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Morphological, physiological and behavioral responses of an intertidal snail, Acanthina monodon (Pallas), to projected ocean acidification and cooling water conditions in upwelling ecosystems
2022
Duarte, Cristian | Jahnsen-Guzmán, Nicole | Quijón, Pedro A. | Manríquez, Patricio H. | Lardies, Marco A. | Fernández, Carolina | Reyes, Miguel | Zapata, Javier | García-Huidobro, M Roberto | Lagos, Nelson A.
Ocean acidification (OA) is expected to rise towards the end of the 21st century altering the life history traits in marine organisms. Upwelling systems will not escape OA, but unlike other areas of the ocean, cooling effects are expected to intensify in these systems. Regardless, studies evaluating the combined effects of OA and cooling remain scarce. We addressed this gap using a mesocosm system, where we exposed juveniles of the intertidal muricid snail Acanthina monodon to current and projected pCO₂ (500 vs. 1500 ppm) and temperature (15 vs. 10 °C) from the southeast Pacific upwelling system. After 9 weeks of experimental exposure to those conditions, we conducted three estimations of growth (wet weight, shell length and shell peristomal length), in addition to measuring calcification, metabolic and feeding rates and the ability of these organisms to return to the normal upright position after being overturned (self-righting). Growth, feeding and calcification rates increased in projected cooling conditions (10 °C) but were unaffected by pCO₂ or the interaction between pCO₂ and temperature. Instead, metabolic rates were driven by pCO₂, but a significant interaction with temperature suggests that in cooler conditions, metabolic rates will increase when associated with high pCO₂ levels. Snail self-righting times were not affected across treatments. These results suggest that colder temperatures projected for this area would drive this species growth, feeding and calcification, and consequently, some of its population biology and productivity. However, the snails may need to compensate for the increase in metabolic rates under the effects of ocean acidification. Although A. monodon ability to adjust to individual or combined stressors will likely account for some of the changes described here, our results point to a complex dynamic to take place in intertidal habitats associated with upwelling systems.
Afficher plus [+] Moins [-]Interaction between walkability and fine particulate matter on risk of ischemic stroke: A prospective cohort study in China
2022
Yang, Zongming | Wu, Mengyin | Lu, Jieming | Gao, Kai | Yu, Zhebin | Li, Tiezheng | Liu, Wen | Shen, Peng | Lin, Hongbo | Shui, Liming | Tang, Mengling | Jin, Mingjuan | Chen, Kun | Wang, Jianbing
Living in walkable neighborhoods has been reported to be associated with a lower risk of cardiovascular disease. Features of walkable neighborhoods, however, may be related to particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅), which could increase risk of cardiovascular disease. The interaction effect between walkability and PM₂.₅ on risk of ischemic stroke remains to be elucidated. In this study, we recruited a total of 27,375 participants aged ≥40 years from Yinzhou District, Ningbo, Zhejiang Province, China to investigate the associations of walkability and PM₂.₅ with risk of ischemic stroke. We used amenity categories and decay functions to evaluate walkability and high-spatiotemporal-resolution land-use regression models to assess PM₂.₅ concentrations. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median follow-up of 4.08 years, we identified a total of 637 incident cases of ischemic stroke in the entire cohort. Higher walkability was associated with a lower risk of ischemic stroke (quartile, Q4 vs. Q1 walkability: HR = 0.59, 95% CI: 0.47–0.75), whereas PM₂.₅ was positively associated with risk of ischemic stroke (Q4 vs. Q1 PM₂.₅: HR = 1.70, 95% CI: 1.29–2.25). Furthermore, we observed a significant interaction between walkability and PM₂.₅ on risk of ischemic stroke. Walkability was inversely associated with risk of ischemic stroke at lower PM₂.₅ concentrations, but this association was attenuated with increasing PM₂.₅ concentrations. Although walkable neighborhoods appear to decrease the risk of ischemic stroke, benefits may be offset by adverse effects of PM₂.₅ exposure in the most polluted areas. These findings are meaningful for future neighborhood design, air pollution control, and stroke prevention.
Afficher plus [+] Moins [-]Carbonation of municipal solid waste gasification fly ash: Effects of pre-washing and treatment period on carbon capture and heavy metal immobilization
2022
Qin, Junde | Zhang, Yunhui | Yi, Yaolin | Fang, Mingliang
Carbon capture has become an important technology to mitigate ever-increasing CO₂ emissions worldwide, and alkali waste is a potential source of CO₂ capture material. Slagging-gasification is a novel technology for treating municipal solid waste (MSW), and the gasification fly ash (GFA) is the only solid residue that is not reused at present due to its high heavy metal content. GFA contains high amounts of Ca(OH)₂ and Ca(OH)Cl, making it protentional for CO₂ capture. In this study, GFA and washed gasification fly ash (WGFA) were treated with CO₂ for different treatment periods. Weight changes of samples were recorded to evaluate the efficiency of CO₂ capture. To assess the properties of treated GFA, pH value, leached heavy metal concentration, mineral composition, and microscopic morphology were studied. The results revealed that GFA and WGFA could adsorb 18.8% and 23.7% CO₂ of their weights, respectively. Carbonation could immobilize heavy metals including Pb, Zn, and Cu when a proper treatment period was applied. An excessive treatment period decreased the efficiency of heavy metal immobilization. Pre-washing is recommended as a pre-treatment method for GFA carbonation, which increased the efficiency to adsorb CO₂, improved the pH of carbonated GFA, and enhanced the effect to immobilize heavy metals.
Afficher plus [+] Moins [-]Per- and polyfluoroalkyl substances enhance Staphylococcus aureus pathogenicity and impair host immune response
2022
Chandra Kumar Mangu, Jagadish | Stylianou, Marios | Olsson, Per-Erik | Jass, Jana
Per- and Poly-fluoroalkyl substances (PFAS) are one of the major persistent environmental contaminants. Epidemiological studies have linked PFAS exposures to altered immunity and increased occurrence of infections in children. However, the mechanisms leading to immune susceptibility to bacterial infections remains unclear. To elucidate the mechanism, transcriptional alteration in the Caenorhabditis elegans model caused by a PFAS contaminated environmental water and two reconstituted PFAS solutions were evaluated using RNA-sequencing. PFAS affected the expression of several genes involved in C. elegans immune surveillance to Gram-positive bacteria (cpr-2, tag-38, spp-1, spp-5, clec-7, clec-172). The combined exposure to PFAS and Staphylococcus aureus significantly reduced C. elegans survival and increased intestinal membrane permeability. Furthermore, the growth of S. aureus in the presence of PFAS increased the expression of virulence genes, specifically, the virulence gene regulator saeR and α-hemolysin, hla, which resulted in increased hemolytic activity. The present study demonstrated that PFAS exposure not only increased C. elegans susceptibility to pathogens by reducing host immunity and increasing intestinal membrane permeability, but also increased bacteria virulence. This presents a broader implication for humans and other animals, where environmental contaminants simultaneously reduce host resilience, while, increasing microbial pathogenicity.
Afficher plus [+] Moins [-]Enhanced removal of sulfur-containing organic pollutants from actual wastewater by biofilm reactor: Insights of sulfur transformation and bacterial metabolic traits
2022
Zhang, Wei | Wu, Yang | Wu, Jing | Zheng, Xiong | Chen, Yinguang
Sulfur-containing organic pollutants in wastewater could threaten human health due to their high malodor and toxicity, and their conversion processes are more complex than inorganic sulfur compounds. Membrane aerated biofilm reactor (MABR), as a novel and environmentally-friendly biofilm-based technology, is able to remove inorganic sulfur in synthetic wastewater. However, it is unknown how sulfur-containing organic pollutants in actual wastewater are transformed in MABR system. This work demonstrated the feasibility of MABR to eliminate sulfur-containing organic pollutants in actual wastewater, and the removal efficiency could be reached at approximately 100%. Meanwhile, over 70% of sulfur-containing organic contaminants were transformed to SO₄²⁻ during the long-term operation. Further analysis indicated that the functional bacteria that participated in sulfur transformation and carbohydrates degradation (e.g., Chujaibacter, Microscillaceaesp., and Thiobacillus) were evidently enriched when treating actual wastewater. Moreover, the critical metabolic pathways (e.g., sulfur metabolism, glycolysis metabolism, and pyruvate metabolism), and the corresponding genetic expressions (e.g., nrrA, tauA, tauC, sorA, and SUOX) were evidently up-regulated during long-term operation, which was beneficial for the transformation of sulfur-containing organic pollutants in actual wastewater by MABR. This work would expand the application of MABR for treating the actual sulfur-containing organic wastewater and provide an in-depth understanding of the organic sulfur transformation in MABR.
Afficher plus [+] Moins [-]Oxidation of sulfamethazine by peracetic acid activated with biochar: Reactive oxygen species contribution and toxicity change
2022
Zhang, Zhibo | Duan, Yanping | Dai, Chaomeng | Li, Si | Chen, Yuru | Tu, Yaojen | Leong, Kah Hon | Zhou, Lang
Peracetic acid (PAA) as an emerging oxidative has been concerned increasingly due to its high oxidation capacity and low byproducts formation potential. This study was to investigate the oxidation of sulfamethazine (SMZ) by PAA activated with activated biochar (ABC) after thermal modification. The results demonstrated that PAA could be effectively activated by ABC to degrade SMZ in a wide pH range (3–9), which followed the pseudo-second-order kinetics (R² > 0.99). Both non-radicals (singlet oxygen) and free radicals (alkoxy radicals, hydroxyl radicals) existed in the ABC/PAA system, and the degradation of SMZ was dominated by singlet oxygen. Humic acid (HA), SO₄²⁻ and HCO₃⁻ slightly inhibited the degradation of SMZ in the ABC/PAA process, while Cl⁻ and Br⁻ promoted the degradation of SMZ. The cleavage of S–N, S–C bond, and SO₂ extraction reaction rearrangement was the main oxidation process of SMZ. Meanwhile, the results of the ECOSAR program showed that the acute toxicity of most by-products was significantly reduced compared to SMZ, which revealed the potential applicability of the ABC/PAA process in the treatment of antibiotics pollution and their detoxification.
Afficher plus [+] Moins [-]Ultraviolet light-activated peroxymonosulfate (UV/PMS) system for humic acid mineralization: Effects of ionic matrix and feasible application in seawater reverse osmosis desalination
2022
Alayande, Abayomi Babatunde | Hong, Seungkwan
The use of membrane-based technology has evolved into an important strategy for supplying freshwater from seawater and wastewater to overcome the problems of water scarcity around the world. However, the presence of natural organic matter (NOM), including humic substances affects the performance of the process. Here, we present a systematic report on the mineralization of humic acid (HA), as a model for NOM, in high concentration of salts using the ultraviolet light-activated peroxymonosulfate (UV/PMS) system as a potential alternative for HA elimination during membrane-based seawater desalination and water treatment processes. Effects of various parameters such as PMS concentration, solution type, pH, anions, and anion-cation matrix on HA mineralization were assessed. The results show that 100%, 78% and 58% of HA (2 mg/L TOC) were mineralized with rate constants of 0.085 min⁻¹, 0.0073 min⁻¹, and 0.0041 min⁻¹ after 180 min reaction time at pH 7 when 0.5 mM PMS was used in deionized water, sodium chloride solution (35,000 ppm) and synthetic seawater, respectively. The reduced efficiency under saline conditions was attributed to the presence of anions in the system that acted as sulfate and hydroxyl radicals’ scavengers. Furthermore, the safety of the treated synthetic seawater was evaluated by analyzing the residual transformed products. Overall, pretreatment with the UV/PMS system mitigated fouling on the RO membrane.
Afficher plus [+] Moins [-]Bioremediation of micropollutants using living and non-living algae - Current perspectives and challenges
2022
Ratnasari, Anisa | Syafiuddin, Achmad | Zaidi, Nur Syamimi | Hong Kueh, Ahmad Beng | Hadibarata, Tony | Prastyo, Dedy Dwi | Ravikumar, Rajagounder | Sathishkumar, Palanivel
The emergence and continual accumulation of industrial micropollutants such as dyes, heavy metals, organic matters, and pharmaceutical active compounds (PhACs) in the ecosystem pose an alarming hazard to human health and the general wellbeing of global flora and fauna. To offer eco-friendly solutions, living and non-living algae have lately been identified and broadly practiced as promising agents in the bioremediation of micropollutants. The approach is promoted by recent findings seeing better removal performance, higher efficiency, surface area, and binding affinity of algae in various remediation events compared to bacteria and fungi. To give a proper and significant insight into this technology, this paper comprehensively reviews its current applications, removal mechanisms, comparative efficacies, as well as future outlooks and recommendations. In conducting the review, the secondary data of micropollutants removal have been gathered from numerous sources, from which their removal performances are analyzed and presented in terms of strengths, weaknesses, opportunities, and threats (SWOT), to specifically examine their suitability for selected micropollutants remediation. Based on kinetic, isotherm, thermodynamic, and SWOT analysis, non-living algae are generally more suitable for dyes and heavy metals removal, meanwhile living algae are appropriate for removal of organic matters and PhACs. Moreover, parametric effects on micropollutants removal are evaluated, highlighting that pH is critical for biodegradation activity. For selective pollutants, living and non-living algae show recommendable prospects as agents for the efficient cleaning of industrial wastewaters while awaiting further supporting discoveries in encouraging technology assurance and extensive applications.
Afficher plus [+] Moins [-]Catchment-scale microbial sulfate reduction (MSR) of acid mine drainage (AMD) revealed by sulfur isotopes
2022
Fischer, Sandra | Jarsjö, Jerker | Rosqvist, Gunhild | Mörth, Carl-Magnus
Laboratory experiments and point observations, for instance in wetlands, have shown evidence that microbial sulfate reduction (MSR) can lower sulfate and toxic metal concentrations in acid mine drainage (AMD). We here hypothesize that MSR can impact the fate of AMD in entire catchments. To test this, we developed a sulfur isotope fractionation and mass-balance method, and applied it at multiple locations in the catchment of an abandoned copper mine (Nautanen, northern Sweden). Results showed that MSR caused considerable, catchment-scale immobilization of sulfur corresponding to a retention of 27 ± 15% under unfrozen conditions in the summer season, with local values ranging between 13 ± 10% and 53 ± 18%. Present evidence of extensive MSR in Nautanen, together with previous evidence of local MSR occurring under many different conditions, suggest that field-scale MSR is most likely important also at other AMD sites, where retention of AMD may be enhanced through nature-based solutions. More generally, the developed isotope fractionation analysis scheme provides a relatively simple tool for quantification of spatio-temporal trends in MSR, answering to the emerging need of pollution control from cumulative anthropogenic pressures in the landscape, where strategies taking advantage of MSR can provide viable options.
Afficher plus [+] Moins [-]Green synthesis of metal-based nanoparticles for sustainable agriculture
2022
Jiang, Yaqi | Zhou, Pingfan | Zhang, Peng | Adeel, Muhammad | Shakoor, Noman | Li, Yuanbo | Li, Mingshu | Guo, Manlin | Zhao, Weichen | Lou, Benzhen | Wang, Lingqing | Lynch, Iseult | Rui, Yukui
The large-scale use of conventional pesticides and fertilizers has put tremendous pressure on agriculture and the environment. In recent years, nanoparticles (NPs) have become the focus of many fields due to their cost-effectiveness, environmental friendliness and high performance, especially in sustainable agriculture. Traditional NPs manufacturing methods are energy-intensive and harmful to environment. In contrast, synthesizing metal-based NPs using plants is similar to chemical synthesis, except the biological extracts replace the chemical reducing agent. This not only greatly reduces the used of traditional chemicals, but also produces NPs that are more economical, efficient, less toxic, and less polluting. Therefore, green synthesized metal nanoparticles (GS-MNPs) are widely used in agriculture to improve yields and quality. This review provides a comprehensive and detailed discussion of GS-MNPs for agriculture, highlights the importance of green synthesis, compares the performance of conventional NPs with GS-MNPs, and highlights the advantages of GS-MNPs in agriculture. The wide applications of these GS-MNPs in agriculture, including plant growth promotion, plant disease control, and heavy metal stress mitigation under various exposure pathways, are summarized. Finally, the shortcomings and prospects of GS-MNPs in agricultural applications are highlighted to provide guidance to nanotechnology for sustainable agriculture.
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