Environmental science. Advances最新文献

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.

Antibiotic resistance is a public health crisis. Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are present in drinking water distribution systems. Metals are known selective pressures for antibiotic resistance, and metallic corrosion products are found within drinking water distribution systems due to the corrosion of metal pipes. While corrosion products are a source of metals, the impact of specific corrosion products on antibiotic resistance has not been investigated. The objective of this study was to determine the impact of six corrosion products—CuO, Cu₂O, Pb₅(PO₄)₃OH, β-PbO₂, Fe₃O₄, and α-FeOOH—on the abundance of ARB and ARGs. Lab-scale microcosms were seeded with source water from Lake Michigan and amended with individual corrosion products. In general, copper and lead corrosion products increased antibiotic resistance, although not universally across different ARB and ARG types. Concentration and speciation of copper and lead corrosion products were found to have an impact on antibiotic resistance profiles. Meanwhile, iron corrosion products had minimal impact on antibiotic resistance. Overall, this study sheds light on how pipe materials may impact antibiotic resistance as a result of corrosion products.

The Global Atmospheric Passive Sampling (GAPS) network and GAPS Megacities network (GAPS-MC) are the only global-scale air monitoring programs for persistent organic pollutants (POPs), which support the Global Monitoring Plan (GMP) of the Stockholm Convention on POPs. The GAPS data represents all five United Nation regions and informs the spatial and temporal trends of listed POPs, their long-range transport in air, and new priorities for POPs monitoring and research. This information contributes to the Effectiveness Evaluation of the Stockholm Convention, which is assessed every six years. To ensure its long-term sustainability and relevance, the GAPS network is engaging in cross-cutting studies across fields of science and policy – leading to more holistic and integrative work on air pollution, health, climate science, and biodiversity. Future work under GAPS will continue to advance areas of intersection and tap-into topics and expertise in areas such as non-target analysis (chemical mixture approaches including transformation products in air), advanced data analysis and land-use assessment methods, top-down and inverse global modeling, global air health assessment/warning systems, and citizen science and outreach.

A novel sensitive, specific, and reversible optical sensor for the palladium(II) ion was created by impregnating an agarose membrane with 4-(2-amino-3-hydroxypyridine-4-ylazo)1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one (AHDDO). Spectrophotometric studies of complex formation between the AHDDO base ligand and Mn²⁺, Cd²⁺, Co²⁺ Hg²⁺, Zn²⁺, Cu²⁺, Pd²⁺, Sr²⁺, Al³⁺, Fe³⁺, Au³⁺, and Ag⁺ metal ions in an ethanolic solution indicated a substantially larger stability for the palladium ion complex. Therefore, the AHDDO was immobilized on a clear agarose film and used as a suitable ionophore for building a selective Pd²⁺ optical sensor. By combining the sensing membrane with Pd²⁺ ions at pH 5.75, a transparent color change from orange to violet was observed. On the immobilization of AHDDO, the effects of ionophore concentration, pH, temperature, stirring, and reaction time were investigated. A linear relationship was observed between the membrane absorbance at 633 nm and Pd²⁺ concentrations in a range from 15 to 225 ng mL⁻¹ with detection (3σ) and quantification (10σ) limits of 4.25 and 14.25 ng mL⁻¹, respectively. For the determination of Pd²⁺ ions, no significant interference from at least 400-fold excess concentrations of a number of possibly interfering ions was found. The sensor exhibits remarkable selectivity for Pd²⁺ ions and can be regenerated through exposure to 0.15 M HNO₃. The sensor has been successfully used to find palladium in biological, soil, road, and water samples.

Pyrite (FeS₂) is the most abundant sulfide mineral on Earth and represents a significant reservoir of iron and sulfur in modern and ancient sediments. Oxidation of pyrite in the terrestrial subsurface is commonly associated with lowering of groundwater pH and release of constituent trace elements to solution. Although the central role of microbial activity in pyrite oxidation is well understood in acid mine/rock drainage and other low-pH (e.g. pH < 2) environments, the role of microorganisms in mediating pyrite oxidation under circumneutral pH conditions is not well understood. Here we demonstrate the potential for aerobic microbial metabolism to promote circumneutral pH oxidation of trace element-bearing pyrite in Cambrian-age sandstones from Trempealeau County, WI (USA). Microbial activity accelerated ca. 2–5 fold the rate and extent of sulfate release (a direct measure of pyrite oxidation) from reduced pyrite-bearing sediments. pH values dropped to 3 in biotic microcosms which contained limited carbonate (dolomite) buffering capacity. The overall surface area-specific rate constant for pyrite oxidation inferred from batch reaction modeling of these microcosms (10^−7.8 mol m⁻² s⁻¹) was ca. 25-fold higher than for the corresponding abiotic reactors (10^−9.2 mol m⁻² s⁻¹). Calcium and magnesium were proportionally released to solution with sulfate as a result of carbonate and/or Ca-aluminosilicate dissolution by acid generated from pyrite oxidation. When the amount of acid from pyrite oxidation exceeded the system buffering capacity, metals were selectively released from the geological material. No significant release of trace metals took place in abiotic reactors, which showed much lower rates of pyrite oxidation. These findings suggest that groundwaters in contact with pyrite-containing geological formations contain microorganisms capable of accelerating the oxidation of native pyrite in those formations. Analysis of microbial community composition in the microcosms by 16S rRNA gene amplicon sequencing showed enrichment in organisms related to taxa associated with chemolithotrophic metabolism (Candidatus Tenderia electrophaga, Thioprofundum lithophicum, and Thiobacillus thioparus) from background levels (<2%) to up to 40% of total sequence reads. A reactive transport modeling exercise demonstrated how microbial acceleration of pyrite oxidation could have a crucial, near-term (<10 years) impact on pH decline and trace element release in response to influx of oxygenated groundwater into previously reduced geological strata. Our results have key implications for controls on the onset of low-pH conditions and associated changes in groundwater quality in drinking water wells located within pyrite-bearing geo

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