Environmental Chemistry Letters最新文献

The rising number of diseases and deaths caused by pollution and modern lifestyle habits is a growing societal concern. Marine ecosystems are both victim to this human behaviour as a recipient of human pollution as well as being a source of medicinal chemicals which can cure a variety of diseases. In this paper, we review the chemical basis of water-based treatments and their effects on human health, while focusing on the threats to marine ecosystems and the potential benefits of balneotherapy, thalassotherapy, and bioactive chemical species. We found that seawater has potential benefits for skin health, demonstrating emollient properties, protection against skin barrier disruption, and inhibition of atopic dermatitis-like skin lesions. We present the putative mechanisms by which minerals, salts, and marine organic matter can slow down disease progression, through their numerous activities, such as anti-inflammatory, antioxidant, and wound healing properties. Water-living organisms also have an impact on such mechanisms by producing biologically active compounds with beneficial effects on human health.

The global hydrogen demand is projected to increase from 70 million tons in 2019 to more than 200 million tons in 2030. Methane decomposition is a promising reaction for H₂ production, coupled with the synthesis of valuable carbon nanomaterials applicable in fuel cell technology, transportation fuels, and chemical synthesis. Here, we review catalytic methane decomposition, with focus on catalyst development, deactivation, reactivation, regeneration, and on economics. Catalysts include mono-, bi-, and trimetallic compounds and carbon-based compounds. Catalyst deactivation is induced by coke deposition. Despite remarkable strides in research, industrialization remains at an early stage.

Water pollution is calling for a sustainable remediation method such as the use of metallic iron (Fe⁰) to reduce and filter some pollutants, yet the reactivity and hydraulic conductivity of iron filters decline over time under field conditions. Here we review iron filters with focus on metallic corrosion in porous media, flaws in designing iron filters, next-generation filters and perspectives such as safe drinking water supply, iron for anaemia control and coping with a reactive material. We argue that assumptions sustaining the design of current Fe⁰ filters are not valid because proposed solutions address the issues of declining iron reactivity and hydraulic conductivity separately. Alternatively, a recent approach suggest that each individual Fe⁰ atom corroding within a filter contributes to both reactivity and permeability loss. This approach applies well to alternative iron materials such as bimetallics, composites, hybrid aggregates, e.g. Fe⁰/sand, and nano-Fe⁰. Characterizing the intrinsic reactivity of individual Fe⁰ materials is a prerequisite to designing sustainable filters. Indeed, Fe⁰ ratio, Fe⁰ type, Fe⁰ shape, initial porosity, e.g. pore size and pore size distribution, and nature and size of admixing aggregates, e.g. pumice, pyrite and sand, are interrelated parameters which all influence the generation and accumulation of iron corrosion products. Fe⁰ should be characterized in long-term experiments, e.g. 12 months or longer, for Fe dissolution, H₂ generation and removal of contaminants in three media, i.e., tap water, spring water and saline water, to allow reactivity comparison and designing field-scale filters.

The rising production of industrial salted waste induces issues of disposal and pollution, calling for advanced methods to treat, purify and recycle the raw salt in the context of the circular economy. The main components of salted waste are organic and mineral fractions. Here we review the methods used to treat salted waste with focus on sources of salted waste, properties and removal of organic matter, and separation of minerals. Organic matter can be removed by pyrolysis carbonization, high-temperature melting, elution, and oxidation. Salt can be separated by evaporative crystallization, salt washing, and nanofiltration.

The negative effects of the accelerating climate change due partly to fossil fuel consumption is calling for the rapid development of sustainable energies such as biohydrogen, which is produced using microorganisms. Here we review biohydrogen production from biomass, with focus on biomass pretreatment, fermentative production, factors affecting production, bioreactors, kinetics and modeling, and improved production with nanoparticles. Pretreatments include chemical, physical and biological methods. Hydrogen production is done by photo-fermentation or dark fermentation. Influencing factors comprise pH, temperature, hydraulic retention time, and the presence of fermentation inhibitors. Continuous stirred tank-, anaerobic fluidized bed-, anaerobic sequencing batch-, up-flow anaerobic sludge blanket- and dynamic membrane reactors are used. Additives include cobalt, nickel and iron nanoparticles. Compared to thermochemical, photochemical and electrochemical processes, biohydrogen production needs more time but is easy to operate, cost-effective and environmentally friendly.

Microplastics have been recently detected in many environmental media and living organisms, yet their transfer and toxicity to humans are poorly known. Here, we review microplastic transfer in the food chain with focus on microplastic pollution sources, methods to analyze microplastics in food, health impact of food-related microplastic exposure, and remediation of microplastic pollution. Microplastic pollution sources include seafood, food additives, packaging materials, and agricultural and industrial products. Remediation techniques comprise the use of microbial enzymes and biofilms. Microplastic detection methods in food rely on separation and quantification by optical detection, scanning electron micrography, and Fourier-transform infrared spectroscopy. Human health impact following microplastic ingestion include cancers, organ and respiration damage, and reproductive impairments. Overall, microplastic toxicity is mainly due to their ability to enter the metabolism, adsorption into the circulatory system for translocation, and difficulty, if not impossibility, of excretion.

Despite the major influence of soils on climate change, carbon sequestration, pollution remediation, and food security, soil remains a largely unexplored media with an extreme complexity of microbes, minerals, and dead organic matter, most of them being actually poorly known. In particular, soil biofilms have recently attracted attention because they strongly influence biogeochemical reactions and processes. Here we review biofilms with focus on their behavior, proliferation, distribution, characterization methods, and applications. Characterization methods include optical, electron, scanning probe, and X-ray microscopy; metagenomics, metatranscriptomics, metaproteomics, metabolomics; and tracking approaches. Applications comprise pollution remediation by metal immobilization or organics degradation; and methane oxidation, carbon dioxide reduction, and carbon sequestration. Advanced methods such as DNA-stable isotope probing and meta-omics have uncovered the multiple functions of soil biofilms and their underlying molecular mechanisms. Investigations have improved our understanding of inter- and intra-kingdom interactions, and of gene transfer. Extracellular materials such as polysaccharides enhance the transport of substances and electrons flow among microorganisms.

Infrastructure deterioration is a threat to developed countries, emphasizing the need for effective management techniques. In particular, the leakage of aged domestic sewer pipeline is a major health issue, yet there is a lack of markers to identify domestic leakage. We studied the pollution in urban waters resulting from domestic sewage leakage into storm drainages. We monitored caffeine, fragrance substances and polycyclic aromatic hydrocarbons (PAHs) in the storm discharge points in five urban districts having separate sewer systems aged from 10 to over 40 years. Results show that caffeine and fragrance concentrations tended to increase with sewer system age. For instance, caffeine concentrations in the areas of sewer systems over 40 years old were at least two orders of magnitude higher than in 10-year-old sewer systems, and were as high as 1–10% of domestic sewage, strongly suggesting the leakage of domestic sewer pipelines. PAHs exhibited consistent patterns across the districts. Overall, we observe that sewer leaking processes can be distinguished by analyzing the levels of organic pollutants.

The rapid growth of textile industry and fast-fashion has led to the production of about 92 million ton of textile waste per year. Nearly 85% of textile waste is disposed of by landfill and incineration, causing serious environmental pollution and huge resource waste, calling for alternative textile production. Here we review the green production of textiles with focus on additive manufacturing, 3- and 4-dimension printing, recycling textile waste, and synthetic and natural fibers. Additive manufacturing technologies, particularly 4-dimension printing, is flexible, green, and allows on-demand manufacturing, which is one solution to the textile waste problem. 4-Dimension printing contributes to the development of intelligent materials, and can create structures that deform in response to external stimuli. Textile waste contains high-quality, low-cost materials that can be re-used and recycled. Applications include smart textiles, flexible electronics, soft robotics, human–computer interaction, and wearable devices.

Microplastics are emerging contaminants that undergo progressive aging under environmental conditions such as sunlight irradiation, mechanical forces, temperature variations, and the presence of biological organisms. Since aging modifies microplastic properties, such as their own toxicity and the toxicity of trapped pollutants, advanced methods to analyze microplastics are required. Here we review methods to analyze microplastic aging with focus on the aging process, qualitative identification, quantitative characterization, and chemometrics. Qualitative identification is done by mechanical techniques, thermal techniques, e.g., thermal degradation and gas chromatography–mass spectrometry, and spectral techniques, e.g., infrared, Raman, fluorescent, and laser techniques. Quantitative characterization is done by microscopy and mass spectrometry. Microplastic aging results in a series of surface physical changes, biofilm formation, chemical oxidation, thermal alternation, and mechanical deterioration. Changes in mechanical and thermal properties allow to differentiate aged microplastics. Infrared and Raman spectroscopy are rapid and sensitive for chemical identification of microplastics in complex environmental samples. Combining two techniques is preferable for accurate detection and categorization.