Environmental Science and Pollution Research最新文献

Kombucha is a popular fermented beverage that involves fermentation using a symbiotic culture of bacteria and yeast (SCOBY) and produces bacterial cellulose (BC). Carbon and nitrogen sources are essential in kombucha processing and BC production. However, studies on cost-effective BC production as an alternative source of leather have remained scarce. This study aimed to assess the effects of various nitrogen and carbon sources on the production of kombucha BC, investigate the qualities, and dye the product using natural colorant. Different nitrogen sources (such as black tea, white tea, and green tea) and carbon sources (honey, sugar cane, palm sugar, and brown sugar) were used to produce kombucha BC, as well as to appraise the product qualities, which were dyed using three distinct natural dyes (coffee, ginger, and sappan wood). The results revealed that different nitrogen and carbon sources produced different BC with different properties. Green tea (N-source) and palm sugar (C-source) containing medium produced a BC thickness of 0.194 ± 0.04 mm with the highest tensile strength (24.42 ± 3.90 g). Different dyes also result in the fabric having different colors: brownish yellow (coffee), yellowish orange (ginger), and red (sappan wood). All BC products showed color stability after 8 months of storing at room temperature. In conclusion, effective BC production could use green tea and palm sugar as the best nitrogen and carbon sources, respectively. Dyed BC showed good visual quality and is promising for its eco-friendly and sustainable application in fashion products.

Polypropylene (PP) disposable face masks (DFMs) are essential for limiting airborne infectious diseases. This study examines the behavior of DFMs under three scenarios: (i) exposure to the natural environment, (ii) simulated high-energy aquatic environments through an abrasion test, and (iii) incorporation into cement-based mortars. In the natural weathering experiment, after 117 days, the DFMs exhibited photodegradation, resulting in chemical alterations in carbonyl and hydroxyl groups. This degradation led to the breakdown of the polymer and the release of microplastics and nanoplastics. Controlled abrasion tests, conducted in a Denver ball with water, sand, and ceramic balls for 2 h, confirmed that water is a critical factor for fiber release from DFMs. These tests resulted in the release of 0.26 g of PP fibers from 20 DFMs (weighing 62 g in total) with a diameter of 20 µm. Weathering and abrasion tests indicated rapid release and degradation of microplastics and nanoplastics, underscoring the importance of pursuing actions like reuse. Ecotoxicological tests revealed that leachates from the DFM-incorporated mortars showed no adverse effects on Daphnia magna or Selenastrum capricornutum, unlike the reference mortar, which caused substantial toxicity to Daphnia magna. Incorporating PP fibers from DFMs into cement-based mortars showed promising potential, as indicated by favorable ecotoxicity and chemical leaching test results.

Rare earth elements (REEs) are emerging contaminants rendering potential risks in soils to environmental quality and human health. The causation between their geochemical signatures and contamination levels with parent rocks and soil properties are critical for REEs risk assessments, which are urgently needed globally. Thus, this study aimed to elucidate cause-and-effect among hydrofluoric-acid-digested total and ethylenediaminetetraacetic acid extracted bioavailable soil REEs and their contamination degree evaluated by pollution indices in 268 soil layer (horizon) samples from 50 soil profiles derived from felsic, intermediate, mafic, ultramafic, and sedimentary rocks in Taiwan. The total REEs was 133 ± 61.9 mg/kg and all individual REEs were classified as minimal contamination by the enrichment factor. The highest total soil REEs was from granite, followed by sandstone and shale, mafic rocks, andesite, and ultramafic rocks. All soils were ranked as significantly pollution risk by the pollution loading index. Furthermore, REEs were accumulated in all subsoils due to the co-translocation with soil colloids during the intensive leaching, corresponding with their higher geoaccumulation index value than those in surface soils. The contamination degree and bioavailable REEs significantly increased with the increasing total REEs. However, the stronger sequestration of clay and free Fe oxides for heavy REEs (HREEs) over light REEs (LREEs) mitigated their bioavailability, especially in the highly weathered soils like Ultisols and Oxisols. This study highlighted the dominance of soil properties in REEs fractionation, where the preferential fixation of soil colloids for HREEs throughout soil profiles reduced their uptake risk for biome even under the rising contamination potential.

Recycling excreta resources through resource-oriented toilet systems (ROTS) holds transformative potential, yet adoption remains limited, especially where benefits could be high. This study aims to understand constraints hindering the adoption of ROTS in one such area in Ethiopia. Based on a survey among 476 households comprising 2393 individuals, we examine the plans to use ROTS and willingness to pay for ROTS and apply structural equation modelling to analyze the drivers of these two outcomes while comparing the explanative power of the extended technology acceptance model, extended theory of planned behaviour, and their combined model. While 40% of households expressed a plan to use ROTS and 20% reported willingness to pay for a subsidized ROTS with a biogas unit, merely 7% revealed both the plan to use and sufficient willingness to pay, highlighting the need to target both these complementary outcomes concurrently. The theory of planned behaviour showed the best explanative power, also revealing that these two outcomes are influenced by partly distinct sets of factors. Findings imply that common efforts to ease objective constraints through subsidies, which incentivize willingness to pay, are necessary but not sufficient for facilitating the adoption of ROTS. To simultaneously enhance intentions to use, it is also recommended to target psychosocial drivers, such as perceived behavioural control and perceived community support, through awareness creation, behaviour change activities, and community engagement techniques.

In 2020, the largest continuous wetland area on the planet, the Brazilian Pantanal, experienced an unprecedented fire that affected the entire ecosystem. Our goal was to elucidate the effects of ash presence following the fire events. We quantified the impact of ashes, collected in four Conservation Units, on soil, water, and atmosphere. On the edaphic system, we tested the impact through behavioral and acute toxicity tests using annelids exposed to contaminated soil at different ash concentrations. We assessed the effect of ash on the flux of soil greenhouse gases. In the water, we examined the impact through tests with the Daphnia similis Claus, 1876. On the edaphic system, Eisenia andrei (Bouché, 1972) exhibited reduced average mortality rates and negative sublethal responses, including behavioral and morphological changes. Annelids displayed rejection responses to the ash substrate, suggesting potential damage to soil function. D. similis showed high mortality rates. We noted an increase in carbon dioxide emissions after ash addition. Changes in soil characteristics were also observed, mainly an increase in minerals. Considering the escalating frequency and intensity of fires in tropical areas due to climate change and deforestation, our findings contribute to understanding the potential ecotoxicological impact of ash in wetlands.

This work is focused on the synthesis and performance of Ni₃(PO₄)₂-based catalysts doped with Cu, Co, Mn, Ce, Zr, and Mg for the complete oxidation of ethanol, aiming at reducing emissions from ethanol-blended gasoline. Nickel phosphate was prepared via the co-precipitation method, followed by impregnation with the specified dopants. The catalysts were thoroughly characterized by XRD, N₂-physisorption, XRF, FTIR and Raman spectroscopy, FESEM, NH₃-TPD, CO₂-TPD, and H₂-TPR to explain their performance. All catalysts achieved complete ethanol conversion (100%) at a temperature below 320 °C. The performance of the catalysts was strongly influenced by the dopant type of which Co, Ce, Mn, and Mg showed high CO₂ selectivity (selectivity > 90% at 95% ethanol conversion temperature (T₉₅)). The mechanism of oxidation is affected by the acido-basicity of the catalysts and the redox properties leading to a reaction through ethylene formation over the acid catalysts and acetaldehyde over the basic catalysts. The redox properties of the doped catalysts play a crucial role in enhancing the catalytic activity and selectivity toward CO₂, as the redox-active dopants facilitate the activation of oxygen species, which are essential for the complete oxidation of ethanol. In particular, Co and Ce demonstrated superior redox characteristics, facilitating the conversion of intermediate species and leading to higher CO₂ selectivity while minimizing undesirable by-products.

Improper management of wood impregnation chemicals and treated wood has led to soil contamination at many wood treatment sites, particularly with toxic substances like creosote oil and chromated copper arsenate (CCA). The simultaneous presence of these pollutants complicates the choice of soil remediation technologies, especially if they are to be applied in situ. In this laboratory study, we attempted to immobilise arsenic (As) and simultaneously degrade polycyclic aromatic hydrocarbons (PAHs) (constituents of creosote oil) by applying a modified electrochemical oxidation method. The supply of iron (Fe) amendments in contaminated soil was done using corroding Fe electrodes as an Fe source and applying an alternating polarity electrical current. Soil with a large fraction of organic matter (25%) and containing 505 mg kg^-1 As and 5160 mg kg^-1 16-PAHs was placed in Plexiglas cells equipped with porewater samplers and an iron electrode pair connected to a power supply unit. The porewater and percolating solution were periodically sampled and analysed over an 8-week period. The modified electrochemical soil treatment led to a decrease in the total concentration of 16-PAHs in soil by 56-68%. The amount of poorly crystalline Fe oxides in the soil substantially increased, especially close to the electrodes, enabling 76-89% of As to be bound to this most reactive Fe fraction. Nevertheless, over 10% of soil As remained in the most soluble and available fraction (exchangeable), most likely due to the decline in soil redox potential over time. This study suggests that electrochemical oxidation of organic soil with mixed contaminants could be used for in situ soil remediation but needs further improvement to achieve more efficient As immobilisation.

Palm kernel shell (PKS) and empty fruit bunch (EFB) are potential biomass resources for producing solid biofuel for energy applications. However, raw EFB and PKS are not uniform in size and pose rotting behavior. Torrefaction and co-pelletization are both effective methods to improve their combustion and mechanical characteristics. This study aims to investigate the effect of torrefaction temperature and the blending ratio of PKS and EFB on the mechanical and combustion characteristics of co-pellets. Initially, PKS and EFB underwent torrefaction process for 30 min at three different temperatures (210 °C, 240 °C, and 270 °C). Then, both torrefied PKS and EFB were blended at five different ratios (0:100, 25:75, 50:50, 75:25, 100:0) with carboxymethyl cellulose as a binder (10% by weight). The results showed that pellet produced at higher torrefaction temperature at 270 °C resulted in an increment of the higher heating value (HHV) but weaker mechanical strength. Pellet with a blending ratio of PKS to EFB (75:25) torrefied at 240 °C showed the comparatively best pellet quality in terms of HHV (17.94 MJ/kg), high tensile strength (3.5 MPa), low ash content (3.97 wt%), and the lowest density changes (0.66%), which satisfy the standard requirements for commercial pellets, indicating that a high-quality biofuel pellet can be produced using torrefaction and co-pelletization.

This study focused on testing the response of the assimilation apparatus of evergreen Pinaceae species to increasing levels of oxidative stress simulated in manipulative experiments. Needles were collected from mature individuals of Pinus mugo, Pinus cembra, Pinus sylvestris, Abies alba, and Picea abies at the foothill (FH) and alpine treeline ecotone (ATE) in the High Tatras (Western Carpathians). The injury index (INX), quantified by the modified electrolyte leakage (EL) method, indicated severe needle damage due to exposure to extremely high levels of O₃. Ozonation induced changes in the chemical composition of the needles, which were detected via gas chromatography-mass spectrometry. The oxidative stability (OxS) indicator derived from INXs was used to determine the stomatal O₃ flux-based critical level CL(OxS), with the threshold value of OxS at -0.05, corresponding to 5% injury to the needles. Assessment of the phytotoxic ozone dose (POD0) under ambient O₃ and field environmental conditions during the 2023 growing season via CL(OxS) revealed that the studied species utilised between 18% (Abies alba FH) and 33% (Pinus mugo ATE) of their O₃ tolerance potential. These results support our hypothesis that Pinaceae species growing in the High Tatras, which are part of the Alpine biogeographical region of Eastern Central Europe, are vulnerable to O₃ concentrations significantly higher than the typical ambient O₃ level in the natural environment.

On October 11, 2018, in the Ulytau region of the Republic of Kazakhstan, the Soyuz-FG launch vehicle carrying a crewed MS-10 spacecraft failed. It resulted in the release into the fragile arid ecosystems of rocket propellants, i.e., jet fuel of toxic hazard class 4 and carcinogenic unsymmetrical dimethyl hydrazine (heptyl, UDMH). In this paper, we described the results of soil surveys conducted in 2018, 2019, 2022, and 2023. In the fragile arid ecosystems in Central Kazakhstan, due to the emergency falling of the launch vehicle, environmental consequences were registered at a total area of about 1350 m², including spillage of jet fuel and UDMH in the territories of 400 m² and 9 m², respectively. The third stage disintegrated and fell down within an area of 4.4 km². Immediately after the emergency crash of the second stage, the content of total petroleum hydrocarbons (TPHs) reached 1645 mg/kg, decreasing 10 times in 3.5 years. At the fuel tank falling site, the concentration of highly toxic carcinogenic UDMH and nitrosodimethylamine (NDMA) reached 22 and 9 mg/kg, which is many times higher than the maximum permissible concentrations. Four years after reclamation, the content of both substances did not exceed 0.05 mg/kg-the lower limit of sensitivity of a highly performed liquid chromatography. The content of TPHs, water-soluble Cl^- and SO₄^2-, and alkalinity from CO₃^2- was significantly (p < 0.05) higher in autumn of 2022, and the content of total N, water-soluble NO₃^- and NO₂^-, and alkalinity from HCO₃^- was higher in spring of 2023. In spring and autumn, the content of exchangeable Ca²⁺ and Mg²⁺, cation exchange capacity was similar (p > 0.05). The presented materials can be used to optimize the restoration of disturbed arid ecosystems and future monitoring work at sites of regular landing of the first stages and emergency crash sites of launch vehicles.