Diatomite coated plate and frame filter press as novel harvest method of microalgae biomass: Design and pilot-scale study.

This study reports the methylene blue (MB) uptake capacity and absorption kinetics of adsorbents obtained by the hybridisation of natural diatomaceous earth with hydrophilic carbon nanoparticles at two different loadings (2 and 5 wt.%). The materials were characterized and tested as adsorbents of MB in acidic and basic pH. The effects of MB concentration (25-400mg‧L-1), contact time (1-120min), and adsorbent mass (10-50mg) on the adsorption process were investigated. The diatomite and diatomite-based adsorbents showed high uptake capacities (highest experimental adsorption capacity qexp464.87mg·g⁻1) and favorable kinetics, well described by the Elovich model, suggesting a chemisorption-driven mechanisms. The Freundlich model provides a superior fit compared to the Langmuir model, particularly for the hybrid samples, indicating a favorable and heterogeneous adsorption mechanism consistent with multilayer adsorption on non-uniform surfaces. Regenerability and reusability of the adsorbents was demonstrated over three MB adsorption-desorption cycles. Effective performance across pH 3-8 highlights their versatility for real-world water treatment applications. The hybridisation also improves the cyclability and the uptake capacities in an acid environment (pH = 3). This high uptake capacity across a broad range of pH values makes the hybrid materials versatile and easy to integrate into existing water treatment systems.

Filth flies pose a health risk because of the microbes they carry outside and inside of their bodies to humans and animals. Mostly synthetic chemical insecticides are used for fly control. Alternative approaches with a different mode of action are needed because of increasing fly resistance to pesticides. We used a modified World Health Organization cone test to determine the efficacy of the minerals produced by diatoms (diatomaceous earth) as a mechanical insecticide against adults of the house fly, Musca domestica, the secondary screwworm, Cochliomyia macellaria, and the grey flesh fly, Sarcophaga bullata, under low and high humidity. The use of mechanical insecticides as an alternative to kill filth flies has received minimal consideration. However, recent research showed that expanded perlite, a new mechanical insecticide made from volcanic rock, was highly efficacious against mosquitoes and flies. Mortality for diatomaceous earth in this paper at 30°C and 50% relative humidity was observed as early as 2 h after exposure with 50% and 90% mortality observed at 3.5 and 4.6 h (the LT50 and LT90, respectively) in M. domestica. The LT50 and LT90 increased as the size of the fly species increased (M. domestica to C. macellaria to S. bullata) and increased for all three species when the relative humidity increased from 50 to 70%. These results suggest dehydration was the mode of action. Scanning electron micrographs of C. macellaria adults 2 h after diatomaceous earth exposure, showed the flies were evenly self-covered with the mineral with no obvious damage to the cuticle. Proof of concept was demonstrated that diatomaceous earth as a residual surface treatment could be used as an alternative for filth fly control.

Dust formulations are important alternatives for bed bug control, yet their efficacy against tropical bed bugs (Cimex hemipterus (F.)), which frequently exhibit pyrethroid resistance, remains poorly defined. We evaluated 2 desiccant dusts (CimeXa, diatomaceous earth [DE]) and 2 chemical dusts (DeltaDust, Drione) against 3 pyrethroid-resistant C. hemipterus strains with documented cuticle variation and compared them with a susceptible Cimex lectularius L. (Monheim). Bioassays simulated continuous exposure, brief (5 min) contact, sublabel (50% rate) application, and horizontal transfer. Desiccant dusts, particularly CimeXa (silica), consistently achieved rapid and complete mortality in resistant C. hemipterus, outperforming DE and pyrethroid-based dusts. Chemical dusts were more constrained: DeltaDust (deltamethrin) was largely ineffective, while Drione (pyrethrin + PBO + silica gel) killed susceptible C. lectularius rapidly (<1 h) but was markedly slower in resistant C. hemipterus, reflecting kdr mutations and cuticle-mediated tolerance. Reduced dosage and brief exposure prolonged survival times, and horizontal transfer produced the greatest delays, although both pathways ultimately resulted in high mortality. Strain comparisons revealed a susceptibility hierarchy (SEL_MY > PEN2_MY > KUL_MY), consistent with cuticle thickness, indicating that thickened cuticles delay desiccant activity under direct exposures. Importantly, the effect of cuticle thickness was minimized for CimeXa under horizontal transfer but persisted for Drione. By linking exposure dynamics with kdr and cuticle-mediated resistance, this study shows that chemical dusts remain strongly constrained by resistance mechanisms, whereas silica-based desiccants-despite delayed action in strains with thickened cuticles-retain superior reliability and represent the most effective dust formulations for sustainable bed bug management.

Quantification, Risk Assessment, and Mitigation of Cashew Allergen Cross-Contact in Shared Roasting Oil Systems.

This study presents the fabrication of tungsten oxide-tungsten disulfide, h-WO3/2H-WS2 (WSxOy), and its integration on the nanostructured diatomaceous earth (DE) microalgae surface to obtain a novel photocatalyst known as DE-h-WO3/2H-WS2 (DE-WSxOy) for the first time. It is significant to mention that the integration of WSxOy on the DE surface is directed toward enhancing the overall photocatalytic properties and performances. The developed novel photocatalyst is characterized using various techniques to study its morphological surface chemistry features, interface interactions and photochemical properties. The novelty of this study lies in the synthesis of a new photocatalyst integrated with microalgae, enabling rapid and high-performance solar-driven degradation. Importantly, through the support of the DE surface, the photocatalyst exhibits higher photocatalytic ability in aqueous phase reactions when compared with WSxOy alone, which could be due to synergistic effects such as higher adsorption properties, dispersibility, stability and more catalytic reaction sites. Furthermore, using rhodamine B (Rh B) as a model pollutant, the designed photocatalyst validated with 99.8% of decoloration efficiency was achieved. The prepared photocatalyst exhibits excellent photocatalytic degradation efficiency under various solution conditions for multiple dyes and mixed dye solutions, demonstrating its potential industrial significance. Besides, this work expanded towards investigating its photocatalytic reaction mechanisms and factors affecting photocatalytic activities. As a proof of concept/pioneering technology, the DE-WSxOy photocatalyst was integrated with PDMS in the form of easily adaptable discs to explore the real-time photodegradation of industrial wastewater (IWW), which can be regarded as next-generation photocatalyst development.

The effectiveness of the entomopathogenic fungus Metarhizium anisopliae and Diatomaceous earth on the adults of stored grain insect’s species i.e. Tribolium caustaneum, Rhyzopertha dominica, Sitophilus granarius were tested at the laboratory of Regional agricultural research institute Bahawalpur. The tests were performed either alone or in conjunction with Grain guard (natural). A dosage rate of 1.7×104 was used for the fungal formulations, while 50 and 100 ppm of Grain Guard (Natural) were administered. The experiment was conducted at a temperature of 30 ± 1℃ and relative humidity of 65 ± 5%. In all treatments, mortality rate of insects was observed following exposure at intervals of 7, 14, and 21 days. After maximum exposure time, at a dosage rate of 100 ppm, T. castaneum, S. granarius, and R. dominica all reached maximum mortality rates of 70.49, 74.62, and 77.21, respectively, when treated with Grain Guard Natural. The corresponding mortality rates for T. castaneum, S. granarius, and R. dominica at lower doses of fungal spores were 26.35, 28.36, and 29.61, respectively. When the fungal formulations and Grain Guard Natural were used together at the maximum dosage rate of 100 ppm+1.7×104, 87.15 percent mortality was noted for T. castaneum, 92.35% for S. granarius, and 95.14% for R. dominica. For R. dominica, S. granarius, and T. castaneum, the proportion of mycotic insects was 81.86, 78.62, and 76.12 at a dosage rate of 1.7×104, respectively.

The development of efficient and recyclable catalysts is a central pursuit in modern chemistry. Homogeneous catalysts, while effective, often suffer from challenges in separation and recovery, driving the exploration of heterogeneous systems. In this context, this study introduces a novel composite photocatalyst, Ru(bpy)2(bda)-Ru(bda)(cp)2@DE (PS/Cat@DE), synthesized by attaching a catalyst (Cat) and a photosensitizer (PS) to diatomaceous earth (DE). The hypothesis that covalently binding the photosensitizer and photocatalyst to the surface of DE could enhance their reactivity and may protect them from degradation was supported by the enhanced photocatalytic performance observed in this study. The composite materials and single components were characterized using UV-Vis and FTIR spectroscopy, as well as SEM, and EDS microscopy. Photocatalytic experiments demonstrated the significantly higher activity of the PS/Cat@DE material compared to equivalent concentrations of the single photosensitizer or photocatalyst components, indicating the crucial role of DE in promoting oxygen evolution.

Abstract The use of direct and treated recycled concrete aggregate (RCA) mitigates natural aggregate depletion, reduces construction and demolition (C&amp;D) waste, and promotes sustainable construction. However, the fire resistance of treated recycled aggregate concrete (RAC) remains a critical concern. This study investigates the physical, mechanical, and microstructural performance of banana fiber-reinforced diatomaceous earth (DE) slurry-treated RAC at room temperature and after exposure to 200 °C, 400 °C, 600 °C, and 800 °C. Three treated coarse RCA types were produced by coating RCA with a slurry containing 5% DE, treated banana fiber (3%, 5%, and 7%), and ordinary Portland cement. The heating methodology followed the ISO 834 standard fire curve, and results were compared to those of concrete made with untreated RCA (UT-RAC) and natural aggregate (NAC). Concrete incorporating optimally treated RCA (5/5-RAC) retained 26–30% more compressive strength than UT-RAC and over 95% of NAC’s strength across all temperature exposures. The density improved by 15–20%, while peak strain decreased by 8.2–18.0%, indicating enhanced stiffness. The splitting tensile strength increased by 18–22%, while mass loss, capillary water absorption, and porosity were reduced by 20%, 25%, and 27.42%, respectively, at 800 °C. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) confirmed improved retention of calcium silicate hydrate (C-S–H) phases and reduced microstructural degradation in treated RAC. The combined action of DE and banana fibers enhanced ITZ densification, C-S–H phase stability, and thermal crack resistance. These findings demonstrate that optimized DE-banana fiber slurry treatment can significantly improve the fire resistance and structural performance of RAC, contributing to sustainable construction.

Abstract In March 2024, a Slovenian warmblood gelding presented with severe pruritus and skin lesions throughout its head, neck and around the base of the tail. The owners had observed increased pruritus in multiple animals within the herd. After careful examination, Bovicola equi were found in all five horses, but not the pony. Horse owners requested an environmentally sustainable treatment plan, which consisted of (a) mechanical removal of lice by shaving and/or combing, (b) application of 0.2 g/horse (0.1 g/pony) neem extract, geraniol (0.5 g/horse, 0.25 g/pony) and diatomaceous earth (250 g/horse, 50 g/pony). Clinical signs ceased 1 week after the initial treatment, no lice were found after 3 weeks, and skin lesions resolved within 6 weeks. Although there was no control group to estimate the true efficiency of the described treatment, upon follow‐up, all horses remained lice‐free for at least 18 months after the last treatment.

HighlightsWhat are the main findings?Use of organic materials in the production process of polymer composites.Enabling the characterization of milling parameters of modern, ecological materials enriched with organic filler.Reducing the amount of environmental waste.What is the implication of the main finding?No effect of diatomaceous earth content on the machinability of the analyzed composites was observed.Excessive temperature in the cutting zone may cause superficial melting, which deteriorates surface quality.During machining, the values of the feed component of the cutting force were below 11N.In this study, the milling process of eco-friendly polymer composites enriched with an organic filler was analyzed. Polyhydroxyalkanoate was filled with 0.5%, 1%, and 2% of diatomite and produced via injection molding. Then, the milling process was performed on the obtained samples to determine the effect of diatomite content on the machinability of the produced composites. The results showed that the analyzed diatomite content in the machined samples had no significant influence on the cutting process. If the cutting parameters are not properly selected, excessive heat generated during machining can lead to a heterogeneous geometric surface microstructure. The milling process resulted in a series of high-quality surfaces (Ra < 2 μm), chip temperatures below 90 °C, and a feed component of the total cutting force below 11 N.

Utilization of agro-industrial wastes as soil amendment manages acidity, remediates heavy metals, and ensures environmental sustainability. The present study aims to test non-conventional organic Si sources, milled rice husk char (TMRHC), and powdered diatomaceous earth (TDE) against burnt lime (TBL) and calcium silicate (TCS) for amending iron (Fe) toxicity and acidity at tillering (TI), panicle initiation (PI), and harvest (HA) of a short duration rice variety Manuratna in lateritic rice wetlands of Kerala. Irrespective of the growth stages of rice, TMRHC recorded the lowest water-soluble Fe (WS-Fe), acid-soluble Fe (AS-Fe), manganese oxide (MnO)-occluded Fe (MN-Fe), and residual Fe (RS-Fe) fraction in soil. WS-Fe indirectly enhanced Fe adsorption into specifically adsorbed lead displaceable Fe (SP-Fe) and AS-Fe, whereas AS-Fe abridged the Fe adsorption between WS-Fe and MN-Fe > OM-Fe. Organic Si sources recorded a strong negative influence on organic matter-occluded Fe (OM-Fe) (standardized path coefficientp = - 0.94), amorphous iron oxide (FeO)-occluded Fe (AM-Fe) (p = - 0.74), and crystalline FeO-occluded Fe (CR-Fe) (p = - 0.53) content in soil. Fractions of Fe and forms of acidity were significantly (p = 0.05) and positively correlated. TBL maintained the highest soil pH at all the critical growth stages (5.90(TI), 6.04(PI), and 5.99(HA)) of rice, which was statistically on par with TMRHC (5.90(TI), 6.02(PI), and 5.96(HA)). The highest reduction of Fe in rice was recorded with TBL at TI (16%) and PI (18.76%), while at HI (21%), TMRHC was found to the most effective. TBL and TMRHC were statistically on par in reducing WS-Fe (at PI and HA), exchangeable acidity and extractable acidity (at TI), and total acidity (at HI). The grain yield of Manuratnarice was found to vary in the order TCS > TMRHC and TBL.

In the presence of diatomaceous earth microparticles, Pickering emulsions of the first kind of epoxy oligomer CHS-EPOXX 530 were obtained. The patterns of change in their rheological properties depending on the oligomer concentration, volume ratio of phases, and content of solid powder stabilizer (diatomaceous earth) were established. In particular, it was found that with an increase in the concentration of the oligomer and stabilizer (diatomaceous earth), there is an increase in interparticle interaction, an increase in the effective viscosity of emulsions, and the formation of a coagulation-thixotropic structure that breaks down under slight shear deformation with the establishment of quasi-Newtonian flow. The nature of the influence of these factors on the physical and mechanical properties of the coatings and films obtained using these emulsions has been established. The data obtained indicate the good film-forming properties of such emulsions and the prospects for their use in various practical applications: as film formers for paint and varnish materials containing a limited amount of organic solvents, non-drying adhesive coatings, and two-component adhesive compositions. In particular, the developed cold-curing adhesive can be recommended for the repair of concrete structures, including bridges, in order to preserve their functional suitability and increase their load-bearing capacity.

Diatomaceous earth (DE) is widely recognized as an effective physical insecticide due to its ability to dehydrate and kill insects. However, emerging evidence suggests that DE and similar artificial materials also induce nanotoxic effects, highlighting the need for a deeper understanding of its insecticidal mechanisms. We examined the effects of DE nanoparticles (DNP) and DE microparticles (DMP) using red flour beetles (Tribolium castaneum) and fruit fly (Drosophila melanogaster) S2 cells. Our results demonstrate that while DMP primarily causes water loss, DNP induces significant cytotoxicity in insects. To uncover the cellular uptake mechanism underlying this nanotoxicity, we screened candidate pathways using chemical inhibitors in S2 cells and identified the involvement of clathrin-dependent endocytosis in the DNP cytotoxicity. This finding was further validated through RNA interference in T. castaneum. Our study elucidates the distinct mechanisms of DE insecticidal activity and establishes DNP as a natural nanoinsecticide with potential for sustainable pest management. © 2025 Society of Chemical Industry.

Abstract The cement industry is responsible for 6-7% of anthropogenic carbon dioxide emissions worldwide. Pollution is not limited to gas emissions; it also includes dust, water, soil and noise pollution; consequently, various alternatives have been explored to mitigate this environmental impact. This project proposes a viable alternative known as hybrid cement; in this binder system, the decarbonization of calcium carbonate is primarily achieved through its reaction with sodium hydroxide in solution under magnetic stirring resulting in an activated powder composed of portlandite. Subsequently, a source of silica - found in natural pozzolans, specifically diatomaceous earth subjected to a prior thermal treatment - is introduced to promote the formation of calcium silicate hydrated type compounds. Finally, ordinary Portland cement is added to obtain the hybrid material under standard curing conditions. The hybrid pastes produced consist of 10 wt.% activated powder, 10-40 wt.% diatomaceous earth, and 50-90 wt.% ordinary Portland cement. The aim of this project was to evaluate the mechanical behavior and reaction products of the hybrid pastes at different curing ages (3 days, 7 days, and 28 days) using both immersion curing and curing chamber. Among the hybrid pastes studied, the highest compressive strength achieved was 39.6 MPa, demonstrating the material’s potential as a viable alternative to conventional cementitious systems. Scanning electron microscopy analysis confirmed the effective formation of calcium silicate hydrated type compounds and ettringite, which was corroborated by X-ray diffraction analysis. Additionally, it was demonstrated that hybrid pastes do not require special curing conditions to improve their mechanical properties.

Dry silica dust-based products for management of ixodids.

The eastern bat bug, Cimex adjunctus Barber (Hemiptera: Cimicidae), is an ectoparasite of bats that can occasionally infest human dwellings, posing a potential public health concern. When found in homes, they are often treated with insecticides labeled for bed bugs (Cimex lectularius L.). However, there are no data available on the efficacy of these pesticides against bat bugs. This study assessed the efficacy of 3 commercial insecticide sprays containing pyrethroid or pyrethroid-neonicotinoid mixture and 2 insecticide dusts containing deltamethrin or diatomaceous earth (DE) against a field-collected strain of bat bugs. One susceptible and 2 resistant bed bug strains were included for comparison. Exposure to dry pyrethroid or a pyrethroid-neonicotinoid mixture residue for 5 min caused 90% to 100% mortality in bat bugs and the susceptible bed bug strain, whereas only 0% to 13% mortality in the 2 resistant bed bug strains. Brief (crossing a 2.5 cm treated band) or continuous exposure to 4.75% deltamethrin dust caused 100% mortality to bat bugs and the susceptible strain of bed bugs, but less than 20% mortality in the 2 resistant strains of bed bugs. DE dust caused 100% mortality to bat bugs and all bed bug strains, but the time to achieve this was much longer than with deltamethrin dust treatment (4 to 6 d compared to 4 h). Bat bugs showed similar susceptibility to the tested insecticides as the susceptible bed bug strain, except that a slower mortality occurred in the CrossFire (0.4% clothianidin, 0.01% metofluthrin, 1% piperonyl butoxide) spray treatment.

A recent outbreak of X-disease, caused by the phytoplasma "Candidatus Phytoplasma pruni," has severely harmed stone fruit production in the Pacific Northwest region of the United States. X-disease is spread by leafhopper vectors, primarily Colladonus montanus reductus in Washington and Euscelidius variegatus in Oregon. Growers rely on frequent insecticide applications and removal of infected trees, but these management recommendations originate from California when the last outbreak occurred in the 1980s. To update insecticide efficacy information for X-disease vectors, we evaluated 23 commercially available insecticidal products via direct spray, spray residues, systemic uptake by plants, or repellency assays. In direct spray bioassays, insecticides containing pyrethrins, pyrethroids, neonicotinoids, or organophosphates caused 100% mortality of C. m. reductus after 24 h. More selective chemistries including cyantraniliprole, flonicamid, and botanical essences also caused high mortality (>70%) of C. m. reductus (Van Duzee). For residues, neonicotinoids and pyrethroids caused the greatest mortality (≥70%) of C. m. reductus. Systemic uptake of neonicotinoids caused significantly higher mortality (51.4% to 100%) than controls (1.4% to 32.4%) of C. m. reductus. Direct sprays and 5 d residues of neonicotinoids caused high mortality (>70%) of E. variegatus. Cherry leaves treated with either kaolin clay or diatomaceous earth had 80% to 90% fewer C. m. reductus residing on them than the controls. Overall, pyrethroids and neonicotinoids were the most effective, but more selective chemistries and repellent clays showed potential and need to be validated in field conditions. Future work should integrate insecticides, repellents, and cultural tactics with phenology-based treatment timings to improve management sustainability.

The efficacy of seven inert materials was studied against bruchid, Caryedon serratus under laboratory conditions on groundnut at the Department of Entomology, N.M. College of Agriculture, Navsari Agricultural University, Navsari during the year 2023-24. Among the different inert materials tested, the minimum per cent adult emergence, pod damage and weight loss were recorded in the treatment of diatomaceous earth at 10 per cent (w/w) after 60, 90 and 120 days of storage, while maximum per cent adult emergence, pod damage and weight loss were recorded in in the treatment of saw dust at 10 per cent after 60, 90 and 120 days of storage. The groundnut pod treated with saw dust kaolinite clay, silica powder and wood ash were found moderately effective against the bruchid, C. serratus.. KEYWORDS :Groundnut, bruchid, Caryedon serratus, inert material, diatomaceous earth, saw dust

Diatomaceous earth (DE), or diatomite, constitutes the fossilized silica frustules of diatoms. Historically utilized as an industrial absorbent and filtration medium, it has recently garnered significant attention as an advanced material in nanotechnology and engineering. This transition is driven by its inherent physicochemical properties, which include a hierarchically porous architecture, high specific surface area, low density, and chemical stability, collectively rendering it an effective natural micro- and nano-structured scaffold. This review provides a systematic examination of the seminal scientific and engineering progress in diatomite research from 2014 to 2025. The analysis is structured around three primary themes: (1) the advancement of sophisticated chemical, physical, and biological strategies for surface activation and functionalization; (2) the rational design and fabrication of hybrid diatomite-based composites incorporating polymeric, metallic, metal oxide, and carbonaceous phases; and (3) the diversification of its application spectrum into domains including catalysis, energy storage (e.g., Li-ion batteries, supercapacitors), construction, environmental remediation, biomedical engineering (e.g., drug delivery, biosensing), and thermal/acoustic management. This work critically evaluates key performance indicators, synthesizes prevalent characterization techniques, and incorporates sustainability analyses from a life-cycle perspective.