Environmental Chemistry Letters最新文献

Recycling reclaimed wastewater, manure, and biosolids in agricultural soils is a sustainable technique of irrigation and fertilization in the context of the circular economy, yet the presence of contaminants such as pharmaceuticals induces the contamination of crop plants, food, and, in turn, humans. Here, we review the transfer of pharmaceuticals in crop plants with focus on pharmaceutical sources and properties, soil characteristics, root uptake, translocation, and accumulation. We discuss pharmaceutical accumulation in crop plants grown on soils amended with reclaimed wastewater, biosolids, and manure. The presence of pharmaceutical metabolites in plants is also summarized. We observed a decrease of the concentration and of the number of pharmaceuticals from wastewater to soils, then to plants, with typically less than 1% of the initial total pharmaceutical amount being detected in edible crop plants. Pharmaceutical accumulation decreases in the order of leaves, fruits, roots, and grain. Leafy vegetables showed the highest accumulation of pharmaceuticals, reaching few thousands of nanograms per gram dry weight. Pharmaceuticals can be degraded into metabolites that also accumulate in edible plants, yet their behaviour and risk for health are poorly known.

Many fossil fuel-derived plastic polymers are causing environmental pollution by microplastics, and are accelerating global warming because they are carbon positive, calling urgently for alternatives such as biopolymers made from modern biomass. Here, I review starch-based biocomposites with emphasis on natural components, applications for paper coating, challenges, and manufacturing. Natural components include polysaccharides, proteins, clay, and metals. Challenges comprise biodegradability, production cost, printing and labeling, policies, the lack of homogeneity and of life cycle assessment, and mismatched expectations of academia and industry. In particular, starch-based packaging has drawbacks that make it unsuitable for food packaging, including poor thermal resistance, barrier properties, and mechanical properties. I observe that the ratio of amylose and amylopectin impacts the barrier and mechanical properties of starch-based films.

The increasing use of metal nanoparticles in industrial products has induced a global pollution, yet their fate in ecosystems is not fully understood. Here, we review the transport and transformation of metal nanoparticles in the subsurface with emphasis on mechanisms, research techniques, and numerical modeling. Transport can be explained by the Derjaguin–Landau–Verwey–Overbeek theory, the colloid filtration theory, advection–dispersion, Brownian diffusion, interception, gravitational sedimentation, attachment–detachment, straining, blocking and ripening, colloid-facilitated transport, hetero-aggregation, and competitive blocking. Transport research techniques include columns, lysimeters, quartz crystal microbalance, and parallel plate and atomic force microscopy. Metal nanoparticle transformation is characterized by diffuse gradient in thin films and combined microscopy and spectrometry. There are transformation, transport, co-transport, and coupling models. Metal nanoparticles are commonly retained in porous media with small grain sizes, rough surfaces, and surface charges opposite to that of the metal nanoparticles. Transport of metal nanoparticles is favored by colloids and competitive blocking during co-transport. The transformation of metal nanoparticles significantly changes the properties and transport characteristics, which limits the predictions of models.

Oil recovery in geological reservoirs can be enhanced by surfactant flooding, yet this technique is limited by surfactant adsorption on rocks. Here we review the use of nano-silica to decrease surfactant adsorption and to recover more oil, with a focus on surfactant flooding and adsorption, nano-silica properties and development, strategies to reduce surfactant adsorption, and the use of other nanoparticles such as zinc oxide, zirconium oxide, and titanium dioxide. During classical waterflooding, more than 60% of the oil remains trapped in reservoirs due to adsorption of surfactants onto reservoir rocks, which can reach up to 2.84 mg/g. The use of nano-silica reduces surfactant adsorption by 43%, lowers the adsorption density to 1.61 mg/g, and, in turn, improves oil recovery from 4.43 to 9.11%.

Wastewater transport and recycling are major issues in the context of global pollution and climate change. In particular, drainage pipe networks are critical urban infrastructures for sewage transportation and flood drainage, yet these pipes are susceptible to structural and functional defects that compromise their integrity and efficiency. Failure in drainage pipelines can lead to catastrophic consequences, including urban flooding, soil contamination, sinkholes, and significant economic losses. Here, we review advanced methods to monitor structural and functional defects of drainage pipe networks. We present common defects of drainage pipe networks. Defect detection methods include software-based methods, acoustic methods, infrared thermography, smart ball systems, ground-penetrating radar, and distributed fiber-optic sensing. We found that integrating multi-sensor fusion, software-hardware synergy, and artificial intelligence significantly improves defect detection accuracy and predictive maintenance. We provide insights for selecting optimal monitoring strategies by comparing the principles, applications, and performance of the detection methods.

Polycyclic aromatic hydrocarbons are ubiquitous occurring in the environment, they originate from various sources such as fossil fuels and combustion products, and some of them display toxic effects. Here, we review polycyclic aromatic hydrocarbons with emphasis on their sources and fate, environmental parameters based on their ratios, toxicity, socioeconomic impact of marine pollution, and polycyclic aromatic hydrocarbons in bivalves of the Back Sea, including Ukraine, Romania, Bulgaria, Turkey, and Russia. We observe that petrogenic pollution dominates in most regions, with phenanthrene being the predominant compound. Elevated polycyclic aromatic hydrocarbon levels were observed near major shipping routes, ports, and industrial zones, particularly along Turkey’s coast, the Constanța area in Romania, and Odessa in Ukraine. Lower contamination levels were recorded in less industrialized areas such as Bulgaria. Seasonal variations indicate higher polycyclic aromatic hydrocarbon concentrations during warmer months, likely influenced by increased recreational and shipping activities. Carcinogenic polycyclic aromatic hydrocarbons accounted for a substantial proportion of total pollutants in some areas, posing risks to marine biota and human health. While western and southern regions exhibit moderate to severe contamination, the eastern Black Sea remains understudied.

Microplastics can enter the human body through various pathways, but their entry into the eyes remains unproven. Since commercial eye drops contain large amounts of microplastics, we hypothesized that microplastics could enter the eyes when applying eye drops. We analyzed 5 samples of eye drops, and ocular surface lavage fluid from 14 volunteers. Then we studied the migration of microplastics and their ocular damage in in vivo rat experiments. Results show a widespread occurrence of microplastics in eye drops and on human ocular surface. We also found that microplastics can even enter the bloodstream via ocular surface. Overall, commercial eye drops appear as an overlooked pathway for microplastic deposition on the human ocular surface. As a consequence, microplastics could elevate ocular oxidative stress, and trigger ocular inflammation.

Carbon neutral energies and fine chemicals are urgently needed in the context of the accelerating global warming and associated extreme weather events. Here we review the conversion of biomass into fuels and chemical compounds with focus on biomass properties, mechanisms of biomass thermal decomposition, bio-oil composition and generation, reactor types, pyrolytic classifications, pyrolysis of pure biomass components, and pyrolysis of wood. The main biomass components, namely cellulose, hemicellulose and lignin, are determined by the Van Soest protocol. Biomass decomposition can be explained by the one-step global mechanism, independent competitive or parallel reactions, the multi-component mechanism, the Broido-Shafizadeh scheme, the secondary tar cracking model and the Ranzi scheme. Pyrolysis can be classified into slow, intermediate, fast, and flash pyrolysis. Reactors comprise fixed bed-, fluidized bed- and multistage reactors.

Lithium is becoming a critical element for the economy due to the rising production of lithium-ion batteries, yet conventional extraction methods are slow, energy-intensive, and environmentally harmful. Recently, these issues have been solved partly by integrating advanced membranes in the extraction process. Here we review methods for lithium extraction with emphasis on conventional methods, membrane-based methods, multi-stage membrane-integrated systems, demonstration projects, techno-economical and life cycle assessment. Conventional methods include solar evaporation, precipitation, ion sieve adsorption, ion exchange, and electrochemical and solvent extraction. Membrane-based methods comprise reverse osmosis, nanofiltration, membrane distillation, membrane crystallization, forward osmosis and electrochemical membrane systems, ion-imprinted and ion sieve membranes, and liquid membranes. Liquid ores such as salt lakes and brines are a major source of lithium extraction and account for 2/3 of the global lithium production. Natural salt lakes and geothermal brines contain small lithium concentrations of 7.5–150 mg/L and high total dissolved solids, of 150–330 g/L. Nanofiltration allows about 85% lithium recovery with magnesium-to-lithium-ion selectivity of 0.4–0.75 and energy consumption of 35–48 kWh/kg. Electrodialysis reduces by 88% the magnesium-to-lithium ion ratio at a lower energy use of 10–38 kWh/kg of lithium. Supported liquid and ion-imprinted membranes are more energy-efficient, of 6–21 kWh/kg, but remain limited to laboratory-scale studies. We observed that the integration of membrane systems with conventional direct lithium extraction methods enhances the upstream lithium enrichment, followed by downstream recovery for more efficient overall lithium extraction.