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Graphene-based nanocomposites and nanohybrids for the abatement of agro-industrial pollutants in aqueous environments
2022
Farhan, Ahmad | Rashid, Ehsan Ullah | Waqas, Muhammad | Ahmad, Haroon | Navāz, Shāhid | Munawar, Junaid | Rahdar, Abbas | Varjani, Sunita | Vēlāyutan̲, T. A.
Incessant release of a large spectrum of agro-industrial pollutants into environmental matrices remains a serious concern due to their potential health risks to humans and aquatic animals. Existing remediation techniques are unable to remove these pollutants, necessitating the development of novel treatment approaches. Due to its unique structure, physicochemical properties, and broad application potential, graphene has attracted a lot of attention as a new type of two-dimensional nanostructure. Given its chemical stability, large surface area, electron mobility, superior thermal conductivity, and two-dimensional structure, tremendous research has been conducted on graphene and its derived composites for environmental remediation and pollution mitigation. Various methods for graphene functionalization have facilitated the development of different graphene derivatives such as graphene oxide (GO), functional reduced graphene oxide (frGO), and reduced graphene oxide (rGO) with novel attributes for multiple applications. This review provides a comprehensive read on the recent progress of multifunctional graphene-based nanocomposites and nanohybrids as a promising way of removing emerging contaminants from aqueous environments. First, a succinct overview of the fundamental structure, fabrication techniques, and features of graphene-based composites is presented. Following that, graphene and GO functionalization, i.e., covalent bonding, non-covalent, and elemental doping, are discussed. Finally, the environmental potentials of a plethora of graphene-based hybrid nanocomposites for the abatement of organic and inorganic contaminants are thoroughly covered.
Afficher plus [+] Moins [-]Nanoporous bimetallic metal-organic framework (FeCo-BDC) as a novel catalyst for efficient removal of organic contaminants
2019
Li, Huanxuan | Zhang, Jian | Yao, Yuze | Miao, Xiangrui | Chen, Jiale | Tang, Junhong
In this work, we report on the synthesis and characterization of nanoporous bimetallic metal-organic frameworks (FeCo-BDC). Effects of synthesis time and temperature on the structures, morphology, and catalytic performance of FeCo-BDC were investigated. Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) were used to reveal the morphological and textural characteristics. The crystal structure and chemical composition of FeCo-BDC were determined by means of X-ray powder diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements. Interestingly, FeCo-BDC grew into the same crystal structure with different morphology in the temperature of 110–150 °C with 12–48 h. The heterogeneous catalytic activity of FeCo-BDC was tested to activate peroxydisulfate (PDS) and peroxymonosulfate (PMS) for removal of methylene blue (MB). The results found that FeCo-BDC synthesized at 150 °C with 24 h exhibited the best catalytic performance for PMS and obtained 100% of MB removal within 15 min. The abundant unsaturated metal active sites of Fe(II) and Co(II) in the skeleton of FeCo-BDC made a great contribution to the generation of sulfate (▪) and hydroxyl radicals (OH), which resulted in the excellent performance for MB degradation.
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.
Afficher plus [+] Moins [-]Effect-directed analysis for revealing aryl hydrocarbon receptor agonists in sediment samples from an electronic waste recycling town in China
2022
Ma, Qianchi | Liu, Yanna | Yang, Xiaoxi | Guo, Yunhe | Xiang, Tongtong | Wang, Yi | Yan, Yuhao | Li, Danyang | Nie, Tong | Li, Zikang | Qu, Guangbo | Jiang, Guibin
Exposure to electronic and electrical waste (e-waste) has been related to a few adverse health effects. In this study, sediment samples from an e-waste recycling town in China were collected, and aryl hydrocarbon receptor (AhR) agonists in the samples were identified using an effect-directed analysis (EDA) strategy. The CBG2.8D cell line reporter gene bioassay was used as a toxicity test, while suspect screening against chemical databases was performed for potential AhR agonist identification where both gas chromatography- and liquid chromatography-high resolution mass spectrometry analyses were run. When the original sample extract showed high AhR-mediated activity, sample fractionation was performed, and fractions exhibiting high bioactivity were chemically analyzed again to reveal the corresponding AhR agonists. In total, 23 AhR agonists were identified, including 14 commonly known ones and 9 new ones. Benzo [k]fluoranthene and 6-nitrochrysene were the dominant AhR agonists, covering 16–71% and 2.7–12%, respectively, of the AhR activation effects measured in the parent extracts. The newly identified AhR-active chemicals combined explained 0.13–0.20% of the parent extracts’ effects, with 7,12-dimethylbenz [a]anthracene and 8,9,11-trimethylbenz [a]anthracene being the major contributors. A diagnostic isomer ratio analysis of polycyclic aromatic hydrocarbons suggested that the major source of AhR agonists identified in these e-waste related sediment samples were probably petroleum product combustion and biomass combustion. In the future, for a more comprehensive AhR agonist investigation, in-house chemical synthesis and purification, and, when necessary, a secondary sample fractionation, would be beneficial.
Afficher plus [+] Moins [-]Batch and continuous adsorption of Cu(II) and Zn(II) ions from aqueous solution on bi-functionalized sugarcane-based biosorbent
2022
Teodoro, Filipe Simões | Soares, Liliane Catone | Filgueiras, Jefferson Gonçalves | Azevêdo, Eduardo Ribeiro de | Patiño-Agudelo, Álvaro Javier | Adarme, Oscar Fernando Herrera | da Silva, Luis Henrique Mendes | Gurgel, Leandro Vinícius Alves
A new one-pot synthesis method optimized by a 2³ experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate pyromellitate (SBSPy), for the removal of Cu(II) and Zn(II) from single-component aqueous solutions, in batch and continuous modes. The bi-functionalization of the biosorbent with ligands of different chemical structures increased its selectivity, improving its performance for removing pollutants from contaminated water. The succinate moiety favored Cu(II) adsorption, while the pyromellitate moiety favored Zn(II) adsorption. Sugarcane bagasse (SB) and SBSPy were characterized using several techniques. Analysis by ¹³C Multi-CP SS NMR and FTIR revealed the best order of addition of each anhydride that maximized the chemical modification of SB. The maximum adsorption capacities of SBSPy for Cu(II) and Zn(II), in batch mode, were 1.19 and 0.95 mmol g⁻¹, respectively. Homogeneous surface diffusion, intraparticle diffusion, and Boyd models were used to determine the steps involved in the adsorption process. Isothermal titration calorimetry was used to assess changes in enthalpy of adsorption as a function of SBSPy surface coverage. Fixed-bed column adsorption of Cu(II) and Zn(II) was performed in three cycles, showing that SBSPy has potential to be used in water treatment. Breakthrough curves were well fitted by the Thomas and Bohart-Adams models.
Afficher plus [+] Moins [-]In Situ Synthesis and Photocatalytic Properties of Titanium Dioxide Nanoparticles on Cotton Fabrics
2019
Bao, Zhanxia | Wang, Shuhua | Yu, Xiaoying | Gao, Yindong | Wen, Zeling
In this paper, nanosized titanium dioxide as catalysts for degrading dye wastewater was in situ synthesized on the surface of cotton fabrics used tetrabutyl titanate as precursor. The morphology and structure of prepared catalysts were characterized by scanning electron microscopy, energy-dispersive spectrometer, and X-ray diffraction. The characterization results showed that anatase nanosized titanium dioxide was successfully synthesized in situ on cotton fabrics and had excellent dispersibility. Subsequently, the effects of irradiation time, catalyst dosage, dye concentration, initial pH value of dye, hydrogen peroxide dosage, and dye type on dye degradation rate were investigated one by one by a photocatalytic performance test. The test results indicated that the degradation rates of methylene blue, methyl orange, and rhodamine B were 90.4%, 81.4%, and 58.3%, separately, at catalyst dosage of 4.8 g/L, initial dye concentration of 10 mg/L, pH of 7, and hydrogen peroxide dosage of 0.24 mol/L, after 4 h of UV irradiation.
Afficher plus [+] Moins [-]Manganese-rich MnSAPO-34 molecular sieves as an efficient catalyst for the selective catalytic reduction of NO x with NH3: one-pot synthesis, catalytic performance, and characterization
2017
Yu, Chenglong | Chen, Feng | Dong, Lifu | Liu, Xiaoqing | Huang, Bichun | Wang, Xinnan | Zhong, Shengbang
Manganese-rich MnSAPO-34 molecular sieves were prepared by one-pot synthesis method for NO ₓ abatement using the ammonia-selective catalytic reduction (NH₃-SCR) technology and characterized using ICP, BET, XRD, FE-SEM, H₂-TPR, NH₃-TPD, XPS, and DR UV-Vis analyses. The experimental results indicate that the Mn content and chemical state, as well as the surface acidity, of the MnSAPO-34 molecular sieves significantly enhance their DeNO ₓ efficiency at low temperatures (ca. 200–300 °C). The manganese-rich MnSAPO-34 was synthesized using a combination of triethylamine and diisopropylamine as the structural directing agents and high Mn loading (n(MnO)/n(P₂O₅) = 0.4). The resulting catalyst exhibits the highest activity among all of the samples with a NO ₓ conversion value of nearly 95% and a N₂ selectivity that is higher than 90% at 220–400 °C. In addition, this catalyst presents higher NO ₓ conversion than the conventional V₂O₅-WO₃/TiO₂ catalysts and other SAPO-based catalysts below 300 °C. Furthermore, the analytical results indicate that the manganese species in the catalyst are mainly in the form of a framework Mn(IV), which could play a significant role in the NH₃-SCR process as the specific active species. The results suggest that controlling the types and content of the organic amine templates and variations in the surface acidity of the catalysts may significantly enhance the SCR activity at lower temperatures.
Afficher plus [+] Moins [-]One-pot synthesis of Cr(III)-incorporated Zr(IV) oxide for fluoride remediation: a lab to field performance evaluation study
2020
Kanrar, Sarat | Ghosh, Abir | Ghosh, Ayan | Mondal, Arpan | Sadhukhan, Mriganka | Ghosh, Uday Chand | Sasikumar, Palani
A low-cost Cr(III)-incorporated Zr(IV) bimetallic oxide (CZ) was synthesized by simple chemical precipitation method for removal of fluoride from contaminated water. The physicochemical properties of CZ before and after fluoride removal were established with several instrumental techniques such as TEM with elemental mapping, SEM with EDX, XRD, IR, XPS, zeta potential measurement, etc. Batch adsorption technique were carried out to understand the factors affecting fluoride adsorption, such as effects of initial pH, adsorbent dose, co-occurring ions, contact time, and temperature. The maximum adsorption capacity observed at pH between 5 and 7. The fluoride adsorption processes on CZ obeyed the pseudo-second-order rate equations and both Freundlich and DR isotherm models. The maximum adsorption capacity of 90.67 mg g⁻¹ was obtained. The thermodynamic parameters ΔH⁰ (positive), ΔS⁰ (positive), and ΔG⁰ (negative) indicating the fluoride sorption system was endothermic, spontaneous, and feasible. The CZ also successfully used as fluoride adsorbent for real field contaminated water collected from the Machatora district, Bankura, West Bengal, India. Graphical abstract Schematic representation of CZ synthesis and its application for lab as well as field water purification purpose.
Afficher plus [+] Moins [-]Remediation of carcinogenic arsenic by pyroaurite-based green adsorbent: isotherm, kinetic, mechanistic study, and applicability in real-life groundwater
2020
Yadav, Manoj Kumar | Gupta, Ashok Kumar | Ghosal, Partha Sarathi | Mukherjee, Abhijit
The removal of the harmful carcinogen arsenic from drinking water by a green technology is a major concern in the field of environmental engineering. The sorptive profile of arsenic remediation by calcined Mg-Fe-layered double hydroxide, fabricated by a one-pot synthesis technique, was investigated to delineate its applicability in real-life water. The physicochemical properties of adsorbent, as demonstrated from spectroscopy and microscopy, which described the existence of amorphous material with significant surface roughness possess selectivity towards arsenic. The isotherm and kinetic along with thermodynamic modeling exhibited the occurrence of spontaneous (ΔG⁰ value = − 8.084 kJ/mol to − 10.942 kJ/mol), endothermic (ΔH⁰ value = 12.135 kJ/mol), and physisorption reactions (Eₐd = 4.103–5.832 kJ/mol, Eₐ = 11.546 kJ/mol, S* = 0.0005 << 1, and ΔHₓ = 9.23–16.29 kJ/mol) with high uptake rate and adsorption potential of adsorbent. The isotherm and kinetics were demonstrated by Temkin (R² = 0.944–0.969) and Elovich (R² = 0.996–0.998) models, respectively, with high statistical significance. The intraparticle diffusion model which established the rate-limiting step is the combination of both film and pore diffusions. The applicability of layered double hydroxide (LDH) material in the real-life water was confirmed by isotherm and kinetic modeling along with the regeneration/reuse potential. The adsorptive removal of arsenic by the LDH material exhibited to be a promising technique without creating any secondary hazard.
Afficher plus [+] Moins [-]Green chemical synthesis of gold nanoparticles by using Penicillium aculeatum and their scolicidal activity against hydatid cyst protoscolices of Echinococcus granulosus
2017
Hydatid disease is a helminth infection with various clinical complications caused by the larval stage of the dog tapeworm Echinococcus granulosus. The scolicidal agents have been broadly applied for inactivation of the fertile cysts up to now, but these scolicidal agents have several side effects on patients. Therefore, this study aimed to explore the scolicidal activity of green synthesized gold nanoparticles (AuNPs) utilizing mycelia-free culture filtrate of Penicillium aculeatum against hydatid cyst protoscolices of E. granulosus. The size and morphology of AuNPs were affirmed by UV–visible spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS) analysis. The Fourier transform infrared (FT-IR) analysis of AuNPs showed the presence of possible functional groups responsible for the bioreduction and capping. The AuNPs were formed relatively uniform with spherical shape and superior monodispersity with the average diameter of 60 nm. Consequently, various concentrations (0.05, 0.1, 0.2, and 0.3 mg/mL) of green synthesized AuNPs and different exposure times (10, 30, 60, and 120 min) were used against hydatid cyst protoscolices. Statistically, the difference between the scolicidal effects of AuNPs were seen extremely significant for all four concentrations and at various exposure times in comparison to the control group (P < 0.0001). The most mean protoscolex elimination ratio was 94% (0.3 mg/mL AuNPs and 120-min exposure time). The current investigation indicated that applying biogenic AuNPs may be considered as a potential scolicidal agent for cystic hydatid disease. However, further studies are required to evaluate the efficacy of AuNPs in vivo.
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