خيارات البحث
النتائج 961 - 970 من 7,240
Remediation technology towards zero plastic pollution: Recent advance and perspectives
2022
Ji, Jianghao | Zhao, Tong | Li, Fanghua
The rapid growth of plastic wastes exceeds efforts to eliminate plastic pollution owing to the outbreak of COVID-19 in 2020 and then aggravates inherent environmental threats to the ecosystem. The paper provided a short introduction relating to the hazards of plastic wastes on environment and a detailed statement about plastic toxicity on human. The article stated on plastic how to enter the body and cause harm for us step by step. Given the toxicity and harm of plastic wastes on human, the degradation of plastic wastes via the physical, chemical and biotic methodologies is looked back. The advanced physical techniques are introduced briefly at firstly. Additionally, evaluate on chemical method for plastic decomposition and review on biotic degradation of plastic. The reactive oxygen species and the enzymes play a crucial role in chemical and biotic degradation processes, respectively. The reactive oxygen species are derived from the activated state of oxides, and the enzymes that aid the microorganism to ingest plastic through its metabolic mechanism are secreted by the microorganism. Subsequently, the potential possibility of upcycling plastic is analyzed from two aspects of the technology and application. The innovative technology utilizes sunlight as driver-power of plastic upcycling. And the carbon capture, utilization and sequestration and the growth substrate provided the novel guided directions for plastic recycle. Lastly, the three suggestions on plastic waste management are expected to establish an economy and efficient plastic sorting system, and two engineering solutions on plastic recycle are to make a contribution for sustainable upcycling of plastic.
اظهر المزيد [+] اقل [-]Identification of novel polyfluoroalkyl substances in surface water runoff from a chemical stockpile fire
2022
Rana, Sahil | Marchiandi, Jaye | Partington, Jordan M. | Szabo, Drew | Heffernan, Amy L. | Symons, Robert K. | Xie, Shay | Clarke, Bradley O.
In 2018, over 30,000 L of fluorine-free firefighting foam was used to extinguish an industrial warehouse fire of uncharacterized chemical and industrial waste. Contaminated firewater and runoff were discharged to an adjacent freshwater creek in Melbourne, Australia. In this study, we applied nontarget analysis using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) to 15 surface water samples to investigate the presence of legacy, novel and emerging per-and polyfluoroalkyl substances (PFAS). We identified six novel and emerging fluorotelomer-based fluorosurfactants in the Australian environment for the first time, including: fluorotelomer sulfonamido betaines (FTABs or FTSA-PrB), fluorotelomer thioether amido sulfonic acids (FTSASs), and fluorotelomer sulfonyl amido sulfonic acids (FTSAS-So). Legacy PFAS including C₆–C₈ perfluoroalkyl sulfonic acids, C₄–C₁₀ perfluoroalkyl carboxylic acids, and perfluoro-4-ethylcyclohexanesulfonate were also detected in surface water. Of note, we report the first environmental detection of ethyl 2-ethenyl-2-fluoro-1-(trifluoromethyl) cyclopropane-1-carboxylate. Analysis of several Class B certified fluorine-free foam formulations allowed for use in Australia revealed that there was no detectable PFAS. Patterns in the homologue profiles of fluorotelomers detected in surface water are consistent with environments impacted by fluorinated aqueous film-forming foams. These results provide strong evidence that firewater runoff of stockpiled fluorinated firefighting foam was the dominant source of detectable PFAS to the surrounding environment.
اظهر المزيد [+] اقل [-]Citric acid modified biochar application at a low dosage can synchronically mitigate the nitrogenous gas pollutants emission from rice paddy soils
2022
Sun, Haijun | Yi, Zhenghua | Jeyakumar, Paramsothy | Xia, Changlei | Feng, Yanfang | Lam, Su Shiung | Sonne, Christian | Wang, Hailong | Shi, Weiming
Raw biochar with high pH possibly stimulated ammonia (NH₃) volatilization in the agricultural soil. We hypothesized that the modified biochar (MBC) with low pH can synchronically decrease the NH₃ and nitrous oxide (N₂O) losses. We performed a two-year experiment to clarify how citric acid MBC influence the NH₃ volatilization and N₂O emission as well as the underlying mechanisms. Two typical paddy soils, i.e., Hydragric Anthrosol and Haplic Acrisol, receiving equal urea N with 240 kg ha⁻¹ but varied rates of MBC with 0, 5, 10, and 20 t ha⁻¹ (named Urea, Urea + MBC5, Urea + MBC10, and Urea + MBC20, respectively) were studied. The results showed that MBC-amended treatments effectively mitigated the NH₃ volatilization from Hydragric Anthrosol and Haplic Acrisol by 29.6%–57.9% and 30.5%–62.4% in 2017, and by 16.5%–21.0% and 24.5%–35.0% in 2018, respectively, compared to Urea treatment. In addition, significantly lower N₂O emissions with averaged 38.3% and 43.1% in 2017, and 51.7% and 26.7% were recorded under Hydragric Anthrosol and Haplic Acrisol, respectively, following the MBC application (P < 0.05). Increased MBC addition performed higher efficacy on mitigating NH₃ volatilization, particularly in the first rice season, while this “dosage effect” was not found for N₂O reduction. Lowered pH in overlying water, enhanced adsorption of NH₄⁺-N and its nitrification rate likely contributed to the lower NH₃ volatilization as result of MBC addition. The nirS and nosZ gene copies were not changed by MBC, while the nirK gene copies were decreased as result of MBC amendment by 8.3%–25.2% under Hydragric Anthrosol and by 21.8%–24.9% under Haplic Acrisol. Consequent lower ratio of nirK/(nirS + nosZ) explained the mitigation effect of MBC on N₂O emission. In conclusion, the present two-year study recommends that MBC applied at a low dosage can perform positive effect on controlling the nitrogenous gas pollutants from paddy soil.
اظهر المزيد [+] اقل [-]Synergistic effects of ozone/peroxymonosulfate for isothiazolinone biocides degradation: Kinetics, synergistic performance and influencing factors
2022
Yang, Zheng-Wei | Wang, Wen-Long | Lee, Min-Yong | Wu, Qian-Yuan | Guan, Yun-Tao
Synergistic effects of ozone (O₃) and peroxymonosulfate (PMS, HSO₅⁻) for isothiazolinone biocides degradation was studied. The synergistic ozonation process (O₃/PMS) increased the efficiency of methyl-isothiazolinone (MIT) and chloro-methyl-isothiazolinone (CMIT) degradation to 91.0% and 81.8%, respectively, within 90 s at pH 7.0. This is 30.6% and 62.5% higher than the corresponding ozonation efficiency, respectively. Total radical formation value (Rcₜ,R) for the O₃/PMS process was 24.6 times that of ozonation alone. Calculated second-order rate constants for the reactions between isothiazolinone biocides and ▪ (kSO₄₋,MIT and kSO₄₋,CMIT) were 8.15 × 10⁹ and 4.49 × 10⁹ M⁻¹ s⁻¹, respectively. Relative contributions of O₃, hydroxyl radical (OH) and ▪ oxidation to MIT and CMIT removal were estimated, which were 15%, 45%, and 40% for O₃, OH and ▪ oxidation to MIT, and 1%, 67%, and 32% for O₃, OH and ▪ oxidation to CMIT at pH 7.0, respectively. Factors influencing the O₃/PMS process, namely the solution pH, chloride ions (Cl⁻), and bicarbonate (HCO₃⁻), were evaluated. Increasing the solution pH markedly accelerated O₃ decay and OH and ▪ formation, thus weakening the relative contribution of O₃ oxidation while enhancing that of OH and ▪. Cl⁻ had a negligible effect on MIT and CMIT degradation. Under the dual effect of bicarbonate (HCO₃⁻) as inhibitor and promoter, low concentrations (1–2 mM) of bicarbonate weakly promoted MIT and CMIT degradation, while high concentrations (10–20 mM) induced strong inhibition. Lastly, oxidation performance of O₃ and O₃/PMS processes for MIT and CMIT degradation in different water matrices was compared.
اظهر المزيد [+] اقل [-]Polybrominated diphenyl ether quinone exposure leads to ROS-driven lysosomal damage, mitochondrial dysfunction and NLRP3 inflammasome activation
2022
Yang, Bingwei | Wang, Yuting | Fang, Changyu | Song, Erqun | Song, Yang
Polybrominated diphenyl ethers (PBDEs) are aromatic compounds that containing bromine atoms, which possess high efficiency, good thermal stability. However, PBDEs had various known toxic effects and were characterized as persistent environmental pollutants. Exposure to a quinone-type metabolite of PBDEs (PBDEQ) is linked with excess production of intracellular reactive oxygen species (ROS) in our previous studies. Here, we observed that PBDEQ exposure led to ROS and mitochondrial dysfunction, which promoted canonical and non-canonical Nod-like receptor protein 3 (NLRP3) inflammasome activation. Further experiments demonstrated that PBDEQ exposure activated Toll-like receptors (TLRs), subsequently regulating nuclear factor kappa B (NF-κB) signaling. Moreover, lysosomal damage and K⁺ efflux were involved in PBDEQ-driven NLRP3 inflammasome activation. Our in vivo study also illustrated that PBDEQ administration induced liver inflammation in male C57BL/6J mice. Cumulatively, our current finding provided novel insights into PBDEQ-induced pro-inflammatory responses.
اظهر المزيد [+] اقل [-]Spatial origin analysis on atmospheric bulk deposition of polycyclic aromatic hydrocarbons in Shanghai
2022
Liu, Ying | Zhang, Xiaomin | Tan, Jianguo | Grathwohl, Peter | Lohmann, Rainer
Atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) onto soil threatens terrestrial ecosystem. To locate potential source areas geographically, a total of 139 atmospheric bulk deposition samples were collected during 2012–2019 at eight sites in Shanghai and its surrounding areas. A multisite joint location method was developed for the first time to locate potential source areas of atmospheric PAHs based on an enhanced three dimensional concentration weighted trajectory model. The method considered spatial and temporal variations of atmospheric boundary layer height and homogenized all results over the eight sites via geometric mean. Regional transport was an important contributor of PAH atmospheric deposition while massive local emissions may disturb the identification of potential source areas. Northwesterly winds were associated with elevated deposition fluxes. Potential source areas were identified by the multisite joint location method and included Hebei, Tianjin, Shandong and Jiangsu to the north, and Anhui to the west of Shanghai. PM and SO₂ data from the national ground monitoring stations confirmed the identified source areas of deposited PAHs in Shanghai.
اظهر المزيد [+] اقل [-]Determination of the human impact on the drop in NO2 air pollution due to total COVID-19 lockdown using Human-Influenced Air Pollution Decrease Index (HIAPDI)
2022
Kovács, Kamill Dániel
This study investigates the relationship between territorial human influence and decreases in NO₂ air pollution during a total COVID-19 lockdown in Metropolitan France. NO₂ data from the confinement period and the Human Influence Index (HII) were implemented to address the problem. The relative change in tropospheric NO₂ was calculated using Sentinel-5P (TROPOMI) satellite data. Hotspot-Coldspot analysis was performed to examine the change in NO₂. Moreover, the novel Human-Influenced Air Pollution Decrease Index (HIAPDI) was developed. Weather bias was investigated by implementing homogeneity analysis with χ2 test. The correlations between variables were tested with the statistical T-test. Likewise, remote observations were validated with data from in-situ monitoring stations. The study showed a strong correlation between the NO₂ decrease during April 2020 under confinement measures and HII. The greater the anthropogenic influence, the greater the reduction of NO₂ in the regions (R² = 0.62). The new HIAPDI evidenced the degree of anthropogenic impact on NO₂ change. HIAPDI was found to be a reliable measure to determine the correlation between human influence and change in air pollution (R² = 0.93). It is concluded that the anthropogenic influence is a determining factor in the phenomenon of near-surface NO₂ reduction. The implementation of HIAPDI is recommended in the analysis of other polluting gases.
اظهر المزيد [+] اقل [-]Pre-differentiation exposure of PFOA induced persistent changes in DNA methylation and mitochondrial morphology in human dopaminergic-like neurons
2022
Zhao, Han | Xie, Junkai | Wu, Shichen | Sánchez, Oscar F | Zhang, Xinle | Freeman, Jennifer L. | Yuan, Chongli
Perfluorooctanoic acid (PFOA) is abundant in environment due to its historical uses in consumer products and industrial applications. Exposure to low doses of PFOA has been associated with various disease risks, including neurological disorders. The underlying mechanism, however, remains poorly understood. In this study, we examined the effects of low dose PFOA exposure at 0.4 and 4 μg/L on the morphology, epigenome, mitochondrion, and neuronal markers of dopaminergic (DA)-like SH-SY5Y cells. We observed persistent decreases in H3K4me3, H3K27me3 and 5 mC markers in nucleus along with alterations in nuclear size and chromatin compaction percentage in DA-like neurons differentiated from SH-SY5Y cells exposed to 0.4 and 4 μg/L PFOA. Among the selected epigenetic features, DNA methylation pattern can be used to distinguish between PFOA-exposed and naïve populations, suggesting the involvement of epigenetic regulation. Moreover, DA-like neurons with pre-differentiation PFOA exposure exhibit altered network connectivity, mitochondrial volume, and TH expression, implying impairment in DA neuron functionality. Collectively, our results revealed the prolonged effects of developmental PFOA exposure on the fitness of DA-like neurons and identified epigenome and mitochondrion as potential targets for bearing long-lasting changes contributing to increased risks of neurological diseases later in life.
اظهر المزيد [+] اقل [-]Visible-light driven dual heterojunction formed between g-C3N4/BiOCl@MXene-Ti3C2 for the effective degradation of tetracycline
2022
Sharma, Gaurav | Kumar, Amit | Sharma, Shweta | Naushad, Mu | N. Vo, Dai-Viet | Ubaidullah, Mohd | Shaheen, Sabry M. | Stadler, Florian J.
In the present study, we have successfully formulated a dual heterojunction of g-C₃N₄/BiOCl@MXene-Ti₃C₂ (GCBM) which was found to be highly active in the visible region. GCBM was found to be highly efficient for the degradation of an antibiotic, tetracycline (TC) as compared to the individual constituting units; g-C₃N₄ and BiOCl. Maximum of 97% TC degradation rate was obtained within 90 min of visible light irradiation for initial concentration of 10 mg/L of TC. Optical analysis exhibited that the synthesized heterojunction showed high absorption in the complete spectrum. The reactive species specified by the scavenger study showed the major involvement of •O₂⁻ and •OH radicals. The charge transfer mechanism showed that 2 schemes were majorly involvement in which Z-scheme was formed between g-C₃N₄ and BiOCl and Schottky junction was formed between g-C₃N₄ and Mxene-Ti₃C₂. The formation of Schottky junction helped in inhibiting the back transfer of photogenerated charges and thus, helped in reducing the recombination rate. The synthesized photocatalyst was found to be highly reusable and was studied for consecutive 5 cycles that generalized the high proficiency even after repetitive cycles.
اظهر المزيد [+] اقل [-]Do industrial parks generate intra-heat island effects in cities? New evidence, quantitative methods, and contributing factors from a spatiotemporal analysis of top steel plants in China
2022
Meng, Qingyan | Hu, Die | Zhang, Ying | Chen, Xu | Zhang, Linlin | Wang, Zian
Industrial parks emit large amounts of anthropogenic heat and aggravate the urban heat island effect, which has become a severe environmental problem worldwide. Few studies explored if the warming effect generated by concentrated industrial facilities (i.e., steel plants in this study) produces an intra-heat island effect in urban built-up areas. Sufficient evidence of an industrial heat island (IHI) effect is lacking, and new quantitative methods are urgently needed to address these issues. Therefore, we proposed a new scheme to quantify the warming effect of large, heat-emitting urban objects versus complex surroundings, and the IHI effect was accordingly defined at a finer scale. This study separated the industrial park from other artificial lands and comprehensively estimated the IHI effects' spatiotemporal variation. The IHI intensities were measured based on varied natural and urbanized references, which provided new evidence for the existence of the IHI effect over space and seasons. The land surface temperature (LST) profiles delineated the downward trend in LST variation from inside to surroundings in the IHI cases on both spatial and temporal scales. The time-series analysis revealed that the IHI effects demonstrated more significant disparities regarding the LSTs between the industrial parks and their surrounding backgrounds during warm seasons than in cold seasons. And a more severe IHI effect was observed in spring and summer, and the weakest IHI intensity occurred in winter. Moreover, the IHI intensity is positively associated to the anthropogenic heat, indicating that the industrial activities contribute to the increased LSTs of the industrial park to a great extent. The rationale of the IHI effect can broaden insight for understanding how urban industrial heat sources influence the regional thermal environment, especially at a finer scale.
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