Innovative DIY drinking water disinfection for underserved communities.

Waterborne pathogens threaten 2.2 billion people lacking access to safely managed drinking water services, causing over a million annual diarrheal deaths. Individuals without access to chlorine reagents or filtration devices often resort to do-it-yourself (DIY) methods, such as boiling or solar disinfection (SODIS). However, these methods are not simple to implement. In this study, we introduced an innovative and easily implemented disinfection approach. We discovered that immersing aluminum foil in various alkaline solutions produces alkali-treated aluminum foil (ATA foil) that effectively adsorbs Escherichia coli (E. coli), Salmonella, and Acinetobacter through the generated surface aluminum hydroxide. For example, a 25 cm2 ATA foil efficiently captures all 104E. coli DH5α strains in 100 mL water within 30 min. Using a saturated suspension of magnesium hydroxide, a type of fertilizer, as the alkaline solution, the properties of the saturated suspension eliminate the need for measuring reagents or changing solutions, making it easy for anyone to create ATA foil. ATA foils can be conveniently produced within mesh bags and placed in household water containers, reducing the risk of recontamination. Replacing the ATA foil with a foil improves the adsorption efficiency, and re-immersing the used foil in the production suspension restores its adsorption capacity. Consequently, ATA foil is an accessible and user-friendly alternative DIY method for underserved communities. Verification experiments covering variations in the water quality and climate are crucial for validating the efficacy of the foil. Fortunately, the ATA foil, with DIY characteristics similar to those of boiling and SODIS, is well-suited for testing under diverse global conditions, offering a promising solution for addressing waterborne pathogens worldwide.

Response of sweet pepper autofluorescence against solar radiation.

Shades are adjusted in sweet pepper cultivation, based on solar exposure levels. Pyranometers and photosensitive films have recently been introduced to smart agriculture. However, there are no means of observing biological responses to solar exposure. In this study, we hypothesized that solar exposure levels affect the visible autofluorescence of sweet pepper under 365 nm illumination. To test this hypothesis, we cultivated sweet pepper plants under two exposure conditions, low (half of the normal) and high (the normal). Fluorescence photography (365 nm illumination) revealed that dark-fluorescent peppers only arise when cultivated under high-exposure conditions (0.7-fold decline at emission of 390 nm for high-exposure conditions). Microscopic and spectroscopic observations showed that blue autofluorescence was accompanied by an accumulation of UVB pigments (1.2-factor increase in the absorbance at 300 nm) and epidermal development (1.3-fold thicker cell wall). This study suggests that the autofluorescence of sweet pepper can possibly be used to understand the response of crop to solar radiation at a fruit level in horticulture.

Fixation of Titanium Dioxide Nanoparticles on Glass Fiber Cloths for Photocatalytic Degradation of Organic Dyes.

Titanium dioxide nanoparticles were fixed on a glass fiber cloth using zeolite synthesis. This led to the formation of a photocatalytic zeolite cloth (PZC). Cloth samples were characterized by various diffraction and scanning electron microscopic techniques. The evoked results showed that zeolite X was synthesized on the PZC, while titanium dioxide was included within the PZC. Additional PZC analyses indicated that the fiber cross-section had three-layered structures. The outer layer (third layer) contained zeolite X. It was found that most of the titanium dioxide nanoparticles were present between the second (amorphous) and third layers (zeolite) but only a few existed in the zeolite layer. The photocatalytic activity of PZC was evaluated based on the degradation of methylene blue in the presence of ultraviolet irradiation. Findings showed that PZC exhibited increased adsorption and degradation activities compared to the glass fiber cloth on which only titanium dioxide nanoparticles were coated.

One-Step Synthesis of Calcium Sulfate Hemihydrate Nanofibers from Calcite at Room Temperature.

In recent years, researchers have made significant progress in the development of inorganic nanofibers (including nanowires). Typically, inorganic nanofibers are synthesized via crystal growth in solution; however, a limited number of studies have focused on their preparation directly from solid raw materials (with no examples of synthesis conducted at room temperature and atmospheric pressure). In this work, we successfully synthesized nanofibers of calcium sulfate hemihydrate (bassanite, CaSO4·0.5H2O) at 20 °C and 1 atm by mixing calcite and dilute sulfuric acid in methanol. The bassanite nanofibers are concluded to be synthesized by the formation of calcium sulfate on the calcite surface and its simultaneous reaction with the generated H2O. Because bassanite exhibits useful physical properties that include high mechanical strength, high thermal stability, and excellent chemical stability, its nanofibers can be widely applied to rubber, plastics, antifriction materials, and paper as a strengthening agent, for heat-resistance, or as a flame retardant, or for creep resistance.