SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Jieli Peng,Yongxing Zheng,Zhenxing Wang,Zhe Dai,Ziqi Guo
In this study, an innovative method was proposed to treat ilmenite by using sodium persulfate (Na 2 S 2 O 8 ) as a surface activator to enhance the flotation of ilmenite. The action mechanism of Na 2 S 2 O 8 on the ilmenite surface was investigated by micro-flotation, adsorption tests, powder contact angle, zeta potential detection, Fourier transform infrared spectroscopy (FT-IR) analysis and X-ray photoelectron spectroscopy (XPS) analysis. Micro-flotation experiments showed that recovery of the ilmenite was effectively enhanced in the pH range of 4.0 ∼ 10.0 by adding Na 2 S 2 O 8 . The adsorption tests illustrated that the introduction of Na 2 S 2 O 8 effectively enhanced the adsorption of NaOL on the surface of ilmenite. The powder contact angle tests presented that the contact angle of samples increased after treatment with Na 2 S 2 O 8 and NaOL. The zeta potential testing results showed that surface potential of the ilmenite treated with Na 2 S 2 O 8 and NaOL was negatively migrated in the pH ranging from 3.5 to 10.0, revealing that the mineral surface adsorbed more oleic acid anions. FT-IR analyses suggested that the chemical adsorption of oleic acid on the surface of ilmenite was enhanced after treating with Na 2 S 2 O 8 . XPS analyses revealed that the addition of Na 2 S 2 O 8 induced a transformation of Fe (+Ⅱ) into Fe (+Ⅲ) and enhanced adsorption of NaOL on the ilmenite surface. A reaction model of Na 2 S 2 O 8 interacting with the surface of ilmenite was proposed to interpret the activation mechanisms.
研究领域:
矿物加工工程
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化学工程
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材料科学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 17
·10394-10407
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IF 3.945
Jing Xiao,Cong Wang,Bai-Qi Feng,Tian-Yu Liu,Shao-Yi Jia,Hai-Tao Ren,Yong Liu,Song-Hai Wu,Xu Han
Although synthesis of oligoaniline (OANI) by persulfate and aniline has been investigated in the recent years, the impact of phenol on the synthesized soluble OANI is still not clear. In this study, our results indicate that phenol and pH mediate the production of the blue water-soluble OANI (OANIblue) in the reaction between sodium persulfate (SPS) and aniline under alkaline conditions, and the yields of OANIblue increase with increasing concentrations of phenol and pH values. Quenching experiments rule out the contributions of SO4˙− and ˙OH to aniline oxidation and imply that the non-radical activation of SPS is an important pathway in the formation of OANIblue. MALDI-TOF-MS analysis indicates that phenol apparently inhibits the polymerization degree of aniline in that the molecular weights of OANIblue gradually decrease from 1586.4 to 684.6 when phenol is increased from 0 to 2.0 mM. FTIR and Raman analyses confirm the structure of aniline oligomers in OANIblue and indicate that phenol inhibits the phenazine-like structure in OANIblue and facilitates the transformation of benzenoid rings to quinoid rings in the oxidation products. However, simultaneous activation of SPS by phenol and aniline is likely to occur in the reaction system with the formation of PhNH˙, as indicated by DFT calculations. The high scavenging reactivity of phenol towards both PhNH2˙+ and PhNH˙ implies that PhNH2˙+ and PhNH˙ are not the intermediates in the formation of OANIblue. DFT calculations also reveal that apart from the one-electron transfer pathway between aniline and SPS, the two-electron transfer pathway is also likely to occur in the presence of phenol, resulting in the formation of PhNH+/PhN˙˙ without producing PhNH2˙+ and PhNH˙. The produced PhNH+/PhN˙˙ intermediates then couple with aniline, PhNH+, aminophenyl sulfate and its hydrolysate to form dimers, trimers, oligomers, and eventually OANIblue. This study not only describes a novel method to prepare water-soluble OANI, but also gives new insight on the importance of phenol in the production of OANIblue.
研究领域:
化学
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材料科学
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DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2021
·Vol. 132
·期 2
·1211-1224
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IF 2.081
Zhang Long,Ge Jianhua,Zhuang Tao,Ding Xiulong,Zheng Xuyang
A series of novel sodium persulfate (Na 2 S 2 O 8 ) modified g-C 3 N 4 photocatalysts were prepared in this study to enhance nitrogen fixation. Characterization results found that the type of precursors and the mass ratio affect the crystal structure, morphology, and optical properties of the modified g-C 3 N 4 . The photocatalysts exhibited considerable nitrogen vacancies (N Vs ) depending on the nature of the different precursors and their mass ratios to Na 2 S 2 O 8 . In addition, the production rate of ammonia of the modified g-C 3 N 4 was significantly higher than that of pure g-C 3 N 4 under optimal conditions. The four cycles show modified g-C 3 N 4 excellent stability. Combined with the results of pH test, the possible mechanism of the photocatalytic nitrogen fixation process using modified g-C 3 N 4 was proposed.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2024
·Vol. 25
·期 23
·12542
·
IF 4.9
Yun Ma,Hui Liu,Liuli Zhu,Yi Xie,Chuanqi Ren,Xiaorong Mo,Xiaoying Liu,Chen Liang,Gang Deng,Shuangquan Yao,Chengrong Qin
The thermal washing of oily sludge using sodium persulfate (SD) assisted by sodium lignosulfonate surfactant has been demonstrated to be an effective method for oily sludge remediation. To further explore the underlying mechanisms of this process, a systematic study was conducted by simulating oily sludge systems consisting of saturated hydrocarbons (SaH), aromatics hydrocarbons (ArH), resins (Res), and asphaltenes (Asp). The effects of reaction conditions, such as pH, sodium lignosulfonate alkyl (LSA) concentration, SD concentration, and washing temperature, were analyzed. Furthermore, the oxidative kinetic mechanism during the reaction process was investigated. The results demonstrated that neither petroleum hydrocarbons nor SD underwent significant chemical transformations when exposed to LSA, while SD exhibited a marked oxidative degradation effect on all four types of hydrocarbons. Oxidation kinetics indicated that sodium hydroxide played a catalytic role, with SD being the main oxidant and particularly efficient in degrading Asp and Res. Meanwhile, LSA contributed to the removal of hydrocarbons by reducing the surface tension of the solution, enhancing solubilization. This study not only elucidates the central role of SD in the thermal washing process but also provides a solid theoretical foundation for the practical application of this technology in oily sludge treatment.
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
Journal of Environmental Chemical Engineering
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2022
·
IF 7.968
Liangzhu Pan,Xiaoping Zhang,Songwen He,Guichang Zhang,Wei Xu
Gold is one of the most fascinating resources in the waste mobile phones’ printed circuit boards (WMPPCBs). In this study, a new process for recovering Au from WMPPCBs by the Na 2 S 2 O 8 -KI system was developed. This process comprises a two-stage leaching process to provide a separation of copper and gold from WMPPCBs. 98% Cu and 78% Fe were dissolved by the 1st base metals' leaching (H 2 SO 4 -H 2 O 2 leaching) step. The leaching of gold from the solid reside of 2nd leaching step was performed to study the effect of Na 2 S 2 O 8 concentration, KI concentration, temperature, and solid-liquid ratio in Na 2 S 2 O 8 -KI leaching system. The results showed that removing most of Cu greatly promoted the leaching efficiency of gold in Na 2 S 2 O 8 -KI leaching system. The mechanism of gold leaching was studied by the thermodynamic analysis. Leaching kinetics data showed that gold leaching followed an intermediate-controlled mechanism with E a , 30.3 kJ mol −1 . The best conditions for leaching of gold in Na 2 S 2 O 8 -KI system were determined to be 0.02 M Na 2 S 2 O 8 , 0.15 M KI, 40 ℃, a solid-liquid ratio of 1: 20 (g/mL), and a stirring speed of 200 rpm. Under the optimal leaching parameters, the efficiency of gold leaching from WMPPCBs attained 96% after 120 min. Due to the non-toxic and low-cost properties of Na 2 S 2 O 8 , the Na 2 S 2 O 8 -KI leaching process is more sustainable than conventional processes (cyanide leaching et al.).
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
Catalysts
·
2019
·Vol. 9
·期 3
·280
·
IF 3.444
Ruijia Lan,Wenbin Su,Jitai Li
A classic carbon material—expanded graphite (EG), was prepared and proposed for a new application as catalysts for activating peroxydisulfate (PDS). EG samples prepared at different expansion temperatures were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and other methods. It was observed that there existed a remarkable synergistic effect in the EG/PDS combined system to degrade Acid Red 97 (AR97). Unlike other carbon material catalysts, sp2carbon structure may be the main active site in the catalytic reaction. The EG sample treated at 600 °C demonstrated the best catalytic activity for the activation of PDS. Degradation efficiency of AR97 increased with raising PDS dosage and EG loadings. The pH of aqueous solution played an important role in degradation and adsorption, and near-neutrality was the optimal pH in this research. It was assumed that the radical pathway played a dominant role in AR97 degradation and that oxidation of AR97 occurred in the pores and interface layer on the external surface of EG by SO4·−and ·OH, generated on or near the surface of EG. The radical oxidation mechanism was further confirmed by electron paramagnetic resonance spectroscopy. The EG sample could be regenerated by annealing, and the catalytic ability was almost fully recovered.Keywords:sodium peroxydisulfate;expanded graphite;mechanism;degradation;acid red 97
研究领域:
环境科学
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催化化学
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DOI
高影响因子
CHEMOSPHERE
·
2020
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IF 5.778
Junliang Wang,Weicheng Zheng,Yuqing Zhang,Shuang Song,I-Ming Chou,Mian Hu,Zhiyan Pan
Degradation of phenol by sodium persulfate (SPS) in hot compressed water (HCW) was investigated in a lab-built fused quartz tube reactor (FQTR) coupled with Raman spectroscopy system. The species of S 2 O 8 2− , SO 4 2− , HSO 4 − , SO 3 2− and HSO 3 − in the reaction system were qualitatively and quantitatively analyzed by Raman spectroscopy. The hydrothermal stability of phenol and SPS at different temperature and the degradation of phenol by SPS were also studied. The results indicated that phenol was not stable in aqueous solution above 200 °C, and that only SO 4 2− was generated in the hydrolysis of SPS at temperatures below 50 °C, and SO 4 2− and HSO 4 − were generated at higher temperatures. The maximum conversion rate (90.93%) and mineralization efficiency (38.88%) of phenol by SPS was obtained at reaction temperature of 300 °C with 180 min reaction time. During the degradation of phenol by SPS, HSO 4 − was the main product and S∗ (not detected by Raman spectroscopy) exhibits a positive correlation with temperature. In addition, a degradation pathway of phenol by SPS was proposed. The degradation data for the kinetic analysis indicated that the reaction followed pseudo first-order kinetics, and the reaction rate constants ( k s ) were given as k 50 °C = 0.0083 min −1 , k 100 °C = 0.0197 min −1 , k 200 °C = 0.0498 min −1 , k 300 °C = 0.0619 min −1 and k 400 °C = 0.0505 min −1 at 30 min reaction. Moreover, the activation energy (12.580 kJ mol −1 ), the enthalpy change (9.064 kJ mol −1 ) and the entropy change (−222.104 J mol −1 ) of the reaction were also calculated.
研究领域:
环境科学
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化学工程
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光谱学
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DOI
PubMed
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2022
·Vol. 85
·期 6
·1813-1823
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IF 2.43
Zhong Dan,He Fu,Ma Wencheng,Wu Yichuan,Dong Jiaju
In this study, we investigated using the main composition of pipe deposits from water distribution networks as catalyst to activate dual-oxidant H 2 O 2 /Na 2 S 2 O 8 system to produce radicals for perchloroethylene and chloramphenicol removal. According to the results, the degradation efficiency of perchloroethylene by H 2 O 2 /Na 2 S 2 O 8 system was 92.05% within 8 h. Due to the slow conversion between ≡Fe 3+ and ≡Fe 2+ , the hydroxylamine was introduced to reduce reaction time. As for the results, the degradation efficiency of chloramphenicol in the H 2 O 2 /Na 2 S 2 O 8 system with hydroxylamine assistance was 73.31% within 100 min. Meanwhile, several key affecting factors and the kinetic models were investigated. The primary radicals were identified by electron paramagnetic resonance and radical scavenging tests. Eleven degradation products were confirmed by high-resolution liquid chromatography-mass spectrometry. The result of this study provided the theoretical basis for resource utilization of pipe deposits in water treatment in case of emerging contamination events.
研究领域:
环境科学
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水处理
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材料化学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Zihao Hu,Beiyang Guo,Huiqi Wu,Fang Zhu,Sridhar Komarneni,Jianfeng Ma
In this paper, MIL-101(Fe) and MoS 2 composites (MIL-101(Fe)/MoS 2 ) were synthesized using a facile solvothermal method . As a new degradation system, the synthesized composites were investigated using persulfate (PS) activation based on visible light (Vis). To establish the superiority of a heterogeneous photochemical catalysis system, the MIL-101(Fe)/MoS 2 was used as the catalyst in the presence of Na 2 S 2 O 8 with visible light irradiation. In the system mentioned, the MIL-101(Fe)/MoS 2 catalyst presented a much better catalytic ability than that of either a single photocatalysis or chemocatalysis system. The better catalytic ability suggests that the MIL-101(Fe)/MoS 2 catalyst was capable of effectively integrating photocatalysis and chemocatalysis leading to the highest degradation efficiency of 85% in 40 min with tetracycline as the target pollutant. The catalytic system MIL-101(Fe)/MoS 2 /PS/Vis degraded TC pollutant by forming species of O 2 ‾, 1 O 2 , hydroxyl radicals (•OH) and sulfate radicals (•SO 4 ‾) to degrade TC. Furthermore, the MIL-101(Fe)/MoS 2 catalyst displayed better catalytic performance compared to those materials that were previously reported, as verified by the good stability (reached 80% after three cycles) and the high TC degradation rate (85%) of the currently developed material. This system may be applicable to the degradation of TC and other challenging organic pollutants .
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Engineering
·
2022
·
IF 12.834
Wei Miao,Yijie Wang,Ying Liu,Hehe Qin,Chengcheng Chu,Shun Mao
In-situ photocatalytic H 2 O 2 production has been receiving increasing attention in recent years for sustainable H 2 O 2 synthesis. Graphitic carbon nitride (g-C 3 N 4 ) is regarded as one of the most promising semiconductor photocatalysts for H 2 O 2 evolution. Introducing N defects in g-C 3 N 4 has been proved to be an effective strategy to enhance photocatalytic activity. However, the photocatalytic mechanism of the N vacancies is ambiguous and different types of N vacancies in g-C 3 N 4 may exhibit different effects on photocatalytic activity. Herein, we develop a facile sodium persulfate eutectic polymerization method to prepare the g-C 3 N 4 with abundant three coordinate nitrogen (N3 C ) vacancies. This type of nitrogen vacancy has not been studied in g-C 3 N 4 for photocatalytic H 2 O 2 production. Our results show that the introduction of N3 C vacancies in the g-C 3 N 4 successfully broadens the light absorption range, and inhibits the photoexcited charge recombination with enhanced O 2 adsorption to promote oxygen activation. The photocatalytic H 2 O 2 evolution from the N3 C -rich g-C 3 N 4 is 4.5 times higher than that of the pristine g-C 3 N 4 . This study demonstrates a novel strategy to introduce N3 C vacancies in g-C 3 N 4 , which offers a new method to develop active catalysts for photocatalytic H 2 O 2 evolution.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2023
·Vol. 234
·期 9
·1-12
·
IF 2.9
Liu Zhanmeng,Wang Min
The removal of cyanide complexes in an actually contaminated soil (pollution level 930 mg CN/kg soil) by sulfate radical (SO 4 •– )-based advanced oxidation processes (SR-AOPs) was investigated in tube and column tests. Experimental parameters including soil/water ratio, sodium persulfate (SP) dosage, Fe 2+ /tartaric acid/SP mole ratio, and reaction time were optimized in the tube test. The column-scale experiment shows that the addition of SP solution at the bottom and middle of the column was more effective than injecting one slug from the column bottom. Experimental results show that more than 98% of total cyanide (TCN) was removed in the soil within 4 h, and the quality of the remediated soil can meet the requirement of construction land. SP dosage of the column experiments is 23.6% higher than that of the tube tests, but no soil-water separation was needed for the column treatment. The soil corrosivity to building materials was only slightly modified by the oxidation treatment, and the numbers of indigenous microbes may quickly restore after nutrient stimulation. Overall, the results underline the significance and the potential of iron chelate-activated SR-AOPs in the remediation of highly contaminated soils by the column oxidation.
研究领域:
环境科学
·
土壤学
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产品关联
DOI
高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2025
·Vol. 114
·期 3
·1-6
·
IF 2.2
Huang Zaoquan,Li Xiaoyuan,Hou Siying,Zhao Yanjie,Lu Haijian,Wang Jun,Deng Yirong
To enhance phenanthrene degradation in soil, the effects of four surfactants on the thermal activation of sodium persulfate (SPS) were investigated. Sodium dodecyl diphenyl ether disulfonate (C 12 -MADS) was found to stabilize SPS by reducing the generation of sulfate radicals from its thermal decomposition. Optimal conditions for the surfactant-assisted persulfate system were determined to be 5 g/L of C 12 -MADS at a temperature of 60°C, achieving an 89.80% removal efficiency of phenanthrene in soil. The presence of OH − increased the system pH and decreased the removal efficiency. These results demonstrate that C 12 -MADS significantly enhanced the oxidation of phenanthrene and improves SPS utilization efficiency, contributing to the development of an effective surfactant-assisted persulfate system for soil decontamination.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
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