The sporadic occurrence of contradictory lab results regarding the presence of asbestos in building materials has raised questions about the quality of routine analyses performed by labs that offer their services on the Swiss Asbestos Forum (FACH) website, which is administered by the Swiss National Accident Insurance Fund (Suva). These labs have committed to a careful preparation of "difficult" samples, such as window putty, tile adhesive and other materials containing often low concentrations of asbestos, so as to increase the likelihood of detection. Most of the labs are accredited for asbestos analysis by their respective national accreditation body, and all have regularly passed proficiency testing (PT) schemes such as the Asbestos in Materials Scheme (AIMS) of the Health and Safety Executive (HSE, Buxton, UK) or the Bulk Asbestos Proficiency Analytical Testing (BAPAT) provided by the American Industrial Hygiene Association (AIHA, Falls Church, VA). Sample sets of pre-tested building materials were shipped to these labs from unsuspicious senders at irregular intervals, approximately once per year since 2019. Error rates were high at the beginning of the program, with a maximum of 17% false negative results in the second round, decreasing to less than 5% in subsequent rounds. The rate of false positives was markedly lower, with a maximum of 3% in the first of five rounds. Overall, Swiss labs performed better than non-Swiss labs, and concentrations greater than 1% were correctly detected more often than those of lower concentrations. The method used (mostly polarized light microscopy (PLM) or scanning electron microscopy (SEM)), as well as accreditation and price of the analyses, did not significantly influence analysis outcomes. Approximately half of the laboratories provided an estimate of the asbestos content in the samples, often with significant discrepancies between individual and reference laboratories. The use of SEM analysis has led to significantly higher asbestos content estimates than PLM analysis.

Photocatalytic CO2-to-CH4 conversion in water remains challenging because selective multielectron proton-coupled reduction requires efficient charge separation and controlled intermediate hydrogenation. Herein, we report an electron-withdrawing-ligand-regulated Pt-site covalent organic framework, Pt-LEW/TBCOF, for selective CO2-to-CH4 photoconversion in CO2-saturated pure water without sacrificial reagents. The donor-acceptor TBCOF scaffold, constructed from tris(4-aminophenyl)benzene-derived donor units and bipyridine acceptor units, provides visible-light absorption and well-defined N-coordination sites for Pt immobilization. A preformed Pt complex bearing an electron-withdrawing fluorinated ligand was incorporated into the bipyridine-containing framework to generate highly dispersed Pt coordination sites with a regulated local electronic structure. TBCOF mainly produces CO with negligible CH4 formation, while ligand-free Pt/TBCOF exhibits only limited CH4 generation and low selectivity. In contrast, Pt-LEW/TBCOF shows a markedly enhanced CH4/CO ratio at the same Pt loading. Increasing the Pt loading to 8.1 wt % affords a CH4 production rate of 53.9 μmol g-1 h-1 with 89% CH4 selectivity among gaseous carbon products under visible-light irradiation. Spectroscopic, photoelectrochemical, and theoretical analyses suggest that the donor-acceptor COF backbone facilitates charge separation, whereas the electron-withdrawing ligand environment modulates the electronic structure and intermediate conversion behavior of Pt sites, favoring further hydrogenation toward CH4. This work suggests that electron-withdrawing ligand modulation of Pt sites may provide a useful approach for regulating product selectivity in the present COF-based photocatalytic system.

The dry reforming of methane (DRM) converts two greenhouse gases, CH4 and CO2, into a synthesis gas, providing a route for CO2 valorization. Bimetallic nanoparticles offer a versatile strategy to improve the performance of monometallic catalyst systems by altering the electronic and local structures of the active metal sites. Here, we investigate SiO2-supported, Co x Pt1-x nanoalloys with varying composition (x = 0.1-0.9) for DRM. Structural characterization using pair distribution function analysis and electron microscopy revealed that the bimetallic nanoparticles feature fcc-type alloy structures with diameters of 1-2 nm, highly dispersed on SiO2. Catalytic evaluation under DRM conditions shows that Pt-rich catalysts exhibit the highest initial CH4 conversion rates, while increasing the Co content lowers the DRM activity and the H2 : CO ratio due to an enhanced reverse water-gas shift activity. When normalized per Pt loading, the initial (20 min) CH4 consumption rates remain largely unchanged, confirming Pt as the primary active site for CH4 activation. Pt-rich catalysts deactivate rapidly with time on stream via coking (graphite), whereas alloying with Co improves their stability by suppressing carbon deposition. However, Co oxidation induces dealloying and contributes to deactivation, in particular at low temperatures (750 °C). Intermediate Co : Pt ratios, i.e., Co0.5Pt0.5-Co0.7Pt0.3, yield the best performing catalyst as they strike a balance between activity, H2 : CO ratio, and stability, enabling an effective utilization of expensive Pt.

This study investigated the impact of high-pressure processing (HPP) on the multi-scale structure, hydration, and pasting properties of corn starch. Corn starch was subjected to pressures ranging from 100 to 600 MPa for holding times of 1 to 5 min. LF-NMR and MRI analyses demonstrated that HPP redistributed water mobility, with a distinct structural reorganisation observed at 200 MPa, characterised by maximum water immobilisation (P2,1 + P2,2 = 3.97%). Thermal analysis via DSC indicated a non-linear shift in the gelatinisation temperatures (To, Tp, Tc), with pressure-reorganised domains exhibiting higher thermal resistance despite a decrease in gelatinisation enthalpy (ΔH). Furthermore, RVA pasting profiles showed that HPP significantly increased pasting temperatures while reducing peak and final viscosities, indicating improved shear stability and suppressed retrogradation. These findings provide a mechanistic framework for using HPP as a precise tool to engineer starch functionality for clean-label food applications.

This study detected and quantified a broad array of critical materials and other elements in U.S. municipal solid waste (MSW) landfill leachates in both the aqueous (i.e., supernatant) and wet solid fractions. A total of 59 elements were measured in 37 landfill leachate samples obtained from six MSW landfills across five U.S. states. Samples were collected from different aged cells, combined leachate streams, or after being treated by a membrane bioreactor (MBR) followed by reverse osmosis (RO). Results found that 24 elements classified as critical materials and eight other elements were independently quantified in at least one leachate sample. Concentrations ranged in the low to high mg/L and mg/kg of wet solids for the supernatant and wet solids fractions, which made up to >98 wt % and <2 wt % of the total leachate sample, respectively. Critical materials not detected included several rare-earth elements (REEs) and several platinum-group metals (e.g., Pt, Pd, and Ru) among others. Most elements were detected in both the supernatant and wet solids phases. Concentrations of several elements (Li, Ni, Co, Cr, Ti, and Al) increased linearly or exponentially with time when cells opened at later years or when the waste age decreased. MBR and RO treatment lead two elements (Ni and Mn) to be effectively concentrated without incurring mass losses, whereas all other elements incurred significant mass losses. Overall, this study provides a foundational step in understanding the critical materials composition of U.S. MSW landfill leachates and highlights key opportunities and challenges for resource recovery.

Winery wastewater contains readily biodegradable organic matter, but some of its components can inhibit anaerobic microbial activity. This study compares two enriched microbial consortia, derived from anaerobic digester sludge (ADS) and mining-process wastewater (MPW), exposed to alcohols, carboxylic acids, and phenolics. Assays were conducted in acetate-fumarate-based media containing low or high concentrations of each compound class and a combined condition containing the compounds at their highest levels. Growth, fumarate consumption, succinate production, acetate turnover, and compound consumption were monitored. Full-length 16 S rRNA gene sequencing showed that ADS was dominated by Proteus (56.9%) and Escherichia (28.6%). MPW showed a more even profile dominated by Proteus (35.8%), Wolinella (32.9%), and Escherichia (23.0%). Under control conditions, MPW showed higher growth (0.284 vs. 0.181 h[-1]) and succinate production rates (0.171 vs. 0.106 g L[-1] h[-1]) than ADS. Alcohols caused little change in fumarate consumption, but high carboxylic acid concentrations reduced fumarate consumption rates to 0.115 and 0.162 g L[-1] h[-1] in ADS and MPW, respectively. Phenolics reduced the ADS succinate production rate to 0.059 g L[-1] h[-1], while MPW remained near its control value (0.169 vs. 0.171 g L[-1] h[-1]). Under combined exposure, ADS maintained fumarate consumption and increased succinate production from 0.106 to 0.157 g L[-1] h[-1], but MPW decreased from 0.125 to 0.092 g L[-1] h[-1]. Both bacterial composition and the chemical conditions of exposure influenced anaerobic resilience. The combined use of taxonomic and metabolic indicators may therefore improve the selection of consortia for the biodegradation and valorization of complex agro-industrial wastewaters, including their integration into bioelectrochemical platforms.

Because of the built-in electric field established at the interface of semiconductors, the construction of heterojunctions represents an efficient strategy to improve charge carrier separation and enhance the photoelectrochemical (PEC) performance. However, the thickness of the space charge layer induced by the built-in electric field is inherently limited, resulting in inadequate separation of the inner photoinduced carriers within the semiconductors due to a lack of driving force. To effectively utilize the built-in electric field, we synthesized CdTe quantum dot-Pt cluster aerogels. The resulting aerogels, featuring interparticle Schottky junctions, endow the semiconductor with a sufficient driving force for charge separation, where the carrier migration distance to the interface is significantly reduced compared to that of traditional bulk semiconductor-based heterojunctions. This unique configuration amplifies the PEC response by ∼60-fold. The interfacial charge-transfer lifetime increased from 40 to 2400 ps. The flexible self-assembly strategy for the construction of aerogels involving semiconductors and metal clusters offers a fresh perspective on enhancing the charge separation within heterojunctions.