•The removal of Zn(II) ions from aqueous solution was studied using natural and MnO
2 modified diatomite samples at different temperatures. • The sorption of Zn(II) on the natural and modified ...diatomite was an endothermic processes, controlled by physical mechanisms and spontaneously. • Adsorption of zinc metal ion on diatomite samples is more or less a two step process. • Adsorption of Zn(II) on natural and modified diatomite could be explained by the mechanism of pseudo-second-order.
The removal of Zn(II) ions from aqueous solution was studied using natural and MnO
2 modified diatomite samples at different temperatures. The linear Langmuir, Freundlich and Dubinin–Radushkevich (D–R) adsorption equations were applied to describe the equilibrium isotherms. From the D–R model, the mean adsorption energy was calculated as >8
kJ
mol
−1, indicating that the adsorption of Zn(II) onto diatomite and Mn-diatomite was physically carried out. In addition, the pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to determine the kinetic data. The experimental data were well fitted by the pseudo-second-order kinetic model. Thermodynamic parameters such as the enthalpy (Δ
H
0), Gibbs’ free energy (Δ
G
0) and entropy (Δ
S
0) were calculated for natural and MnO
2 modified diatomite. These values showed that the adsorption of Zn(II) ions onto diatomite samples was controlled by a physical mechanism and occurred spontaneously.
A number of studies have demonstrated that depth filtration can provide significant adsorptive removal of host cell proteins (HCP), but there is still considerable uncertainty regarding the ...underlying factors controlling HCP binding. This study compared the binding characteristics of two fine grade depth filters, the X0SP (polyacrylic fiber with a synthetic silica filter aid) and X0HC (cellulose fibers with diatomaceous earth (DE) as a filter aid), using a series of model proteins with well‐defined physical characteristics. Protein binding to the X0SP filter was dominated by electrostatic interactions with greatest capacity for positively‐charged proteins. In contrast, the X0HC filter showed greater binding of more hydrophobic proteins although electrostatic interactions also played a role. In addition, ovotransferrin showed unusually high binding capacity to the X0HC, likely due to interactions with metals in the DE. Scanning Electron Microscopy with Energy Dispersive Spectroscopy was used to obtain additional understanding of the binding behavior. These results provide important insights into the physical phenomena governing HCP binding to both fully synthetic and natural (cellulose + DE) depth filters.
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•Improving energy efficiency in centennial Korean historic buildings via retrofit.•Development of retrofit with diatomaceous earth and phase change materials.•Reduce condensation ...risks without damaging the building’s historical value.•The historic building withstands outdoor climates despite no insulation.•Save energy solely with interior finishing materials, without insulation.
Historic buildings require groundbreaking retrofit technology to prevent damage to the exterior appearance of the exterior. This paper presents a retrofit technology to increase the energy efficiency of old historic buildings that were heavily exposed to hygrothermal conditions. The study employed an innovative interior finishing material composed of diatomaceous earth and microencapsulated phase change materials to achieve a trade-off between performance improvement and heritage conservation. Based on previous studies, an optimal formulation was identified through evaluation. The developed retrofit technology displays crack resistance, high latent heat capacity, and remarkable moisture stability. Our analysis revealed that the application of this retrofit solution would effectively reduce moisture levels and mitigate condensation risks without compromising the building’s historical integrity. The retrofit technology yielded a reduction in cooling and heating energy consumption by over 10% while concurrently addressing moisture stability through a decrease in the thermal transmittance of the exterior walls. By utilizing passive technologies and the unique properties of diatomaceous earth, our pioneering research on the sustainable preservation of historic buildings has laid the foundation for widespread retrofit adoption in heritage conservation.
Filtration methods for alcoholic fermented beverages often use filter aids such as diatomaceous earth (DE), which may contain elevated amounts of the heavy metals arsenic (As), lead (Pb), and cadmium ...(Cd). Here, we evaluated factors affecting transfer of these heavy metals from DE to beer and wine. A laboratory-scale filtration system was used to process unfiltered ale, lager, red wine, and white wine with three types of food-grade DE. Filtrate and DE were analyzed for heavy metals using ICP-MS, in addition to LC-ICP-MS for As-speciation analysis. Use of 2 g/L DE containing 5.4 mg/kg soluble inorganic As (iAs) for filtering beer and wine resulted in significant (p < 0.05) increases of 11.2–13.7 μg/L iAs in the filtered beverage. There was a significant (p < 0.05) effect from the DE quantity used in filtration on the transfer of iAs in all beverage types, whereas no alterations were observed for Pb and Cd levels. Methods to wash DE using water, citric acid, or EDTA all significantly (p < 0.05) reduced iAs concentrations, whereas only EDTA significantly reduced Pb levels. Cd concentrations were not affected by any wash method. These data indicate that specific steps can be taken to limit heavy-metal transfer from DE filter aids to beer and wine.
A key element in postharvest IPM is the reduction of chemical residues in food through the use of reduced dosages of less toxic grain protectants. Two laboratory experiments were conducted: ...Experiment I determined the efficacies of straight diatomaceous earths (DEs) – “Chemutsi” (African raw DE), MN51 (new formulation) and Protect-It® (enhanced DE), and two new food grade DE-based formulations (A2 and A3) against adult Prostephanus truncatus (Horn), Sitophilus zeamais (Motschulsky) and Tribolium castaneum (Herbst) admixed with shelled maize. In Experiment II, Chemutsi and Protect-It® were further tested in varying combinations with low-dose deltamethrin and spinosad. At 21 days post-exposure, MN51 800 ppm and 1000 ppm, Chemutsi 1000 ppm, Protect-It® 600 ppm and food grade A3 150 ppm caused S. zeamais mortalities that were not significantly different from the positive control (Protect-It® 1000 ppm). However, after the same exposure period, all the straight DEs (applied at ≤ 1000 ppm) and the DE-based food grade formulations were not effective on P. truncatus and T. castaneum. In low dose combinations, 7 day mortalities showed high S. zeamais susceptibility to both DE-spinosad and DE-deltamethrin while P. truncatus was more susceptible only to DE-spinosad and T. castaneum to Protect-It®-deltamethrin only. At 21 days, all DE-spinosad and DE-deltamethrin treatments were effective and not significantly different from the commercial grain protectant (fenitrothion 1.0% w/w (10000 ppm) + deltamethrin 0.13% w/w (130 ppm)) on all test species. DE-spinosad and DE-deltamethrin combinations significantly suppressed (P < 0.001) F1 progeny for the three test species whereas straight DEs and DE-based food grade formulations did not. Our results showed that at half the label rates or lower, DE-spinosad and DE-deltamethrin combinations were effective alternative grain protectants that are safer and possibly cheaper. We also give the first report on the effectiveness of Chemutsi in combination with spinosad or deltamethrin on maize grain.
•DEs alone were ineffective against both parent populations and F1 progeny.•Prostephanus truncatus was more susceptible to DE + spinosad than to DE + deltamethrin.•Local DE + spinosad and Protect-It®+deltamethrin were most effective on S. zeamais.•DE + spinosad and DE + deltamethrin were effective at half label dose or less.•Local raw DE was effective at ≤1000 ppm combined with low dose spinosad or deltamethrin.
Superhydrophobic surfaces for self-cleaning applications often suffer from mechanical instability and do not function well after abrasion/scratching. To address this problem, we present a method to ...prepare graphene-based superhydrophobic composite coatings with robust mechanical strength, self-cleaning, and barrier properties. A suspension has been formulated that contains a mixture of reduced graphene oxide (rGO) and diatomaceous earth (DE) modified with polydimethylsiloxane (PDMS) that can be applied on any surface using common coating methods such as spraying, brush painting, and dip coating. Inclusion of TiO2 nanoparticles to the formulation shows further increase in water contact angle (WCA) from 159 ± 2° to 170 ± 2° due to the structural improvement with hierarchical surface roughness. Mechanical stability and durability of the coatings has been achieved by using a commercial adhesive to bond the superhydrophobic “paint” to various substrates. Excellent retention of superhydrophobicity was observed even after sandpaper abrasion and crosscut scratching. A potentiodynamic polarization study revealed excellent corrosion resistance (96.78%) properties, and an acid was used to provide further insight into coating barrier properties. The ease of application and remarkable properties of this graphene-based composite coating show considerable potential for broad application as a self-cleaning and protective layer.
Natural inert dust has been used as a grain protectant since the ancient Aztecs of Mexico to this modern era. Natural inert dust is divided into three groups: the first group includes sand, kaolin, ...paddy husk ash, wood ash, and clay; the second group includes mineral dust; and the third group includes natural silicas such as diatomaceous earth and zeolite. Natural inert dust has a unique mechanism for killing insect pests. Inert dust particles penetrate the insects’ exoskeleton, causing dehydration through the cuticle. Relative humidity is a crucial factor affecting the efficacy of inert dust application. Inert dust has been traditionally used by farmers, which impacts the insects, such as decreasing population, no insect resistance, and being environmentally friendly. Problems of using inert dust include visible residues on grain, airborne dust, reduced flowability, bulk density reduction, and adverse effects on downstream processing machinery. Moreover, inert dust is a very light product, thus it may cause human respiratory illness. The inert dust can be applied to the smaller or larger storage containers. Natural silica can be readily integrated into modern agriculture as a pest management solution.
Residual diatomaceous earth (RDE) from winemaking activities is a rich and currently underexploited source of phenolic compounds which ought to be recycled from the perspective of circular ...bioeconomy. In this work, we demonstrate the feasibility of molecularly imprinted polymers (MIPs) for the enrichment of quercetin, a flavonoid at a fairly high content in residual diatomaceous earth. These MIPs were synthesized through free radical polymerization. FTIR confirmed the integration of the functional monomers into the polymeric chains. Batch adsorption experiments were used to assess the retention and selectivity of those MIPs towards quercetin. Commercial resins were compared with the synthesized materials using the same procedures. These adsorption experiments allowed the selection of the best performing MIP for the valorization of RDE extract. This treatment consisted of saturating the selected MIP with the extract and then desorbing the retained compounds using solvents of selected compositions. The desorbed fractions were analyzed using liquid chromatography, and the results demonstrated an increase in quercetin’s fractional area from 5% in the RDE extract to more than 40% in some fractions, which is roughly an eightfold enrichment of quercetin. Moreover, other flavonoids of close chemical structure to quercetin have been rather retained and enriched by the MIP.
Lithium metal based anode with hierarchical structure to enable high rate capability, volume change accommodation, and dendritic suppression is highly desirable for all-solid-state lithium metal ...battery. However, the fabrication of hierarchical lithium metal based anode is challenging due to the volatility of lithium. Here, we report that natural diatomite can act as an excellent template for constructing hierarchical silicon-lithium based hybrid anode for high performance all-solid-state lithium metal battery. This hybrid anode exhibits stable lithium stripping/plating performance over 1000 h with average overpotential lower than 100 mV without any short circuit. Moreover, all-solid-state full cell using this lithium metal composite anode to couple with lithium iron phosphate cathode shows excellent cycling stability (0.04% capacity decay rate for 500 cycles at 0.5C) and high rate capability (65 mAh g
at 5C). The present natural diatomite derived hybrid anode could further promote the fabrication of high performance all-solid-state lithium batteries from sustainable natural resources.
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•Diatomite (DM) had no obvious negative effect on maturity of composts.•DM promoted the transformation from NH4+-N to AAN and HUN, and thus reduced N loss.•The optimum added dosage of ...DM in pig manure composting was at 10% among 0–20%.•10% DM reduced the relative abundance of narG, nirS, nirK and nosZ.
The aim of this study was to investigate the pathways and mechanisms of nitrogen transformation during the composting process, by adding diatomite (0%, 2.5%, 5%, 10%, 15% and 20%) into initial mixtures of pig manure and sawdust. The results revealed that diatomite facilitated the conversion from NH4+-N to amino acid nitrogen and hydrolysis undefined nitrogen, then reduced NH3 and N2O emission by 8.63–35.29% and 14.34–73.21%, respectively. Moreover, the structure and abundance of nitrogen functional genes provided evidence for nitrogen loss. Furthermore, compared with the control (0.03), the treatment blended with 10% diatomite (T3) had the highest value in composting score (-1.27). Additionally, the ratio of carbon and nitrogen (57.30%) was vital for reducing nitrogen loss among all physio-chemical parameters in this study. In conclusion, adding diatomite was a practical way to enhance nitrogen conservation and increase quality of end products, and the optimum added dosage was at 10%.
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