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The research and development of absorbing materials with high absorbing capacity, wide effective absorption bandwidth, and lightweight has always been interesting. In this research, a facile hydrothermal method was used to prepare MnFe2O4, and the grain size of MnFe2O4 decreased with increasing hydrothermal temperature. When the size of MnFe2O4 nanoparticles is less than 10 nm, its quantum size effect and surface effect make its electromagnetic microwave absorption performance greatly optimized. When the thickness of MnFe2O4-110 °C is 2.57 mm, the minimum reflection loss (RLmin) is −35.28 dB. Based on this, light porous diatomite and a three-dimensional polyaniline network are introduced. Diatomite is used as the base material to effectively reduce the agglomeration of MnFe2O4 quantum dots. The relatively high surface area introduced by a three-dimensional network of polyaniline promotes the orientation, interfacial polarization, multiple relaxation, and impedance matching, thereby generating further dielectric loss. Additionally, the magnetic properties of manganese ferrite and the strong electrical conductivity of polyaniline play an appropriate complementary role in electromagnetic wave absorption. The RLmin of MnFe2O4/PANI/diatomite is −56.70 dB at 11.12 GHz with an absorber layer thickness of 2.57 mm. The effective frequency bandwidth (RL < −10 dB) ranges from 9.21 to 18.00 GHz. The absorption mechanism indicates that the high absorption intensity is the result of the synergistic effect of impedance matching, conduction losses, polarization losses, and magnetic losses. [ABSTRACT FROM AUTHOR]

Alkali dissolution is an effective method to regulate the pore structure of porous mineral material. The main chemical composition of diatomite is amorphous SiO 2 , which can be dissolved in alkali dissolution. The diatomite samples with alkali dissolution treatment were systematacially characterized by the particle size analysis, low temperature nitrogen adsorption, MIP, fractal theory, SEM, TEM, XRD, FTIR and surface hydroxyl density to analyze the pore structure and surface properties. And the humidity control performance of diatomite was tested under different temperatures and relative humidities. The relationship among pore structure, surface properties and humidity control performance were analyzed. The results show that alkali dissolution can regulate the mesoporous and macroporous of diatomite, and some new microporous can generate at high alkali dosage. The specific surface area, mesoporous pore volume, proportion of macroporous volume, surface roughness, heterogeneity of pore structure and number of hydroxyl groups on the surface of diatomite are important factors which determining the humidity control performance. The humidity control performance of diatomite is positively correlated with the specific surface area, mesoporous volume, surface roughness, heterogeneity of pore structure and number of hydroxyl groups on the surface, while is negatively correlated with the proportion of macroporous volume. [ABSTRACT FROM AUTHOR]

We have developed a new method for measuring mass dependent Si isotope fractionation via critical mixture double-spiking. Samples need to be spiked before column chemistry to guarantee full equilibrium between the sample and double-spike (29Si–30Si spike). An iterative addition of the double-spike to the sample, usually 2–4 times, is needed to generate a solution very close to the critically spiked mixture. We use a double-pass cyclonic quartz spray chamber, as it gives the highest signal-to-noise ratio. In conjunction with 6 μg ml−1 Si solution to yield intense Si isotope beams, this setup results in an ∼25 V (with 1011 Ω resistor) signal on 28Si+, while on-peak noise is less than 0.06 V. A typical sample analysis comprises 8 repeats (n = 8) of an individual sample measurement (for each repeat n = 1, 168 second analysis time) normalised to bracketing measurements of critically double-spiked NIST SRM 8546 (commonly known as NBS28). Each of these n = 8 analyses consumes about 13 μg of sample Si and yields a mean δ30/28Si with a precision of approximately ±0.03‰ (2 s.e., 2 × standard error of the mean). Over a 16 month period, the reproducibility of the 11 mean δ30/28Si values of such n = 8 analyses of the silicate reference material BHVO-2 is ±0.03‰ (2 s.d., 2 × standard deviation), which is 2 to 8 times better than the long-term reproducibility of traditional Si isotope measurement methods (∼±0.1‰, 2 s.d., δ30/28Si). This agreement between the long-term and short-term variability illustrates that the data sample the same population over the long and short terms, i.e., there is no scatter on the timescale of 16 months additional to what we observe over twenty hours (the typical timescale in one analytical session). Thus, for any set of n repeats, including n >8, their 2 s.e. should prove a useful metric of the reproducibility of their mean. Three international geological reference materials and a Si isotope reference material, diatomite, were characterised via the critical mixture double-spiking technique. Our results, expressed as δ30/28SiNBS28, for BHVO-2 (−0.276 ± 0.011‰, 2 s.e., n = 94), BIR-1 (−0.321 ± 0.025‰, 2 s.e., n = 27), JP-1 (−0.273 ± 0.030‰, 2 s.e., n = 19) and diatomite (1.244 ± 0.025‰, 2 s.e., n = 20), are consistent with literature data, i.e., within the error range, but much more precise. [ABSTRACT FROM AUTHOR]

Glycidyl methacrylate (GMA) was grafted onto diatomite (DE) to improve the interfacial bonding between GMA and rubber using "one-step"/"two-step" methods, respectively. The hydroxyl group on DE and the amine group on γ-aminopropyltriethoxysilane (KH550) react with the epoxy group on GMA in a ring-opening reaction during the process. The modified diatomite was characterized and analyzed by using Fourier transform infrared spectroscopy (FT-IR), X-ray fluorescence spectrometer (XRF), X-ray diffraction patterns, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Natural rubber/diatomite (NR/DE) composites were also prepared using a wet mixing method and investigated the interfacial interactions between different DE and NR in detail using dynamic mechanical analysis (DMA) and rubber process analyzer (RPA). The result showed the improved mechanical properties of NR/DE composites for both "one-step" and "two-step" methods; however, the "two-step" method is found to be more effective. Compared with the unmodified NR/DE composites, the "two-step" modified NR/DE composites exhibited an increase in 37.8% tensile strength, 25.1% tear strength, 11.7% abrasion resistance, and 24% wet slip resistance, respectively. In addition to these, GMA has minimal effect on the elongation at break retention of the rubber composites after aging. These results showed valuable insights for the further application of diatomite in rubber. [ABSTRACT FROM AUTHOR]

Diatoms are photosynthetic microalgae widely diffused around the globe and well adapted to thrive in diverse environments. Their success is closely related to the nanostructured biosilica shell (frustule) that serves as exoskeleton. Said structures have attracted great attention, thanks to their hierarchically ordered network of micro‐ and nanopores. Frustules display high specific surface, mechanical resistance and photonic properties, useful for the design of functional and complex materials, with applications including sensing, biomedicine, optoelectronics and energy storage and conversion. Current technology allows to alter the chemical composition of extracted frustules with a diverse array of elements, via chemical and biochemical strategies, without compromising their valuable morphology. We started our research on diatoms from the viewpoint of material scientists, envisaging the possibilities of these nanostructured silica shells as a general platform to obtain functional materials for several applications via chemical functionalization. Our first paper in the field was published in ChemPlusChem ten years ago. Ten years later, in this Perspective, we gather the most recent and relevant functional materials derived from diatom biosilica to show the growth and diversification that this field is currently experiencing, and the key role it will play in the near future. [ABSTRACT FROM AUTHOR]

Laboratory tests and semi-field evaluation were carried out to examine the acaricidal effect of four concentrations of diatomaceous earth (DE) and sulfur against four mites: Tetranychus urticae (Tetranychidae), Rhizoglyphus echinopus (Acaridae), Tyrophagus putrescentiae (Schrank) (Acaridae), and Amblyseius swirskii (Phytoseiidae). Results revealed that mortality increased as both time and concentration increased. Tetranychus urticae was the most affected mite; LC50 values were 70.4 and 92.0 for immature and adult stages, respectively, after 7 days. For the LC50 concentrations examined, a significant decrease in the total number of immature and adult stages of all mites during seven days was noticed. Under semi-field conditions, the LC50s were calculated for (DE) and sulfur against T. urticae on cucumber plants. The reduction percentage of T. urticae was 66.67 and 50% for (DE) and sulfur, respectively, after seven days of application, with significant differences. [ABSTRACT FROM AUTHOR]

The use of bio‐based building blocks for the synthesis of polymers is increasing day by day. Coatings prepared by modifying bio‐based building blocks such as linseed oil (LO) and diatomaceous earth (DE) are very promising. In this study, bio‐based hydrophobic coatings were prepared by cationic photopolymerization technique using epoxidized linseed oil (ELO) and dimer diamine‐modified diatomaceous earth. The bio‐based coatings with hydrophobic properties were prepared by using the spin coating method. ELO was characterized by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H‐NMR). The thermal properties of the prepared coatings were determined by thermogravimetric analysis (TGA). The pendulum hardness, pencil hardness, and gel content of the prepared coatings were examined. Also, the hydrophobicity of the obtained bio‐based coatings was determined by contact angle measurements. The highest contact angle among the investigated compositions was found to be 110°. [ABSTRACT FROM AUTHOR]

Diatomite's most common application is its use as a sorbent for petroleum substances. Since paraffin is a petroleum derivative, this paper investigates the sorption capacity of diatomite to absorb it. In this paper, the physical and chemical properties were studied for 4 different fractions of diatomite (0–0.063 mm; 0–2 mm; 0.5–3 mm; and 2–5 mm) in the crude and calcined states, and the sorption capacity of diatomite earth for absorbing paraffinic phase-change substances was determined. The physical and chemical studies of the material included conducting an oxide chemical composition analysis using XRF, examining the composition of the mineral phases using X-ray diffraction, and determining the particle size, porosity, and thermal conductivity of the diatomite. Morphology images were also taken for all 8 diatomite variants using scanning electron microscopy. Each fraction was subjected to static calcination at 850 °C for 24 h. The results showed that the calcination of the diatomite increased the porosity of the material and reduced the thermal conductivity coefficient, and most importantly, the sorption capacity to absorb paraffins. The highest sorption capacity was characterized by calcined diatomite powder, that is, diatomite with the smallest particle size. Absorption of paraffinic substances by diatomite exceeding 200 wt.% is possible. Thus, diatomite is one of the feasible candidates for an economical and lightweight building material for making PCM composites for thermal energy storage in buildings. [ABSTRACT FROM AUTHOR]

The detection of impurities in diatomite is a critical issue during the silicon extraction process. Impurities can significantly impact the properties of silicon, compromising the performance of Si solar cells. In the present work, we applied a sensitivity-improved calibration-free LIBS measurement approach to assess the quality of diatomite. Based on the recording of two spectra with different delays between the laser pulse and the detector gate, the method enables the quantification of major, minor, and trace elements. The limits of detection for minor and trace elements were evaluated. Furthermore, we investigated the morphology and properties of the diatomite surface using Energy-Dispersive X-ray Spectroscopy and Scanning Electron Microscopy analysis. This research contributes to process optimization in the fabrication of electronic grade silicon from diatomite for photovoltaic technology and other applications. [ABSTRACT FROM AUTHOR]

In this paper, the results of the technological combustion of SHS heat insulators based on mineral origins are presented. It is shown that after mechanochemical treatment of minerals—diatomite—the kinetic characteristics of the combustion process change, providing targeted formation of the phase composition, structure, and properties of the SHS composite. A positive effect of using various modifiers during the MCT of diatomite—the activation of the combustion process—was established. The selection of modifiers provides an increase in the strength of the synthesized SHS composites as a result of the formation of aluminate compounds in the synthesis products, and a decrease in thermal conductivity to 0.157 W/m*K due to the formation of the ultraporous structure of the samples. [ABSTRACT FROM AUTHOR]

BACKGROUND: Over the past two decades, bed bugs (Cimex spp.) have resurged as common urban pests around the world. The search for efficient and safe control measures has become a key interest among researchers, manufacturers, and pest control professionals. In this study, we evaluated and compared the efficacy of steam, diatomaceous earth (DE) dust, and a combination of both against tropical bed bugs (Cimex hemipterus (F.)) under laboratory and field conditions. RESULTS: In the laboratory study, the mortality of bed bugs after 2 days of exposure to DE dust was 100%. When bed bugs stayed on the surface of an object or in cracks, a brief steam treatment (1 s) caused 100% mortality. However, when bed bugs were hidden under a fabric cover, steam application for 10 s only caused 89 ± 6% mortality. Bed bugs that survived steam treatment exhibited reduced feeding activity. In a 14‐week long study, there was no significant difference in the reduction rate of bed bugs between steam treatment and DE dust treatment. A 37‐week long control study showed that steam and steam plus DE dust treatments eliminated 97–100% of the infestations. CONCLUSION: Applying steam and DE dust are effective strategies for eliminating natural tropical bed bug infestations. Continuous follow‐up monitoring and treatment until no bed bugs are found are crucial in completely eliminating the infestation of tropical bed bugs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To study the remediation effect of sapindus soap liquid modification and combination of passivating agents on Pb and Cd contaminated soil, a polluted soil in Fujian was selected as the research object, the application test method was used to study the influence of modified diatomite and different materials on the change of soil available state content. The results showed that the passivation effect of diatomite after the synergistic modification of sapindus soap liquid and ferrous sulfate was better than that of single diatomite. Among the three compound passivators, when the ratio of LSYT-G+CaO was 7 : 3, the overall passivation effect on the effective Pb and Cd in the contaminated soil was better, the effective states of Pb and Cd decreased by 45.86% and 58.86%, respectively, and the pH increased by 2.68 compared with the control. The passivating agent showed a good repairing effect. According to the fitting results of Langmuir and Freundlich isotherm adsorption models, it was found that the adsorption process of LSYT-G+CaO on Pb2+ and Cd2+ was mainly single-layer adsorption; the adsorption of Pb2+ and Cd2+ by LSYT-G+activated carbon and LSYT-G+phosphorus slag composite materials was mainly a multi-layer adsorption process on heterogeneous surfaces. [ABSTRACT FROM AUTHOR]

Essential oils are interesting active additives for packaging manufacturing as they can provide the final material with active functionalities. However, they are frequently volatile compounds and can be degraded during plastic processing. In this work Rosmarinus officinalis (RO) essential oil was encapsulated into Diatomaceous earth (DE) microparticles and into Halloysite nanotubes (HNTs) and further used to produce eco-friendly active packaging based on polylactic acid (PLA). PLA-based composites and nanocoposites films based on PLA reinforced with DE + RO and HNTs + RO, respectively, were developed by melt extrusion followed by cast-film, simulating the industrial processing conditions. As these materials are intended as active food packaging films, the obtained materials were fully characterized in terms of their mechanical, thermal and structural properties, while migration of antioxidant RO was also assessed as well as the compostability at laboratory scale level. Both DE and HNTs were able to protect the Rosmarinus officinalis (RO) from thermal degradation during processing, allowing to obtain films with antioxidant properties as demonstrated by the antioxidant assays after the materials were exposed for 10 days to a fatty food simulant. The results showed that incorporating Rosmarinus officinalis encapsulated in either DE or HNTs and the good dispersion of such particles into the PLA matrix strengthened its mechanical performance and sped up the disintegration under composting conditions of PLA, while allowing to obtain films with antioxidant properties of interest as antioxidant active food packaging materials. [ABSTRACT FROM AUTHOR]

Diatomites are well-known mineral materials formed thousands of years ago from the skeletons of diatoms. They are found in many places around the world and have a wide range of applications. This article presents innovative research related to the possibility of using diatomite as a filler in composites to improve their sound absorption properties. The results of the study of the effect of diatomite processing (calcination) and its degree of fineness on the sound absorption coefficient of thermoplastic composites are presented. Three fractions of diatomite (0 ÷ 0.063 mm; 0.5 ÷ 3 mm; 2 ÷ 5 mm) and its variable mass proportion (0, 25, and 50 wt.%) were used. The composites were made with flax fibers as a reinforcement, polylactide as a matrix, and diatomite as an additional filler. This paper also presents the results of oxide chemical composition, diatomite mineral phase composition, morphology, and thermal conductivity coefficient of all diatomite fractions studied. In addition, the average particle size for diatomite powder was also determined. The most important of the studies was the determination of the acoustic properties of the aforementioned composites. As a result of the tests, it was found that the smallest fraction of diatomite particles and a variant without thermal treatment give the best effect in terms of sound absorption. [ABSTRACT FROM AUTHOR]

In the production of refined sunflower oil, waxes are removed during the winterization stage, and wax crystals are separated through filtration assisted by filtration aids. Commonly used filtration aids in oil refining include perlite and diatomaceous earth. After winterization, a significant amount of filter cake remains as a by-product and is treated as waste. Today, natural cellulose fibers are being promoted as filtration aids. Their advantages are numerous, both in the production process and from an environmental perspective. However, their only disadvantage is their higher cost. Therefore, in this study, 57 filtration cycles during the industrial sunflower oil winterization step using cellulose-based filtration aids were monitored. Different process parameters, including the pressure differential on the filter, the flow rate of filtered oil, constant pressure period, the quantity of filtered oil, filtration time, the quantity of pre-coating and dosing filtration aids, the volume of filtered oil, the concentration of dosing filtration aid, as well as the mass of separated waxes, were observed. Additionally, artificial neural networks were applied to predict process parameters, optimize the process, and, above all, determine the dosage of filtration aids, which will make the process more economical. The optimal filtration process is performed at a pressure differential of 3.3 bar, lasting a total of 39 h, with 32 h at constant pressure, resulting in 322,503 kg of filtered oil and 90.41 kg of waxes. The optimal quantity of cellulose-based filtration aids employed for pre-coat was 80 kg, and for dosing, 375 kg, with an optimal concentration of 0.12% w/w. [ABSTRACT FROM AUTHOR]

Natural minerals play a key role in the burgeoning field of mineral-reinforced polymers, providing an important element in strengthening and toughening the properties of composite materials. This article presents a comprehensive overview of the use of minerals in mineral-reinforced polymers, covering various aspects of their applications and impact on the final properties of these materials. The potential of various types of natural minerals (for example talc, montmorillonite, halloysite, diatomite) as reinforcements in mineral-reinforced polymers is discussed. Techniques for producing mineral-reinforced polymers using minerals, including the mixing method, impregnation, and coating application, are presented in detail. In addition, the effects of process parameters and component ratios on the final properties of mineral-reinforced polymers are discussed. The latest research on the use of minerals in mineral-reinforced polymers is also presented, including their effects on the strength, stiffness, resistance to environmental conditions, and biodegradation of the materials. Finally, the development prospects and potential applications of mineral-reinforced polymers with minerals in various industrial sectors, including packaging, automotive, construction, and medicine, are discussed. [ABSTRACT FROM AUTHOR]

Background: Tick-borne diseases are an emerging threat to public health throughout the temperate world, leading to a growing field of research aimed at developing and testing intervention strategies for reducing human-tick encounters or prevalence of infection in ticks. Various wide-spectrum chemical acaricides have proven effective for controlling tick populations, but many of these have potential deleterious side-effects on health and the environment. In addition to chemical acaricides, certain compounds such as diatomaceous earth have been shown to have physical acaricidal properties. We hypothesized that dolomitic lime (CaMg(CO3)2, a corrosive, desiccant mineral that is already used extensively in agricultural and forestry contexts to balance the pH of soils, may affect ticks' locomotory activity, habitat position, or survival and that this should manifest as a reduction in the number of questing ticks collected by dragging. Objective: This study aimed to formally assess this hypothesis in a controlled laboratory setting. Methods: We carried out a microcosm experiment, with one control and three treated microcosm trays, each replicating the natural substrate characterizing I. scapularis habitat in northeastern North America. Each tray was infested with 200 living larvae and 50 nymphs, and then treated with 0 (control), 50, 100, or 500 g/m2 of lime powder. Ticks were collected by microdragging 24 and 72 h postliming. Results: Efficacy of liming at reducing the number of collected questing ticks ranged from 87% to 100% for larvae and 0% to 69% for nymphs 24 h postliming and from 91% to 93% for larvae and −47% to 65% for nymphs 72 postliming. Conclusion: This study provides the first experimental evidence of the potential efficacy of liming for impairing activity of questing immature ticks. Given that lime is a low-cost material, that methods for widespread application in deciduous woodlands already exist, and that it has been documented as having a limited negative impact on the environment, further assessment of lime application as a public health risk reduction intervention for tick-borne diseases is warranted. [ABSTRACT FROM AUTHOR]

Summary: In order to better preserve phospholipids (PLs)‐type polyunsaturated fatty acids (PUFAs) and astaxanthin (ASTA), Antarctic krill oil (AKO) undergoes only limited refining steps, which results in the presence of metal ions. This study aims to establish a metal ion removal method for AKO by using adsorbents and investigate the effects of the metal ion removal process on nutritional composition, oxidation state and colour of AKO, as well as the effects of metal oil removal of AKO on its nutrition composition, oxidation stability and colour stability upon accelerated storage. Among the three types of adsorbents including silica gel, diatomaceous earth, and attapulgite soil, the last one showed the best comprehensive removal effects. After optimising the removal conditions, attapulgite soil achieved the removal rates of 92.5%, 90.0%, and 86.4%, respectively, for iron ions, magnesium ions and calcium ions. Compared to the fresh AKO, the processed AKO had no significant differences in peroxide value (POV), thiobarbituric acid reactive substances (TBARS), and total oxidation value (TOTOX), as well as PUFA content and lipid class composition, indicating that the metal ion removal process would not cause significant lipid oxidation. Moreover, the processed AKO looks brighter and more transparent, and had higher detection values in L*, a*, and b* but lower UV‐vis absorption at 295 nm (A295) and 420 nm (A420). This indicated that the metal ion removal process improved the colour quality. After accelerated storage at 60 °C for 8 days, the processed AKO sample had significantly lower values in POV, TBARS, and TOTOX, but significant higher PUFA content than the fresh AKO group. Moreover, the processed AKO sample had the higher values of L*, a*, and b*, as well as A470 and A495, but the lower values of A295 and A420. The above results indicate that the removal of metal ions significantly improved the stabilities of oxidation and colour of AKO. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the potential for producing an aromatic hydrocarbon-enriched fuel from Scenedesmus sp. microalgae using low-cost zeolite in catalytic flash pyrolysis. The methodology adopted in this study involved the use of an analytical micropyrolyzer coupled with a gas chromatograph/mass spectrometer at 500 ºC to assess the effectiveness of the low-cost HZSM − 5 catalyst in deoxygenation, denitrogenation, and aromatization activities of volatile reaction products. The HZSM − 5 catalyst was synthesized using the hydrothermal method, employing low-cost precursor materials, rice husk ash, and diatomite residue as alternative silicon and aluminum sources. The oxygenated and nitrogenated volatile products in non-catalytic flash pyrolysis constituted 51.7% and 15.3%, respectively. Catalytic upgrading of pyrolysis vapors from Scenedesmus sp. microalgae was demonstrated by significant deoxygenation and denitrogenation activity, reaching up to 99%, while chemical industry-relevant classes experienced increased proportions: aromatic hydrocarbons by 5.8-fold, and aliphatic hydrocarbons by 1.7-fold. Around 78% selectivity for aromatic hydrocarbons was achieved, predominantly yielding BTEX (benzene, toluene, ethylbenzene, and xylene). Another significant finding is that 89.8% of the renewable hydrocarbons produced fall within the gasoline range (C5 − C12). This study conclusively indicates that the low-cost HZSM − 5 catalyst shows significant promise for producing high-quality bio-oil through the flash pyrolysis of Scenedesmus sp. microalgae. [ABSTRACT FROM AUTHOR]

This study investigates the application of a novel approach involving reversible crosslinking reaction agent (RXR) and diatomaceous earth to enhance the properties of isotactic polybutene‐1 (PB‐1) resin. The present study diverges from conventional methods by focusing on the combined effects of these two additives on various attributes, including rheological, mechanical, thermal, structural, and morphological properties. A unique crosslinking approach involving a combination of sulfur, accelerator, and peroxide was employed to change the surface of diatomaceous earth, yielding promising results. The rheological investigations revealed that the RXR agent led to a substantial increase in viscosity as a result of a crosslinking reaction, while diatomaceous earth had a minimal impact. The incorporation of both compounds led to a significant reduction in mechanical properties. The addition of diatomaceous earth filler demonstrated anti‐nucleating characteristics, leading to a reduction in both the temperature at which crystallization occurs and the extent of crystallinity. In contrast, the RXR agent has demonstrated an increase in crystallization temperature. The use of diatomaceous earth filler led to a substantial enhancement in thermal stability. Furthermore, FTIR and WAXS analysis revealed that neither diatomaceous earth nor the RXR agent caused significant alterations in crystalline modification. The SEM micrographs revealed the clustering of diatomaceous earth filler, which is likely due to inadequate interactions between the filler and the matrix, explaining the decrease in mechanical characteristics that was found. Highlights: RXR increases viscosity significantly via crosslinking.Both agents decrease mechanical properties.Diatomaceous earth reduces crystallization temperature and degree.Diatomaceous earth filler enhances thermal stability in PB‐1 resin. [ABSTRACT FROM AUTHOR]

In this study, the composite materials based on the incorporation of diatomite of graphene oxide (GO)/reduced graphene oxide (rGO/diatomite) were developed and characterized by different techniques (SEM, XRD, FTIR and BET). Developed composites were used for the first time in the removal of uranium ions from aqueous solutions. In adsorption studies, parameters affecting the adsorption efficiency such as solution pH, temperature, contact time and initial U(VI) concentration were investigated using full factorial experimental design (FFED). ANOVA (analysis of variance) analysis within the 95 % confidence interval of the model applied to control the compatibility of the model and the experimental findings was examined. Langmuir, Freundlich and Temkin isotherms were used to determine the adsorption model and related parameters were calculated. In addition, adsorption thermodynamic parameters such as enthalpy, Gibbs free energy change and entropy were calculated. The uranium removal behaviour on GO/diatomite and rGO/diatomite was better characterized by the pseudo-second order and Langmuir models, indicating that uranium ions were chemically adsorbed onto composite materials. Additionally, it was observed that higher temperatures promoted the uranium removal on GO/diatomite and rGO/diatomite, suggesting that the removal process was a spontaneous endothermic and exothermic reaction, respectively. In addition, the adsorption of U(VI) with GO/diatomite and rGO/diatomite was investigated using density functional theory (DFT) study. Configuration and adsorption energy were determined. The GO/diatomite composite materials can be a promising candidate as an adsorbent for the removal of uranium from aqueous solutions. [ABSTRACT FROM AUTHOR]

The investigation of "Inert Minerals and Botanicals Synergism with Spinosad: co-toxicity against Callosobruchus maculatus in Stored Blackgram" was performed in the Laboratory of the Department of Entomology, Agricultural College, Bapatla, during 2020-21. The inert minerals and botanicals were mixed with Spinosad and used for the bioassay. The data were recorded at 24, 48 and 72 hours after the release of the test insect, and probit analysis was performed to calculate the LD50. By using the LD50 of inert minerals and botanicals alone and in combination with spinosad, the co-toxicity coefficient was calculated. Among all the treatments, the highest co-toxicity coefficient (433.33) was recorded for diatomaceous earth, indicating increased efficacy and synergism between diatomaceous earth and Spinosad. [ABSTRACT FROM AUTHOR]

Bees play an essential role in the sustainability of terrestrial and agricultural ecosystems as pollinators. However, external factors such as pesticides can negatively affect both bees and plants pollinated by bees, as well as human health. Therefore, less toxic or non-toxic plant protection products have become a popular research topic for a sustainable environment. The purpose of this study was to determine the effects of four different commercial products of diatomaceous earth (Bio, Demite, Detech, Detech WP) on workers of Apis mellifera and Bombus terrestris under controlled laboratory conditions. Each diatomaceous earth product was sprayed on the bees as dust particles for 15 seconds at Maximum Field Dose (10 g/m2). While the worker bees in positive control groups (control +) were exposed to flour, those in the negative control groups (control –) were not exposed to any treatment. The highest mortality rates for B. terrestris and A. mellifera were 22% in Detech WP and 16% in Demite, respectively. However, since mortality rates were under 25% for all the tested DE products, they were classified as harmless for both bee species. Additionally, the direct effect of diatomaceous earth products on honey bees and bumble bees was revealed for the first time in this study. [ABSTRACT FROM AUTHOR]

The research was planned to determine the usability of natural diatomite in aquaculture conditions. The effects of using two different sizes and three different amounts of raw diatomite mineral on aquaculture water parameters for freshwater species and their usage characteristics were investigated. The research was carried out in two separate stages. In the first experimental setup, the effects of two different sizes (100–125 µm powder and 3–5 mm granule) and three different amounts of diatomite (2, 4, 6 g/0.5 L freshwater) on water parameters were investigated. At the end of the first stage, a second experimental setup was prepared to determine the possibility of diatomite abrasion and mixing into water. Based on the ideal size and amount of diatomite determined in the first stage, the diatomites were placed in the WP-300F internal filter (with filter sponge), and a trial setup was formed with two groups in three repetitions. As a result of this research, it was determined that 3–5 mm diatomite, at a rate of 6 g per 0.5 L of water, can be recommended to be used for filtration as filtration material and substrate material for freshwater aquaculture applications. [ABSTRACT FROM AUTHOR]

In the geological disposal of radioactive waste, it is imperative to perform long-term assessments of the shielding efficacy and mechanical stability of the surrounding rock. Numerous investigations into the timedependent characteristics of various rock types have been undertaken to predict the long-term mechanical response of rocks. However, the time-dependent behaviors of diatomaceous earth, such as the strain-rate dependency of strength and creep behavior, remain unclear. In this study, constant-strain-rate and creep tests on diatomaceous earth specimens under undrained conditions and a confining pressure of 10 MPa, at both ambient (25 °C) and elevated (80 °C) temperatures were conducted. Although variations in strength (maximum differential stress) were observed between tests conducted at different temperatures, it is inconclusive as to whether the strength variations were primarily induced by temperature variations, as the unintentional deviation in water content between specimens used in the constant-strain-rate tests at 80 °C and 25 °C might have exerted some effects. The strain-rate dependency of strength and the creep behavior of diatomaceous earth were obtained, and a constitutive equation of the variable-compliance type, which accounts for the time-dependent behaviors of rocks, was applied to the obtained experimental results. Formulating an improved constitutive equation through further triaxial compression tests is an issue in the future.

BACKGROUND: Fructo‐oligosaccharide (FOS) belongs to the group of short inulin‐type fructans and is one of the most important non‐digestible bifid‐oligosaccharides capable of biotransforming sucrose using fructosyltransferase (FTase). However, there are no immobilized FTase products that can be successfully used industrially. In this study, diatomite was subjected to extrusion, sintering and granulation to form diatomaceous earth particles that were further modified via chitosan aminomethylation for modification. FTase derived from Aspergillus oryzae was successfully immobilized on the modified support via covalent binding. RESULTS: The immobilized enzyme activity was 503 IU g−1 at an enzyme concentration of 0.6 mg mL−1, immobilization pH of 7.0 and contact time of 3 h. Additionally, the immobilization yield was 56.91%. Notably, the immobilized enzyme was more stable under acidic conditions. Moreover, the half‐life of the immobilized enzyme was 20.80 and 10.96 times as long as that of the free enzyme at 45 and 60 °C, respectively. The results show good reusability, as evidenced by the 84.77% retention of original enzyme activity after eight cycles. Additionally, the column transit time of the substrate was 35.56 min when the immobilized enzyme was applied in a packed‐bed reactor. Furthermore, a consistently high FOS production yield of 60.68% was achieved and maintained over the 15‐day monitoring period. CONCLUSIONS: Our results suggest that immobilized FTase is a viable candidate for continuous FOS production on an industrial scale. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Ceramsites are extensively employed as substrates for adsorbents in studies focused on phosphorus adsorption, leaving ceramsites crafted from diatomite less explored. Diatomite-based ceramsite, with its distinct porous architecture and surface silanol functionalities, is adept at supporting a variety of metal oxides, presenting a distinct advantage over other ceramsite variants. In light of this, the present study embarked on producing diatomite-based ceramsite using diatomite as the foundational material, subsequently enhancing it through the incorporation of Fe, thus yielding an Fe-modified diatomite-based ceramsite. Through adsorption testing, the modified ceramsite demonstrated a significantly improved adsorption capacity of 4.06 mg P/g, marking a substantial enhancement from the initial capacity of 0.9 mg P/g. The process of phosphorus adsorption exhibited a strong alignment with the Langmuir isotherm model and the pseudo-second-order kinetic model. In-depth analyses employing XRD, FTIR, zeta potential, and XPS techniques have revealed that the principal mechanisms driving the adsorption process are centered on interactions involving electrostatic forces, the formation of chemical precipitates, and the exchange of ligands. This investigation not only opens new avenues for the application of diatomite-based ceramsite but also lays down a theoretical foundation for its modification, thereby enriching the spectrum of its utility. [ABSTRACT FROM AUTHOR]

External plasticization is one of the effective ways to toughen epoxy resins. In this study, an inorganic filler (EMD) was prepared by chemical modification of diatomite and was used to fill epoxy resin matrix. The effects of different amounts (5%, 10%, 15%, and 20%) of raw diatomite (RD) and modified‐diatomite (EMD) on the mechanical and thermal properties of epoxy resin composites were studied. The mechanical results showed that the impact strength, tensile strength, and bending strength of EMD/EP were higher than those of RD/EP. The impact strength of EMD‐15/EP reached 5.39 KJ/m2, which was 36.8% higher than that of RD‐15/EP. Thermogravimetric analysis showed that the thermal stability of EMD/EP was better than that of RD/EP. The results of DMA show that the glass transition temperature of EMD/EP was lower than that of RD/EP. Non‐isothermal differential scanning calorimetry study showed that the apparent activation energy of EMD‐15/EP was much lower than that of RD‐15/EP, which proved that EMD could promote the curing of epoxy resin. The Malek method was used to determine that both the RD‐15/EP and EMD‐15/EP curing systems were autocatalytic (Šesták–Berggren) models. [ABSTRACT FROM AUTHOR]

Diatomite deposits in Poland are located in the Podkarpackie Voivodeship, and the only active deposit is in Jawornik Ruski. Therefore, it is a unique material. Improved rock processing methods are constantly in demand. In the research presented here, we have used research methods such as X-ray diffraction (XRD), scanning electron microscope (SEM), particle shape analysis, and appropriate sets of crushing machines. Diatomite comminution tests were carried out on test stands in different crushers (jaw crusher, hammer crusher, high-pressure roller press, ball mill) using different elementary crushing force actions: crushing, abrasion, and impact, occurring separately or in combination. The machines were tested with selected variable parameters to obtain products with a wide range of grain sizes ranging from 0 to 10 mm. The ball mill (yield 87%, system C3) and the hammer crusher with HPGR (high-pressure grinding roller) (yield 79%, system D2 + D3) have the greatest impact on diatom shell release and accumulation in the finest 0–5 μm and 5–10 μm fractions. For commercial purposes, it is important to obtain very fine fractions while keeping the shells undisturbed. [ABSTRACT FROM AUTHOR]

This study discusses an approach that gives the Natural Rubber (NR) vulcanizates an elevated hydrophobic character. The method used a chemically treated filler called diatomaceous earth (DE) to deliver the hydrophobic characteristics to NR. DE has a nanoscale roughness. It was chemically treated with hexadecyltrimethoxy silane to obtain low surface energy. The combination of nanoscale roughness and low surface energy gave superhydrophobic properties to DE. A series of treated-DE was made with varying silane percentages to find an optimum silane to DE ratio to get the maximum possible hydrophobicity. The optimum ratio was recorded as 38% w/w, and the treated DE displayed a superhydrophobic water contact angle (WCA) of 152°. The treated-DE was added to the rubber as a filler during the compounding process. The filler was added in varying amounts of 5 phr, 10 phr, 15 phr, and 20 phr to observe the changes in the hydrophobic property. The wettability and morphology of developed vulcanizates were measured using WCA measurements and scanning electron microscope (SEM) analysis, respectively. NR compounded with 20 phr filler exhibited an enhanced WCA of 136°, compared to the WCA of 92° of the NR vulcanizate with no treated-DE, and displayed improved tensile, and tear properties. [ABSTRACT FROM AUTHOR]

This study explores the potential of biosilica including diatom and diatomaceous earth as alternative silica sources for metakaolin-based geopolymers. Diatomaceous earth, composed of fossilised diatom frustules rich in amorphous silica, and diatoms, a sustainable source of renewable biosilica, are investigated for their effectiveness in enhancing geopolymer properties. Through detailed analyses including FTIR, XRD, and SEM, the study evaluates the impact of these biosilica sources on geopolymer compressive strength and microstructure, comparing them with conventional sodium silicate. Results show that diatoms exhibit significant promise, achieving 28-day strength up to 17.9 MPa at a 30% mass fraction, while diatomaceous earth reaches 26.2 MPa at a 50% addition rate, demonstrating their potential as active silica sources. Furthermore, the study elucidates the role of organic matter in biosilica on geopolymerisation, highlighting its influence on active silica release and the strength performance of products. This study proposes a novel pathway to enhance the sustainability of geopolymers through the utilisation of biosilica from diatoms, contributing to advancements in eco-efficient construction materials. [ABSTRACT FROM AUTHOR]

Diatomite, a natural adsorbent rich in active silica, serves as a valuable precursor for geopolymer synthesis. The safe disposal of diatomite as a failed lead (Pb(II)) adsorbent is critical to prevent secondary contamination. This study investigated the immobilisation efficiency of geopolymerisation for Pb(II)-rich diatomite sludge. Low-grade diatomite with high ignition loss was utilised in the synthesis of alkali-activated geopolymers. It was demonstrated that the geopolymers achieved a compressive strength of 28.3 MPa with a 50% replacement rate of metakaolin by diatomite sludge, which was not a compromise in strength compared to that of the geopolymer with no Pb(II) (26.2 MPa). The leaching behaviour of Pb(II) was evaluated using water and acetic acid, yielding concentrations below 3 mg/L and immobilisation efficiencies of 95% in both scenarios. Analytical techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) elucidated the mineral composition and chemical environment of the geopolymers. These analyses revealed that Pb(II) migrated from diatomite pores, potentially forming soluble hydroxides under sufficient hydroxide, which then participated in condensation with silicon and aluminium monomers, effectively immobilising Pb(II) within amorphous aluminosilicate gels. Furthermore, the formation of the amorphous gels within diatomite pores hindered Pb(II) leaching, encapsulating Pb(II) effectively. This study presents a novel approach to immobilising heavy metals within building materials, enhancing mineral resource utilisation efficiency while addressing environmental contamination concerns. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Neurospora crassa genome has a gene cluster for the synthesis of galactosaminogalactan (GAG). The gene cluster includes the following: (1) UDP-glucose-4-epimerase to convert UDP-glucose and UDP-N-acetylglucosamine to UDP-galactose and UDP-N-acetylgalactosamine (NCU05133), (2) GAG synthase for the synthesis of an acetylated GAG (NCU05132), (3) GAG deacetylase (/NCW-1/NCU05137), (4) GH135-1, a GAG hydrolase with specificity for N-acetylgalactosamine-containing GAG (NCU05135), and (5) GH114-1, a galactosaminidase with specificity for galactosamine-containing GAG (NCU05136). The deacetylase was previously shown to be a major cell wall glycoprotein and given the name of NCW-1 (non-GPI anchored cell wall protein-1). Characterization of the polysaccharides found in the growth medium from the wild type and the GAG synthase mutant demonstrates that there is a major reduction in the levels of polysaccharides containing galactosamine and N-acetylgalactosamine in the mutant growth medium, providing evidence that the synthase is responsible for the production of a GAG. The analysis also indicates that there are other galactose-containing polysaccharides produced by the fungus. Phenotypic characterization of wild-type and mutant isolates showed that deacetylated GAG from the wild type can function as an adhesin to a glass surface and provides the fungal mat with tensile strength, demonstrating that the deacetylated GAG functions as an intercellular adhesive. The acetylated GAG produced by the deacetylase mutant was found to function as an adhesive for chitin, alumina, celite (diatomaceous earth), activated charcoal, and wheat leaf particulates. [ABSTRACT FROM AUTHOR]

The effectiveness of using borate (borax) and fluoride (sodium fluoride) fluxes in the sintering of crystalline (sand) and amorphous (diatomite) silicate raw materials was considered. The change in the density and appearance of samples with varying amounts of fluxes during their heat treatment at different temperatures was described. It was shown that the introduction of 4 wt.% of borax reduces the temperature necessary to reach a density of 1500 kg/m3 by 100°C, and 6 wt.% of borax by 200°C. It was shown that the introduction of fluxes increases the amount of x-ray amorphous glass phase due to depolymerization of the silicon-oxygen network and the formation of a low-temperature melt. [ABSTRACT FROM AUTHOR]

This study employed reactive extrusion to produce micro-composites of high-density polyethylene (HDPE) with different fractions of diatomaceous earth, both unmodified and modified, using a novel reversible crosslinking reaction agent (RXR) consisting of a combination of sulfur, organic peroxide, and an accelerator. The rheological behavior and crosslinking response of the system were measured using dynamic rheological analysis using a torque rheometer. The mechanical characteristics of the system were evaluated through tensile and impact tests. The thermal characteristics were analyzed using differential scanning calorimetry and thermogravimetric analysis, while the structural and morphological properties were analyzed using wide-angle X-ray scattering, Fourier infrared transform, and scanning electron microscope. The mechanical properties of the HDPE resin were diminished by the inclusion of the diatomaceous earth due to aggregation and inadequate interfacial connections, whereas the thermal stability remained unaffected. Furthermore, the presence of diatomaceous earth led to enhancements in both crystallinity and lamellar thickness. The addition of the RXR agent improved the tensile and impacts strengths, caused by the crosslinking reaction. However, it had a detrimental effect on the degree of crystallinity and the size of the crystals formed. Analysis of mechanical, rheological, and crystallization properties demonstrated that the incorporation of diatomaceous earth and the diatomaceous earth-RXR agent combination showed potential as additives for HDPE. [ABSTRACT FROM AUTHOR]

Maize is a major staple food in Africa, its production and post-harvest generally occurs on smallholder farmers' properties, where significant food losses occur in the field during harvesting, processing and storage. Most smallholder farmers lack access to modern methods of harvesting, processing and storage. Generally, the storage structures used are ineffective against storage pests, leading to postharvest losses due to insect pests that, in some cases, can reach about 40% of the total production. Pest control is generally scarce, and when adopted, it is based on local knowledge-based pest control alternatives or on the application of synthetic pesticides known to be harmful to the environment and human and animal health. So, alternative pest control methods commonly found include the use of inert dust as an integrated pest management approach, without residual effects and ideal for food safety. This study aimed to determine the efficacy of charcoal powder (CP) and rock dust (RD) alone or combined with diatomaceous earth (DE) in the control of rice weevil (Sitophilus oryzae). Maize grains were treated and infested by the addition of Sitophilus oryzae, on the day they were treated and, 30 and 60 days after treatment. Mortality was assessed at 10 and 20 days after each infestation. Emerged insects were counted 40 days after the second mortality assessment for each infestation period. At 90 days after treatment, the seed germination test was performed. The best treatments for Sitophilus oryzae control (mortality) and F1 emergence reduction were RD (0.5, 0.25 and 0.10 g/kg), RD+DE (0.5+0.05, 0.25+0.05 and 0.10+0.05 g/kg), and CP+DE (1.0+0.05, 0.50+0.05 and 0.25+0.05 g/kg). The RD and RD+DE remained efficient in maize treated and stored for 60 days. The treatments did not interfere with seed germination. Rock Dusts, RD+DE, and CP have the potential to be used as stored grain protectants, providing economically and environmentally friendly pest control alternatives, especially in small-scale agriculture. In developing countries, especially in sub-Saharan Africa, studies for optimization and introduction of inert dusts tested in this research, have the potential to reduce post-harvest losses, improving food security. [ABSTRACT FROM AUTHOR]

Frying, a prevalent cooking method, subjects oils to high temperatures, causing chemical changes and the formation of harmful by-products. Repeated oil use poses health risks, necessitating effective restoration methods. Agricultural waste ashes, including rice, barley, and oak hulls, were investigated for their adsorption capabilities in comparison to conventional adsorbents. Refined sunflower oil was used, and five filter aids, including Magnesol XL, diatomaceous earth, and agricultural waste ashes, were employed. Rice, barley, and oak hull ashes were prepared and characterized for metal content. Scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy assessed the surface morphology and chemical structure of ashes. The frying process involved heating oil daily for five consecutive days, with each session lasting 4 h, followed by treatment with filter aids. Comparing the agricultural waste ashes, oak hull ash (OHA) exhibited the highest content of silicate which was almost equal to the conventional adsorbents. SEM revealed the surface properties and superior performance of OHA in adsorbing degradation products. FTIR analysis showed similarities in chemical structure between pure silica and oak hull ash. Initial sunflower oil quality was confirmed through various physico-chemical properties. Frying led to quality deterioration, evidenced by color changes, increased refractive index, viscosity, acidity, peroxide levels, and decreased iodine value. This study underscores the potential of agricultural waste ashes, particularly oak hull ash, as effective adsorbents for enhancing the quality of fried sunflower oil. Their comparable performance to conventional adsorbents, cost-effectiveness, and lack of harmful effects position them as viable alternatives in restoring used frying oils for sustainable culinary practices. [ABSTRACT FROM AUTHOR]

BACKGROUND: Wheat grain containers or silos can be perfect habitats for insects, which generate large economic losses to grain production. Natural alternatives to synthetic insecticides have grown in popularity because of health, economic and ecological issues. Diatomaceous earth is a natural compound that has an insecticide effect by enhancing an insect's dehydration with no toxicity on mammals including humans. The aim of this study is to confirm the effect of diatomaceous earth as an insecticide for the wheat grain pest, the red flour beetle Tribolium castaneum (Coleoptera: Tenebrionidae) and demonstrate its underlying mechanisms as an insecticide by open‐flow respirometry and scanning electron microscopy. RESULTS: Survival bioassays of T. castaneum revealed a dose‐dependent insecticide effect of diatomaceous earth. Gravimetric measurements showed that 2 days exposure to diatomaceous earth produces a significant increase of mass loss. Open‐flow respirometry measurements showed an increase of total water emission rate on insects due to an increase of both, respiratory and cuticular water loss. Our study revealed that diatomaceous earth produces an increase of insect's cuticle permeability, which is responsible for elevated cuticular water loss. Scanning electron microscopy images provided visual evidence of the lipid absorbent properties of diatomaceous earth particles, and showed a tendency for higher, although not significant, damaged area of the cuticle's surface from diatomaceous earth treated insects compared to control ones. CONCLUSION: With state‐of‐the art techniques like open‐flow respirometry and scanning electron microscopy, we demonstrated the underlying mechanism of diatomaceous earth as an insecticide and provided new cues for understanding the properties of the cuticle and its ecological importance. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phenanthrene (PHE) is a polycyclic aromatic hydrocarbon categorized as a high priority organic pollutant being toxic for the ecosystem and human health, and its sorption on natural organic or inorganic substances seems a well-promising method for its removal from water streams. The goals of the present work are (i) to assess the capacity of low-cost adsorbents fabricated by treating coffee wastes and diatomaceous earth to remove PHE from water; (ii) to elucidate the role of the pore structure on PHE sorption dynamics; and (iii) to assess the potential to regenerate adsorbents loaded with PHE, by using the novel technology of cold atmospheric plasma (CAP). Diatomaceous earth (DE) and DE pre-treated with sodium hydroxide (NaOH) or phosphoric acid (H3PO4) were chosen as inorganic adsorbents. Coffee waste (CW) and activated carbons (AC) produced from its pyrolysis at 800 °C (CWAC), either untreated (CWAC-800) or pre-treated with NaOH (CWAC-NaOH-800) and H3PO4 (CWAC-H3PO4-800), were chosen as organic adsorbents. The adsorbents were characterized with nitrogen adsorption–desorption isotherms, attenuated total reflectance-Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and mercury intrusion porosimetry. Based on the PHE sorption capacity and pore structure/surface characteristics, the CWAC-NaOH-800 was chosen as the most efficient adsorbent for further equilibrium and kinetic sorption studies. The multi-compartment model was used to describe the PHE sorption dynamics in CWAC-NaOH-800 by accounting for the pore/surface diffusion and instantaneous sorption. The CWAC-NaOH-800 exhibited remarkable values for (i) the specific surface area (SBET = 676.5 m2/g) and meso- and micro-pore volume determined by nitrogen sorption (VLN2 = 0.415 cm3/g); (ii) the macro- and meso-pore volume determined by mercury intrusion porosimetry (VMIP = 3.134 cm3/g); and (iii) the maximum PHE sorption capacity (qmax = 142 mg/g). The percentage of adsorbent recovery after its regeneration with CAP was found to be ~ 35%. From the simulation of sorption dynamics, it was found that at early times, the sorption kinetics is governed by the film diffusion towards the external surface of grains, but at late times, most of the adsorbed mass is transferred primarily to meso-/macro-pores via diffusion, and secondarily to micro-porosity via surface diffusion. Based on the adsorbent characteristics, effect of pH on sorption efficiency, and numerical analysis of sorption dynamics, it was concluded that probably the dominant adsorption mechanism is the π-π interactions between hydrophobic PHE aromatic rings and CWAC-NaOH-800 graphene layers. The high PHE removal efficiency of CWAC-NaOH-800, the successful interpretation of sorption dynamics with the multi-compartment model, and the potential to regenerate PHE-loaded adsorbents with the green and economic technology of CAP motivate a strategy for testing CWACs towards the adsorption of other PAHs, application of adsorbents to real wastewaters, and scaling-up to pilot units. [ABSTRACT FROM AUTHOR]

The present study investigated the insecticidal efficacy of Diaterra®, a native diatomaceous earth, against two significant stored grain pests, the grain weevil, Sitophilus granarius (Linnaeus, 1758), (Coleoptera: Dryophthoridae) and the red flour beetle, Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae). To control of insect pests in stores or warehouses, grain industry relies on synthetic insecticides, but they have significant environmental and health risks. Diatomaceous earth offers a natural and environmentally friendly alternative. In addition, it is safe for wildlife, leaves no residues, and effectively controls pests. In the study, different doses (0.25, 0.5, 1, 2, and 4 g/m2) of diatomaceous earth were applied on concrete and wooden surface. A mortality of 100.0% was achieved for S. granarius on the wooden surface at a dose of 4 g/m2 during the 96-hour and subsequent application periods, whereas for T. castaneum, this rate was recorded as 88.9% under the same dose and a 192-hour application period. On the concrete surface, a mortality rate of 100.0% was achieved for S. granarius at a dose of 4 g/m2 after 120 h of exposure. In contrast, for T. castaneum, this rate did not exceed 59.5% even with the same dose and a 192-hour application period. Under controlled laboratory conditions, a dose of 4 g/m2 of Diaterra® showed efficacy in managing S. granarius populations on wooden and concrete surfaces. The desired level of efficacy was not achieved for T. castaneum on either surface type. Based on the data obtained from this study, it can be concluded that prolonged exposure to diatomaceous earth leads to enhanced insecticidal efficacy against both S. granarius and T. castaneum on different surface types. This study emphasizes the importance of considering application duration and surface type as critical factors in maximizing the effectiveness of diatomaceous earth applications. [ABSTRACT FROM AUTHOR]

The bioefficacy of several inert materials, such as Diatomaceous earth (DE), bentonite, and biochar enhanced with pirimiphos-methyl against Sitophilus oryzae, was used to evaluate the insecticidal activity of three new formulations using the technique of mixing with grain. DE was the most effective material (LC50 3.198 g/kg), followed by biochar LC50 3.709 g/kg, whereas bentonite was the least effective (LC50 3. 979 g/kg). The three materials were loaded with pirimiphos-methyl (0.5%). The formula of Pirimiphos-methyl with DE reported the highest significant effect compared to the other two formulations, with an LC50 value of 0.082 g/kg. DE formula had a co-toxicity coefficient value that was 6.46 times greater than pirimiphos-methyl, followed by the biochar formula, which was 1.74 times more effective, and the bentonite formula, which had a 0.69-fold increase in activity. In the laboratory examination of the wheat's free and compact bulk densities after being treated with LC50s of each dust material, DE slightly affected wheat-free bulk density. Still, both bentonite and biochar reduced the free bulk density. However, all the tested materials decreased in compact bulk density. The germination percentages of wheat treated with LC50 values of DE and bentonite and biochar after 10 days of storage revealed no significant difference between treated and untreated seeds after 7 days of germination. [ABSTRACT FROM AUTHOR]

The reduction in the rheological parameters and dissolution rate of precursors in geopolymer coatings during early hydration significantly contributes to sagging. This study aims to improve the sag resistance of these coatings by incorporating diatomite filler. Rheological testing was conducted to assess the impact of diatomite and its concentration on the yield stress, plastic viscosity, and thixotropy of the geopolymer coatings. The results indicated that diatomite's large specific surface area and high reactivity have a significant influence on the rheological parameters and early dissolution rate of precursors. With a diatomite concentration of 1.1%, the coating exhibited a yield stress of 2.749 Pa and a plastic viscosity of 0.921 Pa·s, maintaining stability, homogeneity, and no sagging at a thickness of 600 μm. Furthermore, the highly active SiO2 in diatomite participates in the secondary hydration reaction of the geopolymer materials led to the formation of substantial C-(A)-S-H gel. This gel enhances internal interconnectivity within the coating, thereby improving its rheological and mechanical properties. [ABSTRACT FROM AUTHOR]

Insufficient analysis of carriers and their interaction with biocontrol agents can lead to ineffective formulations. Therefore, it is important to thoroughly study the compatibility and interactions between carriers and biocontrol agents for high-quality biological formulations. The present study aimed to evaluate the effect of four different formulation compositions containing gum katira biogel, vermiculite, and diatomaceous earth on the survival and infectivity of infective juveniles (IJs) of two entomopathogenic nematodes (EPNs) species namely, Steinernema abbasi and Heterorhabditis indica at 25 and 35 °C. The physicochemical analysis of the prepared formulations revealed their slightly acidic nature with pH ranging from 5.65 to 6.10. Rheological studies validated the solid-like behavior of the developed formulations. The highest survival of S. abbasi IJs was observed in the case of gum katira biogel-vermiculite blended composition at both 25 °C (94.2%) and 35 °C (88.4%) after 90 days of storage. Interestingly, gum katira biogel alone sustained maximum survival percentage (63.5%) of H. indica as compared to control (41.5%) after 90 days at 25 °C. The formulation compositions failed to retain alive H. indica IJs at 35 °C even after seven days of storage. Moreover, the gum katira singly or in combination with vermiculite resulted in superior infectivity against Galleria mellonella (4th instar larvae) as compared to the other treatments in case of both the nematode species. The presence of diatomaceous earth in all the compositions irrespective of moisture and EPN species showed a negative impact on the survival and infectivity of IJs after 90 days of storage. Gum katira biogel alone or in combination with vermiculite was favorable to sustaining the survivability and infectivity of test EPN IJs at ambient storage temperatures. These formulants can further be used to develop biocontrol EPN formulations for organic farming and integrated pest management programs. [ABSTRACT FROM AUTHOR]

Rice grains are often infested by Sitophilus oryzae and Corcyra cephalonica, causing quality and quantity losses. In this study, the insecticidal effects of inert dust (diatomaceous earth (DE), calcium carbonate, kaolin (KA), rock phosphate and silica gel) on S. oryzae adults and C. cephalonica larvae were assayed. Four concentrations of each inert dust were tested at 2,3,4 and 5% on rice grains. Results indicated that diatomaceous earth and phosphate rock 5% lead to the highest insecticidal action with adult mortality of 98.3 and 96.6% for S. oryzae adults, 15 days post-treatment, respectively. As well, diatomaceous earth and phosphate rock 5% lead to the highest insecticidal action with larval mortality of 100.0% for C. cephalonica larvae after 7 days. On the contrary, treatment with 5% silica gel recorded the lowest toxicity to S. oryzae adults (65.66%) after 15 days of exposure. While calcium carbonate 5% resulted from the lowest toxicity C. cephalonica larvae (61.2%) after 7-day exposure. According to the obtained results, the highest reduction in the progeny of S. oryzae adults was registered in treatments with diatomaceous earth (5%) and kaolin (5%), being 91.4 and 91.3%, respectively. As for the highest reductions in the progeny of C. cephalonica larvae, in treatments with diatomaceous earth (5%) and phosphate rock (5%), those were 97.4and 97.2%, respectively. All treatments with inert dust caused a reduction of weight loss and damage of rice grains 60 days post-treatment in comparison with untreated grains. Results showed that all the tested inert dusts treatments except silica gel increased germination percentages of seeds than the control. The obtained results indicated that inert dusts may be considered, safe and available in the local environment, so, they are used as alternatives to insecticides for the control of S. oryzae and C. cephalonica infestations to stored rice grains. [ABSTRACT FROM AUTHOR]

In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth, base, and silanized with GPTMOS (3-glycidoxypropyltrimethoxysilane), OTES (n-octyltriethoxysilane), and MTMOS (methyltrimethoxysilane) silanes. The addition of two types of waxes, synthetic polyamide wax and natural beeswax, were used as a factor to increase the rheological properties of the composites. The obtained samples were characterized in terms of the effect of filler silanization on the degradation rate of the composites. The tests were conducted under different conditioning conditions, i.e., after exposure to strong UV radiation for 250 and 500 h, and under natural sunlight for 21 days. The conditioning carried out under natural conditions showed that the modified samples exhibit up to twice the degradation rate of pure polylactide. The addition of synthetic wax to the composites increases the tendency to agglomerate diatomaceous earth, while natural wax has a positive effect on filler dispersion. For composites modified with GPTMOS and OTES silanes, it was noted that the addition of natural wax inhibited the degree of surface degradation, compared to the addition of synthetic wax, while the addition of MTMOS silane caused the opposite effect and samples with natural wax degraded more strongly. It was shown that, despite the high degree of surface degradation, the process does not occur significantly deep into the composite and stops at a certain depth. [ABSTRACT FROM AUTHOR]