Environmental Chemistry Letters最新文献

Biogenic volatile organic compounds are emitted by plants and influence human and environmental health. They contribute to the formation of pollutants such as ozone and secondary organic aerosols, thereby influencing air quality and climate. Here we review biogenic volatile organic compounds with focus on biosynthesis, release to the atmosphere, distribution at various scales, tropospheric chemical processes, and secondary organic aerosols. Biogenic volatile organic compounds are emitted primarily through enzymatic pathways in response to environmental factors, varying across plant species and ecosystems. These emissions exhibit heterogeneity at multiple scales, influenced by meteorological conditions and plant structure.

Although analytical methodologies are known to generate pollution, universal strategies to decrease their environmental, safety, and health burdens while maintaining performance are lacking. Separation science techniques including sample preparations and chromatography require large amounts of solvent and power to separate, identify, and quantitate pure constituents from their matrices. Recent advancements to green analytical chemistry have now provided comprehensive metrics, such as the analytical method greenness score (AMGS), that allow researchers to better understand their method’s environmental burden, compare it to other methods, and indicate what areas can be addressed to enhance sustainability. Here, we review approaches and technologies that can be used to green analytical separations with a focus on improving the method’s analytical figures of merit. Approaches to green sample preparation are first considered including microextraction techniques in liquid, solid, and supercritical phases and the ability to automate such techniques. We focus on high-performance liquid chromatography and sub- or super-critical fluid chromatography, where it is shown that changing the column dimensions and packing can reduce environmental impact while preserving chromatographic resolution. We review equations to calculate the greenest flow rate at which to operate a separation method, then we discuss of modern ultrafast and high throughput separations. Finally, we describe digital signal processing for analytical signals as a major green technology for the first time. We observed that, using digital signal processing, an ultrafast liquid chromatographic separation of 101 components in just one minute produced an AMGS of 0.12 which is, to our best knowledge, the lowest ever reported.

Microplastics are contaminating air, water, soils, both in populated megacities and in remote areas. Here we review analytical methodologies and occurrence of suspended airborne microplastics in Asia. Forty-three studies on suspended airborne microplastics were examined in thirteen countries across Asia. Abundance of suspended airborne microplastics ranged from 0.93 to 8,865 particles/m³ in indoor locations, 0.017 to 18,880 particles/m³ in outdoor areas, and 0.39 to 19 particles per 100 m³ in the oceanic environment. Suspended airborne microplastics mostly had the shape of fibers and fragments. Polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, and polystyrene polymers were commonly found. The size of plastic particles ranged from 0.43 to 9,555 µm, and the strategies used in sampling and analytical methods can influence the size of suspended airborne microplastics. Occurrence of suspended airborne microplastics in Asia demonstrates a critical pollution issue in the region.

Discovered in 2004, carbon dots have garnered a major attention due to their unique optical properties, nanoscale size, and cost-effectiveness. Their potential uses are applicable for bioimaging, electronics, and the food industry. Carbon dots are promising tools for detecting contaminants, identifying harmful bacteria, and monitoring essential nutrients. Here, we review the safety risks associated with applying carbon dots in the food industry, focusing on their integration into global food safety frameworks. We highlight recent advancements in the detection capabilities of carbon dots, showcasing their sensitivity and specificity in identifying foodborne pathogens and contaminants. We discuss strategies to mitigate potential health risks, such as optimizing carbon dot synthesis to minimize their toxicity and ensuring thorough regulatory assessments. Current research shows that carbon dots improve food safety, but research is needed to address safety concerns and ensure consumer confidence.

Emergence of antibiotic-resistant bacteria from overuse of antibiotics is a significant threat to human health. Photocatalysis utilizing semiconductors like graphitic carbon nitride (g-C₃N₄) is cost-effective for antibiotic degradation, however its efficiency is limited by rapid charge carrier recombination. This can be mitigated by forming heterojunctions with compatible semiconductors. Metal oxides, commonly employed for this purpose, are typically deposited on g-C₃N₄ surfaces, and often agglomerate, resulting in uneven distribution and reduced number of active-sites. Here we present a facile approach for in situ polymerization of g-C₃N₄ sheets onto bimetallic oxide surfaces, facilitating their seamless integration. CoNiO₂ was utilized as substrate for growth of g-C₃N₄, which improved crystallinity and surface area of g-C₃N₄-CoNiO₂ composite. Optimized g-C₃N₄-CoNiO₂-3% achieved a tetracycline degradation efficiency of 95.6%, markedly exceeding 61.3% degradation observed with pristine g-C₃N₄. Extended X-ray absorption fine structure spectroscopy confirmed synergistic interaction between CoNiO₂ and N-coordinating sites of g-C₃N₄ by interfacial Ni–N₂ bond, enhancing electron transport. This interaction is further evidenced by energy-resolved distribution of electron trap patterns from reversed double-beam photoacoustic spectroscopy, which reveal that while g-C₃N₄ displays significant electron trap density peaks around 2.7–2.9 eV. The g-C₃N₄-CoNiO₂ enhances this density, indicating formation of an electrical interface heterojunction that improves electron and hole migration across interfacial boundary. Electron spin resonance measurements confirmed that superoxide anion radicals and holes were main active species in promoting tetracycline degradation. Integration of g-C₃N₄ with bimetallic oxides enhances antibiotic degradation efficiency, presenting a promising and impactful strategy for environmental remediation.

Di-2-ethylhexyl phthalate is a plasticizer of health concern due to its presence in the environment and its association with health issues such as metabolic and neurodevelopment disorders. We review the potential hazards and mechansims of di-2-ethylhexyl phthalate exposure on the metabolism and neurodevelopment. Di-2-ethylhexyl phthalate is closely linked to metabolic diseases such as obesity and diabetes, interfering with adipocyte differentiation and lipid metabolism through multiple pathways, thereby disrupting the energy balance. Di-2-ethylhexyl phthalate is also altering the pancreatic function and glucose metabolism. In terms of neurodevelopment, exposure to di-2-ethylhexyl phthalate is associated with neurological abnormalities, crossing the blood–brain barrier and directly impacting the central nervous system. Early exposure may lead to abnormalities in neuronal migration, synapse formation, and neural connectivity, potentially resulting in cognitive and behavioral consequences. Di-2-ethylhexyl phthalate exposure, particularly during childhood and adolescence, may have long-term effects on learning, memory, and behavior.

The worldwide contamination of waters and food by herbicides is a major health issue, yet the toxic effects of herbicides to non-target organisms and ecosystems have been poorly summarized. Here we review the effects of herbicides belonging to the groups of chloroacetanilides, imidazolinones, sulfonylureas, and pyrimidinylcarboxylic, on small invertebrates, high vertebrates, plants, and the surrounding ecosystems. We describe toxicity in terms of behavioural changes, molecular biosynthesis, endocrine disruption, immunological responses, enzymatic alteration, and reproductive disorders. Strategies to decrease toxic effects are also presented. We observe widespread toxicity threats in amphibians and major aquatic species. Each herbicide group displays a different toxicity risk. For instance, chloroacetanilides display higher risks to soil, aquatic, algal, cyanobacteria, and terrestrial species, whereas alachlor, acetochlor, and metolachlor are highly carcinogenic to humans. Most imidazolinone herbicides cause phytotoxicity in non-target and succeeding crops. Sulfonyl-urea herbicides are severely toxic to soil microbes and succeeding crops. Pyrimidinylcarboxy herbicides are more toxic to soil microbes, aquatic species, and rats.

The world energy consumption has increased by + 195% since 1970 with more than 80% of the energy mix originating from fossil fuels, thus leading to pollution and global warming. Alternatively, pyrolysis of modern biomass is considered carbon neutral and produces value-added biogas, bio-oils, and biochar, yet actual pyrolysis processes are not fully optimized. Here, we review the use of machine learning to improve the pyrolysis of lignocellulosic biomass, with emphasis on machine learning algorithms and prediction of product characteristics. Algorithms comprise regression analysis, artificial neural networks, decision trees, and the support vector machine. Machine learning allows for the prediction of yield, quality, surface area, reaction kinetics, techno-economics, and lifecycle assessment of biogas, bio-oil, and biochar. The robustness of machine learning techniques and engineering applications are discussed.