The behavior of radiogenic particles at solidification fronts

The thermal behavior of insoluble radiogenic particles at the solid-liquid interface of an advancing solidification front and its significance with regard to environmental impact are discussed. It is shown that, unlike classical particles, where the most probable behavior is engulfing by the solidification front, radiogenic particles are more likely to be rejected by the solidification front. Utilizing a simplified physical model, an adaptation of classical theoretical models is performed, where it is shown that, unlike classical particles, for radiogenic particles the mechanism is thermally driven. An analytical expression for the critical velocity of the solidification front for engulfing/rejection to occur is derived. The study could be potentially important to several fields, e.g. in engineering applications where technological processes for the physical removal of radionuclide particles dispersed throughout another substance by inducing solidification could be envisaged, in planetary science where the occurrence of radiogenic concentration could result in the possibility of the eruption of primordial comet/planetoids, or, if specific conditions are suitable, particle ejection may result in an increase in concentration as the front moves, which can translate into the formation of hot spots.

Complete solidification of landfill concentrated leachate using a minimal dosage of mayenite and its reutilization for carbonyl sulfide degradation

Landfill concentrated leachate (CL) contains high concentrations of organic pollutants, salts, and heavy metal ions. Treatment methods for CL include recharge, evaporation, and incineration; however, these processes are challenged by high load demands, treatment complexity, and limited potential for resource recovery. Herein, the mayenite-enriched calcium-aluminum oxide (CaxAlyOz) was used to solidify CL. With an optimal dosage of 30 %, the solidified product, marked as CL-CAOSP, was obtained, which not only mitigates the challenges associated with leachate discharge but also enhances the efficiency of water evaporation due to the lower binding energy at the Ca4Al2O6Cl2•10H2O/Al2O3-water interface compared to that of the water-water interface. To dispose of CL-CAOSP, its organic pollutants underwent a high-temperature pyrolysis carbonization process to form porous carbon, which was tightly combined with the alkali and alkaline earth metals-doped Ca12Al14O32Cl2 to create an efficient hydrolysis catalyst for the toxic gas carbonyl sulfide (COS). The calcined CL-CAOSP is also capable of cyclically solidifying CL up to five times, significantly reducing the required dosage of CaxAlyOz and the generation of the terminal solidified product. These results provide novel treatment and resource utilization technologies for CL, serving as valuable guides for the implementation of CL treatment practices.

Transport processes and coalescence of two entrapping bubbles during upward solidification

The transport processes and coalescence of a pair of bubbles during upward unidirectional solidification of water containing carbon dioxide are numerically investigated. In addition to affecting material microstructure, functional porous materials have applications in biology, tissue engineering, food preservation, and addressing global warming through porous sea ice. In this study, transport equations within the bubble, liquid, and solid phases are solved using the commercial COMSOL software (version 5.2). The results indicate that coalescence is promoted by fluid flow after bubbles make contact. Coalescence is likely when the concentration at the midpoint between two bubbles, each with identical concentrations, matches the concentration within the bubbles over a short distance. It is observed that bubble coalescence is enhanced by increases in horizontal incoming velocity, surface tension, and liquid solute diffusivity, as well as by decreases in Henry's law constant, ambient pressure, partition coefficient, and solid thermal conductivity. The solute concentration around pores also increases with decreasing Henry's law constant and liquid solute diffusivity, and increasing horizontal velocity, ambient pressure, solid thermal conductivity, and surface tension. The predicted contact angle during solidification aligns well with Abel's equation. The development of multiple pores and solute segregation inevitably occurs, influencing the material's microstructure. This can be managed by analyzing all the transport and metallurgical properties and adjusting the related working parameters accordingly.

Thermal performance enhancement of lauric acid using nanomaterials as composite phase change material

In the present work, lauric acid was taken as a phase change material (PCM), and different nanoparticles (NPs) such as SiO2, TiO2, CuO, and ZnO were taken as the supporting materials. CuO NPs were prepared through the co-precipitation technique; SiO2, TiO2, and ZnO NPs were synthesized via the sol-gel technique. These NPs with different weight fractions were dispersed into molten lauric acid, individually. The variations in thermal properties (phase change temperature and latent heat for solid and liquid) of the prepared composite PCMs due to the dispersion of NPs were observed by DSC analyses. An increase in thermal conductivity of the composite PCMs was observed with the increasing weight fraction of NPs. In order to ascertain the long-term utility, a thermal reliability test was conducted on the composite PCMs with repeated heating and cooling cycles. Also, the specific heats of the pure PCM and the composite PCMs were determined as a function of temperature. Further, the experimental investigation was performed on the pure PCM and the prepared composite PCMs to assess their phase change behavior, and the test results clearly proved that the time required for the complete melting and freezing process of the composite PCMs was less when compared to pure PCM. By considering the above facts, the newly prepared composite PCMs can be recommended as a potential candidate for low-temperature solar heating applications.

Coupling effect of solidification and consolidation on characteristics of the dredged silt

Dehydration with a plate and frame filter press is a common method for treating dredged silt from rivers and lakes. The silt is often conditioned by the addition of solidifying materials before plate and frame press filtration and, therefore, is subjected to the coupling effect of solidification and consolidation. In this study, consolidation tests of the silt with cement were carried out and compared with the silt after only solidification or only consolidation in terms of moisture content, unconfined compressive strength, and leaching concentration. The test results showed that the moisture content of the silt can be reduced to less than 60% under the coupling action of solidification and consolidation, which was 22% and 4% lower than with solidification only or consolidation only, respectively. The effect of consolidation improved the solidification process; the unconfined compressive strength increased rapidly in the early stage of curing and was 30-150% higher than that of solidified silt. The coupling effects of solidification and consolidation on the leaching concentrations of Ni and Cr in silt were the most significant, and the lowest leaching concentrations were 60% and 90% lower than those of solidified only and consolidated only silt, respectively.

Pioneering heat transfer enhancements in latent thermal energy storage: Passive and active strategies unveiled

Intermittent renewable energy sources such as solar and wind necessitate energy storage methods like employing phase change materials (PCMs) for latent heat thermal energy storage (LHTES). However, the low thermal conductivity of PCMs limits their thermal response rate. This paper reviews recent progress in active heat transfer augmentation methods for improving LHTES system performance, encompassing mechanical aids, vibrations, jet impingement, injection, and external fields. It compiles findings concerning the optimization of PCM charging and discharging processes. Proposals for future research directions are provided, highlighting the significance of extra energy input for storage. The study highlights how changing the mushy zone constant from 103 to 108 affects a PCM's melt fraction and heat storage. The article also overviews studies using fins and coils to enhance heat transfer in PCM-based LHTES systems. It discusses how geometric and material constraints influence the melting and solidification processes and the heat transfer surface orientation within the storage tank. Various PCMs with different melting temperatures are examined. A broad range of test cases was examined to determine how geometry and orientation-dependent convection affect the phase-changing process. This overview of heat transfer principles offers guidelines for system designers to optimize the geometry of heat transfer fluid (HTF) flow paths and the confinement of PCM to enhance heat transfer efficiency and overall system performance. The results also indicate research gaps for certain PCM melting temperature ranges. Few experimental studies exist for melting temperatures above 60 °C; most focus only on melting rather than solidification. More standardized studies using non-dimensional parameters for coil geometries are advocated.

Dry solidification of chloride salts and heavy metals in waste incineration fly ash by mayenite

There are hazardous substances such as chloride salts and heavy metals in the municipal solid waste incineration fly ash (WIFA). During thermal treatment, the concentrated chlorides promote the volatilization of heavy metals, increasing the ecological risk. The water washing method is also employed as a pre-treatment for WIFA, but a substantial volume of wastewater with high chloride content is produced that poses challenges for effective treatment. This study integrates chemical stabilization with heat treatment method and suggests the utilization of a calcium aluminum oxide-mayenite (CA) for the solidification of chloride salts and heavy metals in WIFA. The experimental results indicate that adding CA for heat treatment has a significant solidification effect on chlorides. Under the conditions of WIFA: CA mass ratio of 1: 1 and temperature of 1200 °C, the chloride ions were solidified by forming Ca12Al14O32Cl2, with a fixation efficiency of up to 85 %, and most of the chlorides in WIFA became insoluble instead of soluble. Most of the heavy metals in WIFA were immobilized and doped into the crystal structure of CA, forming the catalytic metal-rich Ca12Al14O32Cl2 phase, which was subsequently applied to the degradation of chlorobenzene. Under an initial concentration of 512 ppm, the degradation efficiency of chlorobenzene reached 50.4 %. Through the introduction of CA, not only the solidification of chloride and heavy metals is achieved, but the high-value resource utilization of the final heat treatment product is also realized, providing a new method for the disposal of fly ash.

Assessment of effectiveness in stabilization/solidification of arsenic-contaminated soil: long-term leaching test and geophysical measurement

This study focused on evaluating the effectiveness of stabilizer/binding agents in immobilizing arsenic (As) in contaminated soil using both geochemical and geophysical monitoring methods. The effluent from the stabilizer/binding agent's application and control columns was analyzed, and the status of the columns was monitored using electrical resistivity (ER) and induced polarization (IP) methods. As stabilizers/binder, acid mine drainage sludge (AMDS) and steel slag (SS) were used, which delayed As and Ca leaching time and significantly reduced As leaching amount. Determination coefficients for As and Fe leaching exhibited elevated values (control column, R2 = 0.955; AMDS column, R2 = 0.908; and SS column, R2 = 0.833). A discernible decline in the concentration of leached Fe was accompanied by a corresponding reduction in IP. The determination coefficients correlating IP and Fe leaching remained substantial (control column, R2 = 0.768; AMDS column, R2 = 0.807; and SS column, R2 = 0.818). Such IP measurements manifest as instrumental tools in monitoring and assessing the retention capacity of applied stabilizer/binding agents in As-affected soils, thereby furnishing crucial data for the enduring surveillance of stabilization/solidification locales. This research posits a swift and continuous monitoring method for solidification/stabilization locales in situ.

Parametric study of lotus-type pore shape in solid subject to Henry's laws at interfaces

Mechanisms of the length and maximum radius of lotus-type or single pores in ice or nonmetals satisfied by Henry's law at gas-liquid interfaces dissolved by a gas during unidirectional solidification are rigorously investigated and supported by a Table from algebraic predictions involving different dimensionless working parameters. Lotus-type porous materials characterized by directional properties have been often used as functional materials in food, biomedical, and micro- and nano-technologies. Following previous work taking into account solute amount and transport within the pore, and concentration boundary layers on the advancing solid-liquid interface and bubble cap, and the Young-Laplace equation and Henry's law at liquid-gas interfaces, the algebraic study further provides a Table for a quantitative and extensive understanding of different mechanisms of length and maximum radius. Dimensionless parameters include solute transport parameters of Henry's law constant, mass transfer coefficient, partition coefficient, solute gas amount in imposed ambient, and solute transport parameter, and fluid and thermal parameters of solidification rate, imposed gas pressure, hydrostatic pressure, and geometrical parameter of inter-pore spacing. The controlling of the shapes of lotus-type pores is achieved by a good comparison between predicted maximum diameter and inter-pore spacing during freezing of water dissolved by oxygen gas.

Effect of flux components of lightweight aggregate on physical properties and heavy metal solidification performance

The preparation of lightweight aggregate (LWA) by high-temperature sintering is a promising method for recycling solid waste safely, especially for solidifying heavy metals effectively. The main aim of this research was to systematically evaluate the effects of the flux components on LWA, including Na₂O, MgO, CaO, and Fe₂O₃. The physical properties and chromium solidification mechanism of LWA were characterized and analyzed. The results showed that the addition of Na facilitated LWA preparation and Cr solidification, whereas Ca, Mg, and Fe were deleterious to some extent. Further analysis indicated that increasing the Fe₂O₃ content was not conducive to the reduction of Cr because its decomposition reaction creates an oxygen-rich environment. The results of this research could provide a meaningful guide for regulating the composition of raw materials for the production of LWA to treat industrial Cr-containing solid waste.

Risk control of heavy metal in waste incinerator ash by available solidification scenarios in cement production based on waste flow analysis

Incineration is a common method in municipal solid waste management, which has several advantages such as reducing the volume of waste, but with concerns about exhaust gas and ash management. In this study, heavy metals in bottom ash, secondary furnace ash and fly ash of two waste incinerators in Tehran and Nowshahr were analyzed and its control in cement production was investigated. For this purpose, twelve monthly samples of three types of incinerator ash were analyzed. By combining the studied ashes in the raw materials, the quantity of metals in the cement was analyzed. Finally, by investigating four scenarios based on quantitative variations in the routes of municipal solid waste, ash quantity and the related risk caused by its heavy metals were studied. The results showed that the concentration of heavy metals in the three ash samples of the studied incinerators was 19,513-23,972 µg/g and the composition of the metals included Hg (less than 0.01%), Pb (2.93%), Cd (0.59%), Cu (21.51%), Zn (58.7%), As (less than 0.01%), Cr (15.88%), and Ni (0.91%). The best quality of produced cement included 20% ash and 10% zeolite, which was the basis of the next calculations. It was estimated that the reduction of the release of metals into the environment includes 37 gr/day in best scenario equal to 10.6 tons/year. Ash solidification can be considered as a complementary solution in waste incinerator management.

Wood fly ash and blast furnace slag management by alkali-activation: Trace elements solidification and composite application

Wood and biomass are burned in many industries as a sustainable energy source. The large quantities of fly ash produced must be landfilled, leading to environmental concerns. Precipitator wood fly ash (PFA) and ground granulated blast furnace slag (BFS) have been used in this study to prepare alkali-activated composites to manage and recycle the fly ash. After an essential characterization, the influence of parameters such as PFA and BFS content, alkaline activator content (silica moduli of 0, 0.82, 1.32), curing method, and curing duration on the mechanical, chemical, and microstructural properties of the samples have been studied through compressive strength, density, FTIR, and SEM-EDS investigations. The environmental safety and influence of polycondensation on heavy metal stabilization have been examined through ICP-MS. The results prove that oven and hydrothermal curing obtain the early age strength. Despite the variations of strength with duration and type of curing, the compressive strength of samples after 28 days of curing tends to close values for a constant PFA/BFS ratio, due to which the need for energy-intensive curing methods is addressed. ICP-MS shows that the composites can suitably solidify As, Cd, Ba, Cr, Pb, Mo, Se, Hg, Sr, Cu, and Zn. On the other hand, the composites were almost incapable of stabilizing Co and V. Unlike the case for mechanical properties; higher PFA content favours hazardous metal stabilization through polycondensation.

Development of a long-acting tablet with ticagrelor high-loaded nanostructured lipid carriers

Ticagrelor (TCG), an antiplatelet agent, has low solubility and permeability; thus, there are many trials to apply the pharmaceutical technology for the enhancement of TCG solubility and permeability. Herein, we have developed the TCG high-loaded nanostructured lipid carrier (HL-NLC) and solidified the HL-NLC to develop the oral tablet. The HL-NLC was successfully fabricated and optimized with a particle size of 164.5 nm, a PDI of 0.199, an encapsulation efficiency of 98.5%, and a drug loading of 16.4%. For the solidification of HL-NLC (S-HL-NLC), the adsorbent was determined based on the physical properties of the S-HL-NLC, such as bulk density, tap density, angle of repose, Hausner ratio, Carr's index, and drug content. Florite R was chosen because of its excellent adsorption capacity, excellent physical properties, and solubility of the powder after manufacturing. Using an S-HL-NLC, the S-HL-NLC tablet with HPMC 4 K was prepared, which is showed a released extent of more than 90% at 24 h. Thus, we have developed the sustained release tablet containing the TCG-loaded HL-NLC. Moreover, the formulations have exhibited no cytotoxicity against Caco-2 cells and improved the cellular uptake of TCG. In pharmacokinetic study, compared with raw TCG, the bioavailability of HL-NLC and S-HL-NLC was increased by 293% and 323%, respectively. In conclusion, we successfully developed the TCG high-loaded NLC tablet, that exhibited a sustained release profile and enhanced oral bioavailability.

Effect of ultrasonic melt processing and Al-Ti-B on the microstructural refinement of recycled Al alloys

Refining the α-Al grain size and controlling the morphology of intermetallic phases during solidification of Al alloys using ultrasonic melt processing (USMP) and Al-Ti-B have been extensively used in academic and industry. While, their synergy effect on the formation of these phases has not yet clearly demonstrated. In this paper, the influence of USMP and Al-Ti-B on the solidified microstructure of multicomponent Al-4.5Cu-0.5Mn-0.5Mg-0.2Si-xFe alloys (x = 0.7, and 1.2 wt%) has been comparatively studied. The results show that the USMP + Al-Ti-B method produce a more profound refinement effect than the individual methods. In addition, the area of single Fe-rich phases in both alloys with USMP + Al-Ti-B are also refined compared with conventional methods. A mechanism is proposed for the refinement, which are the deagglomerated TiB₂ parties induced by USMP providing more effective nucleation sites for α-Al, and the refined interdendritic regions limited the growth of Fe-rich phases in the following eutectic reaction. Finally, the application of combined USMP + Al-Ti-B methods is feasible in microstructural refinement, resulting in the improving the casting soundness and mechanical properties of alloys.

Effect of alkali-activation conditions on microstructure and heavy metal solidification of alkali-activated converter steel slag and municipal solid waste incineration fly ash

Alkaline-activation technology was an effective means of disposing of low-activity and heavy-metal-containing industrial solid wastes. In this paper, alkali-activated converter steel slag and municipal solid waste incineration fly ash (MSWIFA) were prepared by modulating alkali-activation conditions. The effect of alkali-activation conditions on microstructure of C-(A)-S-H and leaching of lead and zinc, pore solution pH, and the correlation among them were revealed. The results showed that low modulus Na2SiO3 and highly Na2O dosage facilitated the substitution of Al for Si in C-S-H gels and produced C-(A)-S-H exhibited a decreased Ca/Si ratio and an increased proportion of Q3 in Si-O-T chain. The leaching of lead was mainly dependent on Na2SiO3 modulus, and high Na2SiO3 modulus facilitated solidification of lead. The stabilization of zinc was largely affected by pore solution pH, leading to larger leaching in the matrix with high pore solution pH. Higher dosages of Na2O significantly increased compressive strength but were detrimental to stabilization of lead and zinc. The study provided some guidance for selection of alkali-activation conditions for harmless treatment of steel slag and MSWIFA.

Characterization and solidification of heavy metals in sintered solid-waste ceramics made from zinc-extraction kiln slag

Zinc-extraction kiln slag is a hazardous solid waste rich in heavy metals. It is a great challenge to utilize it economically and harmlessly. This study aims to convert this zinc-extraction kiln slag (proportion of 50-60%) into solid-waste ceramics, by simultaneously utilizing other solid waste, fly ash, and desulfurization gypsum. By using X-ray diffraction, leaching experiments, and SEM analysis, the paper studied the solid-waste ceramics 'ability to solidify heavy metals. Under optimal conditions, C5 (zinc-extraction kiln slag, desulfurization gypsum, and fly ash with mass percentages of 60:20:20, at a sintering temperature of 1180 °C) shows an excellent performance with 43.02 MPa bending strength and 0.74% water absorption. The solidification ratios of Cr, Mn, Ni, Cu, and Zn were all exceed 97%. The main phases in the solid-waste ceramics were diopside and hematite. Diopside can efficiently solidify Zn, Mn, and Ni, while Cr and Cu can be solidified in the minor phase of spinel. During the sintering process, the ceramics produced the liquid phase, which promoted crystallization for solid solution of heavy metals and accelerated densification by elimination of pores. The ceramic system with diopside as the main phase not only shows excellent performance but also effectively solidifies heavy metals. Therefore, it is suitable for the resource utilization of metallurgical solid wastes containing heavy metals.

Synthesis of ternary geopolymers using prediction for effective solidification of mercury in tailings

This study used steel slag, fly ash, and metakaolin as raw materials (SFM materials) to create silica-alumina-based geopolymers that can solidify Hg2+ when activated with sodium-based water glass. The experiments began with a triangular lattice point mixing design experiment, and the results were fitted, analyzed, and predicted. The optimum SFM material mass ratio was found to be 70% steel slag, 25% fly ash, and 5% metakaolin. The optimum modulus of the activator was identified by comparing the unconfined compressive strength and solidifying impact on Hg2+of geosynthetics with different modulus. The SFM geopolymer was then applied in the form of potting to cure the granulated mercury tailings. The inclusion of 50% SFM material generated a geosynthetic that reduced mercury transport to the surface soil by roughly 90%. The mercury concentration of herbaceous plant samples was also reduced by 78%. It indicates that the SFM material can effectively attenuate the migration transformation of mercury. Finally, characterization methods such as XPS and FTIR were used to investigate the mechanism of Hg2+ solidification by geopolymers generated by SFM materials. The possible solidification mechanisms were proposed as alkaline environment-induced mercury precipitation, chemical bonding s, surface adsorption of Hg2+ and its precipitates by the geopolymer, and physical encapsulation.

Enhancing road performance of lead-contaminated soil through biochar-cement solidification: An experimental study

The effectiveness of cement-based solidification for remediating heavy metal-contaminated soil diminishes at high levels of contamination. To overcome this limitation, the potential of a biochar-cement composite curing agent to enhance the properties of Pb 2+ contaminated soil was investigated in this study. The permeability, unconfined compressive strength (UCS), and leaching characteristics of the biochar-cement composite material were assessed under varying biochar contents. The results revealed that the addition of 1-5 wt% biochar in cement significantly improved the UCS of the solidified soil. However, excessive biochar contents had a detrimental effect on the strength of samples. Additionally, the incorporation of 3.0% biochar reduced the hydraulic conductivity and porosity to 7.75 × 10-9 cm/s and 43.12%, respectively. Moreover, the biochar-cement composite material exhibited remarkable efficiency in treating highly concentrated Pb2+ contaminated soil, with leaching concentration decreasing significantly with increasing biochar content, falling below the Chinese hazardous waste identification standard. Overall, the utilization of a biochar-cement composite curing agent in the solidification of heavy metal-contaminated soil could be considered a promising subgrade filler technique.

Solidification of heavy metals in municipal solid waste incineration washed fly ash by asphalt mixture

Using asphalt mixture to solidify heavy metals in municipal solid waste incineration fly ash can reduce pollution and realize resource utilization. In this study, the physical and chemical properties of washed fly ash were analyzed, and washed fly ash was added to asphalt mixture as filler instead of mineral powder. The study involved analyzing the mechanical attributes of asphalt mixtures containing washed fly ash, along with examining the characteristics of asphalt binder that incorporates the washed fly ash. Subsequently, assess the potential leaching hazards associated with asphalt mixture incorporating washed fly ash. The test results showed that washed fly ash was a Si-Al-Ca system material, which had small particle size, large specific surface area and many pores. It increased the contact area with asphalt, which improved encapsulation of asphalt and aggregates. The optimal dosage of washed fly ash is 2.5%. At this dosage, the mixture attains optimal high-temperature performance, while both low-temperature performance and the characteristics of washed fly ash asphalt binder align with requirements. Asphalt mixture has solidification on heavy metals, with strongest solidification for Zn, followed by Cu, Cr. A prediction model of leaching amount versus time was constructed for Pb, Ba and Ni, which have weak solidified ability. The cumulative leaching amount of the road within 15 years of service life was calculated through the model, and it was obtained that the addition of washed fly ash will not cause pollution to environment. Overall, this study showed that asphalt mixtures can be used for stabilization/solidification of washed fly ash while saving natural mineral, providing a theoretical basis for the resource application of washed fly ash in asphalt road construction.

Enhancing physical and chemical stability of hygroscopic hydroxytyrosol by cocrystal formation

Hydroxytyrosol (HT) is a natural phenolic compound with potent antioxidant activity extracted from olive trees. It is generally a slightly hydrated viscous liquid at ambient conditions, and it is highly susceptible to oxygen due to the presence of catechol moiety. Although encapsulation technique provides HT in powder form, it does not improve its chemical stability. Herein, we propose an efficient solution to the high hygroscopicity and poor stability of HT. Four cocrystals were first reported, and their intermolecular interactions were analyzed in detail. After cocrystallization, the melting point is increased and the hygroscopicity is significantly decreased. HT cocrystals are thus solid at room temperature. Moreover, hydroxytyrosol cocrystals with betaine (HT-BET) and nicotinamide (HT-NIC) demonstrate superior chemical stability than pure HT, olive extract, and HT encapsulation material. Therefore, cocrystallization can be considered as a promising approach to overcome the application obstacles of HT.

Enhanced Stability and Solidification of Volatile Eugenol by Cyclodextrin-Metal Organic Framework for Nasal Powder Delivery

Eugenol (Eug) holds potential as a treatment for bacterial rhinosinusitis by nasal powder drug delivery. To stabilization and solidification of volatile Eug, herein, nasal inhalable γ-cyclodextrin metal-organic framework (γ-CD-MOF) was investigated as a carrier by gas-solid adsorption method. The results showed that the particle size of Eug loaded by γ-CD-MOF (Eug@γ-CD-MOF) distributed in the range of 10-150 μm well. In comparison to γ-CD and β-CD-MOF, γ-CD-MOF has higher thermal stability to Eug. And the intermolecular interactions between Eug and the carriers were verified by characterizations and molecular docking. Based on the bionic human nasal cavity model, Eug@γ-CD-MOF had a high deposition distribution (90.07 ± 1.58%). Compared with free Eug, the retention time Eug@γ-CD-MOF in the nasal cavity was prolonged from 5 min to 60 min. In addition, the cell viability showed that Eug@γ-CD-MOF (Eug content range 3.125-200 µg/mL) was non-cytotoxic. And the encapsulation of γ-CD-MOF could not reduce the bacteriostatic effect of Eug. Therefore, the biocompatible γ-CD-MOF could be a potential and valuable carrier for nasal drug delivery to realize solidification and nasal therapeutic effects of volatile oils.

Novel synthesis and applications of Thiomer solidification for heavy metals immobilization in hazardous ASR/ISW thermal residue

The present paper reports the novel synthesis and application of Thiomer solidification for heavy metal immobilization in hazardous automobile shredder residues and industrial solid waste (ASR/ISW) thermal residues. The word Thiomer is a combination of the prefix of a sulfur-containing compound "Thio" and the suffix of "Polymer" meaning a large molecule compound of many repeated subunits. To immobilize heavy metals, either ASR/ISW thermal residues (including bottom and fly ash) was mixed well with Thiomer and heated at 140°C. After Thiomer solidification, approximately 91-100% heavy metal immobilization was achieved. The morphology and mineral phases of the Thiomer-solidified ASR/ISW thermal residue were characterized by field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction (XRD), which indicated that the amounts of heavy metals detectable on the ASR/ISW thermal residue surface decreased and the sulfur mass percent increased. XRD indicated that the main fraction of the enclosed/bound materials on the ASR/ISW residue contained sulfur associated crystalline complexes. The Thiomer solidified process could convert the heavy metal compounds into highly insoluble metal sulfides and simultaneously encapsulate the ASR/ISW thermal residue. These results show that the proposed method can be applied to the immobilization of ASR/ISW hazardous ash involving heavy metals.

Strength and deformation characteristics of waste mud-solidified soil

The treatment, disposal, and resource utilization of waste mud are challenges for engineering construction. This study investigates the road performance of waste mud-solidified soil and explains how solidifying materials influence the strength and deformation characteristics of waste mud. Unconfined compressive strength tests, consolidated undrained triaxial shear tests, resonant column tests, and consolidation compression tests were conducted to evaluate the solidification effect. The test results show that with an increase in cement content from 5 to 9%, the unconfined compressive strength of the waste mud-solidified soil increased by over 100%, the curing time was extended from 3 to 28 days, and the unconfined compressive strength increased by approximately 70%. However, an increase in initial water content from 40 to 60% reduced the unconfined compressive strength by 50%. With the increase of cement content from 5 to 9%, the cohesion and friction angles increased by approximately 78% and 24%, respectively. The initial shear modulus under dynamic shear increased by approximately 38% and the shear strain corresponding to a damping ratio decay to 70% of the initial shear modulus decreased by nearly 11%. The compression coefficient decreased by approximately 55%. Scanning electron microscopy and X-ray diffraction tests showed that a higher cement content led to the formation of more hydration reaction products, especially an increase in the content of AlPO4, which can effectively fill the pores between soil particles, enhance the bonding between soil particles, and form a skeleton with soil particles to improve compactness. Consequently, the strength of the waste mud-solidified soil increased significantly while its compressibility decreased. This study can provide data support for dynamic characteristics of waste mud solidified soil subgrade.

High-throughput preparation, scale up and solidification of andrographolide nanosuspension using hummer acoustic resonance technology

The aim of this study was to rapidly develop a sufficiently robust andrographolide nanosuspension (AG-NS) system using hummer acoustic resonance (HAR) technology. The system can effectively improve the dissolution properties of AG, while having high stability and scale-up adaptability. The formulation of AG-NS was optimized in a high-throughput manner using HAR technology and the preparation process was optimized stepwise. Optimal AG-NS with Z-Ave = 223.99 ± 3.16 nm, PDI=0.095 ± 0.007 and zeta potential = -33.20 ± 0.58 mV was successfully prepared with Polyvinylpyrrolidone K30 and Sodium dodecyl sulfate. The optimal prescription was successfully scaled up 100 and 150 times using HAR technology, which was the initial exploration of its commercial scale production. AG-NS was solidified using freeze drying and fluid bed technology, respectively. The optimal AG-NS and its solidified products were exhaustively characterized using various analytical techniques. The high energy input of HAR technology and drying process converted part of the drug into the amorphous state. The in-vitro drug dissolution studies demonstrated relatively higher drug dissolution for AG-NS and its solidified products compared to controls at both the dissolution media (pH 1.2 buffer and pH 6.8 buffer). AG-NS and its solidified products successfully maintained their physical stability in short-term stability and accelerated stability experiments, respectively.