SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Hui Dang,Na Li,Zhidong Chang,Benfeng Wang,Yifei Zhan,Xue Wu,Wenbo Liu,Shujaat Ali,Hongda Li,Jiahui Guo,Wenjun Li,Hualei Zhou,Changyan Sun
In the present case, insoluble lithium in the simulated slag which is obtained by pyrometallurgical processing of spent lithium ion batteries (LiBs) is leached aqueously through transformation of insoluble lithium into soluble lithium via roasting with calcium chloride (CaCl 2 ). The change of both Gibbs free energy and the logarithm of the equilibrium constant, which are taken as functions of temperature for the chlorination reaction of simulated slag with CaCl 2 , are predicted through the simulation with an enthalpy, entropy and heat capacity (HSC) programme. The simulation indicates that CaCl 2 is a favourable and effective chlorine donor in this chlorination reaction to yield lithium chloride (LiCl) when the temperature is not less than 500 °C. These predicted results are tested and confirmed experimentally. A maximum of 90.58% lithium recovery can be yielded with the optimal roasting conditions of a temperature of 800 °C for 60 min and a molar ratio of Cl/Li of 1.8:1, along with subsequent leaching conditions of 60 °C for 30 min with a water/calcines mass ratio of 30:1. X-ray diffraction (XRD) results suggest that most of LiAl(SiO 3 ) 2 in the slag disappears under the best reaction conditions and is transformed into LiCl.
研究领域:
材料科学
·
环境工程
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2018
·
IF 6.434
Zimo Lou,Yizhou Li,Jiasheng Zhou,Kunlun Yang,Yuanli Liu,Shams Ali Baig,Xinhua Xu
Titanium carbide (TiC) with excellent electrical conductivity, chemical and thermal stabilities has been recognized as one of the most promising electrocatalysts. A novel cathode, titanium carbide doped palladium/nickel foam (TiC-Pd/Ni foam), was synthesized via electroless deposition to improve the performance of Pd/Ni foam in electrocatlytic hydrodechlorination (ECH). TiC can be co-precipitated onto the surface of cathode during galvanic replacement reaction between Pd(II) solution and Ni foam. Both constant potential and constant current tests proved that TiC-Pd/Ni foam cathode performed remarkably higher activity for 2,4-dichlorobenzoic acid (2,4-DCBA) than Pd/Ni foam cathode, owing to the excellent conductivity of TiC and enhanced water dissociation over TiC-Pd/Ni foam cathode. Under the optimized reaction conditions of –0.85 V ( vs Ag/AgCl), electrolyte of 10 mM and initial pH of 4, 99.8% of aqueous 2,4-DCBA (0.2 mM) was removed within 90 min. The removal process of the aqueous 2,4-DCBA obeyed first-order decay kinetic model. Over 86.3% of 2,4-DCBA can still be removed by TiC-Pd/Ni foam cathode in the fifth consecutive run within 120 min, which was much higher than that of Pd/Ni foam cathode (37.5%). Consequently, TiC-Pd/Ni foam cathode was a promising design for enhanced ECH activity and reduced operation cost.
研究领域:
环境科学
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材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 51
·41169-41178
·
IF 3.84
Puyou Jia,Meng Zhang,Chengguo Liu,Lihong Hu,Guodong Feng,Caiying Bo,Yonghong Zhou
A novel flame retardant chlorinated phosphate ester based on castor oil (CPECO) was synthesized. Chemical structure of CPECO was characterized with FTIR, 1H NMR and 31P NMR. The application of CPECO as a secondary plasticizer for poly (vinyl chloride) (PVC) not only gained satisfied flame retardancy and mechanical properties, but also substituted for dioctyl phthalate (DOP) partly. Flame retardant properties of PVC plasticized with CPECO was explored with LOI tests, SEM, TGA, TGA-FTIR, TGA-MS and cone calorimeter tests. The results showed that LOI value of plasticized PVC blends could increase from 23.6% to 35.4%. TGA-FTIR and TGA-MS detected that the main pyrolysis products of PVC blends were H2O, HCl, CO2, CO and C6H6. Cone calorimeter tests showed that peak heat release (pHRR) of plasticized PVC blends could decreased from 379.00 to 289.00 kW m−2, total heat release (THR) decreased from 31.78 to 19.12 MJ m−2. The flame retardant mechanism of plasticized PVC blends could be concluded that phosphorous-containing components generated from pyrolysis of CPECO could promote formation of char residual. The char residual was blown by evolving gases which produced a foaming and expansion of the char layer. The carbonaceous char layer is effective to slow mass and heat transfer between the gas and condensed phases and to protect the underlying material from further combustion. The glass-transition temperature (Tg), mechanical properties of PVC blends and migration stability of CPECO were investigated.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2015
·
IF 2.184
Puyou Jia,Meng Zhang,Lihong Hu,Caiying Bo,Yonghong Zhou
A novel chlorinated phosphate based on soybean oil (CPSO) was synthesized and poly(vinyl chloride) (PVC) blends plasticized with CPSO were prepared. The flame retardant properties of PVC blends were investigated with LOI tests, SEM, TGA–FTIR and TGA–MS. The results indicated that LOI value of PVC blends plasticized with CPSO reached to 30.1%. The main pyrolysis gas products of PVC blends were H 2 O, HCl, CO 2, CO and C 6 H 6 . Phosphorous-containing components generated during the thermal degradation of CPSO, most of which were retained in the char residue rather than that in the gaseous phase. They could promote formation of char residue. The char residue was blown by evolving gases which produced a foaming and expansion of the char layer. The carbonaceous char layer is effective in protecting the underlying material from further combustion.
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
POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Mei Wang,Xianghai Song,Jianchun Jiang,Jianling Xia,Mei Li
A zeolitic imidazolate framework material (ZIF-8) was prepared from stoichiometric zinc nitrate and 2-methylimidazole at room temperature in the presence of ammonium hydroxide . The material was characterized by a series of methods and used as a thermal stabilizer for poly (vinyl chloride) (PVC) film. The properties of the stabilized PVC were investigated using Congo red test, thermal aging test and thermal gravimetric analysis (TGA). Compared with the stabilizing efficiencies of some commonly-used reference stabilizers (e.g. CaSt 2 and ZnSt 2 ), the stabilizers including ZIF-8 [such as CaSt 2 /ZnSt 2 /ZIF-8 and ZnSt 2 /ZIF-8] exhibit better initial color stability and long-term thermal stability for PVC. The static thermal stability time was significantly prolonged from 33.13 min for PVC/CaSt 2 /ZnSt 2 to about 128.92 min for PVC/ZIF-8/ZnSt 2 at 180 °C. The superior performance is attributed to the synergistic effect of ZIF-8 and ZnSt 2 . The imidazole ligand of ZIF-8 can strongly absorb hydrogen chloride and form complexes with ZnCl 2 generated from ZnSt 2 in the PVC degradation process. In addition, the double bonds of ZIF-8 may help to form stable compounds with polyenes to further retard the PVC degradation. Dynamic mechanical and tensile properties of the PVC films were also studied.
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
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Xuguang Li,Tong Li,Tong Zhang,Cheng Gu,Shourong Zheng,Haijun Zhang,Wei Chen
Nanoscale titanium dioxide (nTiO2) is one of the most widely used metal oxide nanomaterials. Once released into the environment, nTiO2 may catalyze abiotic transformation of contaminants and consequently affect their fate and effects. Here, we show that the overall catalytic efficiency of nTiO2 for the dehydrochlorination reaction of 1,1,2,2-tetrachloroethane, a commonly used solvent, depends on the crystalline phase and exposed facets of nTiO2, which significantly affect the adsorption capacity and surface catalytic activity of nTiO2. Specifically, under all three pH conditions tested (7.0, 7.5 and 8.0), the overall catalytic efficiency of eight nTiO2 materials (as indicated by the surface-area-normalized reaction kinetic constants) followed the order of rutile > anatase > TiO2(B). For anatase and TiO2(B) materials, the overall catalytic efficiency increased with the increasing percentage of exposed {001} and {010} facets, respectively. Crystalline phase and exposed facets significantly affected adsorption affinities of nTiO2, likely by modulating surface hydrophobicity of nTiO2. Crystalline phase and exposed facets also determined the activity of surface catalytic sites on nTiO2 by dictating the concentration and strength of surface unsaturated Ti atoms, as the deprotonated hydroxyl groups chemisorbed to these reactive Ti atoms served as bases to catalyze the base-promoted reaction.
研究领域:
环境科学
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催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 24
·14330-14336
·
IF 3.108
Minghao Li,Wenzhi Li,Yijuan Lu,Hasan Jameel,Hou-min Chang,Longlong Ma
Biomass derived 5-hydroxymethylfurfural (HMF) is regarded as an important platform molecule for the synthesis of value-added chemicals and fuels, but the high production cost has always been a bottleneck for the industrial scale use of HMF. Different mineral acids (HCl and H2SO4) being used as the catalyst and different salts being used as the reaction promoter were evaluated. It was found that HCl, in combination with NaCl, in a water/γ-valerolactone system showed high selectivity and impressive efficiency for the synthesis of HMF from glucose. The optimal conditions to obtain the best HMF yield (62.45%) were 0.2 M HCl and 0.1 M NaCl at 140 °C with a residence time of 60 minutes. An 18.22% molar yield of LA was obtained as a by-product. The effect of different anions was also investigated, and it was determined that not only the hydrogen ions, but also the nature of the acid and the type of salt played a joint role in improving the HMF yield. In addition, a possible synthesis pathway was proposed for large scale production of HMF.
研究领域:
生物化学
·
可再生资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2013
·Vol. 21
·期 2
·1401-1410
·
IF 2.618
Wu Xiaoliang,Lu Shuguang,Qiu Zhaofu,Sui Qian,Lin Kuangfei,Du Xiaoming,Luo Qishi
Most studies on the treatment of chlorinated contaminants by Fe(0) focus on aqueous system tests. However, few is known about the effectiveness of these tests for degrading chlorinated contaminants such as 1,1,1-trichloroethane (TCA) in soil. In this work, the reductive degradation performance of 1,1,1-TCA by Fe(0) was thoroughly investigated in a soil slurry system. The effects of various factors including acid-washed iron, the initial 1,1,1-TCA concentration, Fe(0) dosage, slurry pH, and common constituents in groundwater and soil such as Cl − , HCO 3
− , SO 4
2− , and NO 3
− anions and humic acid (HA) were evaluated. The experimental results showed that 1,1,1-TCA could be effectively degraded in 12 h for an initial Fe(0) dosage of 10 g L −1 and a soil/water mass ratio of 1:5. The soil slurry experiments showed two-stage degradation kinetics: a slow reaction in the first stage and a fast reductive degradation of 1,1,1-TCA in the second stage. The reductive degradation of 1,1,1-TCA was expedited as the mass concentration of Fe(0) increased. In addition, high pHs adversely affected the degradation of 1,1,1-TCA over a pH range of 5.4–8.0 and the reductive degradation efficiency decreased with increasing slurry pH. The initial 1,1,1-TCA concentration and the presence of Cl − and SO 4
2− anions had negligible effects. HCO 3
− anions had a accelerative effect on 1,1,1-TCA removal, and both NO 3
− and HA had inhibitory effects. A Cl − mass balance showed that the amount of Cl − ions released into the soil slurry system during the 1,1,1-TCA degradation increased with increasing reaction time, suggesting that the main degradation mechanism of 1,1,1-TCA by Fe(0) in a soil slurry system was reductive dechlorination with 1,1-DCA as the main intermediate. In conclusion, this study provides a theoretical basis for the practical application of the remediation of contaminated sites containing chlorinated solvent.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Feng Jiang,Wanqin Wu,Zhengwei Zhu,Songsong Zhu,Huixia Wang,Li Zhang,Zhiyong Fan,Yiping Chen
Chlorpyrifos (CPF) is an extensively used organophosphorus pesticide. Recently, it has attracted increasing attention due to environmental health problems caused by it. Although numerous studies have discovered the dechlorinated photoproduct of CPF, its structure and toxicity remain largely unknown. In this study, we systematically investigated the structure and toxicity of dechlorinated photoproduct of CPF. The CPF degradation experiment was performed, and its products were identified by ultra high performance liquid chromatography-orbitrap fusion tribid mass spectrometer (UHPLC-Orbitrap Fusion TMS). Additionally, bond dissociation energy (BDE) calculations and photoproduct chemical synthesis were employed to determine the structure of dechlorinated photoproduct of CPF. The toxicity of CPF photoproduct was evaluated through the Ecological Structure Activity Relationships (ECOSAR) Class Program, the Toxicity Estimation Software Tool (T.E.S.T.) software, and acute toxicity testing. The results indicated that the dechlorinated photoproduct of CPF was identified as O,O-Diethyl-O-(3,5-dichloro-2-pyridyl) phosphorothioate (Dechloro-CPF), which was produced in large quantity within the first 30 min of photodegradation experiment. The acute and chronic toxicity values of Dechloro-CPF were obviously higher than those for the other two photoproducts. The median lethal dose (LD 50 ) of Dechloro-CPF was 31.6 mg/kg for female mice and 58.4 mg/kg for male mice. This study reveals the photodegradation mechanism of CPF and confirms that Dechloro-CPF was dechlorinated photoproduct of CPF with potential acute toxicity to aquatic species and mammalian (including human). Our findings will contribute to a more comprehensive risk evaluation of CPF in food and the environment.
研究领域:
环境科学
·
毒理学
·
农药研究
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产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Guilin He,Tuqiao Zhang,Yunfei Li,Jinzhe Li,Feiyong Chen,Jun Hu,Feilong Dong
Fleroxacin (FLE) is a widely used fluoroquinolones to cure urinary tract infections and respiratory disease, which has been frequently detected in the aquatic environment. The reactivity kinetics of FLE by chlorine and chlorine dioxide (ClO 2 ) and transformation mechanism were investigated in this study. The results showed that FLE was degraded efficiently by chlorine and ClO 2 , and both reactions followed second-order kinetics overall. The increase of disinfectant dosage and temperature would enhance the degradation of FLE. The highest removal of FLE by chlorine was achieved at a neutral condition (pH 7.4), whereas ClO 2 reaction rates increased dramatically with the increasing pH in this study condition. The number of intermediates identified in FLE chlorination and ClO 2 oxidation was seven and ten, respectively. The piperazine ring cleavage was the principal and initial reaction in both above reactions. Then, the removal of the piperazine group was predominantly in FLE removal by chlorine, while the decarboxylation mainly occurred in FLE removal by ClO 2 . The intermediates increased first and then decreased with time, while three kinds of halogenated DBPs increased with time, indicating the above-identified intermediates were further transformed to the halogenated DBPs. Additionally, compared to chlorine reaction, the reaction of ClO 2 with FLE reduced the formation of halogenated DBPs, but it also induced the formation of chlorite. The analysis of toxicity showed that compared with chlorination, the oxidation of ClO 2 was more suitable for FLE removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2023
·
IF 6.9
Yue Lu,Fangyi Liang,Fanzhi Qin,Linrui Zhong,Jianhong Jiang,Qi Liu,Shoujuan Zhang,Ming Yan,Changzheng Fan,Haoran Dong
The dehalogenation of organohalides has been a research hotspot in bioremediation field; however, the influence of tourmaline, a natural ore that can generate spontaneous electric field, on organohalide-respiring bacteria (OHRB) and their dechlorination process is not well known. In this study, the effect and mechanism of tourmaline on the reductive dechlorination of 2,3-dichlorophenol (2,3-DCP) by Desulfitobacterium hafniense DCB-2 T were explored. The characterization results confirmed that tourmaline had good stability and the optimal dosage of tourmaline was 2.5 g/L, which shortened the total time required for dechlorination reaction to 72 hr. Besides, tourmaline amendment also increased the proportion of 2-chlorophenol (2-CP) from 18% to 30% of end products, while that of 3-CP decreased correspondingly. The theoretical calculations showed that the bond charge of the ortho -substituted chlorine declined from -0.179 to -0.067, and that of meta -substituted chlorine increased from -0.111 to -0.129, which indicated that the spontaneous electric field of tourmaline affected the charge distribution of 2,3-DCP and was more conducive to the generation of 2-CP. Overall, tourmaline with the spontaneous electric field affected the reductive dechlorination pathway of Desulfitobacterium ,and the tourmaline-OHRB combining system might serve as a novel strategy for the bioremediation of environments polluted with chlorinated phenols.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
Environmental Science-Water Research & Technology
·
2022
·Vol. 8
·期 11
·2567-2579
·
IF 5.819
Fang Cheng,Jun Hou,Jun Wu,Yi Xu,Lingzhan Miao,Jun Xia,Zongli Huo
pentachlorophenol (PCP) is a kind of chlorinated aromatic contaminant that brings challenges from an environmental perspective. However, the performance of sulfidated nanoscale zero-valent iron (S-nZVI) in PCP removal remains unknown. In this study, S-nZVI was applied in the treatment of PCP-polluted water under different water chemistry conditions. The results showed that PCP was removed under the combined action of adsorption, dechlorination, and ˙OH-mediated oxidation, among which dechlorination played a leading role while oxidation lagged behind. The amount of adsorbed PCP correlated well with the PCP dechlorination rate constant (kred), except for S/Fe 0 and 0.1 and acidic initial pH (pHinitial) conditions. At neutral and alkaline pHinitial, kred increased with an increase in pHinitial due to the formation of a hydroxide layer that facilitates adsorption. At acidic pHinitial, kred increased with a decrease in pHinitial because hydrogen ions diffusing in the solution participated in the reaction. The effects of solution chemistry, such as anions, organic matter, and oxygen conditions, on PCP adsorption and transformation were also studied. Eight degradation byproducts were observed; the dechlorination products suggested that PCP dechlorination by S-nZVI occurred via a sequential pathway. PCP and its dechlorination products would then undergo ˙OH-mediated oxidation, resulting in products that are beneficial for microbes. Changes to S-nZVI after reacting and the role of sulfur were also discussed. This study confirmed that S-nZVI can be effective in the remediation of PCP-polluted groundwater. Further research is needed to optimize this remediation via coupling microbial technology and controlling the oxygen conditions.
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）