SCIENCE OF THE TOTAL ENVIRONMENT
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2021
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IF 7.963
Wenpei Wu,Lu Han,Xiang Nie,Mingyue Gu,Jing Li,Mengfang Chen
The multiple injections of nanoscale zero valent iron (nZVI) slurry, an efficient method to remediate contaminated groundwater, requires an accurate assessment of the transport and risks of these particles in saturated porous medium . However, the influencing mechanism of nZVI transport under multiple injection conditions is not fully understood. In this experimental study, one-dimensional sand columns were used to evaluate the effects of injection concentrations, particle sizes and surface chemical corrosion on the transport of carboxymethyl cellulose modified nZVI (CMC-nZVI) under triple injection conditions, where the different volumes of NaCl solution were flushed through the columns between the injections. Based on the breakthrough curves and retention profiles under flushing 4 pore volumes of NaCl solution between the injections, the transport of CMC-nZVI particles was gradually enhanced attributable to the exclusion among these particles at injection concentration of 200 mg/L, but the opposite was observed due to large aggregation caused by strong magnetic force among particles at 500 mg/L. However, the magnitudes of enhancement or reduction on maximum C/C 0 under the above injection concentrations were related to the smallest particle size of D h = 3.926 μm because of high particle number concentrations leading to intense competition on depositional sites at 200 mg/L and significant aggregation at 500 mg/L. Conversely, the transport of CMC-nZVI was reduced under flushing 76 pore volumes of NaCl solution between the injections because of pronounced corrosion of CMC-nZVI in water as evidenced by the XPS and XRD analyses of particles. This corrosion could cause the decrease in repulsion among particles due to the increase in surface negative zeta potential and the CMC desorption from nZVI. Accordingly, this study revealed that relative high injection concentrations and chemical corrosion in groundwater could restrain the mobility of nZVI under multiple injection conditions and the potential risks posed by CMC-nZVI are controllable.
研究领域:
环境科学
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地下水修复
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
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2017
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IF 3.091
Weipeng Yang,Tengfei Wang,Zexia Fan
Foam stabilized by particles has been applied in enhanced oil recovery (EOR). However, many difficulties in establishing a foam system with high stability, foamability, and resistance to harsh conditions still exist. In this study, foam stabilized by hydrophobic modified alumina nanoparticles was systematically studied. Sodium cumenesulfonate (SC) was used to modify nanoparticles and generate foam. A competitive effect between nanoparticles and SC was found. Specifically, foam stability increased with SC concentration at lower SC concentration range. Foam with high stability and relatively high foamability was obtained at an SC concentration of 20 mM, and then, foam stability sharply decreased because of the competitive effect. The presence of an electrolyte slowed down the adsorption of SC at the air–water interface by forming an ion pair between the headgroup of SC and the cation, which influences foamability and stability. Meanwhile, the electrolyte also caused detachment of particles from foam due to the decrease of hydrophobicity as a result of the decreased SC adsorption. Despite these effects, the particle-stabilized foam maintained high stability in a wide range of electrolyte concentrations. Sandpack flooding experiments showed that the oil recovery rate increased with SC concentration because of the enhanced foamability and stability, leading to a higher displacement efficiency and water flush resistance.
研究领域:
石油工程
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胶体科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2022
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IF 6.633
Fei Wang,Jiuyan Chen,Yanxiang Li,Taotao Lu,Weifeng Chen,Zhichong Qi,Xinhai Wang,Usman Farooq
Tetracyclines (TCs), a class of antibiotics that are most widely used veterinary and human medicine, possessed an ability to produce irreversible damage towards humans and environment. Antibiotics transport and deposition are critical processes in their environmental fate. In this study, the mobility properties of various TCs such as oxytetracycline (OTC), chlortetracycline (CTC) and tetracycline (TC), in quartz sand columns with sodium dodecylsulfate (SDS), a typical anionic surface-active agent over the pH array of 5.0∼9.0 were investigated. The mobility of TCs through the column was in the order: OTC > TC > CTC. The difference in the molecular structures of various TC antibiotics could explain the trend. Interestingly, SDS enhanced TC transport via deposition site competition between surfactant and TC molecules, increased electrostatic interaction, and steric hindrance. SDS, on the other hand, inhibited OTC and CTC mobility primarily owing to the strong aquaphobic collaboration between antibiotics and the absorbed surfactant on the sand surface (i.e., SDS molecules as bridge agents between antibiotics and sand grains). Furthermore, at higher pH conditions (5.0∼9.0), the enhanced or inhibitory effect of surfactant on the mobility of TCs declined. The observed decrease in the steric hindrance effect, competitive deposition, or hydrophobic interaction was attributed to the decreased deposition of SDS. Innovative information obtained from this work provides insight into the important role of an anionic surfactant on the mobility and deposition of various tetracycline antibiotics in aquifers.
研究领域:
环境科学
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化学
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药学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2025
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IF 7.2
Kangping Huang,Tianwen Zheng,Xinyue Li,Ziyin Yang,Ruoxi Li,Yizhou Liu,Naijin Wu,Moxi Wang,Liqin Zhi,Huilong Luo,Wenxia Wei,Peizhong Li,Xiao Zhang,Heming Wang
β-cyclodextrin (βCD) can significantly improve the reactivity and long-term remediation performance of nano-zero-valent iron (nZVI), but the stability of composite and the migration performance in porous media have been less studied. In this study, a kind of βCD interface-modified iron-carbon composite (BC-nZVI@βCD) was synthesized, the Zeta potential measurements and sedimentation experiments were conducted to study the stability of materials. Afterwards, the migration behavior of BC-nZVI@βCD in porous media was explored by one-dimensional (1D) sand column experiments and a novel two-dimensional (2D) sand tank simulating the groundwater state. Specifically, in 1D sand column experiments, the primary focus was on investigating the relative effluent concentration ( C/C 0 ) and its distribution patterns within the sand column. In 2D sand tank experiment, the ERT technique was utilized to precisely and real-time monitor the migration behavior of the composite through changes in resistivity. The results showed that the suspensions of BC-nZVI@βCD had the best stability and slowest settling rate. 1D sand column migration experiments showed that the mobility of BC-nZVI@βCD was greatly enhanced, and C/C 0 was increased to 0.60. Moreover, the concentrations of Ca 2 + and SO 4 2- had little effect on migration performance. Humic acid (HA) promoted BC-nZVI@βCD migration at low concentrations (10 mM), while inhibited the migration at high concentrations (20 and 40 mM). In 2D sand tank, BC-nZVI@βCD also showed more excellent migration ability, with the migration distance of BC-nZVI@βCD clearly exceeded 0.40 m. Generally, this study provides a new approach for the study of stability and migration performance of iron-based materials.
研究领域:
环境科学技术
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纳米材料
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地下水修复
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胶体与界面化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
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2022
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IF 13.4
Jia Wen,Lisha Yang
Knowledge of the fate and transport of metal-organic frameworks (MOFs) in porous media is essential to understanding their environmental impacts. However, to date, the transport mechanisms of MOFs are not fully revealed. Meanwhile, surfactants can promote MOFs dispersion by forming a stable suspension. They also allow MOFs to migrate in the aqueous environment, which would increase the risks of MOFs being exposed to human health and the ecological environment. In this study, the effect of surfactants type and nanoparticle (NP) concentrations (50, 100, and 200 mg/L) were investigated using a sand column to study the transportability of ZIF-8 NPs in saturated porous media. Surfactants used were categorized into three groups, including cationic surfactants (CTAB, DTAB), anionic surfactants (SDBS, SDS), and nonionic surfactants (Tween 80, Tween 20). Experimental results showed that the ionic surfactants significantly increased the transportability of ZIF-8 NPs. Furthermore, a low concentration of NPs tended to break through the column under ionic surfactant conditions, and the maximum effluent recovery of ZIF-8 NPs (50 mg/L) was 87.4% in the presence of SDS. Nevertheless, ZIF-8 NPs tended to deposit in the inlet of the sand column in the presence of nonionic surfactants due to hydrodynamic bridging and straining. This research provides a comprehensive understanding of the deposition mechanism of ZIF-8 NPs as affected by surfactant types and NP concentrations. Most importantly, the study highlights those ionic surfactants had a significant impact on the mobility of ZIF-8 NPs, which arouses attention to the ecological and human health risk assessment related to the manufacturing of MOFs with the aid of various dispersing agents.
研究领域:
环境科学
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纳米技术
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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