Diatomaceous Research Articles

The impact of contamination on audible noise in AC transmission lines

The objective of this study is to investigate the impact of accumulated pollutants on the surface of a 1000 kV AC transmission line in a specific location in China on its audible noise generation. The line with diatomaceous earth, kaolin, and other pollutants attached to it is modeled by using finite element software, and the study results indicate that the conductivity of the material plays a significant role in influencing the audible noise. In addition, diatomaceous earth has the least effect on the amplitude and lateral attenuation of audible noise, and sodium chloride and carbon powder have the greatest effect. The research in this paper can be used for the reason that dirt particles affect the magnitude of audible noise and these findings offer valuable insights for the management of audible noise.

Residual Efficacy of Two Diatomaceous Earths from Greece for the Control of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) on Wheat and Maize.

We evaluated the persistence and efficacy of two different, in granulometry and content of diatoms, diatomaceous earth (DE) formulations (i.e., DE5 and DE6), against two major beetle species of stored products, i.e., Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). The formulations were applied as powders in soft wheat and maize in two doses of 500 and 1000 mg kg-1 (ppm). Samples of the treated grains were taken on the day of application and every 30 days until completion of the six-month period of storage. Adults of S. oryzae and R. dominica were exposed to the treated grains at 25 °C and 55% relative humidity, and the mortality was measured after 7, 14, and 21 days of exposure. Rhyzopertha dominica survival was not affected by any combination of DE formulation, dose, and commodity. Contrariwise, the DEs caused significant adult mortality of S. oryzae, in most of the cases tested. We observed that DE6 was equally effective in both wheat and maize, and no considerable variations were observed in S. oryzae mortality during the 6-month experimental period. Furthermore, DE6 was more effective against S. oryzae than DE5, a difference that could have potentially contributed to the variations in the diatom granulometry between these two DEs. Thus, a DE treatment of 1000 ppm was shown to provide long-term protection of wheat and maize against S. oryzae, but this is strongly dependent on the DE formulation, commodity, and insect species. Overall, such natural resource-based inert silicaceous deposits could be used with success in stored-product protection with only some minor modifications, such as sieving and drying of the raw deposit.

Improving isotactic polybutene‐1 performance with diatomaceous earth filler and a novel reversible crosslinking reaction agent

AbstractThis 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.

The Effect of Partial Replacement of Cement with Diatomaceous Earth (DE) and Polypropylene Fibers (PPF) on Fresh, Hardened, and Durability Properties of Concrete

This research aims to investigate the fresh and mechanical properties of concrete with diatomaceous earth (DE) and polypropylene fiber (PPF). The cement was partially replaced by DE in the concentration ranging from 5 to 20% by weight; whereas, PPF was incorporated in concrete mix as in range of 0.05–0.20% by cement weight. Totally, 25 different mix proportions were developed and their fresh properties were examined using slump, density and compacting factor tests. Besides, mechanical properties were evaluated by. Using compressive, split tensile, and flexural strength analysis at the ages of 7th, 14th and 28th days. Furthermore, concrete durability properties were evaluated using water penetration, chloride permeability as well as sorptivity tests, which have been performed at the age of 28th day. The result exhibits that the incorporation of D.E slightly affects the slump value meanwhile PPF decreases the fresh values. Furthermore, the combination of DE and PPF in concrete significantly enhances the mechanical properties compared to the control mix. The mix proportion of 15% DE and 0.15% of PPF exhibited a noticeable influence on mechanical properties as well as durability properties compare to control concrete.

Diatomite supported highly-dispersed ZnO/Zn-co-embedded ZIF-8 derived porous carbon composites for adsorption desulfurization

The metal organic framework (MOFs)-derived porous carbon materials with highly dispersed metal active sites were of the exclusive application foreground in many field, such as catalyst, electrochemistry, adsorption desulfurization and so on. However, the loss issue of metal active sites in MOFs frame was indispensable during the high temperature carbonization because of the lower boiling point of many metals, thus fundamentally affecting the atom-scale uniform distribution merit of MOFs-derived porous carbon materials. This work was to provide a novel strategy to address the loss issue of the active metal volatilization in the fabrication of MOFs-derived porous carbon materials. The ZnO nanosheets were pre-grown on the surface of diatomite by using in-situ microwave-assisted preparation, and thereafter the Zn-containing ZIF-8 particles covered the surface of ZnO nanosheets by virtue of the ZnO-induced growth. The results affirmed that the high content Zn-doped porous carbon materials were achieved and the Zn volatilization in MOFs was restrained on account of the occurrence of ZnO on diatomite (DE) surface during the carbonization. The adsorption desulfurization performance of the ZnO/Zn-embedded porous carbon materials/DE (ZnO/Zn/C@DE) was examined by the sulfur-containing compounds in simulated oil. The adsorption desulfurization performance investigation indicated that the ZnO/Zn/C@DE had the optimum adsorption capacities of 45.3 mg/g for benzothiophene and 37.4 mg/g for thiophene. Nonetheless, the competitive adsorption desulfurization finding of toluene in simulated oil showed that the adsorption capacities of ZnO/Zn/C@DE for TH and BT were dramatically descended, suggesting the presence of S-M interaction, wherein S stood for the S atom in a thiophene molecule and their analogs, and M for Zn atoms in porous carbon materials.

Kirigami-inspired artificial spidroin microneedles for wound patches

Intelligent wound management has important potential for promoting the recovery of chronic wounds caused by diabetes. Here, inspired by the field of kirigami, smart patterned high-stretch microneedle dressings (KPMDs) based on gene-modified spider silk proteins were developed to achieve sensitive biochemical and physiological sensing. The spider silk protein (spidroin) has excellent tensile properties, ductility, toughness and biocompatibility. Notably, the kirigami method-prepared kirigami structure of the spidroin MN dressing had a high tensile strength , while its ductility reached approximately 800 %. Moreover, the unique optical properties of photonic crystals allow for fluorescence enhancement, providing KPMD with color-sensitive properties suitable for wound management and clinical guidance. Furthermore, to improve the sensitivity of KPMD-s to motion monitoring, a microelectronic matrix was integrated on its surface. These distinct material properties suggest that this research lays the foundation for a new generation of high-performance biomimetic diatomaceous earth materials for application.

Alkalinity Regulation and Optimization of Cementitious Materials Used in Ecological Porous Concrete.

Ecological porous concrete (EPC) is one of the novel formulations of concrete with unique phytogenic properties. However, achieving both low alkalinity and high strength in EPC proves challenging due to the inherently high alkalinity of the pore environment, which hinders the growth of the plant and affects its ecological benefits significantly. This research investigated the utilization of 15 types of chemical admixtures and diatomaceous earth as alkali-reducing agents to optimize the properties of silicate cementitious materials for the applications of EPC. To identify the most effective agents, the pH value and compressive strength of the cement paste were adopted as the screening criteria for the selection of the essential alkali-reducing ingredients. Subsequently, a composite approach combining chemical admixtures and DE was employed to explore the synergistic effects on the pH and strength of silicate cementitious materials. The results revealed that a combination of 8% DE, 5% oxalic acid, and 5% iron sulfate functioned effectively and resulted in desirable performance for the concrete. This synergistic blend effectively consumed a large amount of Ca(OH)2, reducing the pH of cement paste to 10.48 within 3 days. Furthermore, the hydration reaction generated C-S-H with a low Ca/Si ratio, leading to a remarkable increase in the compressive strength of the concrete, reaching 89.7 MPa after 56 days. This composite approach ensured both low alkalinity and high strength in silicate cementitious materials, providing a theoretical basis for the application and promotion of EPC in the ecological field.

Transforming Natural Eggshell and Diatomite into Bioactive Calcium Silicate Material for Bone Regeneration.

Calcium silicate (CS), a new and important bioceramic bone graft material, is prepared by using eggshells, which have a porous structure and are rich in calcium ions. Furthermore, the preparation of new CS materials using eggshells and diatomaceous earth minimizes their negative impact on the environment. In this study, we prepared CS materials using a high-temperature calcination method. The composition of the material was demonstrated by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. Scanning electron microscopy (SEM) analysis confirmed the porous structure of the CS material. We also introduced ZnO to prepare ZnO-CS with antibacterial properties and showed that ZnO-CS exhibits excellent antibacterial effects through in vitro antibacterial experiments. Subsequent in vitro mineralization experiments demonstrated that ZnO-CS promoted the formation of a hydroxyapatite layer. Furthermore, in vitro cytotoxicity experiments demonstrated that ZnO-CS had very good biosafety and promoted cell proliferation. These findings were confirmed through subsequent cell proliferation experiments. Our results indicate that the novel ZnO-CS is a promising candidate for bone tissue engineering.

Pre-treatment of hydrolysable nuclear organic liquids prior to their waste management: Solid impregnation of vegetable oil on surfactant-grafted clay particles

In the context of advancing nuclear waste management techniques, this study delves into the novel use of surfactant-grafted clay particles for pre-treating hydrolysable nuclear organic liquids. Our research explores the potential of modified clay materials in immobilizing vegetable oil, a surrogate for complex nuclear waste. We investigate the adsorption capabilities of various clays, including metakaolin, diatomaceous earth and sepiolite, when grafted with cetyltrimethylammonium bromide (CTAB) as cationic surfactant, or decyl glucoside (DG) as non-ionic surfactant. This study employs characterization techniques to assess the physicochemical transformations in clays post surfactant-grafting. Grafting was initially highlighted by TGA, where the breakdown of surfactants can be observed. This is also evidenced by measurements of the ζ-potential, which demonstrate a reduction in surface charge upon the addition of the cationic surfactant, excepted for sepiolite for which the surface charge did not change. Additionally, Washburn measurements indicate that the grafting process converts hydrophilic particles into hydrophobic ones. The oil absorption tests indicated that the CTAB-grafted sepiolite demonstrated superior characteristics, notably exhibiting no oil rejection. Consequently, this specifically synthesized powder was utilized in a two-step process consisting in pre-impregnation of oil up to 20 %v of vegetable oil prior to its immobilization within a geopolymer matrix. Furthermore, the outcomes of the leaching tests revealed that the vegetable oil remained effectively confined within the immobilization matrix, ensuring its retention. The research contributes to the goal of enhancing hydrolysable nuclear waste management practices, ensuring long-term sustainability and environmental safety.

Diatomite supported bagel-like hydroxylated mesoporous carbon nitride towards the adsorption desulfurization application

The carbon nitride (g-C3N4) nanosheets was apt to occur the donor-acceptor (D-A) interaction with the sulfides via the influence of the electronic structure of C atoms in the ring. Accordingly, we implemented an environmental- friendly approach to raise the electropositivity of the C atoms of N atoms in the ring of g-C3N4 through the hydroxylation treatment of hydrogen peroxide(H2O2), and afterwards constructed a bagel-like morphology composite ((HO)x/g-C3N4@DE) by virtue of the calcined combination of hydroxylated mesoporous g-C3N4 and diatomite (DE). The characterization results showed that the substantial mesoporous structure was produced in the formation of (HO)x/g-C3N4@DE composite. The adsorption desulfurization experiments showed that the bagel-like hydroxylated mesoporous (HO)x/g-C3N4@DE had the optimum adsorption capacity of up to 42.2 mg/g for thiophene (TH) and 30.8 mg/g for benzothiophene (BT), respectively. Moreover, the adsorption capacities of the hydroxylated mesoporous (HO)x/g-C3N4@DE were dramatically higher than the individual (HO)x/g-C3N4 (18.92 mg/g for TH and 15.64 mg/g for BT), suggesting that the occurrence of the secondary stacked mesopores in the formation of the (HO)x/g-C3N4 on the surface and macro-porous structure of DE affected the adsorption capacity. Lastly, the adsorption mechanism of the hydroxylated mesoporous (HO)x/g-C3N4@DE was proposed.

Tailored chitosan integration in diatomaceous earth particles as a scaffold for fructosyltransferase immobilization in fructo-oligosaccharide production.

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. 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. Our results suggest that immobilized FTase is a viable candidate for continuous FOS production on an industrial scale. © 2024 Society of Chemical Industry.

Diatomite@MoS2 Nanocomposite Layers as Composite Coating Targeting for Mg Alloys Endowed with Properties of Anticorrosion and Antiwear.

Molybdenum disulfide (MoS2) demonstrates promising applications in enhancing the corrosion and wear resistance of metals, but the susceptibility of this nanomaterial to agglomeration hinders its overall performance. In this study, the externally assisted corrosion inhibitor sodium molybdate (SM) was successfully constructed in diatomaceous earth (DE) and molybdenum disulfide (MoS2). This not only served as a molybdenum source for MoS2 but also enabled the preparation of DE@MoS2-SM microcapsules, achieving a corrosion inhibitor loading of up to 23.23%. The corrosion testing reveals that the composite coating, when compared to the pure epoxy coating, exhibits an impedance modulus 2 orders of magnitude higher (1.80 × 109 Ω·cm2), offering prolonged protection for magnesium alloys over a 40 day period. Furthermore, a filler content of 3% sustains a coefficient of friction (COF) at 0.55 for an extended duration, indicating commendable stability and wear resistance. The protective performance is ascribed to the synergistic enhancement of corrosion and wear resistance in the coatings, facilitated by the pore structure of DE, the high hardness of MoS2, and the obstructive influence of Na2MoO4. This approach offers a straightforward and efficient means of designing microcapsules for use in corrosive environments, whose application can be extended in industrial fields. In particular, we promote the application of nautical instruments, underwater weapons, and seawater batteries in the shipbuilding industry and marine engineering.

Preparation and properties of hydrogen storage materials of porous carbon composite diatom skeleton

Using a diatom treated with acid as the base skeleton, and introduced furfuryl alcohol into diatom skeleton was in-situ polymerized, followed by carbonizing, alkali activation, and a series novel hydrogen storage materials of porous carbon composite diatom skeleton (A-PCDS) were prepared. The effect of composites prepared with different concentrations of acid treatment diatomaceous earth on the hydrogen storage properties was investigated. The results showed that the use of suitable concentrations of acid treatment was beneficial to the hydrogen storage properties of the final synthesized materials. The 4 M acid-treated final samples showed stronger hydrogen storage performance relative to the 0.5 M acid-treated final samples, and the hydrogen storage capacity was increased from 3.25 wt% (77K, 5 MPa) to 4.21 wt% (77K, 5 MPa). This results will be of great value for the application and development of high-performance and low-cost hydrogen storage materials, which can be prepared in large quantities.

Application of insecticide dusts for the management of Indian meal moth (Lepidoptera: Pyralidae) wandering larvae under laboratory conditions.

The Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is a very common stored-product pest. The mature larvae wander around searching for suitable places to pupate, offering an opportunity to control this pest. We evaluated the efficacy of 5 insecticide dusts: Alpine (0.25% dinotefuran, 95% diatomaceous earth [DE]), CimeXa (92.1% amorphous silica gel), DX13 (100% DE), Tempo (1% cyfluthrin), and Tri-Die (1% pyrethrin, 10% piperonyl butoxide, 40% amorphous silica) against P. interpunctella wandering larvae by allowing larvae to pass 1-inch treated band, expose to treated vinyl tiles for 5min, and expose to treated harborage (with or without the presence of an untreated harborage). A commercially treated harborage product (Nattaro band) served as a positive control in the exposure to the treated harborage test. Tempo was significantly more effective than other insecticide dusts in the 1-inch band and forced exposure tests but caused only 44% and 54% larvae mortality in the 2 tests. In contrast, CimeXa, Tri-Die, and Tempo caused 84%-89% mortality when the larvae were provided with treated harborages. When both treated and untreated harborages were present, Tempo caused a significantly higher mortality and a lower percentage of emerged adults from larvae than Tri-Die, but not significantly more than CimeXa. Deploying Tempo or CimeXa-treated harborages and/or applying insecticide dust directly into the wall crevices, perimeters of the floor, shipping pallets, and other areas where P. interpunctella larvae hide could be an effective method for the management of the wandering stage of P. interpunctella larvae in storage facilities.

Production and characterization of geopolymers from diatomaceous earth

The world has been facing an increase in the average surface temperature of the earth due to the high release of carbon dioxide into the atmosphere. One of the main responsible for this release of CO2 is the manufacture of Portland Cement, associated with an emission of carbon dioxide of around 7% of the world's total emissions. In this way, there is a need to find alternatives to Portland cement. This work aims to contribute to this endeavor, proposing the application of a solid waste used as a wine filtration agent in the wine industry, diatomaceous earth, containing high amounts of silicon, to produce geopolymers. A geopolymer is an inorganic polymer produced with an aluminosilicate precursor reacted with an alkaline solution that has been studied as an alternative to cement. Diatomaceous earth and alumina were employed in this work as aluminosilicate sources for the geopolymer precursor, while sodium hydroxide and sodium silicate were used as the alkaline solution. The production process involved mixing all these raw materials of the geopolymers to create a fresh geopolymer. Following production, the geopolymers were characterized using XRD, FTIR, SEM-EDS, and pore property analysis. The results revealed that the most favorable geopolymer was produced considering a NaOH concentration of 10 M and a Si/Al ratio of 3,5. This combination resulted in a higher proportion of geopolymer phase, consequently improving mechanical properties.

Synergistic antifungal mechanism of cinnamaldehyde and nonanal against Aspergillus flavus and its application in food preservation

Aspergillus flavus colonization on agricultural products during preharvest and postharvest results in tremendous economic losses. Inspired by the synergistic antifungal effects of essential oils, the aims of this study were to explore the mechanism of combined cinnamaldehyde and nonanal (SCAN) against A. flavus and to evaluate the antifungal activity of SCAN loading into diatomite (DM). Shriveled mycelia were observed by scanning electron microscopy, especially in the SCAN treatment group. Calcofluor white staining, transmission electron microscopy, dichloro-dihydro-fluorescein diacetate staining and the inhibition of key enzymes in tricarboxylic acid cycle indicated that the antifungal mechanism of SCAN against A. flavus was related to the cell wall damage, reactive oxygen species accumulation and energy metabolism interruption. RNA sequencing revealed that some genes involved in antioxidation were upregulated, whereas genes responsible for cell wall biosynthesis, oxidative stress, cell cycle and spore development were significantly downregulated, supporting the occurrence of cellular apoptosis. In addition, compared with the control group, conidia production in 1.5 mg/mL DM/cinnamaldehyde, DM/nonanal and DM/SCAN groups were decreased by 27.16%, 48.22% and 76.66%, respectively, and the aflatoxin B1 (AFB1) contents decreased by 2.00%, 73.02% and 84.15%, respectively. These finding suggest that DM/SCAN complex has potential uses in food preservation.

Effectiveness of nano dust enhanced with pirimiphos-methyl in controlling Sitophilus oryzae on wheat grain

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.

Analytical characterization of filtration laws in filter aid filtration

In this study, the blocking filtration laws introduced by Hermans and Bredée are applied to evaluate filter aid filtration data. A model system is utilized for the filtration experiments, consisting of barium sulphate as the model impurity and diatomaceous earth as the filter aid. Based on the analysis of the filtration data, the relevant process laws are initially identified as cake filtration for the separation of the diatomaceous earth and the so-called missing law for the separation of barium sulphate. The results are substantiated with the aid of X-ray microscopy to monitor the incorporation of the fine particles in the filter aid structure. They demonstrate that the separation of barium sulphate is characterised by both depth migration and accumulation within the growing filter aid structure. The blocking filtration laws derive from a general exponential relationship between blocking rate φ and hight-specific resistance r with the blocking exponent n. Hermans and Bredée presented first the solutions for the four blocking exponents n=2 (complete blocking), n=1.5 (standard law), n=1 (intermediate law) and n=0 (cake filtration). Gonsalves later supplemented the solution for n = 0.5 from a purely logical point of view and called it the missing law, as he could not find a model behind it himself. Thus, for the first time, this study assigns a separation principle to the missing law, which until now has only been discussed theoretically.

Insecticidal activity of two amorphous silica powders applied to concrete surfaces against the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae)

The increased demand for residue-free food grains has led to exploring diatomaceous earth formulations as potential alternatives to synthetic insecticides. In the present study, we evaluated the efficacy of two amorphous silica powders 1 and 2 with different elemental composition, particle diameter, and shape characteristics against the confused flour beetle, Tribolium confusum Jacquelin du Val. The insecticidal activity of the two silica powders was determined by exposing T. confusum adults to silica powder treated concrete arenas at different application rates (0, 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 g/m2) for 12, 24, 36, and 48 h. Mortality assessments were made after 14 d, and adult progeny counts were made at 42 d. Silica powder 2 demonstrated greater efficacy and produced 100% adult mortality and completely inhibited adult progeny production when adults were exposed for 24 h to an application rate of 4.0 g/m2. Complete mortality and complete suppression of adult progeny production was noticed after 36 h exposure to 3.5 g/m2 of silica powder 1. Exposure of T. confusum adults to 6 g/m2 of silica powder 1 and 4 g/m2 of silica powder 2 gave complete mortality after 24 and 20 h, respectively. No adult progeny production was observed when adults were exposed for 24 h to 6 g/m2 and 4 g/m2 of silica powder 1 and silica powder 2, respectively. These findings suggest that the two silica powders hold promise for managing T. confusum, particularly in treating empty bin floors before storing new grains.

EVALUATION OF THE EFFECTIVENESS OF NO REMOVAL USING THE PHOTOCATALYTIC ACTIVATED MATERIAL S-TiO2/DIATOMITE

S-TiO2 typically exhibits high photocatalytic activity, but its powdered form makes it difficult to apply practically in environmental pollution treatment. Diatomite from different locations varies in purity and integrity of the diatomaceous earth, making it a suitable catalyst support for synthesizing mixed-phase S-TiO2 catalysts using the sol-gel technique. The synthesized photocatalyst exhibits photocatalytic activity similar to that of S-TiO2. The NO removal efficiency under the same conditions with different catalyst supports only decreases by approximately 3% within 30 minutes at a reaction rate of 0.0950 min-1, with an optimal mass ratio of 70:30 for S-TiO2 and diatomite. This composite material holds promise for addressing the application of photocatalytic materials in practical environmental treatment, including NO removal and the treatment of other environmental pollutants, as diatomite is a naturally available and environmentally friendly material.