Asia-Pacific Journal of Chemical Engineering
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2023
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IF 1.8
Kai Fei,Zhuo Yi Dong,Li Shi,Xuan Meng,Naiwang Liu
Transformer oil plays a critical role in ensuring the insulation and normal operation of power transformers. However, during operation, the transformer oil would undergo oxidation and degradation, leading to the formation of acids and polar compounds that increase its acidity and degrade its performance. Hence, the recycling and regeneration of aged transformer oil is an essential practice in transformer maintenance, contributing significantly to the extension of a transformer's operational lifespan and the reduction of potential risks. Adsorption separation is a preferred method for regeneration, offering simplicity and high efficiency. This study focuses on impregnated γ-Al 2 O 3 as an adsorbent for acidity removal in waste transformer oil. We conducted static adsorption experiments to investigate the optimal loading amount of the active component and the best calcination temperature for acid removal. XRD technique is employed to monitor the phase changes of the carrier during the calcination process. BET analysis is used to observe variations in the specific surface area and pore volume of the adsorbent during the modification process. DTG-TGA is utilized to assess the weight loss during the calcination process. FTIR is employed to observe changes in functional groups during modification and adsorption processes. Along with these investigations, a study is also carried out to assess the dynamic acid removal performance of the acid-removing adsorbent loaded into a fixed bed. The findings contribute to the development of sustainable methods for regenerating transformer oil, ensuring efficient and environmentally friendly operations.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
CHEMICAL PAPERS
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2022
·Vol. 76
·期 7
·4405-4418
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IF 2.146
Lin Yingzi,Liu Yi,Ren Ruijun,Xiao Feng,Wang Dongsheng
In this study, a ZIF-8 thin layer deposited on the surface of a hydrolyzed polyacrylonitrile (HPAN) membrane was used for highly efficient humic acid removal. The thin ZIF-8 layer was synthesized by using a two-step interfacial synthesis method, based on liquid–liquid interfacial coordination polymerization. The formation of a continuous ZIF-8 layers was confirmed by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The effects of the synthesis conditions including reaction time, precursor concentration, and other operating conditions on the ZIF-8 composite membrane performance were studied using humic acid solution as organic waste. The results showed when the reaction time was extended, or when the precursor concentration was increased, the ZIF-8 layer deposited on the membrane surface became denser. Compared with the unmodified HPAN substrate, the composite membrane deposited with the ZIF-8 layer showed better processing ability for organic matters due to the strong electrostatic interaction of organic matter with the ZIF-8@HPAN membrane and the ZIF-8 particles unique structural characteristics, which shows a great application prospect for humic acid treatment compared with other membrane technologies.
研究领域:
材料科学
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环境工程
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化学工程
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DOI
高影响因子
CHEMOSPHERE
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2022
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IF 8.943
Chaocheng Zeng,Huimin Hu,Chao Wang,Qing Shi,Qiwu Zhang,Mengfei Chen,Qian Wang,Tingting Zhang
Due to the stable chelating effect of organic phosphonates in wastewater, phosphonates with increasing emission are difficult to be removed effectively by traditional ferric salt flocculation , which has posed tough challenges for reducing total phosphorus pollution in recent years. In this work, calcium carbonate (CaCO 3 ) was introduced to work together with the widely investigated flocculant of ferric chloride (FeCl 3 ) to realize an efficient removal of nitrilotrismethylenephosphonic acid (NTMP) at much lower dosage of FeCl 3 . With an aid of synergy effect from together use of CaCO 3 and FeCl 3 , the remaining concentration as low as 0.16 mg−P/L, far below the sewage discharge limit (0.5 mg−P/L), was simply obtained with a significantly reduced Fe/P molar ratio at only 4, resulting from calcium source donor to form more stable Fe–Ca–P tridentate bridging complexes, high affinity towards ferric ions on CaCO 3 surface and slow-release alkaline from CaCO 3 . A comparison among sodium hydroxide (NaOH), calcium hydroxide (Ca(OH) 2 ) and CaCO 3 as additives, was carried out to highlight the advantages of using CaCO 3 and clarify the mechanism for the greatly improved performance by a set of characterizations including XRD, FTIR, Zeta potential , XPS , SEM−EDS and TG analyses. The addition of CaCO 3 in ferric flocculation resulted in further obvious advantages such as 75% shortened settling time and only one−third of sludge volume of the precipitant, beneficial to the sample handling in engineering application. The proposed new approach has been further confirmed to work efficiently on real phosphonate-containing wastewater. Discussion on the interaction between CaCO 3 and ferric salts in phosphonate solutions shed new insights into the working mechanism of using CaCO 3 for the treatment of phosphonates-containing wastewater.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Zhimin Guo,Nan Li,Shixiang Zuo,Chenghong Qiang,Wei Zhan,Zhengping Li,Jiangquan Ma
Piezoelectric materials, which could collect and convert mechanical energy into electrical energy, have recently emerged as promising catalysts for pollutants removal sustainably. Unfortunately, it remains a challenge to enhance the intrinsic piezoelectric property of piezoelectric materials. Herein, for the first time, the polar molecule adenine was introduced as a linking agent in the synthesis process of Zr-based UiO-66 (denoted as AD-U) to enhance the structure asymmetry and piezoelectric properties of UiO-66. The piezoresponse force microscopy (PFM) and ferroelectric hysteresis loop demonstrated that AD-U catalyst exhibited significantly enhanced piezoelectric potential than UiO-66. Furthermore, a series of electrochemical characterization evidenced that AD-U displayed higher charge separation efficiency than UiO-66. As expect, the optimized AD-U shown promoted diclofenac sodium (DCF) piezoelectric degradation efficiency by harvesting stirring energy compared with pure UiO-66. The electron paramagnetic resonance (EPR) spectra and trapping agent experiments convinced that h + play the major role for destroying the DCF molecules. Moreover, three possible degradation pathways of DCF were put forward by DFT and liquid chromatography mass system (LC-MS). Our work offers a new pathway to enhance piezoelectric property of MOFs and extend the application of MOFs in the field of piezocatalysis.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Membranes
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2023
·Vol. 13
·期 1
·78
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IF 4.2
Rui Guo,Jun Zhang,Taona Nashel Mufanebadza,Xinxia Tian,Lixin Xie,Song Zhao
Reverse osmosis (RO) membranes are susceptible to silica scaling, resulting in irreversible degradation of membrane performance. This work covered the fabrication of MIL-101(Fe) for silicic acid adsorption to alleviate the silica scaling of RO membranes. The effect of pH, mixing time and initial concentration on silicic acid adsorption of MIL-101(Fe) was appraised in detail. The adsorption experiments demonstrated that MIL-101(Fe) possessed an excellent adsorption ability for silicic acid with the maximum adsorption capacity reaching 220.1 mgSiO2·g−1. Data fitting confirmed the pseudo-second-order equation and Freundlich equation were consistent with silicic acid adsorption on MIL-101(Fe). Finally, a simulated anti-scaling experiment was carried out using a feed solution pretreated by MIL-101(Fe) adsorption, and the permeance exhibited a much lower decline after 24 h filtration, confirming that MIL-101(Fe) exhibits an excellent application potential for silica-scale mitigation in RO systems.Keywords:MIL-101(Fe) MOF;adsorption;reverse osmosis;pretreatment;silicic acid removal
研究领域:
环境科学
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材料科学
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水处理技术
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DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
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2023
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IF 2.8
Jiayu Feng,Kai Li,Ping Ning,Chi Wang,Xin Sun,Fei Wang,Peng Gao
In this study, a series of Mg-modified γ-Al2O3 sorbents have been introduced to simultaneously remove HCl and HF in a low-temperature environment. These sorbents were prepared by impregnation, and the effects of Mg loading amount and calcination temperature on the performance of the sorbent were investigated. The optimal sorbent (modified by 15 wt% Mg and calcined at 400℃, Mg15/Al2O3-400) exhibited the highest adsorption capacity of all the sorbents tested, 37.89 mg(HF)•gsorbent−1 and 34.54 mg(HCl)•gsorbent−1, respectively. Taking into account an excellent HF(HCl) capacity of the Mg15/Al2O3-400, these sorbents are very promising HF(HCl)sorbents usable in a low-temperature environment. The role of MgO loaded on γ-Al2O3 was investigated by Brunauer−Emmet−Teller (BET) method, X-ray diffractometer (XRD), scanning electron microscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of CO2 (CO2-TPD), and thermogravimetric analysis (TG-DTG). The results revealed that MgO acted as a ‘leading role’ to promote the adsorption activity of the sorbents. BET analysis demonstrated that the Mg modification process did not seriously change the pore type of the γ-Al2O3. CO2-TPD results revealed that the calcination temperature will significantly affect the number and strength of the basic sites on the surface of the sorbent. In addition, XRD and XPS analysis indicated that the consumption of MgO and the accumulation of reaction products on the surface and pores are the main reasons for the deactivation of the sorbent.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2015
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IF 4.642
Ruihua Li,Baoyu Gao,Shenglei Sun,Qinyan Yue,Meng Li,Xudan Yang,Wuchang Song,Ruibao Jia
In this study, a lignin-based flocculant (LNF) was synthesized by grafting amine groups into alkali lignin containing papermaking sludge. Characterization of LNF, such as FTIR, zeta potential, cationic degree, viscosity, and molecular weight, showed that the product was a cationic polymer with high solubility. LNF was used with aluminum sulfate (AS) and polyaluminum chloride (PAC) in humic acid coagulation to demonstrate its efficiency. Coagulation behavior and floc properties of LNF+PAC and LNF+AS dual-coagulant were comparatively evaluated. Results showed that the coagulation aid effect of LNF was independent of aluminum species. Addition of LNF could enhance humic acid removal efficiency and floc properties including size, strength, and fractal dimension significantly. The effect of solution pH on coagulation processes was also studied. Dual-coagulants showed the same variation trend as that of aluminum-based coagulants but enhanced coagulation performance during the investigative pH range. Flocs formed at pH 9 and pH 5 achieved maximum floc size in AS and PAC coagulation systems, respectively. Fractal dimension was relatively high at pH 7–9 due to the sweeping effect of aluminum hydrolysates. Overall, LNF brought in charge neutralization and absorption bridging effect and played a positive role in coagulation processes.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
ENERGY & FUELS
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2017
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IF 3.091
XiangSheng Shao,Guanhao Liu,Jingyi Yang,Xinru Xu
Three kinds of imidazolium ionic liquids were synthesized, and [Bmim][CH3COO] was selected as a result of its higher deacidification rate at a lower cost. Then, the synthetic ionic liquid was immobilized by layered double hydroxides, and the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), electrospray ionization mass spectrometry (ESI–MS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and N2 adsorption–desorption isotherms. The results showed that [Bmim][CH3COO] synthesized by the intercalation method exhibited a better deacidification property compared to the dipping method. When [Bmim][CH3COO]/Mg0.5Ca2.5Al1 (I) synthesized by the intercalation method was used as a reagent, the deacidification rate reached 97.61%. The optimum reaction conditions were at the reagent/oil mass ratio of 0.08, the reaction temperature of 313 K, and the reaction time of 1 h. Moreover, the composites still had excellent performance on deacidification after being repeatedly used 6 times.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
ACS Applied Polymer Materials
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2019
·
IF 0
Xueping Liao,Qiang Zhang
Rapid removal of boric acid is important in many applications such as seawater desalination, boron extracting and water treatment. Although regarded as the most widely used boron-specific adsorbents, ion-exchange resins are often criticized because of the limited adsorption capacity and slow adsorption rate. Herein we report a copper-free synthesis route of mesoporous nanosponges with cis-diols functionalized on the surface, which are used for rapid removal of boric acid and organic micropollutants from water. Different cross-linking reagents are used to regulate the surface morphology and porous structure of cyclodextrin (CD)-scaffolded nanosponges. Staudinger reaction is then conducted to generate amine groups on the primary face of CD for subsequent reaction with d-(+)-gluconic acid δ-lactone, which successfully immobilize high-density cis-diols on the surface for efficient chelating with boric acid. Functional polymer nanosponges have shown similar boron adsorption capacity as the commercial resins, while the time to reach equilibrium adsorption is reduced dramatically from up to 2 days to tens of minutes (up to 60 times faster). Uptake of bisphenol A by these porous polymers is fast and the equilibrium adsorption could be attained in less than 2 min. The presence of immobilized polyols indicates a synergistic effect due to the secondary bonding, which simultaneously decrease the adsorption time and enhance the adsorption capacity. These findings demonstrate the potential application of polyol-functionalized mesoporous nanosponges in rapid flow-through water treatment.
研究领域:
材料科学
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环境科学
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DOI
Journal of Cleaner Production
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2019
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IF 6.395
Shenglei Sun,Yue Gao,Jianwei Zhang,Baoyu Gao,Qinyan Yue,Wei Zhang,Zhihao Lu,Xiaohua Zhu
The effective coagulation aid epichlorohydrin-dimethylamine was synthesized, its co-effect with three ferric iron species in polyferric chloride on humic acid elimination and membrane pollution in coagulation-ultrafiltration hybrid technique were appraised to improve the hybrid water treatment technology and generate cleaner water production by this research. To be specific, dosages of polyferric chlorides 2 and polyferric chlorides&epichlorohydrin-dimethylamine were adjusted according to their coagulation performance in jar tests. Furthermore, properties of generated flocs such as floc size (median particle diameter), strength/recovery factor and fractal dimension feature were monitored and combined with results of membrane fouling resistance under various shear forces to understand the mechanism of membrane fouling. Results indicated that epichlorohydrin-dimethylamine can observably enhance the coagulation performance of all polyferric chlorides, especially at low dosage of 4 mg/L. The higher the epichlorohydrin-dimethylamine dosage, the higher removal efficiencies achieved. In particular, for polyferric chloride with basicity of 1.5, the removal efficiency for dissolved organic carbon raised approximately from 15% to 32% as epichlorohydrin-dimethylamine dosage increased from zero to 1.5 mg/L. Meanwhile, for ultra-membrane 3 applied in this study, addition of the epichlorohydrin-dimethylamine also significantly reduced the total membrane fouling resistance of all coagulated water samples by forming cake layer of low compactness and reducing residual micro-particles, 4 even when shearing forces was introduced. Thereinto, the total membrane fouling resistance reduction of polyferric chloride with basicity of 1.5 was the most obvious, which dropped from 2.8 × 10 8 m −1 to 2.3 × 10 8 m −1 , approximately.
研究领域:
环境科学
·
水处理工程
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DOI
高影响因子
ENERGY & FUELS
·
2019
·
IF 3.021
Zhangjin Wu,Yucui Hou,Weize Wu,Shuhang Ren,Kai Zhang
Sulfur dioxide (SO2) is the main component of air pollution. Recently, sodium lactate (NaLa) aqueous solution (aq) was demonstrated as a highly efficient, renewable, and stable absorbent for SO2 absorption from flue gas. However, sulfuric acid (H2SO4) accumulated during long-term SO2 absorption and desorption cycles. To remove H2SO4 from NaLa (aq) efficiently, a method based on the common-ion effect was proposed in this work. The results indicated that the residual concentration of sulfate anion (SO42–) decreased with decreasing the water content. Residual SO2 in NaLa (aq) did not influence the removal of H2SO4. After the removal, the content of residual SO42– was 0.47 wt % and the removal rate of H2SO4 was 95.6%, with a water content of 34 wt % at 20 °C. In comparison to other reported methods, our method to remove H2SO4 in absorbents did not introduce other ions and block the absorption tower. It was noted that the evaporation of water to decrease the water content was combined with the regeneration of NaLa (aq), without any extra evaporation energy. NaLa (aq) was not changed during the removal process. Moreover, the SO2 absorption capacity in H2SO4-removed NaLa (aq) was comparable to the capacity of virgin NaLa (aq), and no obvious change could be found after 5 cycles of H2SO4 removal. The mechanism of removing H2SO4 from NaLa (aq) studied with Fourier transform infrared spectroscopy indicated that H2SO4 was removed in the form of Na2SO4 without crystal water as a result of the common-ion effect. Furthermore, a new process for SO2 absorption with H2SO4 removal from NaLa (aq) was proposed.
研究领域:
环境科学
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化学工程
·
污染控制
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
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IF 8.4
Yang Yang,Lei Huang,Yongshi Huang,Mahmud Sakil,Kaige Dong,Jingxin Yang,Wei Zhang,Gaosheng Zhang,Mengmeng Jia,Zhu Xiong
Accumulation of pollutants poses significant challenges to advanced membrane process, impacting efficiency and increasing operational costs. Fulvic acid and its analogues, widely distributed natural organic compounds, degrade water quality and produce by-products in traditional water treatment processes. The presence of even trace heavy metals in water, at the same time, can have a long-term impact on human health. Addressing these issues, we developed a novel TiO 2 -polydopamine (PDA) modified polyvinylidene fluoride (PVDF) membrane (TiO 2 -PDA@PVDF) through an environmental-friendly and low-cost sol-gel method. The membrane features dense nano-TiO 2 coverage, facilitated by a crosslinked dopamine layer, enabling in-situ growth of a functional TiO 2 layer via hydrothermal treatment. This hybrid membrane demonstrates superior adsorption, permeation, and photocatalytic self-cleaning capabilities. Performance analysis demonstrates over 90 % removal efficiency for humic acid and 85–95 % for heavy metals (Tl + , Sb 3+ , and Cr 6+ ). During humic acid separation, the initial flux of nano-TiO 2 membrane was 432 L/m 2 ·h, however, the flux attenuation (63 %) was smaller than unmodified membrane (91 %). Notably, the membrane maintained a flux loss ratio of less than 10 % after multiple operations and self-cleaning cycles, showcasing its robustness and sustainability. The TiO 2 -PDA@PVDF membrane not only effectively intercepts and adsorbs contaminants but also recovers its performance through photo-regeneration facilitated by trace hydrogen peroxide and UV light. These results highlight the membrane's potential for sustainable water purification, presenting a promising solution for both fouling mitigation and enhanced efficiency.
研究领域:
环境科学
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材料科学
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水处理技术
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）