WATER AIR AND SOIL POLLUTION
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2024
·Vol. 235
·期 1
·1-15
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IF 3.8
Wang Tingting,Zhang Lucheng,Zhang Mingqing,Yang Fang,Wu Shilong
The widespread use of cyanidation in gold beneficiation leads to a large amount of SCN − in the gold extract tail solution, which poses a threat to the environment and human health. The present study successfully synthesized octadecyltrimethylammonium bromide/bentonite/titanium dioxide (OTAB/Bt/TiO 2 ) photocatalysts through a sol–gel hydrothermal approach. Evaluation of the BET specific surface area, X-ray diffraction (XRD) analysis, UV–vis diffuse reflectance spectroscopy, and zeta potential experiments unveiled the beneficial impact of incorporating OTAB. This inclusion led to an enlargement of the pore size and layer spacing of Bt, broadening the range of photoresponses. Additionally, it effectively neutralized the negative charge residing on the surface of Bt. Consequently, these enhancements contributed to the improved performance of the photocatalytic material in terms of adsorption and catalytic degradation of SCN − . The degradation rate of SCN − reached 98.78% under the reaction conditions of initial SCN − concentration of 50 mg/L, OTAB/Bt/TiO 2 dosage of 0.8 g/L, pH = 8, and reaction time of 300 min. The degradation of the SCN − composite through the OTAB/Bt/TiO 2 photocatalytic process followed a zero-order kinetic model with a calculated rate constant ( k value) of 0.1148 min −1 . Notably, this rate constant was 1.9 times greater than the degradation rate observed in the pure TiO 2 system. The free radical quenching test showed that h + , ∙OH and ∙O 2− were the main oxidizing substances for photocatalytic degradation. The identification of intermediates proved that the complete mineralization of SCN − could be achieved by OTAB/Bt/TiO 2 adsorption and photocatalytic degradation without generating the highly toxic intermediate CN − . Overall, this study provides guidance for the development of more photocatalysts with strong adsorption properties and more effective removal of SCN − from gold extraction tailings.
研究领域:
环境科学
·
材料工程
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2021
·Vol. 16
·期 7
·1101-1113
·
IF 4.204
Jia Han,Dai Jiajun,Wang Tingyi,Xu Yingbiao,Zhang Lingyu,Wang Jianan,Song Lin,Lv Kaihe,Liu Dexin,Huang Pan
Nanoparticles with high surface energy and chemical activity have drawn substantial attention in petroleum industry. Recently, Janus nanoparticles exhibited tremendous potential in enhanced oil recovery (EOR) due to their asymmetric structures and properties. In this study, a series of amphiphilic pseudo-Janus@OTAB (PJ@C18) nanoparticles with different concentrations of stearyltrimethylammoium bromide (OTAB) were successfully fabricated. The structures and properties of PJ@C18 were characterized by Fourier transform infrared spectroscopy and ζ-potential measurements. Based on the emulsification experimental results, the interaction models and the self-assembly behavior between hydrophilic nanoparticles (SiO 2 @NH 2 ) and OTAB molecules at the oil/water interface were proposed, which was further confirmed via the measurements of the contact angle and dynamic interfacial tension. Interestingly, it was found that the change of pH value from 7.5 to 4.0 caused the type reversal of the PJ@C18-1000 stabilized Pickering emulsions. Furthermore, the PJ@C18-1000 stabilized Pickering emulsion system with excellent salt and temperature tolerances (10000 mg·L −1 , 90 °C) significantly improved the oil recovery in the single-tube (more than 17%) and double-tube (more than 25%) sand pack model flooding tests. The findings of this study could help to better understand the construction mechanism of pseudo-Janus silica/surfactant assembly and the potential application of PJ@C18-1000 stabilized Pickering emulsions for EOR.
研究领域:
石油工程
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材料科学
·
界面化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2024
·
IF 8
Zhiying Li,Lei Zhao,Qing Ao,Ge Zhang,Dongqing Kang,Yingli Li,Jian Liu,Gongtao Ding,Zhongren Ma,Yeit Haan Teow,Mohd Shaiful Sajab,Zhiqiang Li,Zifan Wang
Studying the adsorption behavior of cationic surfactants can help to develop more effective strategies to limit their dispersion in the environment. However, there have few studies on the adsorption of cationic surfactants from the perspective of critical micelle concentration (CMC). In this study, with cetyltrimethylammonium bromide (CTAB) and octadecyl trimethylammonium bromide (OTAB) serving as the model cationic surfactants, the effect of CMC on the adsorption behavior of cationic surfactant onto the surface of sodium alginate/silica (SA/SiO 2 ) microspheres was systematically revealed. The adsorption mechanism relative to CMC was investigated under different conditions, including surfactant concentration, pH, temperature, and adsorption time. The results suggest that at identical concentrations, the smaller the CMC value of the cationic surfactants, the greater the adsorption amount (q t ). q t for CTAB and OTAB were 583.2 and 678.0 mg/g respectively, with the concentration higher than their CMC value. When the concentration was lower than the CMC value of the cationic surfactants, q t for CTAB and OTAB were 123.2 and 138.7 mg/g, respectively. The CMC value of CTAB was lower than that of OTAB under identical conditions, suggesting that the adsorption of cationic surfactants is related to their CMC. These results are beneficial for the removal of cationic surfactants by adsorption methods.
研究领域:
环境科学
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Jiale Huang,Dengpo Huang,Yi Liu,Huimei Chen,Xiaolian Jing,Daohua Sun,Qingbiao Li
Gold recovery is of practical significance while functional Au nanostructures are of great interest in modern nanotechnology. In this work, highly and hierarchically branched Au nanowires (AuNWs) were produced to obtain bio-AuNW composites while the Au was effectively recovered from aqueous HAuCl 4 solution by a microorganism-mediated, surfactant-directed (MSD) approach with Lactobacillus spp. cells (LSCs). Ternary coordination of the cell-surfactant-AA played an important role in recovering Au and producing the bio-AuNW composites in the cases of tetradecyl trimethyl ammonium bromide (TTAB), hexadecyltrimethylammonium bromide (CTAB) and octadecyl trimethyl ammonium bromide (OTAB). In contrast, Au recovery could not be achieved with hexadecyltrimethylammonium chloride (CTAC). Strong interaction between [AuCl 4 ] − and the LSCs prior to addition of surfactant (except CTAC) and ascorbic acid (AA) was vital for the highly and hierarchically branched nanostructures. Furthermore, the bio-AuNW composites could serve as excellent surface-enhanced Raman spectroscopy (SERS) substrate. the SERS detection limits of toxic rhodamine 6G (R6G) and 4-mercaptobenzoic acid (MBA) with the bio-AuNW composites are down to 10 −9 and 10 −6 M, respectively. This work therefore exemplifies combining recovery of Au and fabrication of functional Au nanomaterials, which was environmentally benign and application-oriented.
研究领域:
环境科学
·
纳米技术
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材料科学
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生物技术
✓ 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）