Environmental Chemistry Letters最新文献

The increasing pollution of ecosystems by both biological and non-biological contaminants has recently fostered the rapid development of biosensors, thus opening a new investigation area in analytical sciences. Here, we review the applications of immunosensors in food safety, human health, environmental sciences, water pollution, and agriculture. We present the analysis of cancer markers, pathogens, antigens, antibiotics, pesticides, toxins, allergens, hormones, and phytohormones. Immunosensors comprise electrochemical, microgravimetric, optical, and thermometric immunosensors. Immunosensors have advantages such as enhanced sensitivity, selectivity, speed, and cost-effectiveness. In particular, antibody-based biosensors have outperformed traditional methods in identifying and analysing various compounds. Immunosensors are able to detect compounds at nanomolar to picomolar levels.

In the context of the circular economy, there is a need for advanced methods to recover metals from industrial waste, yet classical hydrometallurgical techniques are limited. Here, we review ultrasonic-assisted hydrometallurgical leaching with focus on the use of acids, bases, oxidants, bacteria and electrolysis. Oxidative leaching is done with ferric ions, dioxygen, ozone and hydrogen peroxide. Upscaling is also detailed. Ultrasonication allows to reduce the dosage of leaching agents, to reduce reaction time, and to enhance leaching efficiency. Large-scale equipments are still limited by low cavitation efficiency, low throughput, high usage costs, and high energy consumption.

Food waste production reaches actually about 1.3 billion tonnes per year, corresponding to the emission of 3.3 billion tonnes equivalent of CO₂, thus calling for improved recycling. Here we review food waste conversion into energy and products such as biohydrogen, biogas, biofuel, biodiesel, biochar, bioplastics, fertilizers, animal feed, organic acids, enzymes, and proteins. Food waste can be treated by incineration, pyrolysis, composting, anaerobic digestion, hydrothermal carbonization, and landfilling. Properties of food waste influence the efficiency of conversion.

Global warming and urbanization are likely to increase fires in natural and urbanized areas, requiring advanced fire management techniques such as the use of aqueous film forming foams. However, these foams contains in particular toxic fluorinated compounds that belongs to the class of the so-called ‘forever chemicals’. Here we review aqueous film forming foams with focus on classification, film forming, composition, toxicity, and standards. Foams are classified into aqueous film forming foams, alcohol-resistant foams, and fluoroprotein foams. Foams contain hydrocarbon surfactants, fluorosurfactants, organic solvents, and additives such as pH buffers, stabilizers, salts, corrosion inhibitors, and anti-freeze agents. Firefighting foams are aggregates of small bubbles that efficiently combat liquid fuel fires by forming a vapor-suppressing blanket over the fuel surface. Aqueous film forming foams contain 2–15% of stable perfluorinated molecules. Concerning toxicity, perfluorooctanoic acid has a half-life of more than five years in adult humans. Alternative compounds such as perfluorobutane sulfonate has a shorter half-life of 45 days in adult humans, yet its impact on soil and aquatic ecosystems is not fully understood. The proprietary nature of the aqueous film forming foam formulations is a challenge in developing sustainable firefighting foams.

Pollution, climate change and waste accumulation are critical societal issues calling for advanced methods to recycle matter and clean polluted ecosystems. Here, we review the use of calcium oxide waste-based catalysts for industrial and environmental applications such as biodiesel production, and pollutant degradation and removal. Catalysts can be produced from mud clam shell, eggshell, spent coffee ground, fish bones waste, marble waste, face mask waste, and snail shell. The preparation of composite catalysts, adsorbents, nanoparticles, and photocatalysts is presented.

The rising negative effects of climate change are caused mainly by the increase of atmospheric carbon dioxide concentrations, calling for advanced technologies to extract carbon dioxide from atmospheric air. Here we review carbon dioxide capture from atmospheric air by amine-functionalized silica composites with emphasis on development principles, mechanisms, absorbent criteria, performance determination, and preparation techniques. Amine-silica absorbent preparation for carbon dioxide capture is done by impregnation, chemical graphting, hybrid functionalization, and in situ polymerization. High costs, poor performance, and scalability are actually posing challenges for large-scale deployment.

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.