RSC Advances
·
2016
·Vol. 6
·期 110
·109023-109029
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IF 3.289
Lijuan Lan,Fanglin Du,Chuanhai Xia
Carbon nanotubes (CNTs) supported Pd catalysts (1 wt% and 5 wt%) were prepared by a conventional impregnation method and tested in liquid-phase hydrodechlorination (HDC) of para-chlorophenol (p-CP) under mild conditions (313 K and atmospheric pressure) with H2. CNTs as a catalyst support offered better performance than activated carbon (AC). The conversion of p-CP reached 72% and 82% over 5 wt% Pd/AC and 5 wt% Pd/CNTs, respectively, within 30 min. When the content of Pd was reduced to 1 wt%, the conversion of p-CP over Pd/AC and Pd/CNTs was 55% and 83%, respectively. The mechanism of this phenomenon was studied through catalyst characterization (XRD, TEM, and BET). The abovementioned results indicated that the different activities of the catalysts over different supports mainly resulted from the porous structure of the supports and nanoparticle diameters of the active metal.
研究领域:
催化化学
·
环境科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 29
·期 1
·1289-1300
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IF 4.223
Huang Tao,Du Jing,Yu Danni,Deng Shihan,Zhang Shuwen,Liu Longfei
Aqueous Fe(II)-catalyzed activation commonly deteriorates the oxidation performance of persulfate (PS) to the treatment of organic contaminants. In this study, a PS-doped layered bimetallic hydroxide (Fe–Mn hydroxide) was synthesized to construct a heterogeneously catalytic system to solve the issue brought by homogeneity. The molar ratio of Fe(II) to Mn(II) and the mass ratio of PS to Fe–Mn hydroxide both had a significant impact on the catalytic degradation of p-CP. Reaction temperatures engaged in the most essential role in influencing the degradation and removal of p-chlorophenol (p-CP). The optimal combination of factors for the preparation of PS-hydroxide and the treatment of p-CP was finally determined by significance analysis. The degradation process was appropriately fitted by the pseudo-first-order kinetic model. The benzene ring in p-CP was broken by PS-hydroxide during the adsorption. The surface modification of PS-hydroxide caused by the valence transition of Mn was beneficial to the adsorption and catalytic degradation of p-CP.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Mingyue Liu,Renliang Huang,Chuanxi Li,Mingda Che,Rongxin Su,Shuzhou Li,Jing Yu,Wei Qi,Zhimin He
Nanoscale zero-valent iron has been widely applied in environmental remediation and toxic waste treatment, especially for the degradation of persistent organic pollutants (POPs). However, the dechlorination activity of Fe nanoparticles (Fe NPs) can be suppressed by the precipitation of iron oxides generated from the corrosion of Fe-Pd NPs under alkaline conditions, leading to a decreased dechlorination efficiency. Faced with this challenge, we report a highly effective dechlorination system that functions over a broad pH range and especially well under alkaline conditions in this work. Procyanidin (PROC), a natural polyphenol, was utilized as a stabilizer to manipulate the size distribution of Fe-Pd NPs and, more importantly, as a scavenger of Fe ions to prevent iron oxide precipitation. Experiments and theoretical calculations reveal that the generated Fe ions was mainly present in the form of bis- and tris-PROC-Fe complexes in the reaction solution. Compared with pristine Fe-Pd NPs, the PROC-modified Fe-Pd NPs had a dechlorination efficiency that was increased 20-fold (pH 9.0). Notably, a normalized rate constant was enhanced by more than 2 orders of magnitude compared to the previously reported dechlorination systems. The PROC-modified Fe-Pd NPs showed excellent dechlorination efficiency over a wide pH range (2.3–13.0).
研究领域:
环境科学
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纳米技术
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化学工程
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材料科学
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DOI
高影响因子
CHEMOSPHERE
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2022
·
IF 8.943
Xinyi Jiang,Ye Xiao,Jiana Xiao,Weihua Zhang,Qiu Rongliang
Sewage sludge pyrolysis can effectively dispose of sludge and obtain sludge-derived biochar (SDBC) as an adsorbent for pollutant removal . Recently, persistent free radicals (PFRs), which have also been detected in many types of biochar, have attracted considerable attention for organic pollutant degradation . Sludge collected from a sewage treatment plant was pyrolyzed into SDBC, which contained a large amount of PFRs, and the resulting SDBC was then applied for the removal of p-chlorophenol. An SDBC dosage of 5 g L −1 was applied for treating 5 mg L −1 of p-chlorophenol; the highest removal efficiency of 90% was achieved at pH 3, and 22% of the initial p-chlorophenol was degraded by the SDBC. Hydroxyl free radicals were observed and contributed to the degradation of p-chlorophenol. The spent SDBC was reused five times after regeneration through the desorption of adsorbed p-chlorophenol. The p-chlorophenol removal efficiency remained constant, but the degradation decreased with increasing reuse cycles, suggesting that the p-chlorophenol degradation efficiency was positively correlated with the intensity of PFRs on SDBC. Further modification of the SDBC sample in HNO 3 or NaOH increased the amount of PFRs, and consequently, the degradation of p-chlorophenol under low oxygen conditions, further confirming the crucial role of PFRs in p-chlorophenol degradation. This study provides insights into the application of SDBC, a promising material, for contaminant abatement.
研究领域:
环境科学
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废物管理
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污染物去除
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DOI
PubMed
高影响因子
Catalysts
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2024
·Vol. 14
·期 7
·424
·
IF 3.8
Mingyue Liu,Gang Chen,Zhenjun Song,Zhicai He,Aiguo Zhong,Mei Cui
Catalytic dechlorination of organic chlorides by palladium (Pd) with HCOOH represents one of the most effective and promising techniques for environmental remediation. In this study, we adopted alkaline-modified porous natural sponge as support of a Pd nanocatalyst (Pd@M-Sponge) and HCOOH as a hydrogen source for the hydrodechlorination of florfenicol (FF),o-chlorophenol (o-CP), andp-chlorophenol (p-CP). Favorable conversion efficiency of FF,o-CP, andp-CP was achieved at 25 °C and atmospheric pressure attributed to the small diameter and high catalytic reactivity of the prepared Pd NPs, in addition to the slight internal mass transfer limitation of the prepared Pd@M-Sponge. High reaction rate constants were obtained even in the conditions of a low molar ratio of HCOOH top-CP (10:1) and a high concentration ofp-CP (500 mg/L). The prepared catalyst also demonstrated superior recyclability without any obvious decrease in catalytic reactivity in 20 successivep-CP dechlorination cycles. This work provides an ideal recyclable and cost-effective catalyst based on renewable and biocompatible natural material for the catalytic hydrodechlorination of chlorinated organic pollutants with formic acid and a new view for the exploration and designing of highly reactive and stable catalysts for hydrodechlorination.
研究领域:
环境科学
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催化
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纳米技术
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化学工程
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Qingwen Long,Feng Liu,Yanjie Yuan,Yuting Dai,Chunli Wang,Xuheng Li,Jing Zhang
In this study, heterogeneous Fenton-like catalyst, nano-Fe° encapsulated in hydrothermal carbon (Fe°/HTCC), was prepared via a green chemistry route, aiming at increasing the degradation efficiency of p-chlorophenol (4-CP) by controlling the stability of the catalyst and Fe(III)/Fe(II) cycling in the advanced oxidation process. The degradation of 4-CP by heterogeneous Fenton reactions was conducted with the assistance of visible light, which was monitored with the aid of the HPLC and total organic carbon analysis. The results revealed that Fe°/HTCC composite markedly enhanced both the degradation (100 %) and the mineralization efficiency (∼73.9 %) for 100 mg/L 4-CP within 60 min at pH 4.0. More importantly, the catalyst presented a high stability to resist the side oxidation, where the removal efficiency was maintained even after 5 successive cycling experiments. Electron spin resonance confirmed that in the presence of both HTCC and visible light irradiation greatly enhanced the production of •OH for the degradation and mineralization of 4-CP, which can be attributed to the enhancement of Fe(III)/Fe(II) cycling. This study paves a new way toward the rational design of Fe°–carbon composites as heterogeneous Fenton-like catalysts for potential applications into wastewater treatment.
研究领域:
环境科学
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化学工程
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材料科学
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DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2019
·Vol. 36
·期 6
·942-953
·
IF 2.476
Rong Yachan,Han Runping
Magnetic activated carbon (MAC) was prepared by co-precipitation. These particles had attractive adsorption capacity and could be easily separated from aqueous. MAC was used as adsorbent to remove p -chlorophenol ( p -CP) and p -nitrophenol ( p -NP) from solution in single and binary systems. In a single system, the equilibrium time was 60 min, the best initial pH was 3-8 and 3-6 for p -CP or p -NP adsorption, respectively. The existence of salt ions had little influence on the adsorption process, while surfactant had negative influence. The adsorption quantity from experiments was up to 97.3 mg·g −1 for p-CP and 116 mg·g −1 for p -NP at 293 K, respectively. Freundlich model and pseudo-second-order kinetic model fitted well the adsorption behavior. Thermodynamic parameters were calculated and the results showed that the process was spontaneous, exothermic and entropy production in nature. In addition, p -CP or p -NP-loaded MAC could be well reused by 0.01 mol·L −1 sodium hydroxide solution as regeneration agent. Kinetic process of desorption was fitted best by pseudo-second-order kinetic model. Results from the binary system showed that competitive adsorption existed during the process, and p -NP adsorption on MAC was easier than p -CP. Freundlich model well fitted the adsorption behavior in the binary system. Hydrogen-bonding, electron donor-acceptor and π-π interactions may be the main mechanisms of adsorption. MAC proved to be an excellent adsorbent for the removal of p -CP and p -NP from solution.
研究领域:
环境科学
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化学工程
·
水处理
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DOI
高影响因子
危险品化学品经营许可证（带存储）