Biochar
·
2023
·Vol. 5
·期 1
·1-16
·
IF 12.7
Liu Fenglei,Wang Shanshan,Zhao Chaofeng,Hu Baowei
Herein, a biochar-based composite (Ti 3 C 2 T x @biochar-PDA/PEI) was constructed by decorating Ti 3 C 2 T x and polydopamine on coconut shell biochar via electrostatic self-assembly method. Different characterization techniques were applied to explore the structure, morphology and composition of the sorbents. It was found that the higher porosity and diverse functional groups were conducive for Ti 3 C 2 T x @biochar-PDA/PEI to capture radionuclides, and the water environmental conditions made a great contribution to the adsorption process. The process of removing U(VI)/Cs(I) well complied with the Langmuir isotherm and Pseudo-second-order equations, which indicated that the single layer chemical adsorption occurred on the solid liquid interface. Meanwhile, this produced composite exhibited superior removal performance under complex co-existing ion environment, and the maximum adsorption amounts of U(VI) and Cs(I) reached up to 239.7 and 40.3 mg g −1 . Impressively, this adsorbent still exhibited good adsorption performance after three cycles of regeneration. The spectral analysis and DFT calculation demonstrated that adsorption of U(VI) might be a chemical process, while the adsorption of Cs(I) should be ion exchange or electrostatic attraction. This study demonstrated the potential application of Ti 3 C 2 T x @biochar-PDA/PEI as an effective remediation strategy for radioactive wastewater cleanup. Graphical Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Peigang He,Qikun Wang,Shuai Fu,Meiling Wang,Shengjian Zhao,Xuzhao Liu,Yuqi Jiang,Dechang Jia,Yu Zhou
This paper reports a facile route to prepare bulk zeolites with tunable phase compositions and microstructures by combining hydrothermal treatment and geopolymer precursor technique. Amorphous Na-based geopolymer (NaGP) is transformed into crystalline analcime following hydrothermal treatments. By systematically investigating the effects of hydrothermal conditions on the phase compositions and microstructures of the products, the optimal hydrothermal procedure is screened as treating NaGP in 1 M NaOH solution at 160 °C for 6 h. Furthermore, we achieve control over phase compositions of the resulting bulk zeolites by tailoring the initial Na/K ratio of geopolymer precursors. For instance, treating the geopolymer precursor with a Na/K ratio of 9: 1 under the optimal hydrothermal procedure leads to the formation of zeolite consisting of analcime and zeolite-P. The as-prepared adsorbents exhibit outstanding adsorption performance for the hazardous elements, among which analcime-zeolite-P shows an adsorption efficiency of 93.3% for Cs + , and NaGP exhibits an adsorption efficiency of 99.6% for Sr 2+ . Moreover, we reveal the mechanisms underlying the adsorption of Cs + and Sr 2+ in the adsorbents to be chemisorption . Meanwhile, ion exchanges also occur in NaGP and analcime-zeolite-P during Cs + adsorption. These results render geopolymers and their derived bulk zeolites promising for hazardous elements adsorption.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Ziyu Zhuang,Dongdong Li,Yanfei Fan,Dandan Gao,Dewen Zeng
The construction of a comprehensive thermodynamic model for boron-containing salt brine is important. However, the general lack of the solubility of H 3 BO 3 + salt + H 2 O ternary systems makes it difficult to determine model parameters involving boron species. Here, we systematically determined the solubility isotherms of the H 3 BO 3 + CsCl + H 2 O system at T = (273.15, 298.15, 323.15, 348.15 and 363.15) K. There are three solubility branches corresponding to H 3 BO 3(cr) , CsCl (cr) and a novel adduct in the system. The determined composition of the adduct is 2H 3 BO 3 ·3CsCl. Moreover, the single crystal structure of 2H 3 BO 3 ·3CsCl is solved, suggesting that H 3 BO 3 molecules keep it native plane-triangle structure, but the O atoms coordinate to the Cs ion. We modeled these ternary solubility isotherms using the Pitzer-Simonson-Clegg (PSC) model implemented in the ISLEC program. With the help of the model, a complete polythermal phase diagram of the system was constructed for the temperature range from 250 K to 373.15 K. The determined standard thermodynamic quantities of 2H 3 BO 3 ·3CsCl (cr) from the model are Δ f G m Θ = − 3182.26 kJ∙mol −1 , Δ f H m Θ = − 3496.19 kJ∙mol −1 , S m Θ = 485.85 J∙K −1 ∙mol −1 , C p , m Θ = 320 J∙K −1 ∙mol −1 , respectively.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
高影响因子
NUCLEAR TECHNOLOGY
·
2022
·
IF 1.667
Yanhui Wang,Qiao Jiang,Yexin Yang,Jianfeng Cheng,Chenyang Bao,Yuelong Pan,Yu Liu,Gang Yang,Yangchun Leng,Xianguo Tuo
The alteration of the morphology of bentonite, a key barrier to isolating high-level radioactive waste in deep geological repositories under long-term interaction with groundwater, was studied. Bentonite colloids were prepared from Gaomiaozi bentonite, and its various properties were analyzed by various characterization methods. The effects of various factors on the adsorption of Cs(I) and Co(II) on bentonite colloids were investigated by batch static adsorption experiments. The results showed that the colloids were mainly composed of montmorillonite and were lamellar in shape, with a zeta potential of −enton mV and an average size of approximately 209.10 nm. The adsorption of Cs(I) and Co(II) by the colloids was a rapid process, and 31.78 and 88.24 mg/g, respectively, were adsorbed at equilibrium. Pseudo-second-order kinetic fitting showed that chemisorption plays a dominant role and acid-base interactions affect adsorption by influencing the stability of colloids and the chemical form of simulated nuclides. This work can be helpful for evaluating the safety of waste repositories.
研究领域:
环境科学
·
放射性废物管理
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Jie Sun,Shaolong Wan,Fen Wang,Jingdong Lin,Yong Wang
A variety of catalysts for higher alcohol synthesis from syngas have been under development for potential commercial application, which are still facing challenges, including poor carbon efficiency due to low selectivity to desired products. In this contribution, we systematically studied the effects of temperature, loading of K and Cs, space velocity, and CO2 addition on the alkali-promoted Cu/ZnO/Al2O3 catalysts in order to achieve a high yield of desired higher alcohol products. Our particular focus was to maximize the carbon efficiency by restricting the amount of undesired byproducts, such as lower alkanes and CO2 that could be formed. Among K and Cs promoted Cu/ZnO/Al2O3 catalysts studied, Cs-promoted Cu/ZnO/Al2O3 catalysts exhibit better performance to higher alcohols and higher carbon efficiency than K-promoted counterparts under similar conditions studied. 1.64 mol % Cs-promoted Cu/ZnO/Al2O3 catalyst achieves the highest selectivity to higher alcohols (24.9%) at a CO conversion of 41.6% under 290 °C, 1875 mL g–1cat h–1, 5.4 MPa. The presence of a small amount of CO2 of 2.5 mol % in the feed has negligible effect on the productivity of higher alcohols but significantly suppresses the formation of CO2 byproduct. With the further increase of CO2 in the feed, the formation of CO2 can be further suppressed but at the expense of productivity loss of higher alcohols, which is probably due to the neutralization of surface Cs sites. The best carbon efficiency can be achieved at 8% mol CO2 in the feed.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Jingkun Yuan,Peigang He,Xiaomin Liang,Dechang Jia,Lingyu Jia,Delong Cai,Zhihua Yang,Xiaoming Duan,Shengjin Wang,Yu Zhou
In this paper, a high temperature treatment procedure was designed to evaluate the effect of holding temperature on thermal evolution process of Li + substituted Cs-based geopolymer (Cs 0.7 Li 0.3 GP), including the thermal analysis, phase composition and microstructure evolution. With rising of holding temperature, amorphous unheated Cs 0.7 Li 0.3 GP gradually transformed into a multiphase system during the high temperature treatment process, which consisted of pollucite (CsAlSi 2 O 6 ), spodumene (LiAlSi 2 O 6 ) and amorphous glass phase. In the multiphase system, Cs + ions were in the form of pollucite grains, while Li + ions were in the form of spodumene nanocrystallines distributed in amorphous matrix. The pollucite grains gradually coarsened with rise in holding temperature, and the densification of the resulting products were also improved synchronously, which were related to the presence of amorphous glass phases. The amorphous glass phase would be in a molten state when holding temperature over 800 °C. And the presence of molten amorphous phase would make the mass transfer process easier, which could contribute to the growth of the crystal grains and the elimination of the pores.
研究领域:
材料科学
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2014
·
IF 3.552
Hang Long,Pingxiao Wu,Lin Yang,Zhujian Huang,Nengwu Zhu,Zhixian Hu
Ethylamine modified vermiculite (Ethyl-VER) with high specific surface area and excellent pore structure was prepared to remove cesium from aqueous solution. The physic-chemical properties of the pristine and modified vermiculite were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), specific surface area (BET) and scanning electron microscopy/energy disperse spectroscopy (SEM/EDS). The corroding effect of ethylamine increased the specific surface area of vermiculite from 4.35 to 15.59 m 2 g −1 , and the average pore diameter decreased from 6.8 to 5.34 nm. Batch adsorption experiments were conducted as a function of pH, initial Cs + concentration, contact time, coexisting cations (K + , Na + , Ca 2+ ) and low-molecular-weight organic acids (acetic acid, oxalic acid, citric acid) to illustrate the adsorption behavior. The study found that the adsorption capacity of cesium in aqueous solution was improved from 56.92 to 78.17 mg g −1 after modification. The formation of micropores and mesopores and the increased surface area played a critical role in the enhancement of cesium adsorption. Kinetic experiments indicated that the adsorption process can be simulated well with a pseudo-second-order model. The presence of cations or low-molecular-weight organic acids inhibited cesium adsorption in different degrees. On the basis of our results, Ethyl-VER with good surface characteristics and high adsorption capacity is a suitable adsorbent for cesium removal from aqueous solution.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yujing Chi,Yuan Xu,Chenxiang Xu,Jiming Tian,Ying Li,Boxiang Gu,Haiyan Song,Han Zhang
Selective removal of 137Cs from nuclear wastewater is still a challenge due to the issues of efficient adsorbent exploitation and high concentrations of competitive ions. In this study, two-dimensional-layered Mxene Ti3C2Tx achieved the surface alkaline modification with KOH to be used as an efficient adsorbent for Cs+ removal from model wastewater. Hydroxyl-modified Ti3C2Tx obtained improved the delamination morphology and surface structure compared with the pristine Ti3C2Tx. In addition, the F species in Ti3C2Tx were efficiently removed and the hydroxyl groups were increased after modification. The adsorption efficiency of Cs+ over the hydroxyl-modified Ti3C2Tx was significantly enhanced, being attributed to the improvements in morphology, structure, and properties. 0.05 g of an optimal adsorbent achieved 90% removal of Cs+ with 5 mg·L–1 initial concentration in 50 mL of model wastewater within 5 min at ambient temperature and neutral conditions. Hydroxyl-modified Ti3C2Tx also exhibited high adsorption selectivity for Cs+ in the presence of competitive metal ions such as K+, Na+, Mg2+, and Ca2+. The mechanism study revealed that the ion exchange between [Ti–O]−H+/Cs+ mainly contributed to Cs+ adsorption, and the complexation between the oxygen-containing groups [Ti–O] in modified Ti3C2Tx and Cs was also involved. The hydroxyl-modified Ti3C2Tx was easy to regenerate and exhibited good recyclability for Cs+ adsorption.
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
CHEMOSPHERE
·
2022
·
IF 8.943
Zhenzhen Jiang,Gaoling Liu,Chi Ma,Yafei Guo,Ji Duo,Mingli Li,Tianlong Deng
Efficient and quick removal of radioactive Cs + from wastewater is significant for the safe use of nuclear energy and human health. A novel adsorbent K 1.93 Ti 0.22 Sn 3 S 6.43 (KTSS) was developed for Cs + removal from complex natural water systems. The working mechanism of KTSS for removing Cs + was the synergistic effect of ion exchange and the Cs⋯S binding, which was proved by several characterization techniques. KTSS showed ultrafast kinetics for Cs + adsorption within 1 min with a removal rate of 99%. Meanwhile, KTSS exhibited a higher adsorption capacity of 450.12 mg/g than many other adsorbents to remove Cs + and possessed excellent chemical stability in a wide pH range of 3–12. Thanks to the natural affinity arising from the S 2− ligands, KTSS displayed excellent selectivity for Cs + even in different complex water systems. The separation factors between Cs + and the coexisting ions of Na + , K + , Mg 2+ , Ca 2+ were ranged from 408.61 to 7448.20. Fortunately, by eluting with NaNO 3 the adsorbent could realize the green regeneration and cyclic utilization. Furthermore, it was found that KTSS had tremendous advantages in the removal of Cs + in comparison with the other adsorbents. Consequently, it should be considered that KTSS obtained in this study has great potential in applying ultrafast and high-efficient removal of Cs + from wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Tao Huang,Dongping Song,Lulu Zhou,Hui Tao,Aiyin Li,Shu-wen Zhang,Long-fei Liu
The natural ecosystem will continually deteriorate for decades by the leakage of Cs and Sr isotopes. The exploration of the new materials or techniques for the efficient treatment of radioactive wastewater is critically important. In this study, a dielectric barrier discharge (DBD) configuration was constructed to operate the non-thermal plasma (NTP). The NTP was incorporated into the synthesis of polyaluminum chloride (PAC) in two different procedures to intensify the synthesis of PAC (NTP-PAC) and enhance the further removal of Cs and Sr from wastewater. The employment of NTP in two procedures both had significantly changed the physicochemical characteristics of PAC materials, which facilitated the further adsorption application of NTP-PAC on the treatment of Cs + and Sr 2+ . Different molecular, morphological, and adsorption characteristics were confirmed to the NTP-PAC materials. The heterogeneous adsorption of the NTP-PAC can be appropriately fitted by both the pseudo-first-order kinetic model and the Elovich model. Both physisorption and chemisorption reaction mechanisms were ensured for the heterogeneous adsorption of the NTP-PAC material towards Cs + and Sr 2+ , which guaranteed the excellent adsorption performance of NTP-PAC materials compared to PAC. The electron collisions caused by NTP with alum pulp created highly reactive growth precursors and intensified the nucleation and hydrolysis polymerization of PAC. The employment of NTP explicitly broadens the reaction pathways between PAC and cationic contaminants in the aqueous environment, which expands the application area of PAC materials in environmental sustainability.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energies
·
2022
·Vol. 15
·期 22
·8542
·
IF 3.252
Yue Zhang,Ruixing Li
Nanoscale tungsten bronze can convert near-infrared light into thermal energy. For a chemical synthesis, intermediate products and processes are potentially positive or negative to an end product. In this study, (NH4)2SO4was added into the hydrothermal system of WO3, CsCl, CH3CH2CHO, and NH3·H2O to increase the Cs/W ratio in solution. An intermediate, Cs1.1W1.65O5.5, was isolated. Subsequently, it was confirmed via a kinetics experiment conducted for different times. The results of the NH3·H2O and NH4COOCH3system indicate there are two influence factors that influence the formation of Cs1.1W1.65O5.5: the leaching out of W and imine reactions. A low leaching out rate induces a high Cs/W ratio and low-concentration W in solution, leading to the formation of Cs1.1W1.65O5.5. The imine reaction decreasing CH3CH2CHO restrains the reduction in Cs1.1W1.65O5.5. The increase in CH3CH2COO−with the reduction reaction results in both the micron-size sticks and nano-size equiaxial particles in powder.Keywords:cesium tungsten bronze;intermediate;hydrothermal;synthesis;near-infrared response
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 6
·3063-3071
·
IF 3.049
Jingxuan Long,Wenfeng Zhao,Yufei Xu,Weibo Wu,Chengjiang Fang,Hu Li,Song Yang
Selective hydrogenation of unsaturated compounds is mainly carried out by using high-pressure hydrogen in the presence of a precious or transition metal catalyst. Here, we describe a benign approach to efficiently catalyze the hydrogenation of furfural (FUR) to furfuryl alcohol (FFA) over commercially available cesium carbonate using nontoxic and cheap polymethylhydrosiloxane (PMHS) as hydrogen source. Good to excellent FFA yields (≥90%) could be obtained at 25–80 °C by appropriate control of the catalyst dosage, reaction time, and the hydride amount. FUR-to-FFA hydrogenation was clarified to follow a pseudo-first order kinetics with low apparent activation energy of 20.6 kJ mol−1. Mechanistic insights manifested that PMHS was redistributed to H3SiMe, which acted as the active silane for the hydrogenation reactions. Importantly, this catalytic system was able to selectively reduce a wide range of aromatic aldehydes to the corresponding alcohols in good yields of 81–99% at 25–80 °C in 2–6 h.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）