Environmental science. Advances最新文献

Street litter and the plastic pollution associated with it is an economic and environmental health issue in municipalities worldwide. Most municipal litter data are derived from costly audits, performed by consultants at sparse intervals. Mobile phone apps have been developed to allow citizen scientists to participate in collecting litter data. Both municipal audits and citizen science datasets may be useful not only for informing municipal management decisions but also for increasing scientific understanding of litter dynamics in urban environments. In this analysis, we compare the spatial patterns and composition of litter in Vancouver, Canada, measured through professional municipal audits and with Litterati, a widely used citizen science app. While reported litter composition was consistent across methods, regression analysis shows that spatially, Litterati submissions were more highly correlated with human population patterns than with correlates of litter. We provide method recommendations to improve the utility of resulting data, such that these non-traditional, underutilized datasets may be more fully incorporated into scientific inquiry on litter.

Contamination in and around military radar stations in the Arctic has been an ongoing concern since first identified in the 1980s. This study reports on the environmental impact from a DEW line US military station that was operated on Heiðarfjall mountain in northeast Iceland from 1957 to 1970. This review is conducted as a part of work of the POPs Expert Group of the Arctic Monitoring and Assessment Program (AMAP) for an assessment report on local sources vs. long-range transport of Persistent Organic Pollutants (POPs) in the Arctic. The main resource for this summary is an evaluation of results from several reports on Heiðarfjall Langanes, one from an Icelandic Environmental Authority in 1993 and another from the Canadian Environmental Science Group (ESG) at the Royal Military College of Canada, which was commissioned in 2017 by the owners of the land that was used for the station. The results are compared to findings in scientific papers and reports for contamination at other military radar stations in Canada and Alaska. This review shows considerable contamination on Heiðarfjall over 50 years after the closure of the station and is consistent with findings at other former military stations of the same era and with recent preliminary results from environmental investigation by the Norwegian Geological Institute (NGI). The dump area has around 13 thousand m³ of soil contaminated with petroleum hydrocarbons (PHCs), lead, mercury and tin. The communication area and surrounding are contaminated with polychlorinated biphenyls (PCBs), lead and mercury. In other areas storing oil, soil samples reveal elevated concentrations of PHCs. New monitoring results by NGI with passive water samplers show PCBs 20-fold above the guideline value in a water source below Heiðarfjall, and the prediction and dispersion model indicated an increased concentration of PCBs there for decades to come. From new knowledge on the impact of climate change on the release of contaminants as POPs, it can be concluded that there is a need for further cleanup of the area. The potential for future releases due to climate warming should be included in risk assessments of contaminated military and industrial sites in the Arctic.

In view of selectively recovering precious contents in electronic waste by combined electrochemical leaching and deposition step in the same cell, this study presents electrochemical investigations of the two reactions conducted in green deep eutectic solvents (DESs) for the case of silver. In addition to ethaline 1 : 2 formed from choline chloride and ethylene glycol, propeline 1 : 3 with less nocive propylene glycol was tested. Determination of the density, viscosity and conductivity of the two DES depending on temperature and their water content could lead to ionicity values from 0.70 to 0.90, with a negative effect of these operating parameters. Pure silver can be leached at 1 mA cm⁻² with faradaic yield near 100% from the two DES, provided sufficient temperature and water content below 5 wt%. Electrodeposition was thoroughly examined by cyclic voltammetry and amperometry at transient or steady state at a rotating electrode, leading to Ag(I) diffusivity values in the two DES. Kinetic parameters of the electrodeposition reaction, modelled as irreversible, were also estimated from cyclic voltammograms. Thick silver deposits were produced in 24 h-long tests at 60 °C and 0.25 mA cm⁻² in a dry atmosphere with nearly 100% current efficiency. The deposits were formed by little coalesced regular grains of size 15–20 μm and exhibiting fair adherence.

Water pollution has become a major issue due to the presence of hazardous pollutants resulting from ever-increasing industrial growth, and researchers are actively seeking innovative solutions for water treatment. Graphene Oxide (GO)–polysulfone (PSF) membranes are widely used in water remediation due to their resistance to high pH and harsh chemicals, and their ability to remove water pollutants. These materials have unique two-dimensional structures, tailorable micropores, large surface areas, and fascinating surface properties, making them ideal for water treatment. This review article provides a comprehensive overview of the latest developments in polysulfone-derived membranes modified with graphene oxide, including their separation performance, antifouling effect, and ability to separate and degrade organic pollutants. Additionally, the review article covers membrane performance for filtration of organic dyes, metal ions, radionuclides and salts from contaminated water. The review article also highlights simulation or computational studies and concludes by discussing the challenges and prospects of GO–PSF derived membranes for water remediation.

Direct air capture (DAC), which captures CO₂ from ambient air, is a critical technology to reduce greenhouse gases in the atmosphere in order to avoid climate disasters. Due to the relatively low concentration of CO₂ (400 ppm), a large amount of air needs to be moved through DAC devices, which requires lots of energy. Currently, DAC technologies are deployed mainly in centralized systems and require extensive infrastructure and initial capital cost. A potential solution is to utilize existing infrastructure for DAC. In this study, we propose a distributed DAC system that utilizes existing commercial rooftop heating and air conditioning (HVAC) units to capture CO₂ from the air. There are approximately 15 million such units already installed on commercial buildings in the United States, and they move a large amount of air every day. Adding DAC functionality to these units will significantly reduce the cost of infrastructure and operation. A modular approach was used to introduce DAC into a rooftop unit. Modules filled with triethylenetetramine-functionalized polyacrylonitrile sheets were developed and installed on the condenser coil side of the rooftop unit. The rooftop unit with DAC functions effectively captured CO₂ from the air, and the addition of the DAC modules had little effect on the unit's original functionality. A preliminary techno-economic analysis was also conducted, and the results potentially suggest that utilizing existing commercial rooftop units for carbon capture is a feasible approach to reducing greenhouse gases.

This study presents the findings of an investigation on the dynamics of dissolved organic matter (DOM) concentration and characteristics of four Australian rivers and reservoirs after their catchments had been severely burned by bushfires (wildfires) or impacted by a tropical cyclone. Dissolved organic carbon (DOC) increased immediately following the events, and subsequently decreased. The findings indicate rapid stabilisation of water quality, based on the measured parameters, following the commencement of the first winter after the events (which occurred in mid/end summer). In the fire-affected Middle River catchment, DOC decreased from 30.7 mg L⁻¹ to 10.2 mg L⁻¹ over approximately seven months. In the case of the Herring Lagoon catchment, which was affected by cyclone Uesi, DOC decreased from 15.6 mg L⁻¹ to 1.2 mg L⁻¹ over approximately ten months. However, the DOM present in the surface water exposed to the cyclone showed higher molecular weight, coagulability and UV-vis absorbance than the DOM present in the surface water of fire-affected catchments. The observed rapid increase and then reduction in DOM concentrations after extreme climate events indicates the need for short-term and rapid responses for drinking water treatment. The fluorescence signal of a field-deployable fluorescent DOM (fDOM) sensor showed potential as an online monitoring tool for assessing DOM concentration in surface waters, including under extreme conditions. The rapid identification of high DOM loadings in surface waters following extreme climate events (e.g. using a field deployed fDOM sensor) along with its coagulability characteristics could assist in catchment management and drinking water treatment by enabling timely control decisions in response to the impacts of such events.

We explored the role of biomineralization in industrial waste sludge formation, using the laboratory cultivation of Desulfovibrio sp. OL sulfate reducing species isolated from the Komsomolsky waste sludge (Russia). The most frequently reported sulfate-reducing bacteria (SRB) biomineralization products are various iron sulfides. Here we present first studies of the products of Desulfosporosinus metallidurans, acidophilic SRB from acid mine drainage. We analyzed the biomineralized sample using X-ray diffraction, electron microscopy, X-ray absorption and Mössbauer spectroscopies, and magnetization measurements via First-Order Reversal Curve (FORC) diagram analysis. Our findings show that the biomineralization occurring under pure culture conditions leads to the formation of greigite (Fe₃S₄) nanorods, along with larger microbially mediated crystals of vivianite (Fe₃(PO₄)₂·8H₂O) and siderite (FeCO₃). Energy dispersive X-ray spectroscopy revealed that the crystal sizes of vivianite and siderite were comparatively larger than those of the nanorod-shaped greigite. Transmission electron microscopy and Mössbauer spectroscopy detected ultrafine ferrihydrite (Fe₂O₃·nH₂O) superparamagnetic nanoparticles with an average size of 2.5 nm. FORC analysis showed significant magnetic interactions among these nanoparticles, suggesting their potential for magnetic separation applications. The current study demonstrates that ferrihydrite nanoparticles have a strong magnetic affinity for other crystal phases produced by Desulfosporosinus metallidurans. Therefore, we believe that the investigated bacterial species can be exploited in advanced magnetic separation techniques. This offers a cost-effective and environmentally friendly method for purifying sediments in industrial waste sludge.

A macroalgae (seaweed) herbarium nitrogen isotope (δ¹⁵N) record is produced for the River Mersey and Liverpool South Docks (England) between 1821 and 2018. A modern macroalgae δ¹⁵N record was also produced from September 2022. The herbaria δ¹⁵N record shows a stark difference from 1821 to the present. Lower δ¹⁵N in the early 1800s is attributed to agricultural and raw sewage pollution. From 1970 to the present the herbaria samples record very elevated δ¹⁵N values – peaking in 1978 at +31‰. The 1989 Water Act and privatisation of water companies in the UK had limited impact on the herbarium δ¹⁵N record but indicated a dominance of sewage nitrogen in the River Mersey. Macroalgae δ¹⁵N has become even more elevated since the last herbaria sample in 2013. The herbaria and modern data record some of the highest seaweed δ¹⁵N values (and therefore, sewage nitrogen pollution) recorded to date. This study highlights a novel use of herbaria macroalgae to document past changes in nitrogen pollution in estuarine environments. More poignantly it highlights that the River Mersey – Mersey Estuary is heavily polluted with sewage nitrogen and requires immediate action to resolve this environmental issue.

The environmental impact of microplastics is increasingly being recognized, leading to their inclusion as contaminants of emerging concern. Consequently, it is essential to identify and monitor microplastics and their impact on the ecosystem. In this study, a ball miller was employed to process plastic waste, generating microplastics for the optimisation of separation methods. Microplastics of various sizes and shapes were produced and used to spike the sediments for optimisation of the density separation method. The recovered microplastics ranged from 0.74–5 mm, as confirmed by stereomicroscopy. In addition, the types of polymers present in microplastics were confirmed using Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR). The developed analytical method was employed to study the occurrence of microplastics in river sediments passing through informal settlements after floods. Moreover, the evaluated data confirmed that informal settlements are a major source of microplastics found in the ocean after a flood. Microplastics in river and ocean sediments were predominantly composed of polypropylene, polyethylene, and polystyrene with a size range of 0.90–5 mm. To the best of our knowledge, this study is the first to report the impacts of informal settlements on the ocean during floods in Africa.

The objective of this study was to investigate the occurrence, spatial distribution, and ecotoxicological risk of pesticides and transformation products in surface waters of western Montérégie (Quebec, Canada). A total of 29 samples were collected from 11 rivers during the summers of 2019 and 2021, and the samples were analyzed for 48 pesticides and 8 transformation products. The downstream data were used to assess the ecotoxicological risks based on Quebec's acute or chronic aquatic life criterion (AALC or CALC). Overall, 9 herbicides (glyphosate, S-metolachlor, 2,4-D, metribuzin, atrazine, MCPA, prometryn, dimethenamid, simazine), 3 insecticides (clothianidin, imidacloprid, chlorantraniliprole), and 4 fungicides (azoxystrobin, fluxapyroxad, tebuconazole, carbendazim) were detected at all sampling sites, demonstrating their widespread use in western Montérégie. Glyphosate (87–4095 ng L⁻¹), S-metolachlor (6–2519 ng L⁻¹), and 2,4-D (6–1094 ng L⁻¹) were identified as the most abundant pesticides in surface water. Furthermore, 6 pesticide transformation products (metolachlor ESA, AMPA, metolachlor OA, desethylatrazine, atrazine-2-hydroxy, desisopropylatrazine) were detected at all sampling sites. The concentration of transformation products accounted for 51% on average of the total concentration, demonstrating the abundance of transformation products in surface waters. Neonicotinoids exhibited the highest ecotoxicological risk in the surface water samples with an average CALC risk quotient of 28 for 2019 and 12 for 2021, respectively. The present study offers insights into pesticides occurrence and their ecological impacts on surface waters of western Montérégie and allows for supporting future pesticide management and ecotoxicological risk mitigation strategies.