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Although the vitrification of nuclear waste has a decades‐long history, numerous opportunities still exist to improve its efficiency and to increase the waste loading in glass. This is especially true for the vitrification of low‐activity waste (LAW), which has been historically treated by other immobilization technologies and is less mature than high‐level waste (HLW) vitrification. In this work, we address one of the least understood phenomena during the conversion of nuclear waste feeds to glass—the formation of molten salt and transient glass‐forming melt. Using high‐temperature environmental scanning electron microscopy (HT‐ESEM) in combination with X‐ray diffraction, thermogravimetry, and evolved gas analysis, we have analyzed the complex chemical reactions and phase transitions as they occur during melting of representative HLW and LAW melter feeds. We evaluated the compositions of amorphous phases and the fractions of salt components, and estimated the fractions of molten salt phases present in the feeds as a function of temperature. We show that the maximum fraction of molten salts is ∼4 % and ∼28 % during HLW and LAW feed melting, respectively, and discuss the possibility of molten salt migration in LAW feeds. We also argue that the presence of significant fractions of molten salt phase can hinder the retention of rhenium (and, hence, radioactive technetium), and discuss how the properties of molten salt phase and transient glass‐forming melt are related to primary foam formation and behavior. Finally, we summarize key unanswered questions requiring further research to increase the understanding of the conversion process and enhance the nuclear waste vitrification efficiency. [ABSTRACT FROM AUTHOR]

A key consideration for the successful operation of hybrid energy systems will be the environmental stability of materials used for their construction, particularly when experiencing service environments containing water vapor at high temperatures. Here, we report results from the characterization of siliconized silicon carbide (Si‐SiC) prepared via binder jet additive manufacturing and reactive silicon melt infiltration after being exposed to environments representative of those in solid oxide fuel cell (SOFC) anodes, and to exhaust gases inside a microturbine operating on natural gas. In both cases, it was found that oxide scales formed on the surface and that these scales were dense, continuous, and well‐bonded to the substrates, although there was evidence of transverse and longitudinal cracking most likely as a result of mismatches in the thermal expansion of the scale and the substrate. Measured values of the thickness of the oxide scale were compared to those predicted by parabolic oxidation kinetics of silicon, but the potential effects of silica volatilization induced by water vapor, and silica reduction when exposed to hydrogen are discussed. The overall results showed that the oxide scale is expected to be protective under the conditions of hybrid power generation systems. [ABSTRACT FROM AUTHOR]

A suitable nitrogen (N) application rate (NAR) and ideal planting period could improve upland rice productivity, enhance the soil water utilization, and reduce N losses. This study was conducted for the assessment and application of the EPIC model to simulate upland rice productivity, soil water, and N dynamics under different NARs and planting windows (PWs). The nitrogen treatments were 30 (N30), 60 (N60), and 90 (N90) kg N ha−1 with a control (no N applied −N0). Planting was performed as early (PW1), moderately delayed (PW2), and delayed (PW3) between September and December of each growing season. The NAR and PW impacted upland rice productivity and the EPIC model predicted grain yield, aboveground biomass, and harvest index for all NARs in all PWs with a normalized good–excellent root mean square error (RMSEn) of 7.4–9.4%, 9.9–12.2%, and 2.3–12.4% and d-index range of 0.90–0.98, 0.87–0.94, and 0.89–0.91 for the grain yield, aboveground biomass, and harvest index, respectively. For grain and total plant N uptake, RMSEn ranged fair to excellent with values ranging from 10.3 to 22.8% and from 6.9 to 28.1%, and a d-index of 0.87–0.97 and 0.73–0.99, respectively. Evapotranspiration was slightly underestimated for all NARs at all PWs in both seasons with excellent RMSEn ranging from 2.0 to 3.1% and a d-index ranging from 0.65 to 0.97. A comparison of N and water balance components indicated that PW was the major factor impacting N and water losses as compared to NAR. There was a good agreement between simulated and observed soil water contents, and the model was able to estimate fluctuations in soil water contents. An adjustment in the planting window would be necessary for improved upland rice productivity, enhanced N, and soil water utilization to reduce N and soil water losses. Our results indicated that a well-calibrated EPIC model has the potential to identify suitable N and seasonal planting management options. [ABSTRACT FROM AUTHOR]

As a type of silica-alumina solid waste, fly ash can be utilized to prepare ceramic proppants by partially substituting bauxite due to a similar chemical composition. However, the heavy metal elements in fly ash including Zn and Cd are subjected to be released during high-temperature calcination, causing harm to some extent. In this study, migration, transformation, solidification, and volatilization of heavy metals in proppant at elevated temperatures are systematically studied by various experimental characterization methods. The results show that the solidification effect of the prepared ceramic proppant on the Zn and Cd elements is favorable, with solidification ratios up to 77.16% and 74.34%. The addition of Cd improves the bulk density and strength of the ceramic proppant, while the addition of Zn significantly reduces the strength and increases the water absorption. Additionally, the majority of doped Zn will combine with Al 2 O 3 to form a new phase, zinc spinel ZnAl 2 O 4 , which hinders the formation of the inherent mullite phase. On the contrary, the addition of Cd does not change the phase composition, and the Cd element is mainly solidified in the form of lattice substitution. Finally, the distributions of volatile Zn and Cd in gas- and solid-phase were quantitatively determined by the in situ continuous collection system. In addition, a mathematical model was used to predict the volatilization of heavy metals during the proppant calcination process. [ABSTRACT FROM AUTHOR]

It is well-known that the mining industry in Chile and the world is searching for eco-friendly, highly efficient mineral treatments. This is because the content of toxic elements such as arsenic, antimony, and bismuth have increased in the copper concentrates in the last years. This trend has affected the market of this metal, as well as increased the potential of producing solid wastes that represent a threat to the environment. In this paper, a review on the fundamentals of the current treatments aimed at removing arsenic, antimony, and bismuth from copper concentrates under roasting conditions is presented. The literature survey included the research conducted from 2000 until now and is focused on the different types of roasting of copper concentrates reported in the literature. A summary of the experimental conditions and major findings of each work is discussed. Depending on the type of roasting, the behavior of arsenic, antimony, and bismuth species during the experiments is analyzed. [ABSTRACT FROM AUTHOR]

Polymeric textile materials, now, find extensive application in modern society than previously imagined, particularly in protective clothing. The application of these polymeric materials has been restricted by their flammability and contribution to fire risk. Flame retarding compounds and inherent flame-retardant materials have been introduced to reduce and even halt the flammability of polymers. However, over time, flame retardants tend to leach out of materials. The exposure of polymer textile to varying heat intensities may trigger polymer and flame retardant's volatilization and thermal degradation. Firefighters may be exposed to toxic chemicals through the volatilization of flame-retardant compounds from the bunker gear. Flame retardant's volatilization is associated with thermal degradation of the flame-retardant chemical compounds in the textile material. This review focuses on volatilization of flame retardants from protective textile materials resulting from exposure to heat and seeks to provide the necessary understanding about the release of flame retardants from flame-retardant textiles, particularly firefighting garments. [ABSTRACT FROM AUTHOR]

Iodine deficiency occurs when iodine levels in the soil are inadequate, resulting in limited crop uptake and, as a result, a population with insufficient iodine intake. Iodine deficiency can be avoided by biofortifying commonly consumed crops with iodine. A field experiment was conducted to investigate the effect of iodine biofortification on the nutrient uptake of fruits and plants of ‘shivam’ hybrid tomato. Potassium iodate and chitosan were applied in the form of soil, foliar, and chitosan iodate complex with control comprising 16 treatments (T1 to T16) at different stages of plant growth. Iodine accumulation in tomato fruits and plants was achieved by combining foliar and iodine chitosan forms as electrostatic interaction between chitosan and iodate prevents volatilization and gradually increases the bioavailability of iodine from soil to fruits. Biofortification of iodine throughT14- Chitosan -KIO3Complex (CsKIO3) - (SA)-10Kgha-1 + FA-KIO3-0.3% @ 60 and 90 DAT the iodine content in tomato fruit at green (0.95ppm), pink (1.01ppm) and red ripen (0.99ppm) stages of tomato and introducing it in present-day daily diet may help to reduce iodine deficiency disorder. Iodine biofortification also influenced the uptake of nitrogen, phosphorous and potassium in plants and fruits of tomatoes. [ABSTRACT FROM AUTHOR]

Lithium lanthanum zirconium oxide (LLZO) garnet is a solid‐state lithium ion conducting electrolyte promising all‐solid‐state batteries (ASSB) with high charge rates and good energy density due to its chemical stability against lithium metal anodes. LLZO has a high room temperature Li ion conductivity of ∼0.1–1 mS/cm in its cubic phase, but the stability of the cubic phase and ionic conductivity are highly sensitive to lithium stoichiometry. Stabilizing agents such as aluminum oxide and excess lithium are needed to preserve the cubic phase and compensate for lithium volatility. With the range of the end LLZO products spanning powders, porous membranes to dense membranes combined with sintering/calcination that often exceeds 1000°C, it is challenging to maintain an ideal lithium content given its high volatility from a single base powder. This study was designed to elucidate the sensitivities of aluminum doped LLZO powder synthesis and processing along its path to being utilized in a ceramic‐manufacturing optimized ASSB. By utilizing thermogravimetric analysis in conjunction with in situ X‐ray diffraction analysis of solid‐state LLZO synthesis, it was discovered that the sensitivity of the LLZO cubic phase to lithium volatility can be reduced via early incorporation of excess lithium carbonate during initial phase formation in direct combination with controlled surface‐to‐volume ratios of the powders. Isostatically pressed powders of our LLZO sintered at 1100°C for 2 h showed RT ionic conductivity of 0.3–0.4 mS/cm measured via electrochemical impedance spectroscopy, and an improvement in microstructural uniformity with lowered porosity. The improved suppression of lithium volatilization has important implications for the scalable production of LLZO powders and assembly of ASSBs. [ABSTRACT FROM AUTHOR]

Molish in 1937 coined Allelopathy from two Greek words, 'allelo' (means two organisms) and 'pathy' (means harm). The term defined as plant released metabolites into environment through ecological processes: volatilization, leaching, root exudation and decomposition of plant debris in soil, resulting in detrimental effects on understorey or neighbouring plants sharing the same habitat. This essay aimed to describe the allelopathy researches dealing with the allelopathy in natural and managed ecosystems in the past, present and future. The allelopathy plays an important role in managed ecosystems, particularly in agricultural productivity. The yield reduction of rice (Oryza stiva L.) in the second crop season was 25 to 50 % lower than the first crop season in Taiwan. This phenomenon was designated as auto-intoxication, which is another phase of allelopathy. The potential of allelochemicals are often modified by environmental stresses (temperature, soil pH, drought, nutrients deficiency, light and physiological or biochemical interactions) under varied environmental conditions. The action modes of allelochemicals on the structure and function of plants are via physiological and molecular interactions. Allelochemicals released from plants, microorganisms, or algae can be used as agro-chemicals (Herbicides, fungicides, nematicides and anti-pathogens), these are environmental friendly for sustainable agriculture. For example, the win-win strategy of pasture-forest intercropping results in the kikuyu grass suppresses the weed growth due to the allelopathic effects of kikuyu grass, but is good for the regeneration of chinese fir. Furthermore, the mechanisms of allelochemicals action on crops are discussed. The allelochemicals cover very broad aspects of chemical interactions among organisms, thus, the fundamental studies of natural products from organisms need trainings in multi-disciplinary sciences viz., Biology, ecology, biochemistry, organic chemistry, molecular biology, soil science and earth sciences. The authors coined a new scientific term called "Allelochemicology", which hopefully, inspires young scientists in life sciences to explore this field to solve the most difficult tasks in ecology, sustainable agriculture, pharmaceutical and medicinal applications. The research finding of allelopathy, indeed, can be beneficial to human beings in reaching the Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Polyhedral oligomeric octaphenylsilsesquioxane (OPS) is usually used to improve the oxidative stability, thermal stability and fire-retardant property of polymers. Due to the divergences in the thermal decomposition of the OPS according to thermogravimetric analysis (TGA), a comprehensive study of the thermal behaviors of OPS under air and nitrogen atmospheres was carried out. Sublimation of OPS was proved. Due to the OPS sublimating, the TGA results of OPS depended on the sample mass used in the TGA tests. Two mass loss steps were found under nitrogen, while three steps were found under air. The mass loss of the 1st step was mainly caused by the sublimation of OPS under air and nitrogen. Sublimation of OPS, detachment of phenyl groups and destruction of caged structures happened in the 2nd step under both atmospheres. In the 3rd step under air atmosphere, the residual organic part of the sample was oxidated into carbon monoxide and carbon dioxide. [ABSTRACT FROM AUTHOR]

The article presents new observations of the physical manifestations of internal oxidation and volatilization in SiC/BN/SiC composites. The observations are made on both unbroken and broken minicomposite specimens before and after 12 h exposures at 1000°C in dry air with 10 ppm water vapor. The observations are enabled by a sample preparation method involving ion‐mill sectioning and polishing. Complementary analyses of volatilization and closure of resulting gaps are also presented. The observations show that BN is generally consumed in two stages: (i) through reaction with oxygen along the interfaces with both the fiber and the matrix, producing two concentric annular pockets of borosilicate glass and an intervening annulus of progressively thinning BN; and (ii) subsequent volatilization, through the reaction of boria with trace amounts of water vapor in the environment to form borohydroxide gases. The spatial extent to which these processes proceed is governed by a competition between the outward diffusion of reaction gases through both matrix cracks and interface gaps produced by boria volatilization, and the formation of oxides on the newly exposed surfaces of fibers, matrix, and coating. [ABSTRACT FROM AUTHOR]

Cuspidine-based systems are used to control the crystallization in mold fluxes, which is enabled by CaF2 additions. However, excess CaF2 increases the corrosion of casting machines. Therefore, Na2O and K2O are added to the mold flux system to ensure an optimized crystallization and lubrication ability of the flux with the CaF2 content. This study investigated the effect of substituting Na2O with K2O on the volatilization of fluorine in a CaO–SiO2–CaF2-based slag system at high temperatures. The substitution of Na2O with K2O was performed at 5 mol% intervals. The volatilization was observed by thermogravimetric analysis under several isothermal conditions. The mass loss was measured at a heating rate of 5, 10, and 20 K/min. As the temperature increased, the volatilization of the mixed samples increased. The activation energy was calculated using the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods. A kinetic analysis of the volatilization of fluorine was conducted using the calculated parameters and several known kinetic models. Consequently, the volatilization of the Narich sample was controlled by chemical reactions and that of the K-rich sample was identified to be controlled by a phase-boundary-controlled reaction. These results suggest that the addition of mixed alkali oxide promote the volatilization during the early stages of the reaction. From the post-experimental composition analyses, the remaining Na and K in the samples suggested a different mechanism for the Na and K volatilization. The volatilization of Na increased with time, whereas K volatilized easily during the beginning of the reaction. [ABSTRACT FROM AUTHOR]

In this work, a kind of II;‐VI group ZnTe semiconductor crystal is successfully grown using a Te flux zone melting method from Zn: Te = 3: 7 mole ratio solution. The crystal has standard F43m cubic space group and the a/b/c lattice constants are all calculated to be 6.105 Å. Energy dispersive spectroscopy analysis confirms it has quasistoichiometric ratio and the Zn/Te elements are distributed in the material homogeneously. The polished 1.0 mm thickness (110) wafer exhibits a highest ≈64.5% transmittance near 2400 nm wavelength and the bandgap Eg is deduced as 2.223 eV. ZnTe crystal shows a heavy volatilization start from 910 °C and the weight losing speed is about ≈1.45% min−1. The thermal conductivity k displays good repeatability in the cooling and heating stages, the k value is about 15.8 Wm−1 K−1 at room temperature and is deceased to 3.53 Wm−1 K−1 under 500 °C. These results would be of great reference when ZnTe crystal is used for device design and application in the future. [ABSTRACT FROM AUTHOR]

In this paper, a new kinetic model considering both oxidation and volatilization kinetics is established and applied to analyze the oxidation of SiC-B 4 C- x Al 2 O 3 ceramics and other systems in various oxidation conditions. The effects of diffusion area and volume changes during the oxidation process are considered in this model. The physical meaning of each parameter in this model is explicit and simple. According to this model, the diffusion coefficient of species and the corresponding diffusion activation energy are easily available. The practicability of this model is well verified by the experimental data of SiC-B 4 C- x Al 2 O 3 and other systems oxidized under different conditions. In addition, the practice shows that the model is applicable not only to the systems where oxidation and volatilization coexist, but also to the system where only oxidation plays a major role. We hope the model proposed in this work can be used in other materials with more complex environments. ● A new kinetic model is established and applied to the oxidation analysis of various systems. ● The model quantitatively considers the effects of oxidation and volatilization. ● This more comprehensive model has wider application and better accuracy. [ABSTRACT FROM AUTHOR]

In this study, we investigated the volatility of sodium, potassium, and cesium perrhenates using thermogravimetry (TG) performed on single salts and their binary mixed salts. We performed simultaneous TG and differential scanning calorimetry under a ramp heating condition at 10 °C/min up to 1200 °C to characterize volatilization behavior as a function of temperature. We also performed isothermal TG over a temperature range of 700–975 °C. To estimate the relative differences in the vapor pressure of the alkali perrhenates we adopted a published equation on the vaporization mass loss rate during diffusion-controlled evaporation, applied a proposed equation on the interdiffusion coefficient of vapors, and used the literature data available on vapor pressure for KReO4. Both the temperature ranges of evaporation determined by TG under ramp heating conditions and the vapor pressure estimated from isothermal TG support that the order of volatility of alkali perrhenates is CsReO4 > KReO4 > NaReO4. This result does not support the unusual volatility order of KReO4 > CsReO4 > NaReO4 observed from Hanford LAW glass feeds, which suggests that the volatility of the perrhenates is likely dependent on the composition of salt in which the perrhenates are dissolved. [ABSTRACT FROM AUTHOR]

[Display omitted] • The new method realizes the efficient separation of lithium in the smelting process. • Under the optimal conditions, the volatilization rate of Li was 96.87%. • Lithium volatilizes into the gas phase in the form of LiCl. • The formation and volatilization mechanism of LiCl was revealed. Spent lithium-ion batteries (LIBs) comprise different kinds of valuable metals with recovery and reuse value. Aiming to address the difficulty of recycling lithium from spent LIBs through conventional pyrometallurgy, a new method of high-efficiency separation and recovery of lithium through volatilization is proposed. In this new method, spent LIBs as the raw material, copper slag as the only flux and CaCl 2 as an additive are utilized to recover lithium from spent LIBs. Under the optimal conditions, the volatilization rate of Li was 96.87%. During the smelting process, lithium is volatilized into the gas phase in the form of LiCl, where lithium can be recycled from the dust. In light of the experimental results, the addition of CaCl 2 contributes to the formation of LiCl. The kinetics study showed that the volatilization of LiCl was controlled by an interfacial chemical reaction, and the apparent activation energy was 42.57 kJ/mol. In addition, Li 2 CO 3 could be obtained from lithium-containing dust using a precipitation process. This method achieves efficient separation of lithium during the reduction smelting process. The phase transformation and kinetics of the separation process were investigated, and reaction mechanism was revealed. Importantly, the novel process provides new ideas and perspectives for the separation of lithium from spent LIBs through a pyrometallurgical process. [ABSTRACT FROM AUTHOR]

Some European countries are exploring the idea of replacing dedicated crops with energy cover crops for biogas production. Indeed, energy cover crops can generate consequential biomass without competing with food crops for land use. However, the potential benefits and impacts of this choice are not fully understood. Here, we review what is known about the consequences of energy cover crop usage by examining management regimes and digestate use, including impacts on the environment and cropping system performance. First, compared to cover crops, energy cover crops are intensively managed to produce more biomass (< 5 t DM/ha vs. up to 16 t DM/ha). Second, nitrogen is conserved during anaerobic digestion and is more readily available to crops in digestate than in cover crops residues. However, ammonia is lost via volatilization, which could reduce nitrogen use efficiency, depending on the storage conditions and application method. Third, 43–80% of the crops' initial carbon is transformed into biogas. That said, levels of soil carbon storage may nonetheless resemble those obtained with cover crops left behind because carbon is stabilized during anaerobic digestion and the energy cover crops' roots and stubble are left behind in the soil. Fourth, energy cover crops can act as multiservice cover crops, reducing nitrate leaching, improving soil microbial activity, and enhancing soil physical properties during the fallow period. Fifth, energy cover crop usage can have certain disservices, such as soil compaction, the need for additional inputs (e.g., irrigation, fertilization, pesticides), reduced groundwater recharge, and reduced following crop yield. In summary, expanding the usage of energy cover crops for biogas production does not seem to be an environmental threat. However, care must be taken to avoid the intensification of irrigation and lengthening growing periods to boost biomass, which could reduce food production. [ABSTRACT FROM AUTHOR]

As part of study of the volatilization ruthenium behaviour in a boiling nitric solution, this paper presents the results of experiments dealing with the influence of different parameters (Ru and HNO3 concentrations, temperature, water addition) and the effect of in-situ inhibitors to mitigate potential releases. The amount of Ru volatilized from a nitric solution heated at 130 °C is about 2% of initial inventory. The addition of a low amount of inhibitors allowed to prevent ruthenium volatilization. Alternative strategies examined to restrict volatilization are the temperature decrease and the "water feed", this later is more efficient. [ABSTRACT FROM AUTHOR]

Lightweight aggregates (LWAs) have potential in the harmless resource utilization of Cd-contaminated soil due to their extraordinary ability to effectively solidify heavy metals, although the negative effects of chlorine in the soil are nonnegligible. This work methodically investigated the influence of KCl and MgCl 2 with concentrations ranging from 1% to 5% on the volatilization, and solidification of cadmium in LWAs prepared with contaminated soil and lithium slag. The results indicated that cadmium was discharged out of the LWA in the form of CdCl 2 driven by Cl−, and the remaining cadmium was completely solidified in the LWA in the form of CdFe 2 O 4. It was found that the addition of chloride significantly increased the volatilization ratio of cadmium, and the distribution of the pore structure of the LWAs was more uniform. The effect of KCl on the volatilization ratio of cadmium and the physical properties of LWA is significantly better than that with MgCl 2. It could mainly due to the differences in the release of chlorine free radicals and the content of metal oxides introduced by chlorides. This work could help to understand the migration and transformation mechanism of cadmium in LWAs and guide CdCl 2 emission control technology. Ultimately, it is feasible to realize the resource utilization of Cd-contaminated soil and lithium slag with a cleaner approach. [Display omitted] • Harmless utilization of Cd contaminated soil and lithium slag realized by LWA. • Volatilization of cadmium in the LWA was mainly caused by the escape of CdCl 2. • Solidification of cadmium in LWAs benefits from the formation of CdFe 2 O 4. • Adjustment of metal oxides in raw materials is feasible for CdCl 2 emission control. [ABSTRACT FROM AUTHOR]

Dimethylsilanediol (DMSD) is the common breakdown product of methylsiloxanes such as polydimethylsiloxane (PDMS) and volatile methylsiloxanes (VMS) in soil. In this work, we first present a sorbent selection experiment aiming to identify a sorbent that can trap gas-phase DMSD without causing DMSD condensation and VMS hydrolysis at environmentally relevant humidities. With a proper sorbent (Tenax) identified, the volatilization of DMSD from water and various wet soil and soil materials were measured in a controlled environment. It was demonstrated that DMSD underwent volatilization after soil water was completely evaporated. Various types of soil constituents show drastic differences in preventing DMSD from volatilization. Analysis of the sorbent-captured products provides further insight, most notably that virtually no cyclic methylsiloxanes are formed during the volatilization of DMSD from water or soil materials, except in one extreme case where only traces are detected. [Display omitted] • A reliable method to capture and quantitate volatilized DMSD is presented. • The method is used to understand the mechanism of DMSD sorption/volatilization from soil materials. • Type of soil constituents has a drastic impact on the sorption/volatilization of DMSD. • Little to no cVMS are formed during DMSD desolvation. [ABSTRACT FROM AUTHOR]

[Display omitted] • ATR-FTIR and 2DCOS were combined to study the volatilization of microemulsions. • Different volatilization stages can be segmented by PCA and moving-window 2DCOS. • The successive volatilizations of ethanol, water and menthone were observed. • Microemulsion with peppermint essential oil and composite herbal extract is feasible. Microemulsion is usually a transparent and isotropic liquid mixture composed of oil phase, water phase, surfactant and cosurfactant. The surfactant-framed nanoscale droplets in the microemulsion can penetrate into the skin surface to reduce its barrier function. This makes microemulsion an ideal preparation for the transdermal drug delivery. The permeability of microemulsion may be further enhanced when botanical essential oils that can dissolve the stratum corneum are used as the oil phase. However, the volatility of essential oils is possible to shorten the retention time of the microemulsion on the skin surface. Therefore, analytical methods are required to understand the volatilization process of the microemulsion composed of essential oils to develop the reasonable topical drug carrier system. In this research, Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflection (ATR) accessory cooperated with two-dimensional correlation spectroscopy (2DCOS) to elucidate the volatilization processes of some microemulsions composed of peppermint essential oil. Principal component analysis (PCA) and moving-window two-dimensional correlation spectroscopy (MW2DCOS) revealed the multiple stages of the volatilization processes of the microemulsions. Synchronous 2D correlation infrared spectra indicated the compositional changes during each stage. It was found that the successive volatilizations of ethanol, water and menthone were the major events during the volatilization process of the microemulsion composed of peppermint essential oil. Ethanol can accelerate the volatilization of water, while the composite herbal extract seemed to not influence the volatilization of the other ingredients. After a 20-min-long volatilization process, the remaining microemulsion still contained considerable peppermint essential oil to affect the skin. The above results showed the feasibility of developing the microemulsion composed of peppermint essential oil for the transdermal drug delivery of composite herbal extract. This research also proved that the combination of ATR-FTIR spectroscopy and 2DCOS was valuable to study the volatilization process of the microemulsion. [ABSTRACT FROM AUTHOR]

Urea is the most used nitrogen (N) fertilizer worldwide, but its rapid hydrolysis on the soil surface results in N loss in the form of ammonia (NH3-N). Enzyme inhibitors have been investigated for their ability to reduce NH3-N volatilization, particularly from no-till and surface-limed soils. This study assessed the efficiency of stabilized fertilizers in reducing NH3-N volatilization under different lime rates and application methods. The experiment followed a 2 × 4 × 3 factorial design, with two liming methods (surface application and incorporation), four base saturation levels (50, 60, 70, and 90%), and three urea (45% N) sources: conventional urea, urea + N-(n-butyl)-Thiophosphoric triamide (NBPT), and urea + Boron (B) + Copper (Cu). NH3-N volatilization losses varied from 9.15 to 20.43 kg ha−1, accounting for 11.4 to 25.5% of the applied N rate. Base saturation did not influence NH3-N volatilization. Liming method, however, had a significant effect. Urea + B + Cu was effective in reducing volatilization loss only in soils ameliorated by lime incorporation (23% reduction compared with conventional urea). Urea + NBPT was effective in surface-limed and incorporated soils (up to 55.5% reduction). The results showed that soil management influences the efficiency of stabilized fertilizers and that urea + NBPT provides the best results. [ABSTRACT FROM AUTHOR]

Gasification has played an important role in the sustainable use of waste biomass, providing useful combustible gases in the process. Gasification has an important role in waste management and promotes energy independence for many oil-deficit countries. The gasification process has been studied by various researchers, and improvements have been achieved in its sub-processes such as devolatilization, feed input methods, and so on. We examined the influence of gasifier operation parameters, such as oxidizer content, moisture content in the feedstock, and solar flux input inside the gasifier, on the temperature distribution, velocity distribution, and product gas yields of the gasifier. The results indicate that inducing solar energy at different stages of the gasifier leads to different yields of product gas composition (CO and H2). [ABSTRACT FROM AUTHOR]

The solar cells are the most prominent devices to generate energy from sunlight, however, one of the main factors limiting the efficiency of photovoltaic conversion is the recombination of charge carriers in their active layer, which is generated by the inhomogeneity of the material that constitutes this layer. KBiFe2O5 is a perovskite with a high potential to be applied in the active layer of photovoltaic devices, however, it suffers from poor homogeneity during its synthesis, which is caused by the volatilization of K and Bi of its composition and, consequently, leads to the formation of secondary phases, which can sequester the charge carriers and decrease the efficiency of photovoltaic conversion. Thus, our objective is to evaluate the homogeneity of the powders obtained by the polymeric precursor method, its thermal stability until the formation of secondary phases, and the optical properties. With elemental mapping, it was possible to verify that the powder obtained was highly homogeneous and the band gap of 1.74 eV is within the optimal range for applications involving sunlight. Thus, it was possible to verify that this synthesis method generates highly homogeneous powders and at the temperatures employed does not undergo volatilization of K and Bi. [ABSTRACT FROM AUTHOR]

Urea–nitrogen is commonly lost through ammonia (NH3) volatilization, denitrification, and nitrate (NO3−) leaching. Rejected sago starch (RSS), which is a by-product of sago flour extraction, could be used to minimize NH3 volatilization from urea. Urea granules were coated with different concentrations of RSS (2%, 3%, 4%, 5%, and 6%), and their effects on NH3 emission, soil pH, exchangeable ammonium (NH4+), and available NO3− were determined. The urea was coated with RSS and homogenized using a mini rotary machine. The RSS-coated urea granules were dyed to differentiate their concentrations. The effectiveness of the RSS as a coating material was determined using a closed-dynamic air flow system. The soil used in the NH3 volatilization was the Bekenu series (Sandy loam, Typic Paleudults). This study compared seven different mixture treatments: soil alone (S), 5 g of uncoated urea (U), 5 g of 2% RSS-coated urea (CU1), 5 g of 3% RSS-coated urea (CU2), 5 g of 4% RSS-coated urea (CU3), 5 g of 5% RSS-coated urea (CU4), and 5 g of 6% RSS-coated urea (CU5). Urea coated with RSS, particularly CU1, effectively minimized NH3 loss and improved the retention of soil exchangeable NH4+ and available NO3− compared with uncoated urea because the RSS serves as a barrier to minimizing the concentration of NH3 from urea hydrolysis. Urea could be coated with RSS at the 2% concentration to enhance urea–N efficiency through a reduction in NH3 emission from urea. RSS-coated urea could be an alternative for farmers because of its controlled release of N and economical benefits. Field planting using rice as a test crop to solidify the effectiveness of RSS-coated urea in improving N retention from urea is still ongoing. [ABSTRACT FROM AUTHOR]

In the context of S and N pollutant remediation, this study aimed to develop a methodology to test the ability of wetland plants to reduce atmospheric pollution by S and N. A methodology using 34S and 15N-labeled Sinapsis alba compost and five species (trap plants) used to fix volatile compounds was developed. 18.66% of 34S and 40.63% of 15N produced by Sinapsis alba compost, equivalent to 67 mg of S and 1611 mg of N, were recovered in trap plants, a negligible proportion of the labeling was found in the culture substrate. 34S and 15N atom% excess were two to ten times higher in leaves than in roots. Agrostis stolonifera, Symphytum officinale, and Lythrum salicaria were more efficient to use atmospheric inorganic sources of S and N than Mentha aquatica and Carex riparia. A low concentration of sulfate in the leaf laminas, a high specific leaf area, and a low leaf dry mass content could represent trait patterns that explain higher abilities to fix pollutants. This study confirms that plants can be used to remediate inorganic atmospheric pollution and highlights the importance of plant screening for this environmental function. Novelty statement The removal efficiency of botanical biofiltration is well-documented for Volatile Organic pollutants, but little is known concerning Volatile Inorganic pollutants, such as SO2 and NH3 which can also constitute plant nutrients. We developed a methodology based on the use of 34S and 15N-labeled mustard compost to study the ability of wetland plant species to fix volatile N and S pollutants. This methodology was effective as 19% of 34S and 41% of 15N lost by mustard compost were recovered in trap plants. Among the species used as "trap plants" Agrostis stolonifera, Symphytum officinale, and Lythrum salicaria appeared more efficient to use atmospheric inorganic sources of S and N than Mentha aquatica and Carex riparia. [ABSTRACT FROM AUTHOR]

A carbothermal reduction process simulating EAF process is used to handle the zinc oxide dust, and the zinc in the dust can be extracted and recovered efficiently. The crude zinc and lead-tin alloy were obtained finally. The effects of temperature, holding time, and reductant dosage on zinc volatilization rate were investigated, and the "Pelletizing - Calcination-Carbothermic reduction" experiment was conducted. The results found the optimal reduction condition was as follows: the temperature of 1300?, reductant dosage of 14.04%, and holding time of 120 min. After the calcination at 900? for 120 min, the removal rates of fluorine, chlorine, and sulfur in the dust were 98.18%, 96.38% and 28.58% respectively, and the volatilization rate of zinc was 99.83% in the reduction process. The zinc content of the crude zinc was 68.48%. [ABSTRACT FROM AUTHOR]

• The volatilization ability of toxic elements following the trend of Se > Cd > As. • The element oxides SiO 2 have a strong affinity to elements Cd and As. • The release behavior of As and Cd is mainly attributed to the occurrence states. • Both the occurrence states and lower boiling point jointly determine release of element Se. Briquetting technique can be an excellent energy saving utilization of pulverized coal, and the thermal chemical treatment of briquette has attracted the extensive attention of researchers due to its efficiency and applicability. To reveal the migration and volatilization characteristic of toxic trace elements (As, Se and Cd) during pyrolysis procedure of briquette, this paper studied the effects of mineral composition, pyrolysis parameters and occurrence state on element migration by multidisciplinary methods. Results show that the migration of toxic elements from solid phase to tar and gas phase are accelerated by increasing the pyrolysis temperature. Except for temperature, both the occurrence states and lower boiling point jointly determine release of element Se, while release behavior of As and Cd is mainly attributed to the occurrence states. At the pyrolysis temperature interval of 500–800 °C, the volatilization ability of toxic elements following the trend of Se > Cd > As. The element oxides SiO 2 have a strong affinity to elements Cd and As with high correlation index, which play a key role on Cd and As elements absorption during heat treatment to prevent emission. Due to the easily vaporized characteristics of Se, some other suitable measures should be explored to reduce environmental pollution. [ABSTRACT FROM AUTHOR]

Dimethylsilanediol (DMSD) is a primary degradation product of silicone materials in the environment. Due to its low air/water partition coefficient and low soil/water distribution coefficient, this compound is not expected to undergo sorption and volatilization in wet soil. In an accompanying paper, we confirm that under controlled indoor conditions in test tubes, there is little to no volatilization of DMSD from soil and soil constituents if soil is wet. However, a significant amount of DMSD was volatilized when the soil substrates became air dried. Given the importance of water on the partition and fate of DMSD, we now report a continuation of this study focusing on the relation between DMSD removal and water loss in re-constituted soil columns under outdoor conditions. Consistent with predictions based on its partition properties and reconciling this evidence with previously reported field and laboratory studies, DMSD distribution was found to be largely dependent on water partitioning. The results suggested that DMSD moved upward in soil profile as soil water was evaporated from topmost layers with little DMSD retention by the soil matrix. As soil dried, a fraction of DMSD was sorbed by the soil matrix in the topmost layer, while most of the spiked radio-labeled DMSD was removed from soil through volatilization. [Display omitted] • DMSD volatilization in soil demonstrated in two steps: water moving up and DMSD desolvation. • DMSD volatilizes mainly as DMSD. • Some DMSD becomes non-extractable by binding to the topmost layer of soil upon drying. [ABSTRACT FROM AUTHOR]

Dimethylsilanediol (DMSD) is the degradation product of methylsiloxane polymers and oligomers such as volatile cyclic methylsiloxanes (cVMS). To better understand the environmental fate of this key degradation product, we conducted a three-part study on the movement of DMSD in soil. The objective of this third and final study was to determine the fate of DMSD in soil-plant systems under constant irrigation. Soil columns were constructed using two soils with the upper 20 cm layers spiked with 14C-labeled DMSD. Corn seedlings were transplanted into the soil columns and placed in a field plot underneath a transparent cover that prevented rainwater from reaching the soil columns while allowing soil water to be volatilized freely. The soil-plant columns were regularly irrigated with known amounts of DMSD-free plant growth solution to sustain the plant growth. At pre-determined time intervals (15–67 days), the plant and soil columns were sectioned and the distribution of 14Corganosilicon species in the soil profile and plant parts was determined using a combination of Liquid Scintillation Counting and High-Performance Liquid Chromatography-Flow Scintillation Analysis, while soil water loss was determined gravimetrically. It was found that the majority (>92 %) of DMSD initially spiked into the soil was removed from the soil-plant systems. Although DMSD was transported from the soil to the plant, it was subsequently volatilized from the plant via transpiration, with only a small fraction (∼5%) remaining at the conclusion of the experiments. In addition, little non-extractable DMSD was found in the top layer of soil in the soil-plant systems, suggesting that the air-drying of soil is a necessary pre-condition for the formation of such non-extractable silanol residue on topsoil. [Display omitted] • In the presence of plants, DMSD is found to be removed from irrigated soil via evapotranspiration process. • In contrast with bare soil, little non-extractable DMSD is found in the surface soil layer. • At any given time, only a small amount of the total spiked DMSD was found in plants. • DMSD concentration in the plant was found to decrease exponentially as the plant grew. • Speciation analysis suggests that most of DMSD was volatilized as DMSD. [ABSTRACT FROM AUTHOR]

Existing methods are difficult to directly treat the tailings of Lanping Pb-Zn deposit because of low Pb + Zn content. According to the characteristics of high CaO content (11%) in the flotation products of Lanping low-grade Pb-Zn oxide ore, a carbon thermal reduction method based on rotary hearth furnace (RHF) process was developed. When reaction temperature was above 1000 °C, CaO could realize the transformation of metal sulfides to oxides. Increasing reducing atmosphere was favor of the efficient volatilization of Zn and Pb and the trapping of S. The volatiles in reducing agents could promote the volatilization of zinc. The reduction effect of anthracite and thermal coal was better than that of charcoal. The volatilization rates of Zn and Pb exceeded 98% and 96%, respectively, under the conditions of 1250 °C, 30 min, 20% thermal coal addition and air atmosphere. High quality ZnO dust with a ZnO purity of 83% was obtained. [Display omitted] • Refractory lead‑zinc oxide ore (O-S mixed ore) were treated based on RHF process. • Efficient separation of Zn and Pb from gangue components was realized. • High sulfur fixation efficiency reduced the emission of SO 2 in the environment. • High-quality dust with a ZnO purity of >89% was obtained. [ABSTRACT FROM AUTHOR]

In this study, laser ablation-resistant composite coating consisting of zirconium diboride (ZrB 2) particulate and silicon carbide (SiC) whisker with zirconia (ZrO 2)-sol binder was prepared to meet requirements of anti-laser ablation ability. Laser ablation behavior of as-prepared coating was investigated under varying laser powers. Results revealed that the highest back-surface temperature of coated aluminum substrate was only 150 °C when irradiated at a power density of 6.3 kW/cm2 for 10 s, which is below the maximum allowable temperature of the aluminum alloy substrate (200 °C). After ablation for 10 s, the mass ablation rate of the composite coating was 4.45 mg/s. Apparently, the composite coating exhibited outstanding ablation resistance against high-intensity continuous laser irradiation. At initial stage of ablation, combination of self-healing effect of liquid ZrO 2 –SiO 2 layer and volatilization of B 2 O 3 provide effective joint protecting mechanism. With increasing ablation time, ZrO 2 ceramic barrier layer, product of the pyrolysis of ZrO 2 gel and ZrB 2 filler, becomes progressively more important in maintaining excellent laser ablation resistance behavior, which is normally effective at around ablation pit. [ABSTRACT FROM AUTHOR]

The International Simple Glass (ISG) spherical particles were prepared by Ar–H 2 radio-frequency (RF) plasma, the effect of experimental parameters on the volatilization and size distribution of spherical particles was studied. The results show that the spherical powders can be obtained by RF plasma. The spheroidized powders (112 μm) have a smaller diameter than starting particles (124 μm). The high spheroidization (98%) was achieved under low flow rate of carry gas and low feed rate. In addition, the volatilization of B 2 O 3 and Na 2 O are 23.48% and 56.36%, respectively. The higher feed rate and flow rate of carry gas, the lower volatilization of B 2 O 3 and Na 2 O and well-spheroidization rate. Meanwhile, the particle surface is not completely smooth at low flow rate of carry gas. The distribution of elements was studied by Electro-probe Microanalyzer (EPMA), which shows the distribution of element is nearly homogeneous that provides a possibility for subsequent research. [ABSTRACT FROM AUTHOR]

Oxidation of the Fe-base alloy T22 in humid air at 500 °C was investigated. The samples were exposed for up to 1000 h at 1 bar and 20 bar. The influence of three furnace tube materials, alumina, ET45 and quartz glass, on the oxide scale morphology was investigated. Samples and their cross sections were examined using optical microscopy, scanning electron microscopy, electron probe micro analysis and Raman spectroscopy. Multilayered oxide scales consisting of hematite, magnetite and Fe–Cr spinel were found on all samples. However, the composition and morphology of the oxide scales depend on the furnace tube material and on the system pressure. The system pressure is assumed to change the reaction equilibria and adsorption rates. The tube material changed the initial gas composition by formation of volatile Cr species. This volatilization rate increased at higher system pressures. [ABSTRACT FROM AUTHOR]

Thermomechanical and thermochemical stability of hafnon (HfSiO4) was evaluated for application as an environmental barrier coating (EBC) candidate for SiC/SiC CMCs. High‐temperature X‐ray diffraction (XRD) analysis showed that hafnon has an excellent coefficient of thermal expansion (CTE) match with SiC as well as minimal CTE anisotropy, which supports hafnon as an EBC candidate. Alternatively, high‐velocity water vapor testing at 1,200‐1,400°C showed large amounts of silica depletion from chemical reaction at all velocities and excessive material erosion at steam velocities greater than 190 m/s. HfSiO4 is therefore not suitable as an EBC for turbine applications due to insufficient thermochemical stability in water vapor‐containing combustion environments. [ABSTRACT FROM AUTHOR]

An experiment was carried out during four harvests (two in the cold season and two in spring) with the objective of determining the N losses by leaching and volatilization as well as their dynamics in a Brown Grayish soil in the Central Cuban region at the Experimental Station of Soil "Escambray" in corn crop. Six N levels were applied (0, 60, 120, 180, 240 y 300 kg ha-1 of N) a third of which with ammonium sulfate when planting and the remaining 35 days with urea. Volatilization of ammonium in form of ammonia was determined using Nömmik's method in levels 0, 120 and 240 kg ha-1 to 3, 7, 14, 21, 28 and 35 days after fertilization. The washing of NO3- and NH4+ was quantified using a lysimeter type Ebermeyer. Ammonia losses due to volatilization increased along with N doses in the two seasons, reaching its maximum level between the 3rd and 7th days after the second urea fertilization with values of 25 kg ha-1. NH4+ leaching was insignificant. while NO3- losses increased along with the doses and were approximately 13 % of the applied N reaching values of 47 kg ha-1 in the dose of 300 kg ha-1. It is concluded that in Brown Grayish soil the greatest losses due to ammonium volatilization occur with urea and the greatest leaching occurs in NO3-. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the Strata-X® sorbent, commonly used in cartridges, through analysis by high-performance liquid chromatography coupled with mass spectrometry. Due to the different physical-chemical characteristics of the compounds, different conditions of chromatography and mass analysis were necessary. The developed methods were validated in terms of selectivity, linear range, linearity (coefficient of determination, r2), the limit of detection (LOD), the limit of quantification (LOQ), accuracy (recovery, %), and precision (RSD, %). The results allowed us to select efficient extraction methods, using methanol acidified to pH 2 with formic acid, to elute the herbicides 2,4-D and dicamba in both sorbent materials. Besides, the Strata-X® sorbent was efficient in the sorption of analytes; thus, we indicate it for potential use in air sampling as an alternative to XAD-2. [ABSTRACT FROM AUTHOR]

Introduction: Nowadays, the heavy metals pollution is one of the most important environmental problems. Due to the high cost of common refining methods, the use of microbial biomass is recommended to clean up heavy metals. The aim of this study was to evaluate the interactions of Rhodoterula toruloides strain IR-1395 with mercury. Materials and methods: In this study, the growth rate and types of interactions of the strain IR1395 with mercury in the Sucrose Broth medium were investigated and the amount of mercury accumulated was measured using the Spectrophotometry method. Then, in order to determine the best biosorption conditions, the effect of parameters such as pH, mercury concentration, biomass concentration, contact time, and the temperature was measured. Also, the biosorption was investigated by treated cells with 2,4 dinitrophenol and autoclave. Finally, the biosorbent was characterized by Scanning Electron Microscope equipped with Energy Dispersive X-Ray Analysis. Results: Studies have shown that the maximum growth rate of the strain IR-1395 was after 36 hours and then it entered the stationary phase. Also, this strain was able to the biosorption and bioaccumulation (61.86%) and 10.17% biovolatilization of mercury from the medium at the concentration of 10 mg/l of chloride mercury for seven days. In examining the factors affecting the mercury biosorption, it was indicated that the optimal pH was 4. The highest biosorption was observed at 300 mg/l of mercury in 10 minutes at 15 ˚C. In the study of the effect of 2,4- dinitrophenol treatment and autoclave, it was found that mercury adsorption has reduced by the treated yeast. Finally, the results of the EDX confirmed the biosorption of mercury by this yeast. Discussion and conclusion: By examining the types of interactions of the strain IR-1395 with mercury and its potential in biosorption, it was found that this strain is a valuable microorganism in mercury bioremediation processes from contaminated aquatic environments. [ABSTRACT FROM AUTHOR]

This study presents an evaluation of the viability of using protected urea under different irrigation depths to reduce nitrogen losses caused by the volatilization of ammonia (NH3) under the conditions of the Southwestern Amazon. The study was carried out at the Experimental Station of Embrapa Rondônia, in the municipality of Porto Velho, Rondônia State, Brazil. The experiment was conducted in a Red-Yellow Latosol and arranged in a 5 x 6 factorial design consisting of a combination of five treatments (N sources) with six irrigation depths. The sources of N were as follows: 1) urea (45.5% N); 2) urea (44.3% N) + 0.15% copper and 0.4% boron; 3) urea (45% N) + NBPT; 4) urea (43% N) + sulfur (1%); and 5) control (without N). The irrigation depths were 0, 5, 10, 15, 20, and 25 mm. The results showed that, regardless of the use of urease inhibitors, an irrigation depth of 10 mm is suitable for incorporating urea into the soil and stabilizing N losses from NH3 volatilization. NBPT is the most efficient inhibitor under nonirrigated conditions. All N sources promote increases in the concentrations of nitric and ammonia nitrogen in the soil. In the first 15 days after fertilizer application, the highest concentrations of ammonium were in the 0 - 10 cm and 10 - 20 cm soil layers, and NBPT showed the highest ammonium content compared to that of the other sources in the 0 - 10 cm layer. The nitric nitrogen content in the soil was slightly influenced by the irrigation depth in the first 15 days after fertilizer application. However, the ammonia nitrogen content decreased exponentially with the increase in irrigation depth due to the movement of ammonia in the soil. [ABSTRACT FROM AUTHOR]

• Na volatilizes predominantly through the diffusion-controlled process. • B volatilizes through both diffusion-controlled and chemical reaction processes. • The loss of Na and B results in the higher fraction of BO 3 units and the more polymerized Si-O network. • The loss of Na and B causes the deterioration of the glass thermal stability. During nuclear waste vitrification, loss of sodium (Na) and boron (B) occurs, as these elements are highly volatile at high temperatures, which affects the properties of the glass products. Moreover, the evaporation of volatile nuclides (Cs and Tc) occurs together with that of Na and B, which may cause environmental hazards. Thus far, only a few studies have focused on the volatilization of Na and B from nuclear waste glass and loss-related effects on glass properties. In this study, we investigated the volatilization behaviors of Na and B from a simulated high-level waste glass as functions of heating temperature and dwelling duration, and evaluated the effects of Na and B loss on the glass structure and thermal stability. The results showed that volatilization of Na occurs predominantly through the diffusion-controlled process at a temperature range of 950 °C to 1100 °C, and owing to its higher frequency factor, Na diffuses and volatilizes at a faster rate than that of B. Volatilization of B occurs by both a diffusion-controlled process from bulk to the surface and a chemical reaction process on the surface. Based on the data obtained regarding the composition of Na and B and structure of the glass, a hypothetical model was proposed to explain the volatilization behaviors of Na and B from a structural viewpoint. As the loss of Na and B increases, the amount of BO 4 − reduces, whereas the amount of BO 3 increases; finally, the Si-O network becomes more polymerized and has less thermal stability, resulting in the crystallization of the glass at elevated temperatures. These results would serve as the basis to estimate the amount of Na and B loss and the properties of the glass melt during nuclear waste vitrification, especially in melter idling. [ABSTRACT FROM AUTHOR]

Three novel inorganic-organic hybrid materials, [PbI 3 (BTA-1)] n (1) (BTA-1 = N -((1 H -benzotriazole-1-yl)methyl)- N , N -dimethyl ethylammonium)，[Cu 2 I 3 (BTA-2)] n (2) (BTA-2 = 1-(1 H -benzotriazole-1-yl)- N , N , N -trimethylammonium carbamate) and [ZnI 3 (BTA-3)] n (3) (BTA-3 = 3-(1 H -benzotriazole-1-yl)- N , N , N -trimethylpropane-1-ammonium), have been was prepared by a solvent volatilization method. All three complexes have been characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analysis. Based on different metal iodides, they stack in different structural modes with different cluster cores, such as [PbI 6 ]2- in complex 1 , [Cu 4 I 6 ]2- in complex 2 and [ZnI 3 N]2- in complex 3. The fluorescence analysis show that complex 1 and 2 produced green light when the excitation wavelength was 318 nm and 328 nm, respectively. While complex 3 exhibited near white light when the excitation wavelength was 424 nm (CIE: 0.332, 0.395). It shows that complex 3 can be used as a white light emitting material for direct blue light excitation. By solvent volatilization method, three late-model inorganic-organic hybrid materials, [PbI 3 (BTA-1)] n (1)，[Cu 2 I 3 (BTA-2)] n (2) and [ZnI 3 (BTA-3)] n (3) (BTA = 1 H -benzotriazole), have been prepared. The fluorescence properties showed that complex 1 and 2 produced green light respectively. While complex 3 exhibited near white light (CIE: 0.332,0.395). It shows that complex 3 can be used as a white light emitting material for direct blue light excitation. [Display omitted] • Three luminescent inorganic-organic hybrid materials, 1 – 3 , have been was prepared by a solvent volatilization method. • Based on different metal iodides, they stack in different structural modes with different cluster cores, such as [PbI 6 ]2- in 1 , [Cu 4 I 6 ]2- in 2 and [ZnI 3 N]2- in 3. • This regulation realize complexes' emission from green light to near-white light. • Complex 3 exhibited near white light when excited at 424 nm. It shows 3 can be used as a white light emitting material for direct blue light excitation. [ABSTRACT FROM AUTHOR]

• Limestone and raw cement can reduce the volatilization rate of heavy metals. • Over 50% of heavy metals were transformed into residual state at 1400℃. • 80% of heavy metals remained in clinker and rest was in kiln dust. • Only very few of heavy metals was released into the exhaust flue gas. Cement kiln co-processing always became one of the predominate approaches to dispose hazardous solid waste containing heavy metals. The volatilization and morphology of heavy metals should be paid to more concern during the cement production due to the environmental risk of heavy metals. In this study, the volatilization characteristics and the solidification effect of heavy metals (Pb, Zn Cd and As) during cement kiln co-processing were explored by the lab and pilot scale experiments. At same experimental conditions, the volatilization rate followed as As > Pb > Cd > Zn. Both limestone and cement raw meal have been demonstrated the capability to mitigate the rates of heavy metal volatilization. Notably, cement raw meal displays a more pronounced effect compared to limestone in suppressing volatilization processes. Over 50% of heavy metals were transformed into residual state at 1400 °C, and Cd, As and Zn were easy to be solidified than Pb. A pilot scale experiment proved that more than 80% of heavy metals was solidified, and Zn reached nearly 100%. Moreover, around 80% of Cd, As and Zn were remained in clinker and the rest was distributed in kiln dust particles, only very few amount was released into the exhaust flue gas. This study provides a comprehensive and extensive understanding of the volatilization characteristics and migration patterns of heavy metals in the cement kiln environment. It offers theoretical support for the control of heavy metals during the co-processing of hazardous solid waste in cement kilns. [ABSTRACT FROM AUTHOR]

The intrinsic compatibility of silicon carbide (SiC) and hydrogen (H2) at high temperatures (2000‐2473 K) and pressure near one atmosphere was evaluated through a combination of thermodynamic calculations and hot hydrogen exposure testing. Thermodynamic calculations predict the decomposition of SiC in a hydrogen environment to form free silicon (Si) and free carbon (C). Free Si is predicted to vaporize from the surface as a volatile species, while free C may interact with H2 to form the hydrocarbons CH4 (T < 2100 K) or C2H2 (T > 2100 K). Coupons of high purity chemical vapor deposition (CVD) β‐SiC were exposed to slowly flowing hydrogen at temperatures ranging between 2000 and 2473 K. SiC experienced active attack as the result of H2 exposure, exhibiting linear weight loss kinetics and an Arrhenius dependence of weight loss on exposure temperature. The linear volatilization constant was experimentally evaluated to correspond with an activation energy of 370 ± 18 kJ/mol. Due to the dependence of observed corrosion rates on gas velocity, corrosion of SiC in flowing H2 was determined to be governed by external mass transfer of volatile Si species through the boundary layer. Experimentally derived mass losses were in good agreement with mass losses predicted by a boundary layer limited gas diffusion model. [ABSTRACT FROM AUTHOR]

In the enclosure method, ammonia volatilization from an enclosed soil is commonly estimated by hanging acid-soaked polyfoam pads over the soil sample in an enclosed bottle. Response surface methodology (RSM) was used to optimize polyfoam density (D), pad height (H) and pad saturation with an acid solution (S) to maximize ammonia collection in the polyfoam pads. Three central composite design (CCD) experiments with three polyfoams having low (0.013 g cm−3), medium (0.026 g cm−3), and high (0.037 g cm−3) D were conducted. The pads utilized had heights of 1.25, 2.50, and 3.75 cm saturated with an acid solution (9.8% H3PO3 plus 2% glycerol) to a weight of 5, 9, and 13 times that of the dry pad weight. Models developed for medium and high-density polyfoams were sufficiently reliable to predict ammonia collection response in terms of H and S. The response increased linearly with H and quadratically with S. High D pads collected about 13% more ammonia than that of low or medium D pads. The models predicted maximum ammonia collection in polyfoam pads of density 0.037 g cm−3, height 3.75 cm, and at acid saturation of 10.58 times of the dry pad weight. [ABSTRACT FROM AUTHOR]

The thermochemical stability of Y2Si2O7 was assessed in a high‐temperature high‐velocity water vapor environment to improve the understanding of the mechanisms that lead to SiO2 depletion. Spark plasma sintered Y2Si2O7 specimens were exposed in a steam‐jet furnace at 1000°C and 1200°C for 3‐250 hours, steam velocities of 131‐174 m/s and at 1 atm H2O pressure. These exposures resulted in the selective volatilization of SiO2 to form volatile Si(OH)4 and porous Y2SiO5. Microstructural evolution from fine rectangular pores at short times to larger rounded pores at longer times was observed. Mechanisms contributing to the overall depletion reaction kinetics were evaluated and include the interface reaction to form Y2SiO5 and Si(OH)4 (g), Y2SiO5 coarsening, development of tortuosity in the pore network and diffusion of H2O (g) and Si(OH)4 (g) through pores by molecular diffusion and/or Knudsen diffusion. SiO2 depletion was found to follow parabolic volatilization kinetics (kp = 0.38 µm2/h) at 1200°C indicating the reaction is limited by a diffusion process, most likely the outward diffusion of Si(OH)4 (g) through pores. Results are utilized to assess the viability of Y2Si2O7 and other rare‐earth silicates as environmental barrier coating (EBC) materials for SiC ceramic matrix composites (CMCs). [ABSTRACT FROM AUTHOR]

• The volatilization rate of HCN is an essential factor in photocatalytic cyanide treatment. • Cyanide can be oxidized with TiO 2 using solar light. • The photocatalytic degradation rate is exceeded by volatilization at a pH < 9. • The photocatalytic degradation rate increases with decreasing pH. • The thermodynamic driving force is the main factor governing the photocatalytic oxidation rate. Detoxification of waste water from gold processing is under increasing discussion in recent times. Limits for the release of cyanide are set to protect waterbodies and the soil surrounding gold processing facilities from contaminations. Standards and limits are often based on varying data of the hazardousness. Notably concerning the volatilization of hydrogen cyanide and further reactions of HCN in the environment a variety of findings are published, with data, wide apart from each other, which influence the assessment of the hazard particularly for the workers in processing facilities. Likewise, the determination of the proper amount of volatilized cyanide in degradation experiments is essential for the accurate identification of the degraded part. In photoelectrocatalytic experiments, using TiO 2 films, light, and moderate electrical bias, the volatilization and the degradation rate of cyanide were determined at different pH. It is shown that the volatilization rate at pH < 9 is predominant and cannot be neglected up to pH 13. Indirect vs. direct hole transfer on the semiconductor are discussed. With a new approach to the discussion of the comparability for different photocatalysts and varying experimental conditions we indicate a relationship between the rate constant of the degradation reaction and the difference of the energy of the valence band of the photocatalyst to the redox potential of oxidizable species. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are major pollutants in air, soils and sediments. PAH-polluted soils can be cleaned rapidly by thermal treatment. PAH volatilization is considered as the main process explaining PAH removal at low temperature, yet other processes may occur. Particularly, we hypothesize that thermal transformation can also explain PAH removal, where transformation refers to both degradation and formation of bound PAHs. We thus studied the removal of spiked benzo[a]pyrene at 0.5 mg/g in bauxite soil, fluvo-aquic soil, chernozem soil, montmorillonite, humin, and quartz sand as control, from 100 to 200 °C. We measured concentrations of benzo[a]pyrene in the volatilized fraction and solid residues by high-performance liquid chromatography. We identified transformation products by gas chromatography–mass spectrometry. Results show that the contribution of thermal transformation to the removal of benzo[a]pyrene increased from 24.7 to 58.4 wt% for bauxite soil, from 4.4 to 38.2 wt% for fluvo-aquic soil, and from 11.5 to 35.9 wt% for chernozem soil, with temperature increasing from 100 to 200 °C. Transformation such as oxidation occurred in all samples except in benzo[a]pyrene-spiked quartz sands. Transformation of benzo[a]pyrene was thus partly explained by the presence of clay minerals, as evidenced for the montmorillonite assay where transformation contributed 74.6 wt% to the total removal of benzo[a]pyrene at 200 °C. Overall, our findings demonstrate a major overlooked contribution of transformation to PAH removal at low temperature. [ABSTRACT FROM AUTHOR]

Pesticide residues are one of the major food safety concerns for consumers all over the world, and it is crucial to develop simple, rapid, and effective method for the detection of pesticide residues. In the study, we report the sensitive detection of pesticides with the dynamic surface‐enhanced Raman spectroscopy (dynamic SERS) method. The dynamic SERS method provides excellent detection sensitivity at the metastable state of plasmonic nanoparticles in the sessile drop, which is a critical state between the wet state and dry state during the volatilization process. With this simple and rapid method, the SERS performance towards four pesticides, paraquat, thiabendazole, tricyclazole, and isocarbophos, is investigated with silver nanoparticles (AgNPs) as the enhancing reagents. The characteristic SERS spectra of paraquat, thiabendazole, tricyclazole, and isocarbophos can be detected at concentrations down to 1 × 10−9 M, 5 × 10−9 M, 5.28 × 10−9 M, and 3.45 × 10−7 M, respectively. The pesticides are also discriminable at the same concentrations as the standard solution counterparts from the pesticides spiked vegetable extracts, and linear relationship can be drawn from the characteristic peak intensities and negative logarithm of concentrations of the four pesticides. Therefore, the simple and rapid dynamic SERS method shows great potential in the practical detection of pesticide residues. [ABSTRACT FROM AUTHOR]

The effects of steam pressure, velocity, and composition on SiC oxidation kinetics were studied. Pressure effects were tested at 1200°C from 0.1 to 1.4 MPa at a steam velocity of 0.25 cm/s. Velocity effects were tested in two furnaces at 0.45 MPa, 1200°C and 0.1 MPa, 1600°C with velocities ranging from 0.25 to 137 cm/s. Steam composition was altered by changing the reaction vessel material. Oxide morphology and composition were determined using optical and electron microscopy, and X‐ray diffraction. Porous oxides were observed whenever structural SiC from the reaction vessel saturated the steam with volatilized silica, H2, and CO. Oxidation kinetics were calculated by the change in SiC thickness. The steam velocity/recession rate followed a power‐law relationship of ~ 0.35 while the steam pressure/recession rate followed a power‐law relationship of ~ 1.78. [ABSTRACT FROM AUTHOR]

Slow pyrolysis characteristics of agricultural residue feedstocks (corn brakes, wheat straw, and hazelnut shell) were investigated by simultaneous thermal analysis (STA–TG–DTG–DSC), coupled with mass spectrometry (MS). Thermal decomposition of agricultural residues was divided into three stages, corresponding to removal of water, devolatilization, and formation of bio-char. It was found that differences in thermal behavior of samples are due to differences in their composition. The MS results showed that H2, CH4, H2O, CO2 (C3H8), CO, and C2H6 were the main gaseous products released during pyrolysis. It was shown that hazelnut shells could be a good combustion fuel, since during its pyrolysis at high temperature, more gaseous products compared to other systems are very favored. For hazelnut shell pyrolysis, the CO2 can be used on the large scale for the production of CO-rich syngas. [ABSTRACT FROM AUTHOR]