MINERALS ENGINEERING
·
2024
·
IF 4.9
Zuli Mo,Qingliang Wang,Zhimin Guo,Zhiwu Lei,Fang Hu,Eming Hu,Pengfei Hu
Treatment of uranium-containing wastewater has become an increasingly important research focus with the exploitation and utilization of uranium resources. The introduction of new technologies and continuous updating of existing technologies are the urgent tasks for the treatment of uranium-containing wastewater. Ion flotation is one technology with the potential to address uranium contamination. In this study, the improved ion flotation technique for removing U(VI) from acidic solutions was established by colloidal gas aphrons (CGAs). The CGAs were produced by stirring cetyltrimethylammonium bromide (CTAB) solutions at high speed. Measurements of half-life, gas hold-up, bubble size distribution and zeta potential of CGAs have been performed in this work. In the batch process, as CGAs continued to be added, the uranium removal increased steeply at first then slowly, and finally leveled off. At pH 6, the final uranium removal can reach the highest 99.3 % at an initial uranium concentration of 2.5 mg/L. The effective removal of U(VI) by the CGAs formed by cationic CTAB indicated that U(VI) existed as anionic species under these conditions. It was found that the concentration of carbonate ions in solution increased with the increase of flotation time, which may be caused by the dissolution of carbon dioxide brought in by bubbles. The calculation results of Visual MINTEQ software show that the concentration of carbonate ions generated at pH 6 is sufficient for anionic uranium-carbonate to dominate. In addition, it was found that the size and zeta potential of CGAs all played a significant role in removing U(VI) from the acidic 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
MINERALS ENGINEERING
·
2018
·
IF 2.707
Saizhen Jin,Qing Shi,Qiming Feng,Guofan Zhang,Ziyong Chang
Carboxymethyl cellulose (CMC), a negatively charged polymer, is commonly used as a depressant of talc. However, the separation of pyrite and talc can be deteriorated by the presence of calcium ions, which can facilitate the absorption of CMC onto both talc surfaces and pyrite. In this work, carbonate ions were introduced to solve this problem, and the effects of calcium and carbonate ions on the adsorption of CMC were also studied. Micro-flotation results revealed that CO 3 2 - . not only eliminated the inhibition of pyrite by Ca 2+ and CMC, but also had no influence on the depression of talc at pH 6–10. The surface-specific study confirmed that the adsorption of Ca 2+ onto talc basal planes at pH 8.5 was negligible and could be improved by the presence of CO 3 2 - . . The atomic force microscopy analysis showed the correlation between the coverage of CMC onto talc surfaces in the presence and absence of CO 3 2 - . . A mechanism for the adsorption of CMC onto talc surfaces was proposed based on the morphological differences in the presence and absence of CO 3 2 - .
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2024
·
IF 7.5
Zhiwei He,Hongbo Zhang
Graphical Herein, combination studies were applied to elucidate the reaction mechanism on CO 3 2− hydrogenation into methane at high efficiency in the solvent. We confirmed the reaction is following CO 3 2− to HCOO − , then to CH 4 reaction path and the C−O bond rupture within HCOO − was confirmed to be the kinetically relevant during catalysis. Catalytic conversion of carbon dioxide (CO 2 ) into value-added chemicals is of pivotal importance, well the cost of capturing CO 2 from dilute atmosphere is super challenge. One promising strategy is combining the adsorption and transformation at one step, such as applying alkali solution that could selectively reduce carbonate (CO 3 2− ) as consequences of CO 2 adsorption. Due to complexity of this system, the mechanistic details on controlling the hydrogenation have not been investigated in depth. Herein, Ru/TiO 2 catalyst was applied as a probe to elucidate the mechanism of CO 3 2− activation, in which with thermodynamic and kinetic investigations, a compact Langmuir-Hinshelwood reaction model was established which suggests that the overall rate of CO 3 2− hydrogenation was controlled by a specific C−O bond rupture elementary step within HCOO − and the Ru surface was mainly covered by CO 3 2− or HCOO − at independent conditions. This assumption was further supported by negligible kinetic isotope effects ( k H / k D ≈1), similarity on reaction barriers of CO 3 2− and HCOO − hydrogenation (Δ H ≠ hydr ,Na2CO3 and Δ H ≠ hydr ,HCOONa ) and a non-variation of entropy (Δ S ≠ hydr ≈0). More interestingly, the alkalinity of the solution is certainly like a two sides in a sword and could facilitate the adsorption of CO 2 while hold back catalysis during CO 3 2− hydrogenation.
研究领域:
化学
·
催化科学
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产品关联
DOI
PubMed
高影响因子
Chemosensors
·
2021
·Vol. 9
·期 8
·236
·
IF 3.398
Chuqing Zhang,Yang He,Jianbo Wu,Manqing Ai,Wei Cai,Ying Ye,Chunhui Tao,Pingping Zhang,Quan Jin
Real-time measurements of carbonate ion concentrations in the ocean are critical to advancing marine environmental monitoring and research into deep-sea hydrothermal activity. Herein, we report the first example of deep-sea hydrothermal field exploration using a carbonate ion-selective electrode (ISE). The novel carbonate ISE was composed of a Ni wire as substrate, carbon film as transducers and carbonate-selective membrane layers. This paper describes the preparation process of the electrode and characterises its performance via scanning electron microscopy (SEM) and electrochemical analysis. The detection limit of the electrode for CO32−is 2.821 × 10−6mol/L, the linear response range is 1.0 × 10−5–1.0 × 10−1mol/L and the Nernst slope was −30.4 mV/decade. In April 2021, the carbonate ISE was mounted on multi-parameter sensors with pH and Eh (redox) electrodes for the search of hydrothermal activity at the Southwest Indian Ridge. The simultaneous potential anomalies appeared at this carbonate electrode with the pH and Eh electrodes when passing through the hydrothermal field. The study of the hydrothermal field was supported by the in situ camera video and the sulphide samples. Additionally, the carbonate electrode provides enhanced information of water chemistry for the study of the hydrothermal field.Keywords:ion-selective electrode;carbonate determination;carbon film;hydrothermal field
研究领域:
海洋科学
·
环境监测
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Minghua Nie,Wenjing Zhang,Caixia Yan,Wenli Xu,Leliang Wu,Yuping Ye,Yun Hu,Wenbo Dong
In this study, a favorable CO 3 2− /PMS system for efficient degradation of organic contaminants (acid orange 7 (AO7), acetaminophen, para -aminobenzoic acid, phenol, methylene orange, methylene blue) in water was firstly reported. Under optimal conditions, the decolorization ration of AO7 was 100% within 40 min. Data fitting showed that the AO7 decolorization could be described by the pseudo-first-order kinetics, and the rates constant values ranging from 0.0006 to 0.2297 min −1 depending on the operating parameters (initial PMS, CO 3 2− , AO7 concentrations). Radical scavenging studies revealed that superoxide anion radical (O 2 − ) and singlet oxygen ( 1 O 2 ) rather than sulfate (SO 4 − ) nor hydroxyl (HO ) were the dominant oxidants might be responsible for AO7 degradation. The presence of NO 3 − , HPO 4 2− and low concentration of Cl − , NO 2 − , HCO 3 − , H 2 PO 4 − , HA had no significantly effect on the decolorization of AO7. Adding a higher Cl − concentration displayed favorable effects on the removal efficiencies of AO7, but adding a higher NO 2 − , HCO 3 − , H 2 PO 4 − and HA concentration apparently inhibited this process. The decolorization of AO7 was lower in wastewater in comparison to other natural waters and ultrapure water, which was probably due to the presence of higher concentration of colloids in wastewater. Nevertheless, up to 94.8%, 97.0% and 85.1% of AO7 were degraded from the filtrate, permeate, and retentate phases of wastewater within 60 min, respectively. Consequently, CO 3 2− /PMS would be promising for removal methodology for AO7 in wastewater containing considerable colloids. Finally, three intermediates were identified and degradation pathways of AO7 were proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RARE METALS
·
2024
·
IF 9.6
Ji Lian-Min,Shi Dong,Peng Xiao-Wu,Xie Shao-Lei,Li Jin-Feng,Zhang Yu-Ze,Zhang Li-Cheng,Niu Yong,Chen Gang,Li Li-Juan
China's salt lakes hold significant lithium reserves, yet the development of low-concentration lithium resources from the carbonate brines in Tibet is a pressing matter. Alkyl β-diketones extractants are capable of efficiently extracting lithium from alkaline solutions using an extraction method, but its optimized extraction prerequisite is an extreme alkaline solution with higher pH. This research introduces a process for the effective extraction and separation of lithium and sodium from the carbonate brine of Jieze Caka Salt Lake, utilizing trifluorinated β-biketone HBTA (4,4,4-trifluoro-1-phenyl-1,3-butanedione)–TBP (tributyl phosphate)/kerosene system. A three-stage extraction yielded 98.06% of Li + and 1.69% of Na + from the initial brine with a lower pH of 8.961 and a separation factor ( β Li/Na ) of 2948. The simplified process was then implemented using organic direct recycling without regeneration and scrubbing raffinate reflux for a total of 23 cycles, thereby demonstrating the exceptional effectiveness and stability of this system. The resulting lithium-rich stripping solution, with the Li/Na mass ratio amplified by 747 times, underwent further magnesium removal and precipitation using sodium carbonate to yield a high-purity lithium carbonate product of 99.50%. This study offers a novel approach and technology for the efficient separation of lithium ion directly from a partial-neutral carbonate salt lake with a high Na/Li ratio and low lithium concentration. Graphical abstract
研究领域:
化学工程
·
资源环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Kuo Zhou,Xingfan Wang,Junfang Yang,Fenli Jin,Huan Zhou
The solubility equilibrium of Li+, Na+//Cl–, CO32– −H2O quaternary systems at 323.15 K and 348.15 K was studied via the isothermal solubility equilibrium method, and the complete phase diagrams were obtained including the properties of liquid density and pH. Solid species of LiCl·H2O, Li2CO3, NaCl, and Na2CO3·H2O are found in the quaternary system at 323.15 K and 348.15 K, and one double salt of Li2CO3·Na2CO3 is found at 348.15 K. The liquid phase of two invariant points and five univariant curves at 323.15 and three invariant points and seven univariant curves at 348.15 K in the quaternary system is determined. Li2CO3 covers the largest solid phase region and is hardly influenced by temperature; Li2CO3–NaCl is a stable salt pair, and its cosaturated solubility is the least at the diagonal line of Li2CO3–NaCl.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2018
·Vol. 317
·期 1
·69-80
·
IF 1.181
Wang You-qun,Zheng Zhi-yang,Zhao Yi-kang,Huang Jian-hui,Zhang Zhi-bin,Cao Xiao-hong,Dai Ying,Hua Rong,Liu Yun-hai
Hydroxy-aluminum pillared Na-montmorillonite(OH–Al-MT) was prepared for studying sorption of U(VI) in the existence of soluble calcium (Ca 2+ ), carbonate ion (CO 3 2− ) and humic acid. Various characterizations confirm that hydroxy-aluminum was successfully pillared into Na-montmorillonite (Na-MT). The effects of pH, concentration of Ca 2+ and CO 3 2− as well as HA on the sorption capacity of Na-MT and OH–Al-MT for U(VI) has been investigated by batch experiments. Additionally, the kinetics, isotherms and thermodynamics of adsorption of U(VI) were discussed in detailed. The study indicates that OH–Al-MT can be a potentially promising low-cost adsorbent for removal of U(VI) in wastewaters.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Yu Liu,Yu Xiang,Hui Xu,Huili Li
Photocatalysis is highly efficient for the treatment of dyeing wastewater. However, the wastewater still contains a large amount of nano-TiO 2 after photocatalysis. In order to reduce the cost of nano-TiO 2 , different coagulants were used to improve the solid/liquid separation efficiency. At the same time, the reuse of flocs has raised increasing attention after coagulation. In this study, we report on the recycling of flocs for the production of AlCl 3 and TiO 2 formed flocs (AT 1 ) and Al 13 and TiO 2 formed flocs (AT 2 ) through a simple calcination process. Results indicated the flocs formation processes under different concentration of CO 3 2– were Al species distribution and coagulant dosage dependent. Without HA molecules, the reaction between Al-based coagulants and CO 3 2– are the controlling steps in the coagulation process, and Al a and Al b species had different reaction processes. The influence of HA molecules was also studied, and the HA-Al aggregates which could bridge the TiO 2 nanoparticles , and thus induce sweep flocculation . Consequently, highly enhanced aggregation rate, due to the heteroaggregation between these aggregates and TiO 2 was observed. After calcination, the AT 2 -10 and AT 2 -20 (CO 3 2– : 10, 20 mmol/L) with petal-like structures (mesoporous), relatively high specific surface areas, i.e. 83.98 m 2 /g and 78.38 m 2 /g and high photocatalytic degradation, i.e. 72.79%, 67.78% (compared to nano-TiO 2 , AT 1 -10 and AT 1 -20), were obtained. Additionally, oxygen vacancy (OV) was generated on the surface of the recycled AT 2 -10 and AT 2 -20, which display strong photocatalytic performance for the degradation of MO greater than 65%, under ultraviolet (UV) irradiation and without any sacrificial reagents. This study proposes a new perspective on recycling coagulated flocs for practical application in wastewater treatment .
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
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Yifeng Xu,Rui Sun,Shubo Wang,Fei Fei,Zhangyu Gan,Pin Zhou
With the development of global industry, carbon dioxide emissions surged. The conversion of carbon dioxide from the air results in some CO 3 2− , which can exacerbate environmental disasters like ocean acidification. Therefore, the content of CO 3 2− in seawater is an important indicator of the degree of ocean acidification. In this study, natural fluorescent protein phycocyanin (PC) was used as a fluorescent probe, and a fluorescence detection method was established for quantitative monitoring of CO 3 2− with quick response time (within 50 s), high sensitivity, and selectivity. The fluorescence quenching phenomenon between PC and CO 3 2− was mainly attributed to static quenching. The limit of detection (LOD) was 0.42 μM and the method was successfully applied to monitor CO 3 2− in tap water and seawater, acquiring satisfactory recovery between 99.28 % and 106.40 %. More importantly, paper-based test strips were easily fabricated using PC, enabling the rapid, visual, and on-site detection of CO 3 2− with the aid of a smartphone. The visual detection integrated with the smartphone was converted to data information (RGB value) through a Color Picker APP and successfully used for quantitative identification of CO 3 2− . By capturing fluorescent images and analyzing the corresponding RGB value via a smartphone, the linear calibration ranged from 0.5 μM to 500.0 μM with LOD of 0.11 μM was obtained. Satisfactory recoveries were acquired in tap water (98.00 %-107.50 %) and seawater (97.30 %-101.74 %), respectively. Therefore, integrating the PC fluorescent paper with a smartphone realizes the rapid, visual, and on-site detection of CO 3 2− in the water environment, which is expected to broaden application prospects of monitoring ocean acidification degree.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2021
·
IF 5.221
Yan Kang,Liu Liping,Zhao Hongxing,Tian Lei,Xu Zhifeng,Wang Ruixiang
To overcome the problem of arsenic separation and enrichment from an alkaline leaching solution in arsenic-containing dust, a CO32--type tri-n-octylmethyl-ammonium chloride (TOMAC) method for extracting thioarsenite is proposed in this paper. Considering an alkaline leaching solution as the research object, after vulcanization pretreatment, TOMAC transformation and organic phase saturated extraction capacity were measured, and the extraction mechanism was preliminarily studied. First, Cl−-type quaternary ammonium salt was effectively transformed to HCO3--type by treating organic phase with saturated NaHCO3five times. TOMAC was effectively transformed from HCO3- to CO32- type by alkaline washing with 1.0 mol/l NaOH solution; this washing was repeated thrice. Thereafter, the effects of organic phase composition, phase ratio, extraction time, and temperature on the extraction and separation of arsenic were investigated. The results show that under the conditions of 30% CO32--type TOMAC + 15% sec-octanol + 55% sulfonated kerosene, VO/VA = 1/1, and 5 min extraction at room temperature, the single-stage extraction rate of AsIII is 85.2%. The AsIII concentration in raffinate can be reduced to less than 1.33 × 10−3 mol/l by four-stage countercurrent extraction, and the extraction rate of AsIII can exceed 98.4%.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Zhili Li,Feng Rao,Shaoxian Song,Alejandro Uribe-Salas,Alejandro López-Valdivieso
Effects of common ions, namely hydroxyl ions and carbonate, on the adsorption and flotation of malachite with salicylaldoxime as a collector was investigated, making use of solubility, micro-flotation, zeta potential , contact angle, FTIR, and XPS measurements. The results suggested that hydroxyl and carbonate ions affect malachite recovery through altering solubility of this mineral. Under conditions of lower solubility, more stable copper atoms acted as adsorption sites for retaining salicylaldoxime on the malachite surface, and the collector consumed by copper species in slurry was reduced. This allowed more collectors to get adsorbed onto malachite surface, resulting in improved malachite recovery. Zeta potential, FTIR, and XPS measurements indicated that salicylaldoxime chemically adsorbs onto malachite by forming copper salicylaldoxime chelates, in which two salicylaldoxime molecules react with one copper atom by N atom and the O atom combined with benzene ring .
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）