ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Xin He,Wutong Chen,Feiyun Sun,Zekai Jiang,Bing Li,Xiao-yan Li,Lin Lin
Flow-electrode capacitive deionization (FCDI) is a promising electromembrane technology for wastewater treatment and materials recovery. In this study, we used low-cost Na-modified zeolite (Na-zeolite) to prepare a composite flow-electrode (FE) suspension with a small amount of highly conductive carbon black (CB) to remove and recover NH4+ from synthetic and actual wastewater (200 mg-N/L). Compared with conventional activated carbon (AC), the Na-zeolite electrode exhibited a 56.2–88.5% decrease in liquid-phase NH4+ concentration in the FE suspension due to its higher NH4+ adsorption capacity (6.0 vs. 0.2 mg-N/g). The resulting enhancement of NH4+ diffusion to the electrode chamber contributed to the improved performance of FCDI under both constant current (CC) and constant voltage (CV) conditions. The addition of CB to the FE suspension increased the conductivity and facilitated Na-zeolite charging for NH4+ electrosorption, especially in CV mode. NH4+-rich zeolite can be easily separated by sedimentation from CB in the FE suspension, producing a soil conditioner with a high N-fertilizer content suitable for soil improvement and agricultural applications. Overall, our study demonstrates that the novel Na-zeolite-based FCDI can be developed as an effective wastewater treatment technology for both NH4+ removal and recovery as a valuable fertilizer resource.
研究领域:
环境科学
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水处理工程
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材料科学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Chuanming Zhang,Chunyang Shen,Zhenggang Huang,Hongxin Xu,Yaxiong Zeng,Baohong Guan
Ammonia nitrogen (NH 4 + -N), which exists in the dominant form of ammonium ion (NH 4 + ) under the pH of 6.5–8.5, is one of the regular indexes and the most important pollutants in drinking water. The selective conversion of NH 4 + -N into harmless substances is urgently needed and also a great challenge. Herein we propose a new NH 4 + -N conversion pathway based on a catalytic ozonation process with birnessite-type MnO 2 (δ-MnO 2 ) catalysts. The δ-MnO 2 exhibits a superior performance for NH 4 + -N (1.0 mg/L) removal in adsorption (8.26 %) and oxidation (44.6 %) as well as up to 95.2 % of N 2 selectivity, surpassing almost all the reported O 3 -based catalysts. Unlike the traditional radical oxidation, a singlet oxygen ( 1 O 2 )-dominated nonradical oxidation pathway is confirmed for the efficiently selective conversion of NH 4 + -N to N 2 through the successive dehydrogenation, leading to a 15.0-fold enhancement in NH 4 + -N oxidation rate compared with ozone oxidation. The Mn(III)/Mn(IV) redox sites and surface lattice oxygen in δ-MnO 2 act as the active sites promoting the decomposition of O 3 into •O 2 − and then 1 O 2 via electrons transfer. In application, δ-MnO 2 catalytic ozonation effectively removes NH 4 + -N in real drinking water and presents excellent stability. This work finds a nonradical reaction mechanism in catalytic ozonation for NH 4 + -N selective conversion to N 2 , and solidly solves the problem of low-concentration NH 4 + -N removal from drinking water under the limited pH of 6.5–8.5 condition.
研究领域:
环境科学
·
水处理
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催化
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污染物去除
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Bing Liu,Xiaochen Xu,Yuan Xue,Lifen Liu,Fenglin Yang
An integrated method of simultaneous desulfurization and denitrification from flue gas by catalytic ozonation combined with NH 3 /(NH 4 ) 2 S 2 O 8 absorption was developed for the first time. It consisted of two parts: (1) the catalytic ozonation of NO over FeO x /SAPO-34 to study the effects of the various influencing factors, and (2) the absorption–oxidation of NO x and SO 2 induced by ozone combined with a NH 3 /(NH 4 ) 2 S 2 O 8 solution in a bubble column reactor. In Part 1, results showed that under the optimal condition of a molar ratio of 0.5 for O 3 /NO, a residence time of 3 s, a water vapor volume fraction of 4%, a NO initial concentration of 536 mg/m 3 , and a SO 2 initial concentration of 343 mg/m 3 , the oxidation rate of NO was 55%. The characterizations of poisoned catalyst are briefly discussed. In Part 2, as the gas passed sequentially through the ozonizing reactor and the absorber (NH 3 /(NH 4 ) 2 S 2 O 8 solution of 0.8% ammonia and 0.2 mol/L (NH 4 ) 2 S 2 O 8 ), a NO conversion rate of approximately 92.6% and SO 2 conversion rate of 100% were obtained. The pH of the NH 3 /(NH 4 ) 2 S 2 O 8 solution had a significant impact on the NO conversion. According to the analysis of the composition of products under different pHs, a mechanism of desulfurization and denitrification based on NH 3 /(NH 4 ) 2 S 2 O 8 solutions was proposed. The reaction product as a compound fertilizer contained up to 24.5% nitrogen.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Science China-Chemistry
·
2021
·Vol. 64
·期 10
·1716-1722
·
IF 9.445
Chao Yuguang,Zhang Weiyu,Zhou Peng,Chen Hui,Lu Shiyu,Li Menggang,Zhang Qinghua,Gu Lin,Guo Shaojun
Atomic sites co-catalyst (ASC) on photocatalytic materials possesses an attractive prospect to promote charge carrier separation and tune surface reaction kinetics, yet the synthesis of earth-abundant ASC under low temperature remains a great challenge. Here, a novel in-situ NH 4 + -etched strategy to anchor atomic Mo sites on ZnIn 2 S 4 hierarchical nanotubes (HNTs) with abundant mesopores under mild conditions for promoting charge carrier separation and enhancing light multi-reflections is developed for efficient photocatalytic H 2 evolution. Density functional theory calculations and linear sweep voltammetry demonstrate that the well-defined Mo-S 2 O 1 sites with distinctive coordination configuration and electronic property contribute to the enhanced separation of photo-generated charge carriers and reduced Gibbs free energy for H 2 evolution. Consequently, the well-defined MoSA-ZIS HNTs present an excellent photocatalytic activity with a rate of 29.9 µmol h −1 (5.98 mmol g −1 h −1 ), which is 7.3 times higher than that of ZnIn 2 S 4 nanosheets (NSs), to be among the best ZnIn 2 S 4 -based photocatalysts. The present strategy breaks the high-temperature limitation of conventional top-down thermal dissociation/emitting approach for anchoring non-noble metal atomic sites on catalyst support.
研究领域:
材料科学
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能源化学
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催化科学
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产品关联
DOI
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2022
·
IF 5.443
Zixue Su,Hui Li
This work reports an electrochemical synthesis of (NH 4 ) 3 TiOF 5 mesocrystals consisting of nanocrystalline building units, via oriented particle attachment driven by an external electric field. The obtained (NH 4 ) 3 TiOF 5 mesocrystals are octahedral in shape and can be converted to porous anatase TiO 2 , retaining their octahedral morphology after thermal annealing treatment. A distinctive evolution process for the (NH 4 ) 3 TiOF 5 mesocrystals with octahedral morphology is revealed, which includes the nucleation and growth of primary small octahedral particles, oriented aggregation of six primary octahedral particles into one large secondary particle, formation of mesocrystalline octahedrons by crystallographic fusion, dissolution of the octahedrons into small nanoparticles, followed by oriented aggregation of the dissolved nanoparticles to form micrometer-sized octahedrons. The alignment and subsequent oriented attachment of nanoparticles driven by an external electric field enable the rapid growth of (NH 4 ) 3 TiOF 5 mesocrystals within 40 s, compared with the tens of hours usually required for the growth of NH 4 TiOF 3 mesocrystals using a hydrothermal method.
研究领域:
材料科学
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纳米技术
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电化学
·
晶体生长
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产品关联
DOI
高影响因子
Chem
·
2019
·
IF 18.205
Mingyang Xing,Bingkun Chen,Ji Feng,Wenjing Xu,Yaocai Bai,Yi Zhou,Chunyang Dong,Haizheng Zhong,Jinlong Zhang,Yadong Yin
Great interest has recently emerged in the development of quantum dots (QDs) that are capable of direct white-light emission for solid-state lighting. The conventional synthesis routes often involve surface modification and ligand displacement, which usually lead to undesired QD aggregation and fluorescence quenching. Here, we report a new strategy to synthesize QDs (ZnS, CdS, CdTe, and CsPbBr x I 3-x ) directly in colloidal SiO 2 to produce QDs@SiO 2 composites, displaying direct white-light emissions. By taking advantage of the NH 4 + trapped inside the silica colloids, we introduce metal cations through ion-exchange reactions into the microporous network of silica and then produce QDs directly within the silica colloids. This “trapped-NH 4 + ” strategy represents a new platform for the synthesis of novel functional nanocomposites by allowing convenient incorporation of various nanoparticles into sol-gel-derived colloidal matrices.
研究领域:
材料科学
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纳米技术
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光学材料
·
无机化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Ketao Shi,Youbing Zhu,Zhen Xu,Nianming Jiao,Hui Wang
The metal coordination state and the corresponding acid property of zeolite closely relate to its catalytic performance. In this study, DBD-plasma (dielectric barrier discharge-plasma), a low-temperature and energy-efficient external activation method, was proposed to activate the NH4+-type ZSM-5 zeolite and to regulate the Al coordination. It was found that DBD treatment could efficiently decompose NH4+ species at 115 °C, far below that required for calcination (550 °C). Characterizations, including X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), 27Al magic angle spinning nuclear magnetic resonance (27Al MAS NMR), and pyridine-adsorption infrared spectroscopy (Py-IR), revealed that DBD-plasma treatment could inhibit zeolite framework destruction and retain more framework Al and mesoporous structure, thus improving the stability and enhancing the amount of medium-strong Brønsted acid sites. In n-hexane cracking, DBD-activated zeolite exhibited improved conversion and C2–C4 olefin selectivity due to the enhanced monomolecular cracking pathway induced by increased Brønsted acidity, while reducing aromatics and coke formation by suppressing side reactions. This paper presents an alternative method that is more energy-efficient, highly effective, and capable of regulating the metal coordination and acidity of ZSM-5 zeolite.
研究领域:
催化
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材料科学
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化学工程
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yuanping Fang,Congli Chen,Bin Cui,Haiyan Li,Dandan Zhou
Frequent occurrence of trace antibiotics in reclaimed water is concerning, which inevitably causes aquifer contamination in the case of managed aquifer recharge (MAR). Global governments have formulated strict reclaimed water standards to ensure the safety of water reuse. Recent studies have found that improved antibiotics removal is intimately associated with high ammonia-oxidizing activity. However, the role of NH 4 + -N in the removal of residual antibiotics of reclaimed water during MAR remains unknown. NH 4 + -N removal and the effects of ammonia oxidation on antibiotics biodegradation in the aquifer are the most significant facts for solving the above collision. In this work, the effects of NH 4 + -N (0, 1 and 5 mg/L) in a model refractory antibiotic (oxacillin (OXA), 100 μg/L) attenuation were deciphered by employing three individual simulated MAR columns, which so called N0, N1 and N5. The results showed that 5 mg/L NH 4 + -N in influent upregulated the abundance of amo genes by 28.9 %-68.0 % in N5. And the enriched functional genes encoding key degradation enzymes enhanced the OXA removal by 18.7 % and alleviated the oxidative stress caused by antibiotics. Subsequently, antibiotic resistance genes (ARGs), mobile gene elements (MGEs) and human bacterial pathogens (HBPs) abundance were all significantly decreased. Moreover, the intimate association between ammonia-oxidizing microorganisms (AOM) and candidate OXA degraders based on microbial network analysis further supported the significance of AOM on OXA biodegradation. This study provides comprehensive evidence that appropriate amounts of NH 4 + -N are beneficial in antibiotics and antibiotic resistance risk reduction, providing compelling insights for refine NH 4 + -N recharge limitation.
研究领域:
环境科学
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水资源管理
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微生物学
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生物技术
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Changhao Wu,Xudong Yu,Nan Zhang,Jing Li,Qi Li,Yousheng Yang,Ke Chen,Bo Yang,Shuang Wang,Yiping Liu,Zhenwen Xing
To solve the massive accumulation of gypsum generated from polyhalite leaching and secondary gypsum, this study investigated phase equilibria of the ternary system NH 4 + , Ca 2+ // SO 4 2- - H 2 O at 323.2 K and 348.2 K. The phase diagrams included 2 invariant points, 3 univariate curves, and 3 crystallization regions corresponding to (NH 4 ) 2 SO 4 , CaSO 4 ·2H 2 O, and double salt koktaite (NH 4 ) 2 Ca(SO 4 ) 2 ·H 2 O. As temperature increased, the crystallization region of CaSO 4 ·2H 2 O contracted, whereas those of (NH 4 ) 2 SO 4 and koktaite expanded, indicating that the temperature-enhanced was beneficial to improve the crystallization efficiency of koktaite. Guided by multitemperature phase diagram, the influencing factors and optimal conditions of the comprehensive utilization process of phosphogypsum were explored. The synthesis of koktaite achieved maximum efficiency under conditions of 1: 1.5 molar ratio, 348.2 K reaction temperature, 90 min duration, and 250 rpm agitation. Concurrently, under solid-liquid ratio of 1: 0.5 and after three leaching cycles of 30 seconds each, the yield of CaSO 4 ·2H 2 O production reached 99.80% with a purity of 99.52%. However, the purity and yield of product decreased due to the accumulation of impurities during the cycles, stabilizing after 6 cycles (koktaite yield: 98.50%; purity: 95.69%; (NH 4 ) 2 SO 4 yield: 97.69%; purity: 95.42%). Granulated koktaite released NH 4 + through layer-by-layer dissolution, which prolonged the dissolution time, and the complete dissolution time was 6 times and 24 times longer than that of ungranulated koktaite and (NH 4 ) 2 SO 4 . This work integrates theoretical phase behavior analysis with process engineering to establish a circular resource recovery strategy for synthesizing high-value products from phosphogypsum.
研究领域:
物理化学
·
化学工程
·
材料科学
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环境科学
·
无机化学
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产品关联
DOI
高影响因子
Advanced Energy Materials
·
2025
·Vol. 15
·期 36
·e02595
·
IF 26
Xiang Ji,Yi Li,Yanlong Wang,Jian Jiang,Maowen Xu,Jianhui Zhu
Rechargeable Fe-ion batteries with overwhelming cost/environmental benign superiorities hold great promise in large-scale charge-storage applications. However, there is still a lack of competitive cathodes with prominent capacity and long-term cyclability. To overcome these constraints, a unique Fe 2+ /NH 4 + co-insertion strategy is proposed, enabling both doubled reversible capacity and cyclic life of Berlin green (FeHCF) cathodes. The Fe 2+ insertion proves to induce FeHCF lattice contractions, alter ligand environment/activation energies of low-spin Fe III, and hence boost the redox conversion depth, while NH 4 + co-insertions help to elevate the cathode capacities by utilizing Fe 2+ -unoccupied reaction sites. Besides, they generate hydrogen bonds between inserted NH 4 + ions and N atoms in FeHCF, capable of vastly strengthening the cathode's cyclic durability. Cathodes in such collaborative dual-cation electrolytes exhibit a remarkable capacity of 162 mAh g −1 (4 A g −1 ) and far prolonged operation lifespan (over 1000 cycles) when compared to single-cation cases. The assembled full cells demonstrate impressive energy densities up to 70.4 Wh kg −1 , and far superior capacity retention of 88% after all the cycling. This work may offer a simple/feasible, and effective route to render high-capacity and long-lasting cathodes for future/practical Fe-ion battery systems.
研究领域:
储能
·
电化学
·
材料科学
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电池技术
·
可持续能源
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Yuanning Yue,Ying Liao,Jiarong Lu,Yue Pan,Meiyu Zhang,Guiyue Chen,Xin Zhou,Xinyu Kuang,Hui Zhao,Xiaobo Chen,Xiang Feng,Hao Yan,Yibin Liu,Chaohe Yang
Recognizing and modifying the acid property-dependent catalytic characteristics of catalysts are of great importance for Prins condensation reaction. Herein, a series of metal-doped M-NH 4 -PW catalysts ( M =Pt, Fe, Ir, Ru) are successfully synthesized for Prins condensation reaction of formaldehyde and propylene to produce 4-methyl-1,3-dioxane. Our findings demonstrate that the catalytic performance of M-NH 4 -PW catalysts is influenced by the chemical nature of metal site properties with different electron transfer abilities. Specifically, the new Lewis acid decorated by Pt metal on 4-H site is more favorable for the selective adsorption of formaldehyde and activation of its C O bond. Additionally, the synergistic effect between Pt metal sites and nearby O in [PW 12 O 40 ] 3− promotes the formation of C C bonds between protonated formaldehyde and propylene. Consequently, the Pt-NH 4 -PW catalyst exhibits high conversion (> 80 %) and simultaneous selectivity towards 4-methyl-1,3-dioxane selectivity (65 %). This strategy may provide valuable insights for developing efficient multifunctional catalysts for Prins condensation reactions.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Yanrong Cheng,Xia Guo,Delan Ge,Wenlin Xu,Yaqiong Wang
Broadening the polarity range of polymer-based aqueous two-phase systems (ATPSs) is of practical significance. Recently, ionic liquids have been used as adjuvants to modify the polarity and properties of PEG-rich phases in PEG/salt ATPSs. However, thus far, only short alkyl (containing less than 8 carbon atoms)-chained ionic liquids have been able to promote the extraction performance of ATPSs; long alkyl-chained ionic liquids have decreased the extraction performance significantly due to their distribution in the bottom phase. In the present study, we found that by complexing with Triton X-100 (TX-100), long alkyl-chained imidazolium ionic liquids [C n mim]Br (n = 10 and 12) as adjuvants were enriched in the top phase of PEG/salt ATPSs, and hence, the polarity difference of the two phases were increased. By extracting two model substances (S-mandelic acid (MA) and l -tryptophan (Trp)), it was concluded that, although the long alkyl-chained [C n mim]Br adjuvant decreased the extraction performance of the ATPS substantially, the long alkyl-chained [C n mim]Br/TX-100 complex as the adjuvant enhanced the extraction performance of the ATPS significantly. Compared with the case without an adjuvant, when the [C 12 mim]Br/TX-100 complex and the [C 10 mim]Br/TX-100 complex were used as the adjuvants, the partition coefficients of MA and Trp in the PEG 600/(NH 4 ) 2 SO 4 ATPS were increased up to 3 ∼ 4 times, much better than those with short alkyl-chained ionic liquid as the adjuvant. Moreover, the [C 12 mim]Br/TX-100 complex is more conductive to the transfer of MA into the PEG-rich phase, and the [C 10 mim]Br/TX-100 complex is more conductive to the transfer of Trp into the PEG-rich phase.
研究领域:
生物化学
·
分离科学
·
工业化学
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产品关联
DOI
高影响因子
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