ENVIRONMENTAL POLLUTION
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2021
·
IF 8.071
Han Zhang,Ronghua Li,Zengqiang Zhang
At present, the simultaneous removal of organic dyes and heavy metals in complex wastewater has raised considerable concern, owing to their striking differences in physicochemical properties . Adsorption, as one of the few removal methods, has attracted extensive attention and gained popularity. Herein, a versatile EDTA and chitosan bi-functionalized magnetic bamboo biochar adsorbent (ECMBB) was synthesized for coinstantaneous adsorption of methyl orange (MO) and heavy metals (Cd(II) and Zn(II)). In this case, the as-synthesized ECMBB composites inherited favorable anionic MO removal performance from bamboo biochar (BB) obtained at 700 °C through electrostatic attraction, hydrogen bonding and π-π interaction, also enhanced the binding of cationic metals by introducing amino groups of chitosan and carboxyl groups of EDTA. In the unitary system, the removal of MO, Cd(II) and Zn(II) by three as-prepared adsorbents can be well illuminated by pseudo-second-order kinetic model and Langmuir isotherm theory. The saturated capture amounts of ECMBB at 25 °C are 305.4 mg g −1 for MO, 63.2 mg g −1 for Cd(II) and 50.8 mg g −1 for Zn(II), which, under the same conditions, are 1.3, 2.6 and 2.5 times those of chitosan-modified magnetic bamboo biochar (CMBB) and 1.9, 6.1 and 5.4 times those of magnetic bamboo biochar (MBB), respectively. Remarkably, in MO-metal binary system, coexisting MO visibly enhanced the adsorption of Cd(II) and Zn(II), while coexisting heavy metals had no significant impact on MO adsorption. Furthermore, ECMBB exhibited no significant loss in adsorption efficiency even after eight adsorption-desorption experiments. This study lays the foundation for fabricating desired integrative biochar adsorbents in the simultaneous purification of organic and metallic pollutants from complex wastewater.
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高影响因子
CELLULOSE
·
2021
·Vol. 29
·期 2
·941-952
·
IF 5.044
Hu Tao,Hu Xiaoli,Tang Cheng,Liu Dan
This paper describes the synthesis of a novel chelating material derived from cellulose, and its heavy metal ion adsorption properties from aqueous solution. The first section of this paper reports the chemical grafting of cellulose, that amino acetic acid groups were grafted onto the cellulose by in situ synthesis, a novel yet unreported modified cellulose derivative N,N-(dicarboxymethylaminoethyl, carboxymethyl)aminoethylamine carboxymethyl cellulose amide was synthesized. This obtained adsorbent was characterized by elemental analysis, infrared spectroscopy (IR) and Solid State Nuclear Magnetic Resonance (SSNMR) 13 C NMR spectroscopy. In the second section, the adsorption of Cu 2+ and Pb 2+ from single metal ion aqueous solutions onto this adsorbent were evaluated and analyzed by the Freundlich and Langmuir models. Further more, adsorption capacity for Ba 2+ , Mg 2+ , Mn 2+ , Co 2+ , Zn 2+ , Pb 2+ , Ni 2+ and Cu 2+ , and the competitive adsorption of this adsorbent between ions were also evaluated by ICP spectroscopy. The results indicated that this modified cellulose exhibited adsorption properties similar to those of EDTA, and showed good adsorption capacity for a wide range of metal ions.
Graphical abstract
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Sheng Liang,Xiaoting Hu,Haolin Xu,Zhenchao Lei,Chaohai Wei,Chunhua Feng
The present study aims to gain molecular insights into how peroxomonosulfate (PMS) reacts with ethylenediaminetetraacetic acid (EDTA)-Ni II at alkaline pH by conducting experimental tests and density functional theory (DFT) calculations. We first show experimental evidence that the decomplexation of EDTA-Ni II and simultaneous formation of Ni hydroxide precipitates can be successfully achieved with the addition of PMS under alkaline conditions. At pH 11.0 or above, the aqueous Ni concentration is substantially reduced from 2.0 to below 0.1 mg L −1 within 60 min. We then propose an alternative reaction pathway in which Ni II rather than EDTA is attacked by PMS, leading to the production of high-valent Ni species (in the form of EDTA-Ni IV =O). This is a key and highly oxidative species being further self-decomplexed to Ni III hydroxides. Our findings suggest that the involvement of Ni IV species might be a viable redox pathway that plays an important role in promoting decomplexation.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Jiahong Wang,Yao Chen,Tongtong Sun,Atif Saleem,Chuanyi Wang
A novel amino-functionalized magnetic adsorbent (Fe 3 O 4 @C@DETA) was developed for adsorption of Cr(III) and Cr(III)-EDTA from wastewater. Fe 3 O 4 @C@DETA were successfully prepared by modification of Fe 3 O 4 @C with diethylenediamine (DETA), which exhibits a core-shell structure and sufficient saturation magnetization. Fe 3 O 4 @C@DETA exhibits much better adsorption performance for Cr(III) and its chelates than the Fe 3 O 4 @C because of newly introduced amino active sites. The enhanced adsorption capacity of Fe 3 O 4 @C@DETA for Cr(III) is 44.74 mg g −1 (at 25 °C and pH 3.0), which is due to the surface coordination with the newly introduced amino functional sites. The Cr(III)-EDTA anions as a whole was adsorbed through the electrostatic interaction with protonated amino species of the Fe 3 O 4 @C@DETA and have maximum adsorption capacity of 47.27 mg g −1 (at 25 °C and pH 3.0). The adsorption data of free and EDTA coordinated Cr(III) were followed the Langmuir equation, while the adsorption dynamics was well explained by pseudo second order model indicating the chemical nature of adsorption process. The higher concentration of Ca 2+ ions in the wastewater compete for adsorption sites and inhibit the Cr(III) removal, while on other hand Ca 2+ ions promotes the adsorption of Cr(III)-EDTA, because of electrostatic interaction with adsorbent active sits. Furthermore, the adsorbent can be easily separated by external magnetic field and regenerated in acidic solution. The adsorbent is stable, recyclable and have more than 75% regeneration efficiency and can be repeatedly used in the adsorption process.
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CHEMOSPHERE
·
2019
·
IF 5.108
Huajing Zhou,Jun Luo,Yuancai Chen
Ethylenediaminetetraacetic acid (EDTA) could form stable complexes with toxic metals such as nickel due to its strong chelation. In this study, with the same doping level of Co and N, MoO 2 and ZIF-67 were used as precursors to prepare MoO 2 @Co/N and FeC@Co/N electrocatalysts for the modified graphite felt cathodes in heterogeneous-electro-Fenton-like reaction (HEFL) system. The X-ray diffraction and X-ray photoelectron spectroscopy results indicated that both of the catalysts are dominated with pyridinic N (2.42% and 2.82%) upon co-doping Co/N, and FeC@Co/N exhibited an obviously higher additional sp -hybridized nitrogen ( sp -N) peak. The co-doping of Co/N induced the lattice modifications to produce more lattice defects, where pyridinic N and sp -N, related with the active sites (C–N, Co-Nx), were formed at near-ring defects along sheet edges through the nitrogen replacement of C C groups. FeC@Co/N demonstrated superior oxygen reduction reaction catalytic activity in terms of Cyclic Voltammetry and Rotating Ring-disk Electrode, and exhibited the remarkably higher current density (30 mA) and lower onset potential (−0.208 V) in Linear Sweep Voltammetry analysis. In the FeC@Co/N/CF modified HEFL system, despite the generated H 2 O 2 concentrations (62.5 mg L −1 ) is not very high, the reducing reaction of ≡Fe(III)/Co(III)–OH could get the electron directly from the cathode, which would greatly reduce the consumption of H 2 O 2, high utilization efficiency of H 2 O 2 (η: 87.63%) could greatly improve the EDTA-Ni removal (97.5%) and TOC (92.6%). This work demonstrates the feasibility of utilizing FeC@Co/N/CF as a cathode for breaking metal-complex in HEFL process.
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NANOTECHNOLOGY
·
2016
·Vol. 27
·期 31
·315101
·
IF 3.573
Jia Liu,Yating Zhao,Yu Cui,Yang Yue,Yikun Gao,Qinfu Zhao,Jie Liu,Siling Wang
A structurally controllable fluorescence-labeled hollow mesoporous carbon (HMC) was simply prepared to improve the oral bioavailability of insoluble drugs and further trace their delivery process in vivo. The hollow structure was derived from an inverse replica process using mesoporous silica as a template and the fluorescent label was prepared by doping the carboxylated HMC with a confinement of Eu3+/Gd3+-EDTA. The physicochemical properties of the composites were systematically characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and photoluminescence spectra tests prior to studying their effects on drug-release behavior and biodistribution. As a result, the thickness of the carrier's shell was adjusted from 70 nm to 130 nm and the maximum drug loading was up to 73.6%. The model drug carvedilol (CAR) showed sustained release behavior compared to CAR commercial capsules, and the dissolution rate slowed down as the shells got thicker. AUC0-48h and Tmax were enlarged 2.2 and 6.5 fold, respectively, which demonstrated that oral bioavailability was successfully improved. Bioimaging tests showed that the novel carbon vehicle had a long residence time in the gastrointestinal tract. In short, the newly designed HMC is a promising drug carrier for both oral bioavailability improvement and in vivo tracing.
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Journal of Coatings Technology and Research
·
2024
·
IF 2.3
Guo YanXin,Wang Jinwei,Su Xinyong,Tang Can,Wang Jiaao
SiO 2 -EDTA composite particles are prepared by using nano-silicon dioxide (SiO 2 ) as the loading particle and ethylenediaminetetraacetic acid (EDTA) as the scaling inhibitor. Then, SiO 2 -EDTA particle and polytetrafluoroethylene (PTFE) micro powder are added in water-based silanized maleic anhydride-g-poly(1,2-butadiene) (SiMLPB) to fabricate composite coatings with good anti-scaling and anti-corrosion properties. The water contact angles (WCA) of SiMLPB increase to a maximum of 103° with the addition of PTFE at 3 wt% and then decrease slowly; based on this formulae, the WCA improves to 109 o when SiO 2 -EDTA is added up to 2 wt%. SiMLPB/PTFE coatings exhibit good corrosion resistance with the addition of PTFE; the SiMLPB/3%PTFE/2%SiO 2 -EDTA composite coating possesses impedance (| Z | 0.01Hz ) value at 2 orders higher than that of the SiMLPB/PTFE0 coating at low frequency, suggesting the much greater improvement in corrosion resistance due to the synergistic effects of adding nanoparticle as a surface modifier and EDTA as a corrosion inhibitor. The deposition of CaCO 3 on this SiMLPB/PTFE/SiO 2 -EDTA composite coating reaches 0.0132 g/cm 2 after 120 h scaling test, which is about 79% lower than that on the pure SiMLPB coating, resulting from the chelation of EDTA that promotes the formation of more unstable scales. The improvements in both anti-corrosion and anti-scaling performances are attributed to the hydrophobic function of PTFE and nanoparticle as well as the dual functions of EDTA at an appropriate addition of SiO 2- EDTA.
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ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Runzi Zhang,Shunbi Xie,Qianyan Zhang,Ying Gao,Xiang He,Shanshan Jin,Junhao Leng,lian Zhang,Yi He
Background Chloramphenicol (CAP) is a broad-spectrum antibiotic, and its continuous use in human medicine, livestock has resulted disturbances in ecosystem stability. The complex background and low concentration of CAP in aquatic environments present significant scientific challenges for its sensitive detection. Currently detection techniques such as high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) are hindered by their complex procedures and high costs. Surface-enhanced Raman spectroscopy (SERS), due to its unique ability for fingerprint recognition, has emerged as a powerful tool for analysis and detection. However, it is often limited by the low kurtosis expression of the target. Result The water-soluble explosive polyethylenimide grafted calcium carbonate (PEI@CaCO3) microcapsule was utilized to encapsulate the signal probe Ag@4-NTP and combine it with a semiconductor SERS substrate Zn 0.995 Ce 0.005 O, enabling ultra-sensitive detection of CAP through a signal attenuation strategy. Moreover, magnetic molecularly imprinted polymers (MMIP) and nucleic acid aptamers were employed as capture probes for achieving rapid and direct magnetic separation, followed by layer-by-layer assembly to construct the sensor probe. In the presence of CAP, the aptamers and rMMIPs selectively recognized the target, forming a PEI@CaCO 3 @Ag@4-NTP@Apt@CAP@rMMIPs "sandwich" structure (Microcapsule@Apt@rMMIPs). After multiple magnetic separations, the "igniter" EDTA solution was added, causing the CaCO 3 capsules to rapidly "explode" and release a significant amount of Ag@4-NTP. This was then applied to the "signal booster" semiconductor SERS substrate. Under optimal conditions, this method exhibited a detection range of 1.0 × 10 −5 M to 1.0 × 10 −15 M, with a detection limit of 6.84 × 10 −16 M. Significant The unite of magnetic MIP and nucleic acid aptamer to form a “sandwich” structure, in combination with a semiconductor SERS substrate, not only enhances the sensor's sensitivity but also offers significant economic advantages. Moreover, this innovative technology holds great promise for accurate and highly sensitive detection of pollutants in complex environments.
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ENVIRONMENTAL TECHNOLOGY
·
2023
·
IF 2.8
Wenyan Wang,Yunlan Xu,Dengjie Zhong
Ni-EDTA is widely present in electroplating effluents. It cannot be effectively removed by traditional wastewater treatment methods due to its chemical stability. In this study, copper sulphide/cuprous sulphide doped zero-valent iron@carbon (ZVI@C/CuS/Cu2S) was prepared to active peroxymonsulphate (PMS) to decomposition Ni-EDTA. The ZVI@C/CuS/Cu2S + PMS process shows excellent performance under neutral or even alkaline conditions. This is due to the acceleration of ZVI electron transport by CuS/Cu2S, the autocatalysis of CuS/Cu2S itself, and the synergistic effect of CuS/Cu2S and Ni-EDTA. The removal efficiency of 50 ppm Ni-EDTA electroplating effluents reached 99.53% at 10 min, and the discharge water can meet the Chinese emission standard. The influences of the main parameters such as initial pH value, catalyst, PMS and initial Ni-EDTA concentration on removal efficiency was systematically investigated.
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JOURNAL OF POROUS MATERIALS
·
2020
·Vol. 28
·期 1
·299-310
·
IF 2.183
Ma Zixuan,Li Fang,Jia Aizhong,Zhang Xiao,Wang Yanji
The highly efficient adsorbents with fast adsorption rate, high adsorption capacity and selectivity as well as good reusability were successfully synthesized through fabricating 3D spherical-chain porous silica material and grafting modification with ethylenediaminetetraacetic acid (EDTA) for the selective removal Cu(II) from wastewater. The obtained adsorbents were characterized by XRD, FT-IR, SEM, TEM, XPS, N 2 adsorption–desorption and back titration. The results indicate that the 3D framework structure is adjustable in a certain range by varying the parameters of the synthesis system. And the adsorption performance of the materials was investigated under different conditions such as pH, contact time and initial metal ions concentration. Under the experiment conditions, the synthesized adsorbent is efficient in removing Cu(II) and the adsorption equilibrium could be achieved within only 5 min, and the kinetic data are well fitted by pseudo-second-order and Langmuir isotherm models. The prepared adsorbents display good selective adsorption of Cu(II) and can be feasibly regenerated without evident decrease even after five recycles. Basing on the obtained results, the plausible adsorption mechanism was proposed and analyzed.
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CRYSTENGCOMM
·
2018
·Vol. 21
·期 11
·1691-1700
·
IF 3.304
Zhikun Wang,Wenfeng Han,Huazhang Liu
Uniform, free-standing and cubic SrF2 microparticles were successfully fabricated by a facile hydrothermal method with ethylenediaminetetraacetic acid (EDTA) as the chelating agent. The influences of preparation conditions, such as the pH value, amount of EDTA and hydrothermal time, on the formation of SrF2 crystals were investigated. The formation mechanism of cubic SrF2 particles was proposed based on the experimental results. Following calcination in air at 500 °C, SrF2 particles were evaluated as the catalyst for the pyrolysis of 1-chloro-1,1-difluoroethane (HCFC-142b, CH3CClF2) to vinylidene fluoride (VDF, CH2CF2) at 350 °C and a space velocity of 600 h−1. The results indicate that SrF2 cubes exhibit high catalytic activity with a HCFC-142b conversion of about 70% and a selectivity to VDF of 80–87%. No significant deactivation was observed within the time on stream of 30 h. With the reaction temperature increased to 450 °C, the conversion of HCFC-142b is close to 94%, while the selectivity to VDF remains almost unchanged. Although the SrF2 catalyst prepared by the conventional precipitation method also shows high conversion, its selectivity to VDF is only around 50–70%. We suggest that the surface acidity and specific surface area play major roles in the catalytic performance. Compared with the temperatures for industrial manufacture of VDF of 650–700 °C, the SrF2 catalysts provide a promising pathway to produce VDF at much lower temperatures.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yaxin Qin,Fengfeng Zhou,Tingting Wang,Wei Liu,Lizhi Zhang
The remarkable stability and detrimental environmental impacts of nickel(II)-ethylenediaminetetraacetic acid (Ni(II)-EDTA) complexes originated from electroplating effluents have sparked a growing curiosity about their efficient remediation. In this study, L -cysteine functionalized zero-valent iron (C-ZVI bm ) was synthesized via a ball-milling method and employed as a heterogeneous Fenton-like catalyst to decomplex Ni(II)-EDTA and immobilize Ni(II) from wastewater. The results demonstrated that the pseudo-second-order kinetic rate constant (2.096 L·mol −1 ·min −1 ) for EDTA degradation in the C-ZVI bm /H 2 O 2 system was 123.3 times that in the ZVI bm /H 2 O 2 system (0.017 L·mol −1 ·min −1 ). The incorporation of L -cysteine onto the surface of ZVI significantly enhanced the H 2 O 2 activation, reactive oxygen species ( OH, O 2 − , and 1 O 2 ) generation, and the sequential Ni(II)-EDTA decomplexation and EDTA degradation. The results of capture experiments revealed that 1 O 2 played a crucial role in the degradation of EDTA in the C-ZVI bm /H 2 O 2 system. The optimization of the experimental variables indicated that the degradation of EDTA and the reduction/adsorption of Ni(II) were antagonistic in the C-ZVI bm /H 2 O 2 system, resulting in an efficient reduction/immobilization of Ni(II) and an inhibition of EDTA degradation at a higher dosage of C-ZVI bm . Our findings provide new insights into the promising heterogeneous Fenton-like process that enables the decomplexation of Ni(II)-EDTA, the degradation of EDTA, and the synchronous immobilization of Ni(II).
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