Environmental Chemistry Letters最新文献

Water contamination by organic, inorganic, and microplastic pollutants poses significant threats to ecosystems and public health, emphasizing the need for advanced remediation strategies. Here, we review the water treatment with composites including bacterial cellulose, with focus on synthesis and modification of bacterial cellulose and composites, and application in water treatment. Synthesis of bacterial cellulose can be done in static, agitated and bioreactor cultures. Composite materials include metal oxides, metal organic frameworks, polymers, graphene and magnetic materials. Applications comprise the removal of microplastics, heavy metals, oil, and organic and inorganic pollutants. Bacterial cellulose is biodegradable, biocompatible, and possesses customizable surface chemistry and structure, enabling exceptional pollutant removal. Surface modifications add functional groups such as hydroxyl and carboxylate groups, while reinforcement strategies improve mechanical and chemical properties. Composites exhibit pollutant removal efficiencies of up to 99.9% and oil separation stability of 99% even after 20–50 cycles. Mechanisms including adsorption, photodegradation, flocculation, and biodegradation are discussed.

Gadolinium-based contrast agents are used in more than 30 million magnetic resonance imaging procedures worldwide each year. These gadolinium complexes are excreted in urine and then end up polluting wastewater, leading to gadolinium concentration increase in rivers, known as the ‘gadolinium anomaly.’ Here we studied gadolinium recovery from patient urine using ligand-associated organosilica media impregnated with N,N,N′,N′-tetraoctyl-diglycolamide, a chelating agent traditionally used in separating lanthanides from actinides in nuclear waste applications. Gadolinium-containing urine was acidified with nitric acid and tested in batch and packed bed column experiments. Sorbent media and precipitate solids were analyzed using advanced characterization tools. Results show that more than 85% of the gadolinium was recovered with a 12.8 mg g⁻¹ sorption capacity. A two-cycle column study produced over 99% pure gadolinium through stripping, oxalic acid precipitation, and calcination. A binding mechanism with a 1:3 chelation and matching kinetics for a pseudo-second-order rate model can help design scaled-up systems.

Classical extraction involves several time-consuming and costly steps using toxic solvents. Here, we combined the preparation of a cyclodextrin-based supramolecular deep eutectic solvent and the extraction of spent coffee grounds by microwave irradiation in a single step. We tested two new solvents, randomly methylated-β-cyclodextrin:propylene glycol and hydroxypropyl-β-cyclodextrin:ethylene glycol, and compared the results with two classical solvents, chloride:urea (1:2) and ethanol/water 80/20 vol%. We also used classical Soxhlet extraction. We calculated the sustainability of the process using ComplexGAPI. Results show that the optimal one-step extraction conditions were 15 min of irradiation at 80 °C with the addition of 10 wt% water. Under these conditions, the two new solvents showed higher extraction yields of antioxidants and polyphenols than choline chloride:urea (1:2) or ethanol/water 80/20 vol%. Similarly, the half maximal effective concentration and gallic acid equivalent of the Soxhlet extracts were 5 and 3 times lower, respectively, than those obtained with hydroxypropyl-β-cyclodextrin:ethylene glycol (1:40) 10 wt% water. The composition of the extracts from the one-step process was similar to that of the Soxhlet extract. Sustainability analysis revealed low energy consumption, reduced unitary operations and less waste production.

Cyanobacteria are photosynthetic prokaryotes and major contributors to global biogeochemical cycles. They possess powerful biological activity, high adaptability to extreme environment, rapid growth rate and genetic editability. Here, we review cyanobacteria with focus on their application in environmental pollution and biomedicine. Cyanobacteria can be used for pollutant removal, biofuel and biochar production, template for drug discovery, hypoxia-related disease therapy, anticancer, antiviral, antibacterial, antioxidant and antifibrotic. Spiral-shaped cyanobacteria are excellent carriers for drug delivery. The oxygen-producing capacity of cyanobacteria is promising in the treatment of hypoxia-related diseases.

Nanoplastic pollution is poorly known, in particular because research is actually mainly done using synthetic polymeric nanospheres that are not representative of environmental nanoplastics, which are very diverse in their composition, size, and shape. Here we review environmentally relevant nanoplastics with focus on their production, characterization, quantification, stability, aggregation, and toxicity. Production of environmentally relevant nanoplastics can be done by mechanical  and physicochemical methods. Toxicological studies focus on internalization and toxicity on human cell lines, and bioaccumulation and systemic effects on model organisms.

The worldwide microplastic pollution in waters requires efficient removal techniques, yet actual wastewater treatment methods are limited. Here we review the use of microalgae for microplastic removal, with focus on microplastics in aquatic systems and wastewaters, legislation and regulations, common removal techniques, and microalgae for microplastic removal. We describe the mechanisms involved in microalgae-microplastics aggregation. We also present the criteria for selecting adequate microalgae for microplastics removal from wastewater.

Soil carbon sequestration is a climate engineering process that could significantly reduce global warming, yet actual estimates of soil organic carbon sequestration in China’s croplands are probably underestimated. Here we estimated soil organic carbon sequestration across China’s croplands from 1980 to 2018 using four different methods. We found that the average sequestration rate in China’s croplands is 298.5 kg ha⁻¹. We present management strategies that could increase the mean soil organic carbon stock by 58.2 Mg ha⁻¹. Insights into the potential for region-specific strategies to enhance soil carbon sequestration are given.

The presence of natural and synthetic toxic compounds in the environment requires the development of advanced detection methods. Here we review proteomics technologies for toxicity screening, with focus on principles, current status, mass spectrometry-based proteomics, protein microarray, and in-frame tagging method. Concerning mass spectrometry-based proteomics, we detail liquid chromatography-tandem mass spectrometry, label-free quantification, and thermal proteome profiling. We discuss the integration of the latest advances in proteomics technologies, such as single-cell proteomics, data-independent acquisition, and multi-omics approaches.

Chemical weapons, designed for mass harm, are posing risks of contamination, accidents, and ecological damage, and thus require their destruction. However, destruction of chemical weapons is challenging, notably in the Russian Federation due to the large scale and complexity of chemical weapons stockpiles, the diverse toxic agents stored under varying conditions, logistical and political obstacles, financial constraints, and the disposal process. Here we review the Russian Federation’s chemical weapons disposal program with an emphasis on the political context, declared chemical weapons stockpiles, methods for destruction, health and environmental issues, and nerve agents. We analyze stockpiles totaling nearly 40,000 tonnes of chemical agents across seven facilities, focusing on their composition, storage conditions, and destruction technologies. Methods such as neutralization, bituminization, and thermal destruction are compared. Environmental risks include arsenic migration and groundwater contamination near disposal sites. We observe the limitations of using bitumen salt masses as a safe disposal method.

Soil organic carbon is crucial for soil fertility, productivity, and global carbon cycling. Despite significant progress in understanding carbon persistence and turnover, the underlying mechanisms require further study. A key challenge is visualizing and characterizing the spatial distribution of carbon within intact soil. This study introduces a novel approach to map carbon content at 35 µm resolution and composition at 22 µm resolution in intact environmental samples using synchrotron X-ray spectromicroscopy. X-ray fluorescence maps provided an overview of total carbon distribution, identifying carbon-rich regions. Near-edge X-ray absorption fine structure spectromicroscopy was then used to obtain spatially resolved carbon speciation data within these regions. This method allowed the analysis of relatively large intact samples, of 16 mm in diameter and 15 mm in height, preserving various root and organic matter fragments as well as pores ranging between 35 and 850 µm. Spectral fitting with reference standards revealed distinct spatial patterns of aromatic, aliphatic, and carboxylic carbon compounds associated with different structural features. Aromatic carbon was enriched around root fragments and the soil matrix; while, carboxylic compounds were concentrated at pore–matrix interfaces, indicating a correlation between soil pore structure and carbon chemical composition. This novel approach provides significant insights into the interplay between pore architecture and organic molecular diversity, key factors governing carbon protection and persistence in soils.