ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2020
·
IF 4.872
Teng Xu,Feng Nan,Xiaofeng Jiang,Yuling Tang,Yunhang Zeng,Wenhua Zhang,Bi Shi
This work was conducted to study the effect of soil pH (4.0, 6.0, and 8.0) on the transport, fractionation, and oxidation of trivalent chromium [Cr(III)]. Variation in pH altered soil chemical and mineralogical properties such as zeta potential, cation exchange capacity and redox potential of natural soil. Breakthrough curves and batch sorption experiments coupled with fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses demonstrated that the easy mobility of Cr(III) in pH 4.0 soil was dominated by the limited coordination effect. The high retention of Cr(III) in pH 8.0 soil was mainly ascribed to the hydrolysis. Incubation experiments indicated that the proportions of Cr in exchangeable fraction decreased with increasing of soil pH and incubation time, and kinetics analysis revealed that the time dependent transformation was controlled by mass transfer and chemical processes (e.g., hydrolysis, ion association). The XPS confirmed the oxidation of Cr(III) in pH 8.0 soil during the incubation period. Furthermore, the content of toxic hexavalent chromium [Cr(VI)] was positively associated with time and initial concentration of Cr(III) released. These results revealed the hazardousness of Cr(III) in soil contaminated simultaneously by inorganic acid and alkali.
研究领域:
环境科学
·
土壤化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Yunfeng Xu,Kaili Wang,Qinghao Zhou,Liting Zhang,Guangren Qian
The ability of thiol-modified humic acids (HAs) to release arsenic in tailings soil after being modified with different sulfur-containing reagents were significantly improved. The structure and physicochemical properties of humic acid (HA) before and after thiol-modification were characterized. The 3-MPTS-HA treated with 3-mercaptopropyltrimethoxysilane (3-MPTS) effectively improved the mobility of arsenic, and its reducing ability was increased from 2 mmol g −1 to 3.54 mmol g −1 . The S content of humic acids were also significantly increased after treatment with sulfur-containing reagents, in which the oxygen-containing functional group (e.g., C = O, C–O) on the surface of HA may be the active sites for binding with sulfur-containing reagents. It was found in the XPS spectrum that because the thiol group is easily oxidized, there are many S forms in thiol-modified HA. The –SH content in Na 2 S·9H 2 O-HA, l (+)-Cysteine-HA (Cys-HA), thioglycolic acid (TGA-HA) and 3-MPTS-HA was determined by fluorescence method to be 13.9, 78.45, 90.34, and 192.29 μmol g −1 , respectively. The study demonstrated that surface thiol modification can increase the abundance of thiol in HA and enhance reactivity, which will further promote the application of HA in the treatment of heavy metal contaminated tailing soil.
研究领域:
环境科学
·
土壤学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 11
·7219-7226
·
IF 2.757
Xie Jinchuan,Lin Jianfeng,Zhou Xiaohua,Li Mei,Zhou Guoqing
Low-solubility contaminants with high affinity for colloid surfaces may form colloid-associated species. The mobile characteristics of this species are, however, ignored by the traditional sorption/distribution experiments in which colloidal species contributed to the immobile fraction of the contaminants retained on the solids as a result of centrifugation or ultrafiltration procedures. The mobility of the contaminants in subsurface environments might be underestimated accordingly. Our results show that colloidal species of 239 Pu in three-phase systems remained the highest percentages in comparison to both the dissolved species and the immobile species retained on the granite grains (solid phase), although the relative fraction of these three species depended on the colloid types. The real solid/liquid distribution coefficients ( K
s/d ) experimentally determined were generally smaller than the traditional K
s/d (i.e., the K
s+c/d in this study) by ~1,000 mL/g for the three-phase systems with the mineral colloids (granite particle, soil colloid, or kaolinite colloid). For the humic acid system, the traditional K
s/d was 140 mL/g, whereas the real K
s/d was approximately zero. The deviations from the real solid/liquid K
s/d were caused by the artificially increased immobile fraction of Pu. One has to be cautious in using K
s/d -based transport models to predict the fate and transport of Pu in the environment.
研究领域:
环境科学
·
放射生物学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Shiyan Sun,Yunxuan Weng,Yu Han,Caili Zhang
Polylactic acid (PLA), a biodegradable polymer with low flexibility, is commonly plasticized with small molecules like tributyl citrate (TBC) for film production. However, these plasticizers, which lack chemical bonds or strong intermolecular interactions with the matrix, tend to migrate to the film surface over time. Their inclusion often compromises material strength for flexibility, increasing elongation at break but reducing tensile strength. In this research, by combining citric acid with n-butanol (B) and poly(ethylene glycol) diglycidyl ether (E), we synthesized three plasticizers, namely TE 3 , TE 2 B 1 , and TE 1 B 2 , to enhance the flexibility of PLA. TE 2 B 1 and TE 1 B 2 are equipped with butyl ester groups that offer effective plasticizing effects. Additionally, the incorporation of long-chain alkyl featuring epoxy groups can boost the interaction with PLA. The results showed that the epoxy groups of the long-chain alkyl plasticizers can improve the elongation at break without compromising tensile strength significantly. The migration of plasticizer from PLA matrix can be reduced by strong interactions like chemical bonds, entanglements, and hydrogen bonding with PLA. TE 1 B 2 demonstrated the best plasticizing effect. Adding 15 portions of TE1B2 and TBC separately increased PLA's elongation at break to 304 % and 242 %, with tensile strengths of 36.1 MPa and 22.3 MPa, respectively.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Xin Wang,Shengyan Pu,Jiaqi Ding,Jing Chen,Peng Liao,Delai Zhong,Daniel C. W. Tsang,John C. Crittenden,Linling Wang
Clay minerals are ubiquitous in subsurface environments and have long been recognized as having a limited or negligible impact on the fate of arsenic (As) due to their negatively charged surfaces. Here, we demonstrate the significant role of kaolinite (Kln), a pervasive clay mineral, in enhancing As(V) immobilization during ferrous iron (Fe(II)) oxidation at near-neutral pH. Our results showed that Fe(II) oxidation alone was not capable of immobilizing As(V) at relatively low Fe/As molar ratios (≤2) due to the generation of Fe(III)–As(V) nanocolloids that could still migrate easily as truly dissolved As did. In the presence of kaolinite, dissolved As(V) was significantly immobilized on the kaolinite surfaces via forming Kln–Fe(III)–As(V) ternary precipitates, which had large sizes (at micrometer levels) to reduce the As mobility. The kaolinite-induced heterogeneous pathways for As(V) immobilization involved Fe(II) adsorption, heterogeneous oxidation of adsorbed Fe(II), and finally heterogeneous nucleation/precipitation of Fe(III)–As(V) phases on the edge surfaces of kaolinite. The surface precipitates were mixtures of amorphous basic Fe(III)–arsenate and As-rich hydrous ferric oxide. Our findings provide new insights into the role of clay minerals in As transformation, which is significant for the fate of As in natural and engineered systems.
研究领域:
环境科学
·
土壤化学
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产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Zhiyong Wang,Baotao Huang,Xinchao Li,Yi Pan,Zhaohui Zheng,Jinni Deng
Because of low surface energy, silicone polymers would easily peel off from polypropylene (PP) substrate as hydrophobic coatings and they are incompatible with PP in melt-blending process as well. Therefore, ethylene polymers modified with both silicone and alkane side-groups were prepared by nucleophilic substitution in this work. It was confirmed that these prepared polymers could migrate and aggregate to the surface of the blends at that melting temperature when blended with PP due to the low surface energy and high entropy of silicone side groups. Meanwhile, chain entanglement was achieved between alky side-groups of silicone polymers and polymer chain of PP by melt-blending process, so that the compatibility of the blends was improved and the bonding force of two polymers increased simultaneously. Accordingly, molding blends with stable and durable hydrophobility were successfully gained based on migration of silicone and entanglement of alkane and PP. It’s noticeable that the water contact angle of the blend remained to be about 106° from 113°, even soaking in acid (pH = 1) and alkali (pH = 14) solutions, deionized water and anhydrous ethanol, or under multiple strong frictions. This will provide a facile and effective strategy to endow general materials with durable antifouling properties directly by injection molding without additional coating.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Fei Wang,Jingyi Shang,Qiang Zhang,Taotao Lu,Yanxiang Li,Xinhai Wang,Usman Farooq,Zhichong Qi
This study aims to understand how surfactants affect the mobility of tetracycline (TC), an antibiotic, through different aquifer media. Two anionic and cationic surfactants, sodium dodecylbenzene sulfonate (SDBS) and cetyltrimethyl ammonium bromide (CTAB), were used to study their influence on TC mobility through clean sand and humic acid (HA)-coated sand. HA coating inhibits TC mobility due to its strong interaction with TC. Both surfactants promoted TC mobility at pH 7.0 due to competitive deposition, steric effect, and increased hydrophilicity of TC. CTAB had a more substantial effect than SDBS, related to the surfactants' molecular properties. Each surfactant's promotion effects were greater in HA-coated sand than in quartz sand due to differences in surfactant retention. CTAB inhibited TC transport at pH 9.0 due to its significant hydrophobicity effect. Furthermore, in the presence of Ca 2+ , SDBS enhanced TC transport by forming deposited SDBS-Ca 2+ -TC complexes. On the other hand, CTAB increased TC mobility due to its inhibition of cation bridging between TC and porous media. The findings highlight surfactants' crucial role in influencing the environmental behaviors of tetracycline antibiotics in varied aquifers.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2022
·Vol. 29
·期 53
·80693-80704
·
IF 5.19
Wei Qiqi,Chen Jiuyan,Zhang Qiang,Lu Taotao,Farooq Usman,Chen Weifeng,Qi Zhichong
Colloid-mediated contaminant mobility is absolutely critical for the environmental behavior of contaminants such as antibiotics in water resources. In this study, the influences of phosphate (a commonly inorganic ligand in the environment) on the ferrihydrite colloid-mediated transport of tetracycline (TC, a typical antibiotic) in porous media were investigated. In the absence of colloids, phosphate promoted TC mobility due to the competitive deposition of phosphate and TC on the sand surface as well as the electrostatic repulsion. Interestingly, ferrihydrite colloids could inhibit TC transport; however, the inhibitory effect of the colloids was weakened by the addition of phosphate. This phenomenon stemmed from colloid-associated TC mobility, the increased electrostatic repulsion induced by adsorbed phosphate, and deposition site competition effect. Another interesting finding was that the impacts of phosphate on the colloid-mediated mobility of TC were pH-dependent. That is, phosphate exhibited a weaker effect on the inhibitory role of ferrihydrite colloids in TC mobility at pH 5.0 than that at pH 7.0; specially, ferrihydrite colloids acted as possible carriers of TC and facilitated antibiotic transport at pH 9.0. The observations were ascribed to different influences of phosphate on the binding affinity of ferrihydrite toward TC and the mobility of free TC under different pH conditions. Therefore, the findings of this study provide useful information about the fate and co-transport of antibiotics and natural mineral colloids in the presence of inorganic ligands in the aquatic environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Tong Luo,Ji Qi,Juan Yu,Chunpeng Wang,Fuxiang Chu,Jifu Wang
Hydrophobic conductive gels have attracted much attention in underwater sensing as the soft robots and wearable sensors. Among the various methods for preparing conductive gels, UV-initiated polymerization shows advantages of rapid curing and significant energy savings. However, traditional commonly used photoinitiators in UV-initiated polymerization often migrate or diffuse within conductive gels, especially with prolonged use or underwater, posing potential environmental and health risks. Herein, a novel lignin-based macromolecular photoinitiator (L-BF) is first designed by incorporating benzoylformate into the lignin backbone, demonstrating excellent UV absorption, high radical initiation efficiency, and hydrophobicity. Subsequently, hydrophobic eutectogels (HEG) are prepared via UV-initiated polymerization using L-BF as photoinitiator. The HEG shows excellent mechanical properties (toughness of 5.67 MJ m − 3 and strain of 941%) and scarcely L-BF migration underwater. Moreover, the hydrophobic network of L-BF endowed HEG with hydrophobicity (water contact angle exceeds 110°; swelling ratio is <5.8%), superior underwater adhesion (255 kPa), even maintained excellent sensing performance (gauge factor of 4.69), and long-term reproducibility (20 000 cycles) in air and underwater. Validation confirms the potential of HEG as an effective wearable sensor for underwater posture monitoring and communication, advancing the use of lignin and low-migration conductive gels in marine exploration.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Fei Wang,Jiuyan Chen,Yalei Xu,Usman Farooq,Taotao Lu,Weifeng Chen,Xinhai Wang,Zhichong Qi
Knowledge of the mobility of tetracycline (TC) antibiotics in porous media is critical to understand their potential environmental influences. The transport characteristics of TC in sand columns with three different surfactants, including Tween 80, sodium dodecylbenzene sulfonate (SDBS), and didodecyldimethylammonium bromide (DDAB) under various conditions were investigated in this study. Results demonstrated that all surfactants enhanced TC transport under neutral conditions (10 mM NaCl at pH 7.0). The observation was attributed mostly to deposition site competition, higher electrostatic repulsion between TC molecules and sand grains, steric hindrance, and the increase of TC hydrophilicity. Furthermore, the order of the transport-enhancement effects was generally observed as follows: DDAB > SDBS > Tween 80. The trend was controlled by the variation in the physicochemical properties of surfactants. It was noticed that the presence of Cu 2+ (a model divalent cation) in the background solution, the cation-bridging contributed to the promotion effects of DDAB or Tween 80 on TC mobility. Interestingly, SDBS considerably suppressed TC transport due to the precipitation of SDBS–Cu 2+ complexes onto sand surfaces. Moreover, the enhancement order of surfactants at pH 5.0 was similar to that pH 7.0. However, DDAB could inhibit TC transport in sand columns at pH 9.0, which were mainly caused by the decrease of electrostatic repulsion and the hydrophobicity induced by the binding cationic surfactant. Findings from this work provide novel insight into involvement of surfactants in antibiotic transport behaviors in the subsurface environment.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 32
·46542
·
IF 1.901
Yangze Huang,Erlei Yu,Yanke Li,Zhong Wei
A series of hyperbranched poly(ɛ-caprolactone) (HPCLs, denoted as D X ) with different molecular weights were synthesized by the copolymerization of GPCL (PCL initiated by glycidol) and succinic anhydride. The chemical structure of D X was characterized by 1 H-NMR gel permeation chromatography and inherent viscosity, and D X was used as the plasticizer for poly(vinyl chloride) (PVC) compared to traditional plasticizer di-(ethylhexyl) phthalate (DEHP). The thermal properties, morphology, mechanical properties, and migration stabilities of PVC films were explored with differential scanning calorimetry, thermogravimetric analysis, scanning electron microscope, tensile, and migration tests. PVC/D 1 exhibited the best plasticization efficiency up to 107%, with enhanced tensile strength (18.5 MPa) and ultimate elongation (416%) compared to PVC/DEHP (11.5 MPa and 375%, respectively). PVC/D 1 exhibited remarkably high plasticization efficiency as compared to PVC/DEHP at a plasticizer concentration of PVC below 40 wt %. Moreover, the migration test for PVC/D X films exhibited minimal plasticizers migration even at very harsh conditions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46542.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Mengya Liu,Lulu Lu,Qiang Zhang,Usman Farooq,Taotao Lu,Yanxiang Li,Deliang Li,Zhichong Qi
The mobility and deposition of sulfonamide antibiotics (SAs) in soil porous media may be impacted by the presence of rhamnolipid (a typical biosurfactant), which is ubiquitous in the natural environment. Herein, the transport characteristics of various SAs, such as sulfamerazine (SMZ), sulfamethazine (SMT), and sulfanilamide (SNM) in soil columns with rhamnolipid, were explored. The mobility of SAs in the soil columns was in the sequence of SNM > SMT > SMZ. The observation was mainly due to the differences in the hydrophobic properties of various antibiotics. Interestingly, rhamnolipid inhibited the mobility of the three SAs over a broad solution pH range (5.0–9.0) primarily because of the interactions between the hydrophobic groups of the deposited rhamnolipid on the soil surfaces and parts of SAs molecules (i.e., rhamnolipid acted as a bridging agent between soil and antibiotic). Furthermore, at a given rhamnolipid concentration, the inhibitory effect of rhamnolipid on SMZ transport was the greatest among the three antibiotics due to SMZ’s greatest hydrophobicity . Additionally, the transport-inhibition influence of rhamnolipid declined as the solution pH values rose. This phenomenon was attributed to the decline of the bridge effects induced by the decreased adsorbed rhamnolipid on soil surfaces. Innovative findings from this study provide helpful information regarding the contribution of biosurfactants on the environmental behaviors of these ubiquitous antibiotic contaminants in soil-water systems.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）