CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yun Fan,Haijun Zhang,Meihui Ren,Yichi Zhang,Yun Li,Longxing Wang,Jiping Chen
It is of great significance to develop the low-temperature catalysts for the reduction in emission of chlorinated aromatic hydrocarbons (CAHs) from the industrial thermal processes. In this work, the bimetallic Ce-Zr/UiO-66 catalysts were synthesized by a solvothermal method to degrade CAHs. Powder X-ray diffraction, Fourier transform infrared spectra and X-ray photoelectron spectroscopy analyses showed that cerium was successfully incorporated into the lattice of Zr/UiO-66 without destroying the structure of metal–organic frameworks. The activities of Ce-Zr/UiO-66 catalysts for CAHs degradation varied with the concentration of cerium. Ce 0.2 Zr 0.8 /UiO-66 with the highest surface area (1502 m 2 g −1 ) presented the highest efficiency (>85%) for hexachlorobenzene degradation at low heating temperature (100–150 °C) with less formation of polychlorinated dibenzo- p -dioxins and dibenzofurans. Appropriate amount of water (5 wt%) and nitrogen atmosphere were beneficial to improve degradation efficiency. The degradation products proved that hydrodechlorination and oxidation of CAHs both occurred on the catalysts.
研究领域:
环境化学
·
催化
·
材料科学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2023
·Vol. 34
·期 44
·445601
·
IF 3.5
Shuyuan Xu,Bingbao Mei,Fengjiao Li,Jianing Mao,Changxing Huang,Yufeng Yan,Ningning Chen,Yinghua Xu,Meiqin Shi
The application of electrochemical hydrodechlorination has been impeded due to the low utilization and activity of Pd catalyst. Herein, a series of Pd catalysts were prepared via the controllable evolution of Zn state during the pyrolysis of ZIF-8 nanosheet. Various forms of Pd with different chemical surroundings were generated upon the combined use of galvanic displacement and ion exchange process. Electrocatalytic hydrodechlorination of 4-chlorophenol was performed and the electrocatalytic hydrodechlorination efficiency of Pd/CN reaches 100% within 3 h at extra low Pd concentration. The coexistence of zero-valent Pd (Pd0) and nitrogen coordinated Pd (Pd–N) was verified by XAFS which provide multiple active sites for focusing on adsorbing H* and cracking C–Cl respectively. The synergetic effect between different chemical state of Pd for efficient hydrodechlorination of chloroaromatics and scheme for dexterous preparation of Pd based electrocatalyst are proposed and discussed.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2013
·Vol. 26
·期 3
·355-360
·
IF 0.632
Lai Bin,Zhao Yi,Yan Li‐feng
The conversion of cellulose to 5‐hydroxymethylfurfural (HMF) has been investigated by a one‐pot consecutive reaction. At first, cellulose was depolymerised into glucose via a fast degradation of cellulose in molten ZnCl 2 in the presence of hydrochloric acid, and the yield of glucose is 75% in 120 s at reaction temperature of 95 °C. Then, DMSO was used as solvent and different kinds of metal chloride were added as catalysts, and the conversion was carried out continuously at 110–130 °C for 0.5–4 h. The yield of HMF was 53% when CrCl 3 were used as catalyst. The one‐pot two steps conversion was carried out at atmosphere pressure, and it is a simple route to prepare HMF from lignocellulosic feedstock on a large scale.
研究领域:
生物化学
·
可再生资源与能源
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhiwei Zhao,Yu Li,Fei Wang,Zhitao Xu,Sai Zhang,Li Li,Junyu Fan,Jie Liu
Monitoring and regulating the formation of toxic byproducts in advanced oxidation processes (AOPs) is of great significance for their practical application in water treatment. In this work, we found that dichloroacetonitrile (DCAN), a common N-containing byproduct in chloramination disinfection, can be formed with the co-presence of g-C 3 N 4 and chloride in a peroxymonosulfate (PMS) system. The measured value was 12.01 μM within 12 h under the given conditions. Structure analysis of raw and used g-C 3 N 4 demonstrated that g-C 3 N 4 decomposition indeed occurred, and C = N bonds acted as primary active sites, releasing N resources for subsequent DCAN formation. Additionally, multiple parameters, including the reactant (i.e., g-C 3 N 4 , PMS, Cl - , phenol) dose and solution pH, were observed to remarkably affect the yield of DCAN. Phenol was identified as the organic precursor of DCAN and may cooperate with inorganic chloramine to promote DCAN formation via the decarboxylation pathway. This study highlights the generation of DCAN in N-involved catalyst-based AOPs and improves understanding of the DCAN formation mechanism.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Carbon Trends
·
2024
·
IF 3.1
Conglin Zhang,Haichao Li,Zezhong Lin,Bingxuan Du,Xingping Zhang
Using PVC as raw material and KOH as activator, the carbon adsorption material with ultra-high specific surface area up to 5677.2 m 2 /g was prepared by chemical activation method, and its structure was characterized to study its adsorption performance on methylene blue solution; the activated mixture was analyzed for chlorine element and the recovery of chlorine element was calculated. The results show that the surface of the obtained activated carbon material is in the shape of smooth lotus root flakes with well-developed pore structure; the adsorption value of methylene blue adsorption can reach 765.0 mg/g, which can adsorb methylene blue solution quickly and efficiently; the elemental chlorine can be recovered efficiently with a recovery rate of 95.33 %, which can effectively reduce the toxic hydrogen chloride gas produced in the process of PVC pyrolysis. Excellent adsorption capacity of H 2 , CO 2 and CH 4 . This experiment can provide an effective method for the harmless treatment of PVC.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Wan-Ting Yang,Yang-Yang Xie,Shi-Mei Xu,Gang Wu,Yu-Zhong Wang
The increasing accumulation of plastic waste, particularly polyvinyl chloride (PVC) plastics containing halogens, has led to severe environmental issues. To achieve environmentally friendly treatment and upcycling of PVC , this study presents a straightforward two-step method for converting PVC into porous carbon materials. First, PVC is subjected to ambient temperature ball milling in a KOH/polyethylene glycol (PEG) system to efficiently remove chlorine atoms (degree of dechlorination up to 93.88 %), yielding a crosslinking precursor. Subsequently, the precursor is carbonized via co-carbonization with K 2 CO 3 , resulting in a layered porous carbon material with a high surface area and abundant micropores and mesopores. This method significantly reduces the emission of the corrosive gas HCl during carbonization while improving the carbon yield. The prepared carbon material exhibits excellent electromagnetic wave (EMW) absorption performance, with a minimum reflection loss (RL) of −47.65 dB at a thickness of 3.5 mm and filler loading of 10 wt%, along with an effective absorption bandwidth (EAB) of 4.96 GHz. This method has the potential to be extended to practical PVC products and represents a new approach to the upcycling of waste PVC.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Carbon Capture Science & Technology
·
2025
·
IF 10.5
Haoyu Xiao,Guocheng Wang,Shengwei Feng,Shuaishuai Lei,Yang Yang,Yingquan Chen,Haiping Yang,Hanping Chen
Understanding the influence of polyvinyl chloride (PVC) on carbon nanotube (CNT) production from waste plastics is essential for enhancing the high-value utilization of real plastic waste. Hence, the influence of chlorine (Cl) on plastic catalytic pyrolysis for CNT formation was investigated from the perspective of Cl in the volatile phase and the catalyst phase, aiming to find the potential strategy to mitigate the impact of Cl. The results showed that catalyst reduction effectively converts Fe 2 O 3 into a more stable Fe 2 AlO 4 spinel structure, thereby safeguarding the active Fe site from deactivation. The carbon yield increased from 17 wt% to 25 wt%, in the instance of real plastic with roughly 10 wt% PVC content. And, at a lower catalytic temperature (600 °C), the catalyst also displays increased resistance to hydrogen chloride (HCl) volatiles. Optimal adjustment of pyrolysis and catalytic temperatures can significantly mitigate catalyst deactivation by Cl and produce CNT with a maximum carbon yield of 28 wt%. This work proposes a pioneering anti-chlorine process designed to recover high-value products from plastic waste, advancing carbon sequestration strategies.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2017
·Vol. 228
·期 6
·1-9
·
IF 1.702
Gan Guojuan,Qiu Lin,Wu Huan,Hong Huachang,Mazumder Asit,Pan Xiangliang,Liang Yan
Occurrence of halonitromethanes (HNMs) in drinking water has been a concern recently due to the potentially high human health risks of HNMs. Mechanisms of formation of HNMs during disinfection has remained controversial. The objective of this study was to investigate the effects of nitrite on the formation of trichloronitromethane (TCNM), a dominant HNM species occurring in chlorinated water. Polyhydroxy-phenols (hydroquinone, catechol, resorcinol, and phloroglucinol) and sugars (glucose, maltose, and lactose) were compared as surrogates/model compounds of common organic precursors of humic and non-humic substances in natural organic matter, respectively. The results showed that TCNM was not detectable after chlorinated sugars with the addition of nitrite. Upon chlorinating the polyhydroxy-phenols, TCNM formation varied greatly among different compounds, i.e., resorcinol > phloroglucinol > catechol >> hydroquinone. The results demonstrated that TCNM formation in the presence of nitrite was a function of aromaticity as well as the position and number of hydroxyl groups on the benzene rings of a compound, and the TCNM formation potential of humic substances was greater than that of non-humic substances. For catechol, resorcinol, and phloroglucinol, TCNM formation varied greatly with pH but generally remained stable with the increase of reaction time and temperature.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL QUALITY
·
2016
·Vol. 45
·期 6
·1933-1940
·
IF 2.238
Guojuan Gan,Rongwu Mei,Lin Qiu,Huachang Hong,Qingjun Wang,Asit Mazumder,Shikai Wu,Xiangliang Pan,Yan Liang
Catechol, nitrite, and dissolved metals are ubiquitous in source drinking water. Catechol and nitrite have been identified as precursors for halonitromethanes (HNMs), but the effect of metal ions on HNM formation during chlorination remains unclear. The main objective of this study was to investigate the effect of metal ions (Fe 3+ , Ti 4+ , Al 3+ ) on the formation of trichloronitromethane (TCNM) (the most representative HNM species in disinfected water) on chlorinating catechol and nitrite. Trichloronitromethane was extracted by methyl tert-butyl ether and detected by gas chromatography. The results show that metal ions promoted the formation of TCNM and that the enhancement efficiency followed the order of Fe 3+ > Ti 4+ > Al 3+ . Trichloronitromethane formation increased greatly within 2 h, and a basic condition (pH 8–9) favored TCNM formation more than acidic or neutral conditions. The conjoint effect of the metal–ion mixtures was shown to be similar to that of the single metal ion having the highest promoting effect on TCNM formation. Our results strongly suggest that metal ions play a significant role in enhancing TCNM formation. Core Ideas Metal ions increased TCNM formation during chlorination of catechol and nitrite. Type and concentration of metal ions affected TCNM yield. Effect of metal ions on the formation of TCNM varied with pH. Conjoint effect of metal ions on TCNM formation was not obvious.
研究领域:
环境科学
·
化学
✓ 已验证
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
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
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
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）