Sustainability
·
2022
·Vol. 14
·期 19
·12872
·
IF 3.889
Zihan Lang,Lidong Xue
Triclosan (TCS) has been widely employed as active ingredient in household products and has received attention for its hepatotoxicity, endocrine disruption and disturbance on immune function. Polylactic acid (PLA) has been highlighted as an alternative biodegradable microplastic, and the knowledge about the adsorption affinity towards TCS is limited. In this study, the ability to act as carrier of TCS by PLA and non-biodegradable microplastics, including polystyrene (PS), polyvinyl chloride (PVC) and polyethylene (PE) with different particle sizes were explored. The influence factors (e.g., dosage, pH and salinity), adsorption kinetics and isotherms were also investigated. Batch experiment results indicated that the TCS adsorption onto PLA and non-biodegradable microplastics exhibited a pronounced pH-dependent pattern (pH of 4, 7 and 10), and the adsorption capacity decreased gradually as pH increased. Furthermore, the adsorption capacity of TCS on PS, PVC and PE decreased as salinity increased from 0 to 3.5%, while no significant inhibition for the sorption capacity of PLA was observed. The adsorption kinetic data of TCS was best fitted with the pseudo-second order model. The Freundlich model with R2(0.999) was suitable to describe the adsorption isotherms of TCS on PLA, while the isotherms data of TCS on PS, PVC and PE was fitted by linear and Freundlich model. The higher adsorption capacity of PLA (38.6 mg g−1) compares to those of PS, PVC and PE (31.3, 11.4 and 9.64 mg g−1, respectively), illustrated by the fact that the physicochemical properties of microplastics have a noticeable impact on adsorption process, and the biodegradable PLA is a stronger vector than the non-biodegradable microplastics.Keywords:triclosan;polylactic acid;vector;pH-dependent
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
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Jianjun Wang,Wenheng Li,Zihan Zhou,Zhiyong Gao,Yuehua Hu,Wei Sun
Fluorite is usually separated from calcite by froth flotation method using large amounts of sodium silicate depressant, which can cause trouble in the loss of fluorite and wastewater treatment. In this study, green and low-cost 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP or H 4 L) was used as pH-dependent switch to initially depress fluorite for calcite pre-removal at pH 6.0, and then activate fluorite for further upgrading fluorite concentrate at pH 8.0. The depressing behavior and mechanism were reported in this work. H 2 L 2− was the dominant form of HEDP, and a stronger chemical adsorption of H 2 L 2− on fluorite hindered the subsequent adsorption of sodium oleate (NaOL), while that of the calcite showed the opposite result. Two active O atoms in H 2 L 2− could well match in interatom distance with two Ca sites on fluorite to form Ca-H 2 L complexes. The pH-dependent switch reagent reported here may open a new avenue for more selective separation among mixed mineral systems.
研究领域:
矿物加工工程
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环境科学
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产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2023
·
IF 4.4
Xiang Mao,Xia Zhao,Hao Hu,Zequan Li,Wei Xiong,Yujiao Wei,Wei Gao
Work to combat counterfeiting has always been crucial to defending the interests of the public. The usual anti-counterfeiting marks are now fundamental and easy to imitate. Therefore, it is more beneficial to anti-counterfeiting work to develop an anti-counterfeiting mark with more variations to make forgery more difficult. Due to its exceptional stability and fluorescence variability, carbon dots (CDs), a newly developed fluorescent material, offer a wide range of potential applications in anti-counterfeiting. However, there currently needs to be more CD applications in multi-level anti-counterfeiting, and additional issues include high cost and environmental contamination. Therefore, considering the problems of green environmental protection and cost, CDs with excellent green (530 nm) and blue (475 nm, 486 nm) luminescence properties were prepared by a one-step reaction of m-phenylenediamine and glucose. The average fluorescence lifespan is longer than 5 ns, and the optimal quantum yield can reach 37%. Due to the large number of protonated amino groups and surface carboxyl functional groups, the prepared carbon dots exhibit green and blue fluorescence emission modes under acidic and alkaline conditions, respectively. Based on this situation, we produced CD ink and successfully used it for multi-level anti-counterfeiting.
研究领域:
材料科学
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化学
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环境科学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Hongbo Lu,Chunli Wang,Xueming Liu,Jing Zhang,Zhang Lin,Zhengping Hao,Gang Pan
Arsenic sulfide sludge (ASS) is a typical precipitation product of acid smelting wastewater. Previous study reported that when exposed to sunlight, the release and oxidation of As(III) in ASS were markedly accelerated. However, the key factor to trigger the photocatalytic transformation of ASS is still unclear. Herein, we revealed that the coexisting Fe(II)/Fe(III) ions were critical to promote the photo-oxidation of released As(III) under visible light. We further validated that Fe(II)-stimulated photo-oxidation mechanism of As(III) in ASS was pH-dependent. In acid conditions, OH and SO 4 − were promoted by Fe(II)/Fe(III) cycling catalysis with the assistance of the reductive sulfur species from ASS, e.g. S 2− and SO 3 2− , and thus accelerated the oxidation of As(III). While in neutral conditions, the nascent ferric hydroxide colloids enhanced the oxidation rate of As(III) via photo-induced ligand-to-metal-charge transfer (LMCT) mechanism. These findings help in predicting and controlling the fate of real arsenic-containing sludge in sunlit environments.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 11
·5206-5217
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IF 3.925
Yajie Wang,Xianhe Gong,Xin Dong,Xiuzhen Tao,Yingchun Luo
In this study, the kinetics of arsenite (As(III)) removal in a ferrihydrite/oxalate system under irradiation was investigated, and the effects of pH, ferrihydrite dosage, As(III) initial concentration, and oxalate concentration were evaluated. Ultraviolet A (UVA) irradiation significantly promoted As(III) removal in the presence of ferrihydrite and oxalate. The greatest removal efficiency of As(III) (92.5%) was observed under the following conditions: pH 3.0, 100.0 μg L−1 As(III), 0.0125 g L−1 ferrihydrite, 0.1 mmol L−1 oxalate, and after 90 min under UVA irradiation. The removal of As(III) in the ferrihydrite/oxalate system was strongly pH-dependent. Mechanistic investigations indicated that HO˙ was the primary oxidant for As(III) photo-oxidation in the ferrihydrite/oxalate system. Surface adsorbed hydroxyl radical (HOads˙) was the dominant oxidant over the entire pH range in the presence of oxalate, and the hydroxyl radical in aqueous solution (HOaq˙) made only a small contribution under acidic conditions. The sources of HO˙ were also strongly dependent on pH; HO2˙/O2˙− was the precursor of HO˙ under acidic conditions, while photo-generated holes gradually became the main source of HO˙ as the pH increased. The photo-oxidation of As(III) mainly occurred on the surface of ferrihydrite. Although some ferrihydrite transformed into goethite during the removal process, the iron oxides showed good reusability for up to five regeneration cycles. The findings indicate that As(III) can be efficiently removed by the ferrihydrite/oxalate system and provide guidance for developing effective treatment strategies for As(III)-contaminated waters.
研究领域:
环境科学
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化学
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DOI
高影响因子
Life-Basel
·
2020
·Vol. 10
·期 4
·45
·
IF 2.991
Rongcan Lin,Yueqiao Wang,Xin Li,Yan Liu,Yufen Zhao
Ultraviolet (UV) irradiation is considered an energy source for the prebiotic chemical synthesis of life’s building blocks. However, it also results in photodegradation of biology-related organic compounds on early Earth. Thus, it is important to find a process to protect these compounds from decomposition by UV irradiation. Herein, pH effects on both the adsorption of peptides on montmorillonite (MMT) and the abilities of peptides to resist UV irradiation due to this adsorption were systematically studied. We found that montmorillonite (MMT) can adsorb peptides effectively under acidic conditions, while MMT-adsorbed peptides can be released under basic conditions. Peptide adsorption is positively correlated with the length of the peptide chains. MMT’s adsorption of peptides and MMT-adsorbed peptide desorption are both rapid-equilibrium, and it takes less than 30 min to reach the equilibrium in both cases. Furthermore, compared to free peptides, MMT-adsorbed peptides under acidic conditions are well protected from UV degradation even after prolonged irradiation. These results indicate amino acid/peptides are able to concentrate from aqueous solution by MMT adsorption under low-pH conditions (concentration step). The MMT-adsorbed peptides survive under UV irradiation among other unprotected species (storage step). Then, the MMT-adsorbed peptides can be released to the aqueous solution if the environment becomes more basic (releasing step), and these free peptides are ready for polymerization to polypeptides. Hence, a plausible prebiotic concentration–storage–release cycle of amino acids/peptides for further polypeptide synthesis is established.Keywords:pH-dependent;adsorption;peptides;UV radiation protection;montmorillonite
研究领域:
前生物化学
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地球化学
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天体生物学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2015
·
IF 3.615
Yang Li,Lin-Dong Liu,Lu Liu,Ying Liu,Hong-Wei Zhang,Xu Han
In this study, three trivalent Mn (oxyhydr)oxides, bixbyite (α-Mn 2 O 3 ), hausmannite (Mn 3 O 4 ) and manganite (γ-MnOOH) were synthesized and used as persulfate (PS) activators in phenol oxidation. Of these three Mn (oxyhydr)oxides, only γ-MnOOH shows a good catalytic activity in PS activation with more than 80% phenol oxidized within 360 min in the full pH range. With increasing concentrations of PS and γ-MnOOH, phenol removal efficiency increased. TOC results also suggest that phenol oxidation at pH 11 is more complete than those at pH 7 and 3. We further confirm that mechanism involved in phenol oxidation is pH dependent in γ-MnOOH/PS system. Although SO 4 − and OH were both found under acidic and alkaline conditions, they did not contribute equally under different pHs. At pH 11, SO 4 − and OH generated from PS activation efficiently oxidize phenol. At pH 3, the strong oxidation activity of γ-MnOOH and an oxidative intermediate formed between S 2 O 8 2− and γ-MnOOH primarily contribute to phenol oxidation. At pH 7, an oxidative intermediate formed between γ-MnOOH and S 2 O 8 2− is the predominant oxidative species in phenol oxidation.
研究领域:
环境科学
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化学
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 10
·9636-9646
·
IF 2.8
Li Chenguang,Qu Ruijuan,Chen Jing,Zhang Shuo,Allam Ahmed A.,Ajarem Jamaan,Wang Zunyao
Triclosan (TCS) is an antibacterial and antifungal agent widely used in personal care products, and it has been frequently detected in the aquatic environment. In the present study, the acute toxicity of TCS to Daphnia magna , Photobacterium phosphoreum , Danio rerio , and Limnodrilus hoffmeisteri was assessed under different pH conditions. Generally, TCS was more toxic to the four aquatic organisms in acidic medium. The LC 50 values for D. magna and D. rerio were smaller among the selected species, suggesting that D. magna and D. rerio were more sensitive to TCS. In addition, the oxidative stress-inducing potential of TCS was evaluated in Carassius auratus at three pH values. Changes of superoxide dismutase (SOD) and catalase (CAT) activity, glutathione (GSH) level, and malondialdehyde (MDA) content were commonly observed in all TCS exposure groups, indicating the occurrence of oxidative stress in the liver of C. auratus . The integrated biomarker response (IBR) index revealed that a high concentration of TCS induced great oxidative stress in goldfish under acidic condition. This work supplements the presently available data on the toxicity data of TCS, which would provide some useful information for the environmental risk assessment of this compound.
研究领域:
环境科学
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毒理学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2015
·Vol. 20
·期 9
·16709-16722
·
IF 2.416
Hai-Min Shen,Wen-Jie Zhou,Xin Ma,Hong-Ke Wu,Wu-Bin Yu,Ning Ai,Hong-Bing Ji,Hong-Xin Shi,Yuan-Bin She
A pH-dependence of the Brønsted acid-catalyzed oxidation of sulfides to the corresponding sulfoxides with H2O2is reported for the first time based on our systematic investigation of the catalytic performance of a series of Brønsted acids. For all of the Brønsted acids investigated, the catalytic performances do not depend on the catalyst loading (mol ratio of Brønsted acid to substrate), but rather depend on the pH value of the aqueous reaction solution. All of them can give more than 98% conversion and selectivity in their aqueous solution at pH 1.30, no matter how much the catalyst loading is and what the Brønsted acid is. This pH-dependence principle is a very novel perspective to understand the Brønsted-acid catalysis system compared with our common understanding of the subject.Keywords:sulfide;oxidation;sulfoxide;pH-dependence;Brønsted acid
研究领域:
化学
·
催化科学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jiayan Wu,Quanyun Ye,Meiqing Chen,Leiye Sun,Sheng Liu,Linqing Liu,Pingxiao Wu,Nengwu Zhu
The heteroaggregation of nanoplastics with minerals has been widely investigated. However, few studies have focused on the interaction between similar negatively charged clay minerals and nanoplastics, especially how their interactions affect the migration of heavy metals. This study investigated heteroaggregation of kaolinite (a model of natural mineral) with polystyrene nanoplastics (PSNPs) and the effect of heteroaggregates on lead (Pb 2+ ) sorption . Dynamic light scattering (DLS) measurement highlighted that PSNPs owned higher colloidal stability than kaolinite in aquatic environments. Due to the surface charge heterogeneity of kaolinite, the heteroaggregation behavior between kaolinite and PSNPs was highly pH-dependent. At pH 3.0 and 6.0, kaolinite particles with positively charged edge surfaces favored the association of PSNPs. PSNPs were found to be primarily attached on the kaolinite edge (010) surface, followed by Al-terminated (001) and Si-terminated (00 1 ¯ ) surfaces based on density functional theory (DFT) calculations. At pH 10.0, they had negligible interaction due to the strong electrostatic repulsion. Interestingly, kaolinite carried more negative charges after heteroaggregation with PSNPs, resulting in slower edge-to-face homoaggregation and higher dispersibility, and thus increasing the sorption capacity for Pb 2+ . This investigation provided a new understanding of nanoplastics interactions with negatively charged minerals and highlighted the vital role of nanoplastics in mineral stability and contaminant migration.
研究领域:
环境科学
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土壤化学
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污染生态学
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DOI
高影响因子
DYES AND PIGMENTS
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2021
·
IF 4.889
Kui Wang,Qi-Qi Wang,Mi-Ni Wang,Ya-Jing Xie,Xuan Qiao,Siyang Xing,Bolin Zhu
In this work, a water-soluble fluorescent and colouring macrocycle deprotonated-calixpyridinium was obtained by a simple pH modulatory strategy. This type of fluorescent and colouring macrocyclic skeleton as host will be certainly applied in a large number of fields, especially in the sensing area. Herein, a near white-light emission was carried out by an innovative method of deprotonated-calixpyridinium-based host–guest interactions employing camptothecin sodium as the guest. Moreover, the pH-responsive luminescence color change of calixpyridinium–camptothecin sodium complex was further applied for the high selective detection of arginine in pure water and real samples, which is quite important in the accurate diagnosis of various disorders. The newfound pH-dependent luminescent and colouring properties of calixpyridinium will also provide an alternative idea for the development of other novel fluorescent and colorimetric macrocyclic sensors.
研究领域:
分析化学
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生物传感
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医学诊断
✓ 已验证
DOI
高影响因子
ACS ES&T Water
·
2025
·
IF 4.3
Wen-Long Wang,Peng-Hui Liu,Jung-Hyun Son,Hang Su,Min-Yong Lee,Hong-Ying Hu,Qian-Yuan Wu,Uwe Hübner
The combination of ozonation and Mn(II) (O3/Mn(II)) is expected to synergistically eliminate recalcitrant organic micropollutants in water. However, the decay of O3, formation of •OH and reactive manganese species (RMnSs), and synergism in micropollutant degradation have not been comprehensively understood. Herein, the synergism of O3 and Mn(II) was observed to be pH-dependent. Compared to ozonation alone, O3/Mn(II) preferentially formed Mn(V and VI) and slightly increased •OH yield (from 0.22 to 0.30) at acidic pH 4–5, while it preferentially formed Mn(VII) and significantly increased OH yield (from 0.52 to 0.74) at circumneutral pH 6–7. Thereafter, O3/Mn(II) prominently increased RMnS exposure at acidic pH, while it dramatically diminished O3-exposurse to increase •OH exposure at circumneutral pH. As a result, O3/Mn(II) outperformed ozonation alone for the degradation of various O3-resistant micropollutants (3.7–7.9 times faster). For example, the RMnSs (82.7% contribution) and •OH (84.2% contribution) were the dominant contributors to the degradation of the isothiazolinone biocide (5-chloro-2-methyl-4-isothiazolin-3-one) at acidic and circumneutral pH, respectively. Mn(II) can enhance the removal of O3-resistant micropollutants in relatively clean waters (e.g., tap water), but its effectiveness was limited in more contaminated waters (e.g., WWTP effluent). These findings support the practice and pH optimization of the O3/Mn(II) in various water types.
研究领域:
环境科学
·
水处理工程
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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）