Environmental Chemistry Letters最新文献

Germanium is a critical element used in optical materials, electronic semiconductors, optical fibers, catalysts, sensors, medicine and health. Worldwide, 36% of the annual refined germanium comes from lead zinc sulfide ores, and more than 90% of germanium enters the zinc smelting system as an associated impurity with the zinc roasting sand. Here we review the recovery of germanium in zinc smelting processes, with focus on germanium reserves, applications and demand, recovery methods and extraction mechanisms. Recovery methods include tannin precipitation, ion exchange and solvent extraction. Extraction mechanisms are described for acidic, alkaline, neutral and synergistic extractions.

The conversion of biomethanol into olefins is a sustainable alternative to fossil fuels, yet this reaction is limited by the deactivation of the silicoaluminophosphate zeolite catalysts due to its microporosity, which promotes coke deposition. Here we synthesized a fibrous silica-wrapped silicoaluminophosphate catalyst by microemulsion and seed-assisted hydrothermal method. This catalyst was characterized by X-ray diffractometer, Fourier transform infrared spectroscopy, nitrogen physisorption, field emission scanning electron microscopy, transmission electron microscopy, and ammonia temperature-programmed desorption. The catalytic performance was evaluated from 300 to 500 °C, followed by a stability test conducted at 500 °C for 30 h. Coke deposition on spent catalysts was analyzed using thermal gravimetric analysis, oxygen temperature-programmed oxidation, ultraviolet–visible, and Raman spectroscopy. Results show a 54% extension of the catalyst lifetime, and a 31.4%w reduction in coke formation. These findings are explained by the fibrous silica wrapping that creates a surplus mesoporosity beyond conventional hierarchical structure, enabling improved accessibility, reduced diffusion resistance, and suppressed coke formation.

Monitoring virus concentrations in wastewater is crucial for tracking community viral spread, yet reliable virus enrichment and detection methods are lacking. We compared four preconcentration-detection methods for tracing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in wastewater: ultrafiltration and covalent affinity resin separation, paired with either reverse transcription-quantitative polymerase chain reaction (PCR) or reverse transcription-digital PCR. Tests were conducted on raw sewage from a campus dormitory septic tank in May 2023. Results show that the concentrations of coronavirus RNA in wastewater enriched by ultrafiltration were higher than those enriched by covalent affinity resin separation, regardless of the detection methods used. Digital PCR exhibited detection rates of 45.4% using covalent affinity resin separation, and 77.3% using ultrafiltration. These detection rates were 36.4% and 72.7% higher than those using quantitative PCR. A correlation coefficient of 0.70 between concentrations measured by quantitative and digital PCR was only observed for samples enriched by covalent affinity resin separation.

The global increase in greenhouse gas emissions is mainly due to electricity and heat generation, transportation, manufacturing and construction, and agriculture. In particular, agriculture produces underutilized waste that generates greenhouse gas emissions and other pollutants. Here we review the conversion of farming waste into energy, with focus on waste from agriculture, livestock, poultry, and pisciculture. Energy production techniques include pelletization, pyrolysis, gasification, liquefaction, anaerobic digestion, and fermentation. In thermochemical processes, the biofuel yield is controlled by temperature, pressure, heating rate, feedstock concentration, reaction time, catalysts, and reactor type. In biological processes, the biofuel yield is controlled by pretreatment intensity, microorganisms, substrate loading, temperature, volatile solids, reaction time, and inhibitors.

Per- and polyfluoroalkyl substances and nanoplastics frequently co-occur in environmental matrices, yet the effects of co-exposure on cellular responses upon ingestion are poorly understood. Here, we exposed human intestinal Caco-2 cells to perfluorooctanesulfonic acid, nanoplastics, and their combination. Cell painting-based phenomics was used to map phenotypic alterations across subcellular structures, and untargeted metabolomics using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was employed to assess metabolic changes. Results show that perfluorooctanesulfonic acid predominantly affected the actin cytoskeleton, Golgi apparatus, and plasma membrane, while nanoplastics primarily targeted mitochondria. Combined exposure disrupted the endoplasmic reticulum, RNA, and mitochondria. Perfluorooctanesulfonic acid reduced levels of carnitines, free fatty acids, nucleotides, and sugars, whereas nanoplastics inhibited ceramides, triglycerides, sphingomyelins, and additional free fatty acids. Combined exposure produced a metabolic profile resembling that of nanoplastics, with specific differences attributed to perfluorooctanesulfonic acid. Overall, nanoplastics appear as the main drivers of the co-exposure effects.

Aflatoxin B1 is a mycotoxin produced by the fungus Aspergillus that contaminates food, notably grains and peanuts. Aflatoxin B1 is hepatotoxic, causing necrosis, and cirrhosis, and is classified as an hepatocarcinogen. Traditional methods for detecting aflatoxin B1 such as thin-layer chromatography, high-performance liquid chromatography, enzyme-linked immunoassay, and liquid chromatography–tandem mass spectrometry, have limitations including high costs, complex preparation procedures, and occasionally low sensitivity. Here, we review DNA-based biosensors for aflatoxin B1 detection with emphasis on electrochemical and optical sensors. Electrochemical biosensors are based on electrochemical impedance spectroscopy, amperometry, voltammetry, and potentiometry. Optical sensors involve colorimetry, surface plasmon resonance, fluorescence, and electrochemiluminescence. Sensors combine nano and composite materials, such as gold nanoparticles, black phosphorus nanosheets, graphene oxide, niobium carbide, photonic crystals, and liquid crystals. DNA-based biosensors, such as aptamer biosensors, are efficient, rapid, sensitive, affordable, and selective to detecting contaminants and pathogens.

Phosphogypsum, a major by-product of phosphoric acid production, can be recycled. Nonetheless, phosphogypsum contains impurities such as heavy metals, fluoride, and phosphate, which can decrease the performance and contaminate the environment, calling for pretreatment or solidification methods. Here, we review phosphogypsum with emphasis on impurities and their hazards, solidification methods, and treatment methods for use in road construction. Solidification involves blending phosphogypsum with inorganic cementitious materials, adding additives, geopolymers, biological treatments, and biochar adsorption. Phosphogypsum can be blended with electrolytic manganese residues, granulated blast furnace slag, and inorganic cementitious materials. Additives comprise polymers, surface modifiers, and curing agents. We observe that solidification methods display more advantages than pretreatment methods. The combination of phosphogypsum with inorganic cementitious materials, polymer surface modifiers, curing agents, geopolymer materials, and biomass materials can effectively solidify various impurities, though the effectiveness varies across different solidification methods. There are four solidification mechanisms: physical encapsulation, chemical precipitation, ion exchange, and adsorption. When solidified in road engineering applications, phosphogypsum show reduced leaching levels of arsenic, lead, while maintaining a good road performance.

Peptide-based chemicals are promising for numerous applications including home and personal care and medical treatments. To better understand and control the environmental fate of peptide-based chemicals, in-depth knowledge on the specificity of wastewater peptidases is needed. Here, we employed multiplex substrate profiling by mass spectrometry to obtain specificity profiles of extracellular peptidases derived from influent and aeration tanks of three full-scale wastewater treatment plants. Specificities were confirmed by fluorogenic peptidase substrates. Our results revealed highly similar specificity profiles across wastewater treatment plants. We found that hydrolysis by extracellular wastewater peptidases is favored when positively charged amino acid residues surround the cleavage site and disfavored when negatively charged amino acid residues surround the cleavage site.

The coronavirus disease COVID-19 is primarily transmitted through person-to-person contact, but meteorological conditions may influence its spread and severity. High levels of indoor ozone are known to inactivate the virus, yet the impact of low-level tropospheric ozone remains unclear. We thus hypothesized that tropospheric ozone, influenced by seasonal conditions, may mitigate viral spread. We studied the influence of ozone concentration, temperature, and humidity on the COVID-19 reproduction number in three large Israeli cities during 2020–2021. The effect of these parameters was also analyzed in laboratory experiments on viral inactivation. Field results show that in winter, under low temperature and low humidity, the COVID-19 reproduction number decreases with an increase in ozone concentration. In contrast, in the summer, under high temperature and high humidity, the COVID-19 reproduction number increases weakly with an increase in ozone concentration. This seasonal variation is attributed to ozone’s dual effects. Indeed, in winter, ozone inactivates the virus, whereas in summer, ozone primarily impacts human respiratory health, which indirectly favors COVID-19 transmission. Nonetheless, experimental results did not fully align with the field survey, showing increased virus inactivation with an increase in temperature.

Global microplastic contamination of almost all biological and environmental media is an emerging threat to human health that recently fostered intense research. Here, we review polyethylene terephthalate with focus on microplastics, characteristics, uses, concentration, degradation, toxicity, and remediation. Plastic remediation can be done by landfills, incineration, pyrolysis, and biodegradation. We present microplastic occurrence in food, beverages, dust, wildlife, and human tissues. We observed inconsistencies in measurement techniques, limitations in detection reliability, and gaps in risk assessment.