at a power density of 0.745 mW/cm2 (392.1 W/kg). And this Co-1//AC ASC device exhibits a good cycling stability and practical application in energy storage field. This study provides a new strategy for the pristine thiol-functionalized MOF and its conversion nanostructures for energy storage applications.

Exogenous allyl isothiocyanate mitigates the drought stress by regulating the stomatal characteristic, antioxidant capacity, and glucosinolate metabolism in pakchoi

Drought is a global issue that has increasingly garnered worldwide attention. Glucosinolates (GSLs) are significant sulfur-containing compounds in cruciferous plants such as pakchoi (Brassica rapa L. ssp. chinensis), and their primary biological functions are exerted through their hydrolysis products. Allyl isothiocyanate (AITC), which is one of the degradation products of GSL, plays a crucial role in plants’ response to environmental stresses. To date, the drought-resistant mechanism of AITC has not been fully explored. This study investigated the effects of spraying different concentrations of AITC solutions (1 mM and 10 mM) on the growth parameters, stomatal characteristics, antioxidant indices, and glucosinolate metabolism of pakchoi under drought stress, compared to a control group treated with distilled water. The results shown that under drought stress, AITC spraying enhanced the plant's water retention capacity and restored their growth by promoting stomatal closure and improving photosynthetic capacity in pakchoi; mitigated oxidative stress damage and augmenting the plant's water absorption by increasing the activities of antioxidant enzymes and the concentrations of osmoregulatory substances in pakchoi; the application of AITC restored the glucosinolate metabolism in pakchoi, inhibiting the downregulation of genes associated with GSL synthesis and the upregulation of genes related to degradation that is induced by drought stress, thereby maintaining the balance between GSLs and ITCs.. In conclusion, AITC application alleviated the inhibition of pakchoi growth under drought stress by fostering stomatal closure, bolstering antioxidant defenses, and modulating glucosinolate metabolism.

Fabrication of CNC-AC bionanosorbents from the residual mass of Magnolia champaca l. Bark after methanol extraction for wastewater treatment: Continuous column adsorption study

In this current study, a new class of multifunctional biobased ecofriendly nanosorbents namely crystalline nanocellulose-activated char (CNC-AC) nanosorbents were fabricated by employing a much more innovative and beneficial solvent evaporation induced phase separation (EIPS) technique. While the crystalline nanocellulose (CNC) were extracted from a very much new, innovative, and beneficial agrowaste source namely banana tree (M. oranta) rachis fibers by conducting a series of chemical treatments like scouring, alkali treatment, bleaching, and acid hydrolysis reactions. Additionally, the biochar were synthesized from the residual mass of Magnolia champaca L. barks after methanol extraction and functionalized by 30 % H3PO4 to improve their overall properties. Besides these the fixed-bed continuous column adsorption study were carried out by optimizing the various influential factors such as preliminary concentration and flow rates of the inlet wastewater solution, along with the nanosorbent bed heights into the applied column. For better understanding the overall physicochemical, thermomechanical, and morphostructural behavior of the newly fabricated polyfunctional CNC-AC bionanosorbents the samples were characterized by conducting FTIR-ATR, FESEM, BET, XRD, TGA analysis. Meanwhile the treated and nontreated water specimens were examined by conducting AAS and UV–vis-NIR techniques. The obtained results recommended that the newly produced CNC-AC nanosorbents have contained a quite number of active edges/binding sites along with substantial sp. surface area (around 316.95 m2/g). Additionally, they possessed a crystallinity index about 59.98 ± 0.027 %, greater thermal steadiness up to 600 °C, and outstanding 2D honeycomb-like mesoporous peripheral surface microstructure with a promising spherical shapes and smaller size nearly 5–10 nm. The highest removal capacity were found at 538.91 mg/g and 455.70 mg/g for Pb2+ and CR respectively. Additionally, for better understanding the experimental breakthrough curves (BTC) were evaluated by several well established column models while the maximum R2 value was found around 0.999 for the Thomas model and reduced chi squire (χ2) value was around 0.0001.

Enhanced continuous lithium extraction using self-designed porous nanosorbent fibers in a fixed-bed system: Optimization and mechanistic insights

This study introduced a novel lithium/aluminum layered double hydroxide (Li/Al-LDH) nanosorbent fiber (Li-PNF) engineered for continuous lithium extraction from brine using a fixed-bed system. These fibers featured a three-dimensional interconnected mesh structure and were distinctively encapsulated with needle-like Li/Al-LDH, exhibiting a layer-by-layer configuration. Compared to conventional Li/Al-LDH, Li-PNFs demonstrated abundant mesoporous structure and larger average pore size, facilitating the mass transfer and molecular diffusion of Li+ ions. Li-PNFs possessed a static lithium adsorption capacity of approximately 13.0 mg/g, with notable selectivity against Na+ and K+. Additionally, the Li+ binding energy across three distinct sites within the atomic structure of Li-PNFs proved advantageous, particularly at the Triangle-site-Al-overlapping-O3, which reached −5.72 eV. Fixed-bed adsorption experiments confirmed that lower feed flow rates, higher initial lithium concentrations, and increased bed heights significantly enhanced the Li+ capture efficiency, achieving up to 23.83 % in a single fixed-bed experiment. Based on the prediction of adsorption penetration curves using four empirical models, it was found that the Clark and Thomas models could accurately predict the behavior of Li+ penetration through the bed. Fixed-bed desorption results indicated that optimal lithium recovery was achieved at lower feed rates, reduced lithium concentrations in the desorption solution, and elevated temperatures. Finally, the excellent cyclic adsorption/desorption performance and low preparation cost of Li-PNF further highlighted its potential for real industrial applications, offering a significant advancement in the field of lithium extraction technology.

Performance of tube-in-tube membrane microreactor in E2/EE2 degradation via UV/H2O2/TiO2 process

The tube-in-tube membrane microreactor is an advanced system designed for the continuous removal of contaminants of emerging concerns (CECs) from urban and industrial wastewater. Despite its high removal efficiency, critical questions remain regarding the impact of various operational parameter: (i) flow rate of contaminants, (ii) oxidant dosage, (iii) concentration of the H2O2 stock solution, and (iv) pH of the H2O2 stock solution. This study addresses these questions, with particular focus on the previously unexplored effects of H2O2 concentration and pH. We investigated the degradation of estrogens 17β-Estradiol (E2) and 17α-Ethinylestradiol (EE2) using a UV/H2O2/TiO2 process using a membrane tube-in-tube reactor assembled with an inner glass fiber microfiltration membrane, coated with the catalyst TiO2-P25, and an outer quartz tube. Synthetic contaminated solution [E2/EE2]inlet = 500μgL-1 was fed in the reactor annulus and the H2O2 stock solution with different pHs (2, 3, 4, 5, 6.8, 8) and concentrations ([H2O2]stock solution = 3000, 6000, 9000 and 12000mgL-1) was fed through the membrane pores (radial permeation) or injected upstream the reactor inlet with different dosages ([H2O2]inlet = 0, 5, 10, 15, 20mgL-1) by means of a syringe pump. Experiments were performed under UVC irradiation and dark conditions. The highest observed removal rate was, approximately, 2.9µM/min for both estrogens, achieved after 7min of reactor operation, highlighting the reactor’s potential for effective CEC degradation under optimized conditions.

Application of continuous stirring tank reactor for controllable synthesis of Cu7S4 nanocrystals

As a typical model for a chemical reactor in industry, the continuous stirring tank reactor has been widely used in waste-water treatment, industrial catalysis, and biological fermentation as well as great application prospects in the synthesis of nanomaterials. In this report, a convenient lab-scale continuous stirring tank reactor was assembled and utilized to synthesize Cu7S4 nanocrystals by injecting cupric bromide and sulfur solution in the presence of ascorbic acid and polyethyleneimine at 60 °C. The morphology control of Cu7S4 nanocrystals was accomplished by simply adjusting the agitation speed. Cu7S4 nanofibers with an average diameter of 48 ± 4.42 nm and a length of several micrometers were obtained at 80 rpm. Cu7S4 nanoplates with a thickness of 89 ± 13.56 nm and a plane size of 103 ± 16.47 nm were synthesized at 90 rpm, and the size of the nanoplates was regulated by continuously increasing the agitation speed from 90 rpm to 1000 rpm. Furthermore, the influences of two additional conditions (the mean residence time and the concentration of the feed solution) on the morphology of Cu7S4 nanocrystals, were also investigated. Therefore, these results could facilitate the understanding of the behaviors of CSTR in the synthesis of Cu7S4 nanocrystals and could also provide an important reference for the continuous synthesis of other nanoparticles.

Effect of test related factors on the degradation of cement-based materials on acetic acid exposure

Abstract Exposure of concrete to various acids can hardly be overstated due to the widespread use of concrete in the construction industry. The effect of selected factors on the degradation of ordinary Portland cement (OPC 53 grade) paste and mortar exposed to acetic acid is investigated in this paper. Various test parameters such as mass loss, loss in cross-sectional area, relative dynamic elastic modulus (RDEM), loss in flexural and compressive strength are used to assess the selected factors and the results obtained are analysed to determine the most favourable test conditions for degradation, that can be adopted for developing an accelerated test method. The factors used for the investigation are replenishment of acid solution, concentration of acid solution, ratio of surface area of specimen to volume of liquid acid solution (S/L), shape of the specimen and nature of the specimen. This paper also investigates the interrelationships among test parameters and adopts interpretation of acid consumption to assess the aggressiveness of the acid solution. It was found that renewing conditions and high concentrations of acid solution (0.5 M) indicate rapid degradation. The aggressiveness of 0.125 M acetic acid solutions in renewing conditions is about 5 times that of non-renewing conditions respectively. The rate of degradation is inversely related to S/L ratio. Cylindrical specimens have a marginal increase in degradation than prismatic specimens. It is preferable to evaluate acid attack on mortar specimens rather than paste specimens due to higher loss in cross-sectional area and relative dynamic elastic modulus (RDEM).

Effect of shell composition on watertightness and mechanical performance of cement-based capsules used as self-healing additives of cement

The aim of this work is the development of cementitious macro-capsules for self-healing cement and concrete materials. Emphasis is placed on shell properties, including size, thickness, strength, and volume to active component ratio. This enhancement is aimed at protecting the healing agent and ensuring adequate reactivity upon crack formation, surpassing survivability considerations. To this direction, core/shell particles have been produced following the pan-coating method, while different types and concentrations of setting acceleration solutions for the shell stabilization were studied. The formation of core-shell capsules encompasses the formation a spherical core through agglomeration, followed by simultaneous spraying of cement powder and a setting acceleration solution for the shell formation, under continuous rotation. The microstructural characteristics of the shell were studied through scanning electron microscopy (SEM), while the reactivity of the protected core (reactive agent) inside the hardened mortar mixtures was evaluated using thermogravimetric analysis (TGA). Moreover, the crushing load of the capsules under compression and their survivability during mixing process were examined and interpreted in relation to their diameter, circularity, and shell thickness.The results revealed the ability of the encapsulation methodology proposed to tailor the shell properties and modify the capsule properties so as satisfy the requirements of different applications. The use of setting accelerators during shell formation proved essential for enhancing the density and the strength of the shell layer. As a consequence, this leads to macro-scale capsules with elevated survivability rate and core reactivity.

Concentration and cavitation in the Riemann solutions to the Umami Chaplygin Euler equations

The concentration phenomena in fluid dynamics can be mathematically described by delta-shocks. With the introduction of flux-function, the Riemann problem for the Euler system with Umami Chaplygin gas equation of state is discussed. What Umami Chaplygin gas means is that the fluid obeys the pressure–density relation where the pressure is negative and is a new generalization of Chaplygin gas. The solutions with six kinds of structures are constructed. Unlike the Chaplygin gas, the delta-shock occurs in solutions, even though the system is strictly hyperbolic and two characteristic fields are genuinely nonlinear. The generalized Rankine–Hugoniot relation and entropy condition for delta-shock are clarified. Additionally, the phenomena of concentration and cavitation and the formation of delta-shocks and vacuum states in solutions are identified and analyzed as the Umami Chaplygin gas pressure and flux-function vanish simultaneously. It is proved that as the pressure and flux-function drop to zero, any solution consisting of two shocks tends to the delta-shock solution of the pressureless Euler system, and any solution consisting of two rarefaction waves tends to the vacuum Riemann solution of the pressureless Euler system. Finally, some numerical results exhibiting the processes of formation of delta-shocks and vacuum states are presented.

Kaempferol Extends Male Lifespan Under Blue Light Irradiation in Drosophila.

Short-wavelength blue light is ubiquitous in daily life and has a lasting destructive influence. Its potential harm to biological health is significant. This study used Drosophila as a model organism to investigate the protective effects of kaempferol, a flavonoid, against the toxicity of blue light. It also examined its physiological effects on Drosophila under blue light irradiation. In this experiment, fruit flies were fed with three different concentrations of kaempferol solutions (0.1, 0.01, and 0.001 mol/L) dissolved in food. The survival rate and physiological indexes of Drosophila were investigated under blue light irradiation of 2500 lux. The results showed that 0.1 mol/L kaempferol increased the activity of male flies during the day and significantly extended the male survival time under blue light irradiation. However, the study found that kaempferol did not significantly prolong the survival time of Drosophila in the oxidative stress experiment, and no significant difference was observed in the feeding experiment. In summary, our research found that kaempferol, at the concentration of 0.1 mol/L, has a protective effect on Drosophila under blue light irradiation, potentially achieved through alterations in circadian rhythm.

The impact of Microbially Induced Calcite Precipitation (MICP) on sand internal erosion resistance: A microfluidic study

Fine particle internal erosion involves the detachment, transport, and deposition of fine particles within soil, significantly impacting agriculture, engineering, and environmental protection. Microbially induced calcite precipitation (MICP) has proven to be an effective method for controlling internal erosion. To optimize MICP protocols for effective erosion control, understanding the microscopic mechanisms by which MICP reduces fine particle erosion is essential but remains unclear. In this study, microfluidic chip experiments were conducted to observe the characteristics of calcium carbonate crystals and fine particles before and after MICP reinforcement and erosion. Through quantitative analysis of the calcium carbonate produced by MICP and eroded fine particles, the effects of bacterial density, concentration of cementation solution, and flow rate on the efficiency of MICP in resisting soil internal erosion were investigated. In addition, three primary mechanisms by which MICP reduces fine particle erosion were identified. Firstly, in situ sand stabilization occurs when calcium carbonate generated by MICP bonds and encapsulates fine particles, forming larger particles that remain stable under erosive flow conditions. Secondly, regional sand stabilization is achieved as MICP-produced calcium carbonate crystals narrow or block the flow channels, preventing extensive migration of fine particles. Lastly, adjacent particle stabilization is facilitated by calcium carbonate crystals, which remain stable during water flow erosion and alter the erosion flow lines, creating zones adjacent to the crystals where fine particle movement is minimized. These findings provide a deeper understanding of the role of MICP in erosion control and can inform the development of more effective erosion mitigation strategies.

Experimental study on the vacuum dehumidification performance of PVA/CaCl2 selective permeation membrane under vortex conditions

Vacuum membrane dehumidification is a promising power-saving isothermal dehumidification technology, and the development of low-cost and efficient selective permeation membranes is beneficial to its application. In this study, the dehumidification performance and mechanism of the PVA/CaCl2 water vapor selective permeation membrane are investigated experimentally. The effects of the CaCl2 concentration in the casting membrane solution, the permeation side vacuum level, and the inlet air flow rate and relative humidity on the dehumidification performance are discussed. In addition, the effect of the deflector fins on the dehumidification performance is analyzed. The results show that the vortex coupled dissolution-diffusion theory can explain the experimental results. In addition, from the point of view of dehumidification capacity per unit power consumption, the best concentration of CaCl2 in casting membrane solution is 2.08 %, and the worst permeation side vacuum level is 60 kPa. The higher the inlet air flow rate and relative humidity under the deflector fins, the better the dehumidification performance. The dehumidification performance can be significantly improved by the deflector fins, which increase the COP by 38.31 %∼146 % and the selectivity by 35.85 %∼147 %.

Preparation of aragonite-rich whisker materials from magnesium slag and salt lake bischofite and its effects on cement properties

This study develops an innovative wet carbonation process utilizing Magnesium Slag(MS), Salt Lake Bischofite (SLB), and CO2 to prepare carbonized materials mainly composed of aragonite and active silica gel, all raw materials were solid wastes. Subsequently, it was employed as Supplementary Cementitious Materials (SCMs) additive in cement, with the goal of efficiently capturing carbon dioxide and transforming aragonite whiskers into high-value products. Investigated the parameters influencing the formation of aragonite, including temperature and the concentration of the SLB solution, while exploring the nucleation and growth mechanisms of aragonite. The findings reveal that under 80 °C, the suspension of MS with 0.83 % SLB solution swiftly produces needle-like aragonite whiskers with single crystal lengths ranging from 10-20 μm and diameters of 0.3–0.5 μm. With the increase in SLB concentration, the aspect ratio of aragonite whiskers decreases. Additionally, highly polymerized amorphous silica gel was also detected. Therefore, Carbonated Aragonite-type Magnesium Slag (CAMS) (34.0901 m2/g) exhibits a significantly larger specific surface area compared to MS (0.9877 m2/g), representing an enhancement factor of 34.5 times, which concurrently bolsters its capability to adsorb reactive ions. During the carbonation process, 1 g of MS can sequester and solidify 0.403 g of CO2. Furthermore, incorporating CAMS as SCMs into cement mixtures notably enhances both the compressive and flexural strengths of cement mortar. These findings offer a sustainable approach to the recycling of solid waste, CO2 sequestration, and the improvement of cement-based material properties.

Membrane fouling in integrated forward osmosis and membrane distillation systems – A review

With the increase in water consumption, especially by the industrial and agricultural sectors, more strategies capable of increasing the recovery and reuse of water resources have been sought. An example of technology that assists in this challenge is membrane separation processes. However, systems that use this type of separation may be limited by the phenomenon of fouling. Integrated systems such as forward osmosis (FO) with membrane distillation (MD) have several advantages, such as obtaining a high-quality permeate from raw wastewater, the constant regeneration of the draw solution, which assists in continuous operation, and the possibility of association with biological tanks that enable nutrients recovery. However, these systems face limitations related to low flux values caused by membrane fouling. Therefore, the present review seeks to study fouling in integrated FO-MD systems to understand the main challenges of applying this technology and achieving higher permeate flux values. From the most recent studies, many strategies are being evaluated, such as different membrane materials, deposition of antifouling materials on membrane surface, feed temperature, draw solution substances, concentration and temperature, use of spacers and new modules configurations. That way, the low flux from those systems may be bypassed, enabling FO-MD systems scale up.