CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Shams Ali Baig,Jin Zhu,Lisha Tan,Xiaoqin Xue,Chen Sun,Xinhua Xu
Elevated concentration of arsenic in water supplies is detected worldwide and therefore becomes a global issue. Calcination process is known to increase the adsorbent hardness for its effective application in column-based treatment. In this study, magnetic honeycomb briquette cinders (MHBC) and its calcined products: MHBC(A) and MHBC(N) were employed for the adsorptive removal of As(III) in fixed-bed column. Characterizations revealed that the calcination at 1000 °C under nitrogen has significantly increased the adsorbent particles size; favored phase transformation and improved saturation magnetization (>20 emu g − 1 ). Additionally, the new iron silicate phase (Fe 2 SiO 4 ) in aqueous medium generated highly reactive iron oxide species (=FeOOH), which effectively bind As(III) from the influent water by ligand exchanges. In contrast, calcination under dynamic air drastically reduced the saturation magnetization (<1 emu g − 1 ) and assisted to form segregated magnetite, quartz and hematite, as revealed in XRD patterns. The breakthrough curve of each column was compared with Thomas model and found that the model could be applied to estimate As(III) adsorption in fixed-bed column. Thomas model suggested parameters follow the order: MHBC(N) > MHBC > MHBC(A) and the maximum solid phase concentration ( q T ) was found to be about 56.07 mg g − 1 for MHBC(N). The column beds could be successfully regenerated using 200 bed volume of 10% NaOH solution. This study suggests that the selective calcination process need to be integrated with the adsorbent development process for the efficient removal of As(III) from contaminated water using column-based treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2018
·
IF 4.155
Li Yinong,Tian Chen,Liu Weizhen,Xu Si,Xu Yunyun,Cui Rongxin,Lin Zhang
Nano-Mg(OH)2 is attracting great attention as adsorbent for pre-concentration and recovery of rare earth elements (REEs) from low-concentration solution, due to its superior removal efficiency for REEs and environmental friendliness. However, the nanoparticles also cause some severe problems during application, including aggregation, blockage in fixed-bed column, as well as the difficulties in separation and reuse. Herein, in order to avoid the mentioned problems, a carbon cloth (CC) supported nano-Mg(OH)2 (nano-Mg(OH)2@CC) was synthesized by electrodeposition. The X-ray diffraction and scanning electron microscopy analysis demonstrated that the interlaced nano-sheet of Mg(OH)2 grew firmly and uniformly on the surface of carbon cloth fibers. Batch adsorption experiments of Eu(III) indicated that the nano-Mg(OH)2@CC composite maintained the excellent adsorption performance of nano-Mg(OH)2 toward Eu(III). After adsorption, the Eu containing composite was calcined under nitrogen atmosphere. The content of Eu2O3 in the calcined material was as high as 99.66%. Fixed-bed column experiments indicated that no blockage for Mg(OH)2@CC composite was observed during the treatment, while the complete blockage of occurred to nano-Mg(OH)2 at an effluent volume of 240 mL. Moreover, the removal efficiency of Mg(OH)2@CC was still higher than 90% until 4,200 mL of effluent volume. This work provides a promising method for feasible application of nanoadsorbents in fixed-bed process to recycle low-concentration REEs from wastewater.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2019
·Vol. 26
·期 6
·1831-1838
·
IF 1.947
Mutyala Suresh,Yu Ya-Dong,Jin Wei-Guang,Wang Zhi-Shuo,Zheng Deng-Yue,Ye Chun-Rong,Luo Binbin
Composite material, tetraethylenepentamine (TEPA) incorporated UiO-66 was prepared by impregnation method to study CO 2 capture in a fixed bed reactor, atmospheric pressure. All synthesized adsorbents were characterized using PXRD, N 2 adsorption–desorption isotherms, FT-IR, TGA, SEM, and Elemental analysis. Characterization results have revealed that incorporated TEPA was present within pores of UiO-66. CO 2 adsorption was higher on TEPA incorporated UiO-66 compared to UiO-66. It was due to the chemical interaction between –NH 2 and CO 2 . High CO 2 adsorption capacity 3.70 mmol g −1 was obtained on 30TEPA/UiO-66 at 75 °C, 1 bar. Because of more flexibility and high dispersive nature of TEPA at this temperature. The same CO 2 adsorption capacity was obtained in each adsorption cycle without decomposition of the amine on 30TEPA/UiO-66. Avrami adsorption kinetic model has suggested adsorption of CO 2 on composite material was chemical adsorption and deactivation model suggested an initial rate of adsorption was higher on TEPA incorporated UiO-66.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Evans Dovi,Aaron Albert Aryee,Alexander Nti Kani,Farid Mzee Mpatani,Jianjun Li,Zhaohui Li,Lingbo Qu,Runping Han
Several pollutants found in industrial wastewater , such as Congo red dyes (CR), have been shown to be toxic to organisms. To protect human health and the environment, industrial effluents must be purified before being released into bodies of water. In order to effectively remove CR from the solution, amino functionalized walnut shells (WNS) were synthesized. Batch and fixed-bed column systems were used in this research. The Langmuir isotherm model fits the experimental findings well in these two systems, whereas the pseudo-second-order and Thomas kinetic models characterize batch and column CR adsorption, respectively. The adsorption capacity of ACWNS toward CR was to 224.4 mg g −1 at 303 K from Langmuir model. Electrostatic interactions and hydrogen bonding may be the mechanisms. The column research showed that adsorption was more favorable at low inlet solution concentration, low flow rate, or high column depth. The column mass transfer capacity parameter (B) increased with increasing concentration (0.461, 1.59, and 2.47 for 50, 100, and 150 mg L −1 , respectively) owing to a greater driving force for CR adsorption onto ACWNS, while adsorbate–adsorbent affinity (β) exhibited a reverse trend. The regeneration property of CR-loaded ACWNS was excellent using NaOH solution. The thermodynamic study revealed that CR removal was both spontaneous and endothermic. ACWNS is promising to remove CR from the solution.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2023
·
IF 6.2
Xiangyue Wei,Yixin Pan,Jisheng Kou,Rui Huang
The removal of selenium (IV) from aqueous solutions was the focus of research that led to the discovery of a novel type of composite adsorbent called FeS@h-BN nanocomposite . This adsorbent was studied, characterized, and put to use in a fixed bed column. SEM, FTIR, XRD, and XPS analyses were conducted to learn more about the coated layer's surface properties. The effect of several adsorbent materials on the remediation of Se(IV) in dynamic water was examined. The Adams-Bohart model, the Thomas model, and the Yoon-Nelson model were all utilized to get optimal fits to the kinetic data obtained from the adsorption process. Moreover, the Adams-Bohart model was only applicable to the beginning portion of the dynamic behavior of the FeS and FeS@h-BN columns. The Thomas and Yoon-Nelson models were sufficient for describing the breakthrough curve under all experimental conditions. For this dynamic process, the theoretical breakthrough curve profile was compared to an experimentally derived profile. It was discovered that FeS@h-BN nanocomposites are the most effective at removing Se(IV), and the adsorption of Se(IV) by a variety of adsorbent materials is enough for all three dynamic models.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fanhui Meng,Lina Wang,Muhammad Asif Nawaz,Qian Wang,Zhiyuan Gong,Zhong Li
Direct conversion of syngas to light hydrocarbons has been intensively studied in recent years; however, the high selectivity of light hydrocarbons is still a challenging task to achieve a high CO conversion. Here, a bifunctional catalyst consisting of a methanol synthesis catalyst (CZA) and a methanol to dimethyl ether (DME) catalyst (Al 2 O 3 ) was employed with a hydrocarbon synthesis catalyst (SAPO-34), for syngas conversion to light hydrocarbons in a dual fixed-bed reactor. The conversion of simulated intermediates CO/CO 2 /DME/N 2 /H 2 with a molar ratio of 9/6/4/5/76, obtained from syngas conversion to DME over CZA and Al 2 O 3 , was studied over SAPO-34 zeolites. It was found that SP34-0.1 with Si/Al ratio of 0.1, exhibited low amount of strong acid (0.60 mmol/g) and high selectivity to light olefins (74.1%), while SP34-0.4 with Si/Al ratio of 0.4 exhibited high amount of strong acid (1.00 mmol/g) leading to high selectivity of light paraffins (88.4%). The in-situ DRIFTS analysis illustrated that DME can be rapidly adsorbed on the hydroxyl site of SAPO-34 and decomposed into the surface methyl species, where SP34-0.4 could produce more dimethylcyclopentenyl cationic species than SP34-0.1. It was suggested that the overall reaction route led to a high selectivity to light olefins (84.2%) with a CO conversion of 61.2% on (CZA + Al 2 O 3 ) catalyst combined with SP34-0.1, while a high selectivity to light paraffins (76.3%) could be achieved by combining with SP34-0.4 at 70.3% CO conversion. Since, the current study interprets that the selectivity of hydrocarbons can be adjusted by regulating the acidity of SAPO-34 to achieve a high CO conversion in the dual fixed-bed reactor scheme.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2014
·
IF 3.019
Jie Zhang,Xingjun Wang,Fuchen Wang,Jie Wang
The hydrogasification of three low rank coals (YX lignite, XD lignite and ZD subbituminous coal) was carried out in a fixed-bed reactor to investigate the effects of hydrogen pressure on the formations of gaseous, liquid and char products. The reactor was typically heated at a rate of 15 °C/min up to 700 °C with a holding time of 60 min under various hydrogen pressures up to 5 MPa. The yields of BTX (i.e., benzene, toluene, and xylene) and naphthalene increased with increasing hydrogen pressure up to 5 MPa for all three coals, but more significant for XD and ZD coals. The compositional analysis of char revealed that the chars produced by the hydrogasification had higher molar ratios of H/C and lower molar ratios of N/C than those produced by the pyrolysis in N 2 atmosphere, whereas the former chars had higher or lower molar ratios of S/C than the latter chars from case to case depending principally on coals. The apparent reaction rate constants of the chars hydrogasification in the isothermal stage as a function of hydrogen pressure were found to follow a power equation of the power exponents varying with coals.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Hailong Li,Qin Yang,Wenqi Qu,Yong Feng,Lijian Leng,Jiexia Zhao,Fanyue Meng,Zequn Yang,Jianping Yang
The critical challenge to achieve cost-effective elemental mercury (Hg 0 ) capture from coal combustion flue gas by using mineral sulfides lies in developing a facile method to realize their fixed-bed application, which hence exhausts the adsorption capacity of mineral sulfides and optimize their economic-sustainability. In this work, a feasible and facile synthesis procedure based on a one-step cetyltrimethylammonium bromide (CTAB) assisted precipitation procedure was proposed to overcome this challenge. During this process, the CTAB played a crucial role to effectively confine the particle size of copper sulfide (CuS) in nanoscale and stably anchor it over the macroporous polyurethane foam (PUF) skeleton. The macropore-enriched CuS/PUF as synthesized was merited for its high throughput morphology, nanoscale particle size of CuS, homogeneous distribution of active components, and multiform surface sulfur ligands, which is promising to be used in a fixed-bed scenario to achieve efficient Hg 0 sequestration. These benefits co-derived an excellent Hg 0 sorbent with extremely high uptake capacity and adsorption rate (265.6 mg g −1 and 2.16 mg g −1 min −1 ), exceeding those of other mineral sulfides and traditional activated carbons as reported in previous studies by folds, even by magnitudes. With such an outstanding Hg 0 sequestration performance and a macroporous structure, it can be reasonably concluded that the CuS/PUF will be a potential sorbent to be adopted in a fixed-bed scenario, which optimizes the cost-effectiveness of mineral sulfide based sorbents and extend their application flexibility for the Hg 0 adsorption from coal combustion flue gas.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Yaqiu Tao,Lulu Tao,Zhigang Pan,Simin Qiu,Xiaodong Shen
Formic acid is a promising hydrogen storage material for its high H 2 capacity, easy transfer and moderate H 2 regeneration conditions. Active carbon supported Mo 2 C with or without Co doping were used as the heterogeneous catalyst in the decomposition of a high concentrated aqueous solution of formic acid up to 50% on a fixed bed reactor. For a given flow rate and reaction temperature, though higher volume of H 2 is produced per unit time, the increase in formic acid’s concentration reduces both H 2 selectivity and formic acid conversion rate. At 250 °C, a stream of 236 mL/min H 2 was generated continuously at a high H 2 selectivity (91%) and formic acid conversion rate (86%), from a 10% formic acid fed at the flow rate of 5 mL/min. High reaction temperature improved the conversion of formic acid feed at little expense of H 2 selectivity. The doping of Co in the Mo 2 C lattice improves the H 2 selectivity to 100% at 100–200 °C. A life time study showed the stability of this system by the remained high H 2 selectivity in formic acid decomposition. This work of using active carbon supported molybdenum carbides and high concentrated aqueous formic acid, opens up a new route for the portable H 2 generator using formic acid as a hydrogen storage material at no environmental risk.
研究领域:
化学工程
·
能源科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Tianqing Zhou,Chaojian Zhang,Lungang Chen,Yue Yao,Shuxiang Lu,Xiaoyuan Liao
The direct synthesis of 2,5-furandicarboxylic acid (FDCA) from readily renewable fructose, would provide a cost approach without separation of 5-hydroxymethylfurfural (HMF). The method would realize efficient and continuous production, reduced by-products, without cumbersome HMF separation process, and reduced production costs. In this work, we succeeded in converting fructose directly into FDCA over combined Amberlyst-15 and Pd/Al 2 O 3 in fixed bed reactor. We firstly time, compared One-bed two-catalysts (OBTC), and two-bed two-catalysts (TBTC) system. For the individual merits of the Amberlyst-15 and Pd/Al 2 O 3 , the catalytic performance of the combined beds is significantly improved compared with individual one. The high yields of FDCA (48 %) and fructose conversion (100 %) were obtained, respectively. Our one-step continuously method makes the FDCA production much more economical, energy-saved.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Hao Chen,Haonan Wu,Yuting Dai,Hong Shi,Xingxing Sun,Fengxian Qiu,Tao Zhang
Rare element resource (Te) loss and heavy metal (Cd) pollution, derived from waste photovoltaic CdTe cells, have attracted considerable attention in the cleaner production and environmental protection field. However, there are several technical barriers in conventional adsorption strategies for the continuous recovery Te(Ⅳ) and Cd(Ⅱ) due to single-component recovery, inefficient adsorbent utilization and less automation. Herein, this work presented a fixed-bed-column adsorption system for the continuous adsorption recovery of tellurium and cadmium from a simulated CdTe leachate using functional sludge-based adsorption fillers (LDO/SF and EDTA@LDH/SF) that prepared from water-processing sludge via hydrothermal synthesis, thermal activation and surface modification technologies. Breakthrough curves were analyzed for adsorption columns, considering initial concentration, flow rate, and filler height, with parameters evaluated using the Thomas and BDST models to determine the optimal separation parameters. During the continuous adsorption process, the column adsorption system with the filler layer height of 4 cm and liquid delivery rate of 1 mL/min can be used for continuous separation of more than 1000 mL of a simulated CdTe leachate and exhibits adsorption efficiencies of more than 96% and 82% for Te(Ⅳ) and Cd(Ⅱ), respectively. More importantly, the elution procedure was used to treat the column adsorption system with ion adsorption acceptances of 83% and 90% for Te(Ⅳ) and Cd(Ⅱ), respectively. Meanwhile, the functional sludge-based fillers demonstrated great regeneration and recycling capabilities, thus maximizing the utilization of adsorbents and saving treatment costs. This study has established a robust technical solution for the continuous recovery of tellurium and cadmium from simulated leachates, providing a practical framework for evaluating the efficiency of adsorption filler columns in actual applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Desalination and Water Treatment
·
2016
·
IF 1.272
Kang-Kang Yan,Jiao Huang,Xue-Gang Chen,Shu-Ting Liu,Ao-Bo Zhang,Ying Ye,Mei Li,Xiaosheng Ji
Rice husk ash (RHA) is a promising low-cost adsorbent. Meanwhile, the magnetic and catalytic capabilities of ferrite nanoparticles make it efficient for water purification. In this study, we prepared RHA and rice husk/CoFe2O4 composite (RHC) and studied their methylene blue (MB) adsorption capacities in fixed-bed columns. The column regeneration was also investigated. Both RHA and RHC are amorphous materials with Brunauer, Emmet and Teller (BET) surface area of >180 m2 g−1 and mesopore volume of >0.1 cm3 g−1. The CoFe2O4 nanoparticles are mainly located on the inner surface of RHC, which significantly increased the mesopore volume and average pore size but decreased the BET surface area and micropore volume. The adsorption ability of RHC was investigated in a fixed-bed column, with RHA as control. The effects of column parameters including bed height, flow rate, and inlet MB concentration on breakthrough curves were studied. The mathematical models, such as bed-depth service time (BDST), Thomas, and Yoon–Nelson models were applied to predict the breakthrough curves. It was found that BDST model fitted the breakthrough curves best. Results showed that the breakthrough time of RHC is more than two times than that of RHA, which may be attributed to the catalytic performance of CoFe2O4 nanoparticles. The exhausted RHA and RHC were retreated by three methods and eluted of the column with ethanol caused the highest regeneration efficiency. In addition, fixed-bed tests of RHA and RHC on real dye wastewater demonstrated that these adsorbents have good practical value and application prospect.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）