HYDROMETALLURGY
·
2020
·
IF 3.338
Xintao Yi,Guangsheng Huo,Wei Tang
The extraction of Fe(III), Ni(II) and Co(II) from a Ni(II)-Co(II) solution containing Fe(III) was analyzed in a chloride medium using a mixed extractant consisting of 50% ( v /v) tributyl phosphate (TBP), 20% (v/v) 2-octanol and 30% (v/v) kerosene. The extraction of 0.5 mol/L Fe(III) in 4 mol/L hydrochloric acid reached 97%, and the consumption of chloride ions was investigated. Nickel(II) ions were not detectably extracted by TBP, with an inclusion of <1.1%. Compared with Fe(III), TBP extracted only a small amount of Co(II). The iron complexes formed by TBP and 2-octanol were [H 2 FeCl 4 · 2TBP] and [H 2 FeCl 4 · 5(2-octanol)], and the possible compositions of Co-containing extracts were [H 2 CoCl 4 · 2TBP] and [H 2 CoCl 4 ] · n[2-octanol]. An industrial process consisting of two-step extraction was designed to achieve the separation of Co(II) and Fe(III), resulting in a decrease in the Fe/Co mass ratio from 0.46 to <3.5 × 10 −4 in the raffinate.
研究领域:
化学工程
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Xin Yang,Lu Yao,Yu Wang,Xinran Zhang,Pengfei Ren
Algae blooms can clog filtration tank, release toxic cyanotoxin and produce undesirable disinfection byproducts (DBPs) in post-chlorination, which brings challenges to conventional water treatment processes. In this study, peroxymonosulfate (PMS) was tested for its ability to improve Fe(III) coagulation of Microcystis aeruginosa in water treatment. Compared with conventional Fe(III) coagulation, the presence of PMS resulted in the formation of larger floc and thus better algae and turbidity removal. The removal of algae by PMS-enhanced Fe(III) coagulation (PMS-Fe(III)) process reached 97.5% at 1 mM PMS, which was 1.5 times higher than that by Fe(III) coagulation alone. The oxidization of surface-adsorbed extracellular organic matter destabilized the algal cells and enhanced their coagulation without greatly damaging the cells’ integrity. Simultaneously, about 80% of Microcystin-LR, a cyanotoxin, was degraded in the enhanced process. Moreover, the formation of DBPs and their associated toxicity during the subsequent chlorination were decreased by 49.2% and 13.6%, respectively. The production of trihalomethanes, haloacetic acids and haloacetronitriles was particularly abated. SO 4 •- and HO • , which were formed from PMS activation through redox cycling of Fe mediated by the existing natural organic matter, were mainly responsible for algae removal. The results indicate that supplementing Fe(III) coagulation with PMS is a promising option for treating water during algal blooms.
研究领域:
环境科学
·
水处理工程
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DOI
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Shuhui Sun,Shu Wang,Yuxuan Ye,Bingcai Pan
Considerable amount of phosphorous is present as organic phosphonates (usually in the form of metal complexes, e.g., Ca(II)-phosphonate) in domestic and industrial effluents , which cannot be effectively removed by traditional processes for phosphate. Herein, we employed a proprietary process, i.e., Fe(III) displacement/UV irradiation/co-precipitation (denoted Fe(III)/UV/NaOH), to enable an efficient removal of Ca(II)-phosphonate complexes from water. The combined process includes three basic steps, i.e., Fe(III) replacement with the complexed Ca(II) to form Fe(III)-phosphonate of high photo-reactivity, UV-mediated degradation of Fe(III)-phosphonate to form phosphate and other intermediates, and the final phosphorous removal via co-precipitation at pH = 6. The operational conditions for the combined process to remove a typical phosphonate Ca(II)-NTMP (nitrilotrismethylenephosphonate) are optimized, where ∼60% NTMP is transformed to phosphate with the total phosphorous reduction from 1.81 mg/L to 0.17 mg/L. Under UV irradiation, the cleavage of NTMP is identified at the C-N and C-P bonds to form the intermediate products and phosphate in sequence. Also, the combined process is employed for treatment of two authentic effluents before and after activated sludge treatment, resulting in the phosphorous drop from 4.3 mg/L to 0.23 mg/L and from 0.90 mg/L to 0.14 mg/L respectively, which is much superior to other processes including Fenton/co-precipitation. In general, the combined process exhibits great potential for efficient removal of phosphonates from contaminated waters .
研究领域:
环境科学
·
水处理技术
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产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2024
·
IF 1.8
Weihua Zhong,Jinwang Bai,Yunjun Luo,Dianbo Zhang,Chen Liang,Xiangdong Chen
Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fiber is currently one of the best-performing organic fibers; however, its low UV aging resistance limits its use. To improve the UV aging performance of PBO fibers, a novel PBO-Fe-PDA fiber was created by depositing a biomimetic structure of polydopamine (PDA) on the surface of PBO fibers with the transition metal ion Fe3+ as the active center. The surface morphology and elemental composition of PBO-Fe-PDA fibers were investigated. It was revealed that Fe3+ formed a coordination bond structure with the oxazole ring, and PDA was successfully loaded onto the surface of PBO-Fe fibers. After UV aging, the crystallinity and crystallographic orientation of PBO fibers significantly decrease, microcrystals inside the fibers slip, and the size of microvoids in the fibers rises. As a result, the strength of PBO fibers was significantly decreased after UV aging. The anti-UV aging capacity of PBO-Fe-PDA fibers, on the other hand, has been enhanced, as evidenced by a slight drop in crystallinity and crystallographic orientation and a significant decrease in the size growth of internal microvoids in the fibers after UV aging. The tensile strength retention of PBO-Fe-PDA fibers after UV aging increased by 93.13% when compared to PBO fibers without altering the fibers’ initial strength. The testing results show that this surface modification method is simple to employ and extends the service life of PBO fibers significantly.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 14
·2794
·
IF 5.2
Shushan Gao,Chonghao Zhu,Liangfei Ma,Chenghai Liu,Hongqiong Zhang,Shengming Zhang
To reduce the usage of petroleum-based plastic products, a lignin-based film material named aminated lignin/Fe(III)/PVA was developed. The mixture of 8 g lignin, 12 mL diethylenetriamine, 200 mL NaOH solution (0.4 mol·L−1), and 8 mL formaldehyde was heated at 85 °C for 4 h; after the aminated lignin was impregnated in the Fe(NO3)3solution, a mixture of 3 g aminated lignin/Fe(III), 7 g PVA, and 200 mL NaOH solution (pH 8) was heated at 85 °C for 60 min; after 2 mL of glycerin was added, the mixture was spread on a glass plate to obtain the aminated lignin/Fe(III)/PVA film. This film demonstrated hydrophobicity, an UV-blocking function, and a good slow-release performance. Due to the formation of hydrogen bonds between the hydroxyl groups of lignin and PVA, the tensile strength, the elongation at break, and the fracture resistance of the film were 9.1%, 107.8%, and 21.9% higher than that of pure PVA film, respectively. The iron content of aminated lignin/Fe(III)/PVA was 1.06 wt%, which mainly existed in a trivalent form. The aminated lignin/Fe(III)/PVA film has the potential to be used as a food packaging material with anti-ultraviolet light function and can also be developed as other packaging materials, such as seedling bowls, pots for transplanting, and coating films during transport.Keywords:lignin;polyvinyl alcohol;Fe(III);packaging material;slow-release function
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CLAY SCIENCE
·
2022
·
IF 5.907
Qianqian Chang,Boqiang Gao,Hu Yang
In this work, a series of novel composite adsorbents (k-TAFe) was designed and fabricated through a one-step method, that is, the chelation crosslinking of tannic acid, kaolin particles and different contents of Fe(III). k-TAFe had a high efficiency in adsorption of various fluoroquinolones antibiotics (FQs) from water. The detailed performance of k-TAFe in FQs adsorption, including the influences of Fe(III) content, solution pH, inorganic and organic additives, adsorption time and FQs' concentration, has been investigated systematically using ofloxacin (OFL), one of popular FQs, as an example. The maximal OFL uptake of k-TAFe was 0.405 mmol/g at an initial pH of 6.0. On the basis of the analysis of the x-ray photoelectron and fourier transform-infrared spectra before and after adsorption, the comparison in the apparent performance of k-TAFe in adsorption of seven FQs with similar structures and their two sub-structural analogs, and theoretical calculation, multiple adsorption mechanisms, including chelating effect, hydrogen bonding, electrostatic attraction , and π-π electron–donor–acceptor interactions, were involved and discussed in detail. Among them, chelating effect due to Fe(III) played a key role in OFL adsorption, and the addition of kaolin particles synergistically enhanced Fe(III) fixed on the composite adsorbents, increased the Fe(III) contents, and caused an improved OFL uptake of k-TAFe. Because of the evident advantages of environmental-friendliness, high adsorption performance and low cost, k-TAFe as an efficient adsorbent has notable application potentials in removal of FQs from water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Nan Wang,Huijuan Chai,Xuelin Dong,Qian Zhou,Lihua Zhu
Iron(III) ethylenediaminetetraacetate (Fe(III)EDTA) is widely used in iron fortification for reducing iron deficiency, and its determination is urgently needed. The present work developed a fluorescent method to straightforwardly determine Fe(III)EDTA by using photoluminescent carbon dots (C-dots) with the aid of F − ions as the masking agent of free Fe 3+ ions. In the presence of F − ions, only Fe(III)EDTA selectively quenched the photoluminescence of C-dots, and both Fe 3+ and Fe 2+ as well as other carboxylic acids have no effect on the emission of C-dots. The sensing mechanism was attributed to the ligand-tailored electron transfer process from C-dots to Fe 3+ . Under optimum conditions, this method showed a linear calibration plot over the Fe(III)EDTA range of 1.0–200 μmol L −1 and a detection limit of 0.4 μmol L −1 . The proposed method was successfully applied to determine Fe(III)EDTA in real samples with acceptable recoveries of spikes (95%−110%) and repeatability (RSD, 4.2%−9.5%).
研究领域:
分析化学
·
食品科学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Chengcheng Xu,Jing Deng,Shijun Zhu,Xiao Ling,Songtu Shen,Hongguang Guo,Qiongfang Wang,Xueyan Li
The introduction of ascorbic acid (AA) into Fe(III)/PS system exhibited extremely high activity on the removal of N,N-diethyl- meta -toluamide (DEET) and other pollutants. The removal efficiency of DEET within 30 min reached 90.13%, its dynamic curve obeyed second-order kinetic model and the k obs was calculated to be 0.150 L·mg −1 ·min −1 . Compared with other reducing agents, AA was tested to be the most suitable. The optimal dosages of Fe(III), PS and AA were tested to be 0.1, 1.0 and 0.5 mM, respectively. Furthermore, the introduction of AA extended the working pH to 2.5–9.3. Common anions posed different degrees of inhibition on DEET degradation at relatively high concentration, while a small dosage of HCO 3 − (<1 mM) abnormally exerted a positive role. In terms of reaction mechanism, scavenger experiment and EPR observation illustrated that ·OH and ·SO 4 − dominated DEET degradation, yet slight Fe(Ⅳ) was also found during the reaction, which indicated that Fe(Ⅳ) may also contribute to DEET removal. Different from the rapid consumption of Fe(II) in Fe(II)/PS system, Fe(II) in Fe(III)/PS/AA system entered a dynamic equilibrium state in the later stage of the reaction, which can decompose PS to form ·SO 4 − continuously. Furthermore, the reduction and chelation ability of AA both functioned a key role. According to the degradation intermediates identified by LC-MS analysis, the degradation pathways of DEET could be divided into two directions, which covered opening benzene ring and removing side chain.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Qianyu Wei,Qiuhu Lin,Zezhen Zhang,Lili Wu,Chaocan Zhang
Polyvinylidene fluoride (PVDF)/polyhexamethylene guanidine (PHMG)/tannic acid (TA) coatings have some degree of hydrophilicity but lack stability. To improve the hydrophilicity and stability of antimicrobial PVDF/PHMG/TA membranes, Fe(III) is introduced into the composite system. As a weakly acidic hydrophilic nanoion, Fe(III) can enhance the hydrophilicity and resistance to contamination of the membranes. Furthermore, the stability can be enhanced because a three-dimensional cross-linked coating structure is formed by the complexation of Fe(III), TA and PHMG. This work investigates the effects of different tannic acid concentrations and pH conditions on the hydrophilicity, anti-pollution and stability of the modified coatings. The surface morphology of the membranes was analyzed by field-emission scanning electron microscopy. Additionally, the hydrophilicity and the antipollution performance were evaluated based on the water contact angle, submerged oil contact angle, emulsion flux and flux recovery rate. The stability was evaluated by the changes in flux recovery rate and water contact angle before and after emulsion scouring and ultrasonic treatment. The results show that the modified membranes have favorable hydrophilicity and stability after the addition of Fe(III). The water contact angle can be reduced to 19°, the pure water flux can reach 13,850 L·m −2 ·h −1 , and the emulsion flux can reach 2650 L·m −2 ·h −1 . Moreover, 99.68% flux recovery was achieved after 7 days of deionized water flushing, and the water contact angle remained almost unchanged.
研究领域:
材料科学
·
环境工程
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2012
·
IF 2.474
Zhujian Huang,Pingxiao Wu,Xing Zhang,Xiaorong Wang,Nengwu Zhu,Jinhua Wu,Ping Li
In this study, intercalation of Fe(III) complexes [Fe(Ox) 3 ] 3− and [Fe(Cit) 2 ] 3− in Mg 2 Al layered double hydroxides (LDHs) had been carried out by different routes: direct self-assembly, reconstruction and anion exchange. The result of XRD indicated that these two kinds of Fe(III) complexes intercalated LDHs (LDHs/Fe-complexes) could be successfully synthesized by anion exchange obtaining two well crystallized LDHs both with a large basal spacing. The chemical environment of iron ion in the intercalated Fe complexes was determined by FTIR , XPS and XAFS, the results of which concertedly proved that the intercalated Fe complexes were well preserved in the interlayer of LDHs. The arrangement of the Fe(III) complexes anions in the galleries of LDHs was studied by one-dimensional electron density projection. The results showed that the [Fe(Ox) 3 ] 3− anions were probably accommodated in the gallery of LDHs as an interdigitated bilayer arrangement, and the [Fe(Cit) 2 ] 3− were perpendicularly arranged against the LDHs sheets. Through the research, it is proved that the obtained LDHs/Fe-complexes markedly enhanced the UV–vis absorption ability of Fe complexes.
研究领域:
材料科学
·
无机化学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 21
·8952-8959
·
IF 3.288
Hehe Qin,Jinhong Fan,Shun Mao
The Fenton method is an important water treatment process. However, the mechanism of the Fenton reaction is still not widely recognized. In this article, the autocatalysis process responsible for the degradation of 4-chlorophenol (4-CP) as well as the generation of Fe(II) and the decomposition of H2O2 is elaborated using a Fe(III)/H2O2 system. It was found that the one electron reduction of Fe(III) to Fe(II) via oxidization of H2O2 to ˙HO2 is not spontaneous according to the standard electrode potential rather than being limited by the rate constant of 0.0027 M−1 s−1 in view of the Haber–Weiss circulation. However, the reaction of Fe(III) and 4-CP is spontaneous with a second-order kinetic rate constant of >0.12 M−1 s−1 and a conversion rate of 0.56%, which triggers the switch of the Fenton-like reaction as a real rate-determining step. The circulation of Fe(III) to Fe(II) in the proposed Fenton-like reaction mechanism depends on the organic species and various intermediates, which indicates its reaction selectivity, preferable for organics with a stronger thermodynamic and kinetic activity. Besides, a slight pH decline with time-scale and the stoichiometric ratio of ˙OH to H2O2 and H2O2 to 4-CP being 1 and 2, respectively, pointed to the new proposed reaction mechanism. The discovery of the new reaction mechanism might promote the theoretical and technical advancement of the Fenton-like process.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Jiahang Liu,Xiaoyang Li,Yingying Chu,Ling Yuan,Ruolin Lv,Weiming Zhang
The conventional Fe(III)/H 2 O 2 system is of low efficiency on the removal of most organic pollutants. However, we discovered that the Fe(III)/H 2 O 2 system was robust on remediating tetracycline (TC) in water (0.109 min −1 for the pseudo-first kinetic constant), and the reaction was even slightly faster than that in the conventional Fe(II)/H 2 O 2 system (0.105 min −1 ). The addition of TC could also initiate the degradation of other refractory pollutants in the Fe(III)/H 2 O 2 system. Complexation between Fe(III) and TC with the stoichiometric ratio of 1:1 was observed. Electron transfer from TC to Fe(III) gave rise to the slight production of Fe(II), which served as the initiator of the following Fenton reaction. •OH was ascertained as the main reactive species through quenching experiments, EPR tests and the probe method, while O 2 • − /HO 2 • was also a subsidiary contributor. Hydroquinone intermediates were proved to be generated through the hydroxylation of the benzene ring of the TC molecule by •OH and thus facilitate the reductive transformation of Fe(III) to Fe(II). This study analyzes the relationship between molecular structural features of TC and the catalytic efficiency of ferric Fenton-like reactions. We expect to shed light on new mechanistic insights on autocatalysis in the Fenton-like catalytic processes.
研究领域:
环境科学
·
化学
✓ 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）