Environmental Chemistry Letters最新文献

Polypropylene is widely used in textiles, injection molding, and film production, yet the metabolic toxicity of polypropylene microplastics is poorly known due to the limitations of analytical techniques. Here, we used internal extractive electrospray ionization coupled with high-resolution mass spectrometry and non-targeted metabolomics analysis to investigate the impact of polypropylene micro- and nanoplastics sizes and doses on metabolic dysregulation in Nile tilapia organs and tissues. Results show an upregulation of inflammatory mediators, including arachidonic acid and its derivatives, which affect critical metabolic pathways such as glycerophospholipid, arachidonic acid, and sphingolipid metabolisms. The inflammatory and neurotoxic effects exhibited a dose-dependent relationship.

Organic water pollution is calling for advanced remediation methods such as the Fenton process, yet actual procedures involve transition metals at acidic pH, and generate only one oxidant, the hydroxyl radical. Here we used a solution of magnesium ions, bicarbonate ions, and hydrogen peroxide at pH 7.4 to generate reactive oxygen species for degrading dimethyl sulfoxide and acetamidophenol, as models of water pollutants. The performance and the identification of degradation products were assessed by nuclear magnetic resonance and high-performance liquid chromatography. Results show the generation of several oxidizing agents such as hydroxyl radical, carbonate anion radical, and superoxide. The novel aspect is that the Fenton-like process can be achieved with Mg²⁺ serving only as a template to facilitate redox reactions rather than participating directly. The mechanisms for generating oxidizing radicals suggests potential applications in both environmental cleanup and biological processes.

Traditional industrial methods of the leather industry produce toxic chromium-containing wastewater and solid wastes, calling for alternative procedures. Here, we review greener technologies to produce leather with focus on principles to design materials, high-efficiency chrome tanning, chrome-free processes, e.g., organic tanning, combination tanning, nanomaterial-based tanning, and tanning agent-free technology, as well as high-performance post-tanning using multifunctional polymers, integrated tanning-dyeing systems, and socioeconomical aspects. High-efficiency chrome tanning is done by high-exhaustion chrome tanning or inverse chrome tanning, which reduce the usage of chrome. Organic tanning employs biomass-derived and polymeric tanning agents.

The rapid development of vanadium redox flow batteries has recently boosted research in methods to obtain high-purity vanadium pentoxide, the active material of battery electrolytes. Here, we review techniques for producing high-purity vanadium pentoxide with emphasis on methods published in Chinese that are not well-known by Western academia. We describe purification methods, chlorination, and eco-friendly processes. Purification can be done by precipitation, solvent extraction, and ion exchange. We propose three viable approaches for industrialized applications.

Contamination of groundwater by microplastics is a major health concern because groundwater is a major source of drinking and agricultural water. Here, we review microplastics with focus on contamination sources, characteristics, migration, water quality, ecological and health risks, and preventive and removal strategies. Contamination sources include landfills, waste dump leachates, wastewater treatment plants, industrial waste streams, land use, agriculture, urban and residential activities, and atmospheric transport and runoff. Contamination levels reach up to 6,832 microplastics per liter of groundwater. Membrane technologies, such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis, achieve 93–99% removal of microplastics.

Climate change is increasing the frequency of extreme weather events such as vegetation fires. Vegetation fires emissions contain numerous organic compounds that impact the Earth system and human health. Here, we review the sources, stability, transport, degradation and geochemical records of levoglucosan, a dehydration monosaccharide produced by the pyrolysis of cellulose and hemicellulose. Levoglucosan has been detected in aerosols, water, snow and ice, and lake or marine sediments. Analysis of levoglucosan in environmental and geological samples enable the identification of temporal rhythms and detailed features of changes in vegetation fire patterns, ranging from individual events to seasonal to annual scales, up to glacial-interglacial cycles.

Water scarcity and wastewater pollution are major health issues, yet traditional wastewater treatment technologies are limited by high operational costs and energy demands, and membrane fouling. Here we review low-cost ceramic membranes for wastewater treatment and bioenergy production, with emphasis on bioreactors, and microbial fuel cells to generate electricity. Ceramic membranes display high filtration performance and resistance to harsh conditions, achieving water flux rates up to 250 L/m² per h, significantly outperforming polymeric membranes. Ceramic membranes are now affordable due to recent advances in as clay-based ceramics, extrusion and electrospinning. Ceramic membranes integrated into microbial fuel cells and anaerobic bioreactors could enhance power generation by 20% and biogas yield by 15–30%. Surface modifications and nanomaterial use have reduced fouling by up to 60%, yet issues of biofouling and high fabrication costs persist.

The aviation sector is a major emitter of fossil fuel-derived carbon dioxide contributing to global warming. For instance, jet fuel consumed by the aviation industry is 1.5–1.7 billion barrels per year, resulting in 705 million metric tons of carbon dioxide emissions. Aircraft manufacturers have set ambitious goals, aiming for carbon-free growth post-2020 and a 50% reduction in greenhouse gas emissions by 2030. This issue can be solved by replacing fossil fuels with biofuels produced from modern biomass, thus meeting the carbon neutral objective. Here, we review the technologies to convert biomass into jet biofuel with focus on reactants, catalysts, and the chemistry of combustion. Reactants include alcohols, oil, esters, fatty acids, gas and sugars. Catalysts include Fischer–Tropsch catalysts, palladium, platinum, ruthenium, nickel, and molybdenum. The utilization of jet biofuels could potentially reduce greenhouse gas emissions by up to 80%. We also discuss economic implications.

Biodegradable plastics have been developed as an alternative to fossil fuel-derived plastics, yet knowledge on pollution by microbioplastics has not been summarized. Here, we review microbioplastics with focus on their formation from biodegradable plastics, their mobility, distribution, impact on soils and aquatic organisms, and their management by recycling, incineration, composting, anaerobic digestion, and landfill disposal. We observe that incorporating carbon–oxygen ester linkages into the molecular backbone of biodegradable plastics, together with plant-derived additives, should enhance the usability of biodegradable plastics by augmenting thermal stability and barrier properties. Separation, recycling, and anaerobic digestion of biodegradable plastic materials should generate methane and biofertilizer.

The wide use of anticoagulant rodenticides for rat control has led to indirect poisoning of non-target birds, mammals, and vertebrates by anticoagulant rodenticides, yet contamination of insects is poorly known. We studied the behavior of two cockroach species feeding on commercial rodenticide bait formulations under laboratory conditions. Rodenticides comprised brodifacoum, difenacoum, and bromadiolone. We measured bait uptake by cockroaches, mortality, and their anticoagulant rodenticide body burden after 21 days of exposure. Results show that rodenticide residue levels in cockroaches ranged between 0.01 and 1.32 ± 0.15 µg/g dry weight. No mortality associated with rodenticide bait consumption was observed over a 21 days exposure period. Cockroaches consumed up to 50% of offered bait when attracted by this formulation, otherwise close to none. Overall, insects such as cockroaches may contribute to the environmental spread of anticoagulant rodenticides.