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Effect of flupyradifurone on zebrafish embryonic development
2021
Zhong, Keyuan | Meng, Yunlong | Wu, Juan | Wei, You | Huang, Yong | Ma, Jinze | Lu, Huiqiang
Evaluation of the toxicity of pesticide residues on non-target organisms in the ecosystem is an important part of pesticide environmental risk assessment. Flupyradifurone is a new type of butenolide insecticide produced by Bayer, who claims it to be “low toxic” to non-target organisms in the environment. However, there is little evidence in the literature to show how flupyradifurone affects aquatic organism development. In the current study, zebrafish embryos were treated with 0.1, 0.15, and 0.2 mg/mL of flupyradifurone within 6.0–72 h past fertilization (hpf). We found that the half-lethal concentration (LC₅₀) of flupyradifurone for zebrafish embryos at 96 hpf was 0.21 mg/mL. Flupyradifurone decreases the heart rate, survival rate, and body length of zebrafish embryos. The flupyradifurone treatment also led to the failure of heart looping, and pericardial edema. Moreover, flupyradifurone increased the level of reactive oxygen species (ROS) and decreased the enzymatic catalysis of catalase (CAT) and superoxide dismutase (SOD). Alterations were induced in the transcription of apoptosis-related genes (bcl-2, bax, bax/bcl-2, p53 and caspase-9) and the heart development-related genes (gata4, myh6, nkx2.5, nppa, tbx2b, tbx5 and vmhc). In the current study, new evidences have been provided regarding the toxic effects of flupyradifurone and the risk of its residues in agricultural products and the environment.
اظهر المزيد [+] اقل [-]ZIF-8 templated assembly of La3+-anchored ZnO distorted nano-hexagons as an efficient active photocatalyst for the detoxification of rhodamine B in water
2021
Karuppasamy, K. | Rabani, Iqra | Vikraman, Dhanasekaran | Bathula, Chinna | Theerthagiri, J. | Bose, Ranjith | Yim, Chang-Joo | Kathalingam, A. | Seo, Young-Soo | Kim, Hyun-Seok
The use of lanthanum-anchored zinc oxide distorted hexagon (La@ZnO DH) nanoclusters as an active material for the photodegradation of rhodamine B (Rh–B) dye via hydrogen bonding, electrostatic, and π-π interactions is examined herein. The active photocatalyst is derived from porous zeolite imidazole frameworks (ZIF-8) via a combined ultrasonication and calcination process. The distorted hexagon nanocluster morphology with controlled surface area is shown to provide excellent catalytic activity, chemical stability and demarcated pore volume. In addition, the low bandgap (3.57 eV) of La@ZnO DH is shown to expand the degradation of Rh–B under irradiation of UV light as compared to the pristine ZIF-8-derived ZnO photocatalyst due to inhibited recombination of electrons and holes. The outstanding physicochemical stability and enhanced performance of La@ZnO DH could be ascribed to the synergistic interaction among La3+ particles and the ZnO nanoclusters and provide a route for their utilization as a promising catalyst for the detoxification of Rh–B.
اظهر المزيد [+] اقل [-]Yeast biomass-induced Co2P/biochar composite for sulfonamide antibiotics degradation through peroxymonosulfate activation
2021
Peng, Yuanyuan | Tong, Wenhua | Xie, Yi | Hu, Wanrong | Li, Yonghong | Zhang, Yongkui | Wang, Yabo
Advanced oxidation processes (AOPs) based on peroxymonosulfate (PMS) activation have attracted increasing attention in recent years for organic pollutants removal. Herein, we put forward a facile method to form cobalt phosphide/carbon composite for PMS activation. Combining impregnation approach with pyrolysis treatment enabled the formation of Co₂P/biochar composites using baker’s yeast and Co²⁺ as precursors. The as-synthesized products exhibited excellent catalytic activity for sulfamethoxazole (SMX) degradation over the pH range 3.0–9.0 b y activating PMS. For example, 100% of SMX (20 mg L⁻¹) removal was achieved in 20 min with catalyst dosage of 0.4 g L⁻¹ and PMS loading of 0.4 g L⁻¹. Near zero Co²⁺ leaching was observed during catalytic reaction, which remarkably lowered the toxic risk of transition metal ion in water. Meanwhile, the reusability of catalyst could be attained by thermal treatment. SMX degradation intermediates were identified by liquid chromatography-mass spectrometry (LC-MS), which facilitated the proposal of possible SMX degradation pathways. Ecological Structure Activity Relationships (ECOSAR) analysis indicated that SMX degradation intermediates may not pose ecological toxicity to the environment. Further investigation verified that Co₂P/biochar composites could set off PMS activation not only for the degradation of SMX but also for other sulfonamides. In this study, we not only developed a facile method of utilizing environmental-benign biomass for transition metal phosphide/carbon composite formation, but also achieved highly efficient antibiotic elimination by PMS-based AOP.
اظهر المزيد [+] اقل [-]In situ catalytic reforming of plastic pyrolysis vapors using MSW incineration ashes
2021
Ahamed, Ashiq | Liang, Lili | Chan, Wei Ping | Tan, Preston Choon Kiat | Yip, Nicklaus Tze Xuan | Bobacka, Johan | Veksha, Andrei | Yin, Ke | Lisak, Grzegorz
The valorization of municipal solid waste incineration bottom and fly ashes (IBA and IFA) as catalysts for thermochemical plastic treatment was investigated. As-received, calcined, and Ni-loaded ashes prepared via hydrothermal synthesis were used as low-cost waste-derived catalysts for in-line upgrading of volatile products from plastic pyrolysis. It was found that both IBA and air pollution control IFA (APC) promote selective production of BTEX compounds (i.e., benzene, toluene, ethylbenzene, and xylenes) without significantly affecting the formation of other gaseous and liquid species. There was insignificant change in the product distribution when electrostatic precipitator IFA (ESP) was used, probably due to the lack of active catalytic species. Calcined APC (C-APC) demonstrated further improvement in the BTEX yield that suggested the potential to enhance the catalytic properties of ashes through pre-treatment. By comparing with the leaching limit values stated in the European Council Decision, 2003/33/EC for the acceptance of hazardous waste at landfills, all the ashes applied remained in the same category after the calcination and pyrolysis processes, except the leaching of Cl⁻ from the ESP, which was around the borderline. Therefore, the use of ashes in catalytic reforming application do not significantly deteriorate their metal leaching behavior. Considering its superior catalytic activity towards BTEX formation, C-APC was loaded with Ni at 15 and 30 wt%. The Ni-loading favored an increase in overall oil yield, while reducing the gas yield when compared to the benchmark Ni loaded ZSM catalyst. However, Ni addition also caused the formation of more heavier hydrocarbons (C20–C35) that would require post-treatment to recover favorable products like BTEX.
اظهر المزيد [+] اقل [-]Applications of water-stable metal-organic frameworks in the removal of water pollutants: A review
2021
Zhang, Shu | Wang, Jiaqi | Zhang, Yue | Ma, Junzhou | Huang, Lintianyang | Yu, Shujun | Chen, Lan | Song, Gang | Qiu, Muqing | Wang, Xiangxue
Because the pollutants produced by human activities have destroyed the ecological balance of natural water environment, and caused severe impact on human life safety and environmental security. Hence the task of water environment restoration is imminent. Metal-organic frameworks (MOFs), structured from organic ligands and inorganic metal ions, are notable for their outstanding crystallinity, diverse structures, large surface areas, adsorption performance, and excellent component tunability. The water stability of MOFs is a key requisite for their possible actual applications in separation, catalysis, adsorption, and other water environment remediation areas because it is necessary to safeguard the integrity of the material structure during utilization. In this article, we comprehensively review state-of-the-art research progress on the promising potential of MOFs as excellent nanomaterials to remove contaminants from the water environment. Firstly, the fundamental characteristics and preparation methods of several typical water-stable MOFs include UiO, MIL, and ZIF are introduced. Then, the removal property and mechanism of heavy metal ions, radionuclide contaminants, drugs, and organic dyes by different MOFs were compared. Finally, the application prospect of MOFs in pollutant remediation prospected. In this review, the synthesis methods and application in water pollutant removal are explored, which provide ways toward the effective use of water-stable MOFs in materials design and environmental remediation.
اظهر المزيد [+] اقل [-]Ozonation catalysed by ferrosilicon for the degradation of ibuprofen in water
2021
Huang, Yuanxing | Liang, Manli | Ma, Luming | Wang, Yaowei | Zhang, Daofang | Li, Liang
The search for optimal catalysts to improve the working efficiency of ozonation has always been an important issue in the research field of advanced oxidation processes. In this study, a novel catalyst, ferrosilicon, was selected as the catalyst in heterogeneous catalytic ozonation to degrade ibuprofen (IBP) in water and treat real pharmaceutical wastewater. During the procedure, 45#ferrosilicon exhibited the best catalytic activity. Under the optimized experimental conditions, the IBP removal reached 75%, which was a great improvement compared to the 37% removal by ozone alone. The 45#-ferrosilicon-catalysed ozonation also achieved 68% TOC removal for real pharmaceutical wastewater, which was 31% higher than that by ozone alone. The degradation pathway of IBP was proposed using GC/MS. The EPR test proved that the main active species in the system were free active radicals •OH, and the measured accumulative •OH amount was 102 μmol. The characterization results show that the nascent metallic oxides, hydroxides, and hydroxyoxides on the ferrosilicon surface facilitated the decomposition of ozone molecules and generation of free active radicals. The removal of target organic contaminants in the water was mainly attributed to the oxidization of these highly active species.
اظهر المزيد [+] اقل [-]Interactions between pyrene and heavy metals and their fates in a soil-maize (Zea mays L.) system: Perspectives from the root physiological functions and rhizosphere microbial community
2021
Wang, Yuhui | Li, Manjie | Liu, Zhaowei | Zhao, Juanjuan | Chen, Yongcan
The co-occurrence of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in agricultural soils has become a worldwide food crop security concern. Pot experiments, rhizosphere microbial metagenomic sequencing, and root metatranscriptomic sequencing were performed to investigate the interactions among pyrene, Cu, and Cd in a soil-maize (Zea mays L.) system. This study provided direct evidence that the co-presence of PAHs and heavy metals changed the root physiological functions and the rhizosphere microbial community, which subsequently influenced the fate of the contaminants. Co-contamination at low levels tended to enhance the uptake potential and biodegradation performance of the plant, whereas increased contaminant concentrations produced opposite effects. The co-presence of 1000 mg/kg Cu decreased the abundance of Mycobacterium in the rhizosphere and reduced pyrene degradation by 12%–16%. The presence of 400–750 mg/kg pyrene altered the metabolic processes, molecular binding functions, and catalytic activity of enzymes in the maize roots, thus impeding the phytoextraction of Cu and Cd. Competitive absorption between Cu and Cd was observed for the 800–1000 mg/kg Cu and 50–100 mg/kg Cd co-treatment, in which Cu showed a competitive advantage, enhancing its root-to-shoot translocation. These findings provide important information for the production of safe crops and for the development of phytoremediation technologies.
اظهر المزيد [+] اقل [-]Effects of biochar on catalysis treatment of 4-nonylphenol in estuarine sediment and associated microbial community structure
2021
Hung, Chang-Mao | Huang, Jinbao | Chen, Chiu-Wen | Hsieh, Shu-Ling | Dong, Cheng-Di
The effect of pyrolysis temperature on the generation of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge biochar (SSB) and the removal of hazardous chemicals from esturine sediments by SSB and sodium percarbonate (SPC), exemplified by 4-nonylphenol (4-NP) were studied. SSB synthesized at 500 °C (SSB500) achieved the highest 4-NP degradation efficiency of 73%, at pH₀ 9.0 in 12 h of reaction time. The enhanced 4-NP degradation was attributed to the SSB500 activation activation of SPC that produced sufficient •OH and CO₃⁻• due to electron-transfer interaction on the Fe–Mn redox pairs. The microbial community diversity and composition of the treated sediment were compared using high-throughput sequencing. Results showed SSB/SPC treatment increased the microbial diversity and richness in the sediments. Proteobacteria were the keystone phylum, while Thioalkalispira genera were responsible for 4-NP degradation in the SSB/SPC treatment. Over all, results revealed the change in the bacterial community during the environmental applications of SSB, which provided essential information for better understanding of the monitoring and improvement of sustainable sediment ecosystems.
اظهر المزيد [+] اقل [-]Column tests for evaluation of the enzymatic biodegradation capacity of hydrocarbons (C10–C50) contaminated soil
2021
Kadri, Tayssir | Robert, Thomas | Rouissi, Tarek | Sebastian, Joseph | Magdouli, Sara | Brar, Satinder Kaur | Martel, Richard | Lauzon, Jean-Marc
Though many studies pertaining to soil bioremediation have been performed to study the microbial kinetics in shake flasks, the process efficiency in column tests is seldom. In the present study, soil columns tests were carried out to study the biodegradation of soil contaminated with a high concentration of diesel (≈19.5 g/kg) petroleum hydrocarbons expressed as C₁₀–C₅₀. Experiments were done with crude enzymatic cocktail produced by the hydrocarbonoclastic bacterium, Alcanivorax borkumensis. A. borkumensis was grown on a media with 3% (v/v) motor oil as the sole carbon and energy source. The effects of the enzyme concentration, treatment time and oxidant on the bioremediation efficiency of C₁₀–C₅₀ were investigated. A batch test was also carried out in parallel to investigate the stability of the enzymes and the effect of the biosurfactants on the desorption and the bioconversion of C₁₀–C₅₀. Batch tests indicated that the biosurfactants significantly affected the desorption and alkane hydroxylase and lipase enzymes, maintained their catalytic activity during the 20-day test, with a half-life of 7.44 days and 8.84 days, respectively. The crude enzyme cocktail, with 40 U/mL of lipase and 10 U/mL of alkane hydroxylase, showed the highest conversion of 57.36% after 12 weeks of treatment with a degradation rate of 0.0218 day⁻¹. The results show that the soil column tests can be used to optimize operating conditions for hydrocarbon degradation and to assess the performance of the overall bioremediation process.
اظهر المزيد [+] اقل [-]Selective production of singlet oxygen from zinc-etching hierarchically porous biochar for sulfamethoxazole degradation
2021
Sun, Chen | Chen, Tong | Huang, Qunxing | Duan, Xiaoguang | Zhan, Mingxiu | Ji, Longjie | Li, Xiaodong | Yan, Jianhua
Porous carbons are appealing low-cost and metal-free catalysts in persulfate-based advanced oxidation processes. In this study, a family of porous biochar catalysts (ZnBC) with different porous structures and surface functionalities are synthesized using a chemical activation agent (ZnCl₂). The functional biochars are used to activate persulfate for sulfamethoxazole (SMX) degradation. ZnBC-3 with the highest content of ketonic group (CO, 1.25 at%) exhibits the best oxidation efficiency, attaining a rate constant (kₒbₛ) of 0.025 min⁻¹. The correlation coefficient of the density of CO to kₒbₛ (R² = 0.992) is much higher than the linearity of the organic adsorption capacity to kₒbₛ (R² = 0.694), implying that CO is the intrinsic active site for persulfate activation. Moreover, the volume of mesopore (R² = 0.987), and Zeta potential (R² = 0.976) are also positive factors in PS adsorption and catalysis. In the mechanistic study, we identified that singlet oxygen is the primary reactive oxygen species. It can attack the –NH₂ group aligned to the benzene ring to form dimer products which could be adsorbed on the biochar surface to reach complete removal of the SMX. The optimal pH range is 4–6 which will minimize the electrostatic repulsion between ZnBCs and the reactants. The SMX degradation in ZnBC/PS system was immune to inorganic anions but would compete with organic impurities in the real wastewater. Finally, the biochar catalysts are filled in hydrogel beads and packed in a flow-through packed-bed column. The continuous system yields a high removal efficiency of over 86% for 8 h without decline, this work provided a simple biochar-based persulfate catalyst for complete antibiotics removal in salty conditions.
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