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
·
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Jiasheng Zhou,Zimo Lou,Kunlun Yang,Jiang Xu,Yizhou Li,Yuanli Liu,Shams Ali Baig,Xinhua Xu
In the present study, carbon black (CB), multi walled carbon nanotubes (MWCNTs), and granular activated carbon (GAC) were employed to support palladium (Pd) catalyst. The prepared Pd/CB, Pd/MWCNTs and Pd/GAC moveable catalysts were aimed to address the common issues (easy loss of catalyst and poor long-term performance) of normal fixed catalysts. The results of various characterizations (e.g., TEM, XRD, and XPS) clearly show that the Pd nanoparticles were successfully loaded onto the carbon-supports, especially CB and MWCNTs. And more importantly, the morphologies, Pd distribution, and chemical structure of these moveable catalysts were almost not changed after 3 h reaction. The moveable Pd/CB, Pd/MWCNTs, and Pd/GAC catalysts had good reactivity for 2,4-dichlorobenzoic acid (2,4-DCBA) dechlorination, and Pd/CB exhibited the best performance. The Pd/CB also shows the best adsorption capacity of 2,4-DCBA and dechlorination product (benzoic acid, BA), and the adsorption of BA was significantly inhibited in the presence of current due to the repulsion between the both negatively charged compounds and adsorbents. The removal of 2,4-DCBA and the generation rate of BA was improved with a pre-adsorption process, which was a promising strategy with higher dechlorination rate and shortened electrolysis time. Moreover, the loss of Pd catalyst was negligible during the 10 consecutive cycles experiment, and the improved longevity could be expected. These results suggested the good reactivity, stability, and reusability of moveable Pd/CB catalyst.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Palanisamy Vasudhevan,Luo Shuhao,Zhang Ruoyu,Velu Manikandan,Dong Yu,Sandhanasamy Devanesan,Prakash Kumar Sarangi,Hui Ma,Saurav Dixit,Shengyan Pu
Chlorinated aromatic compounds are extremely dangerous, transmittable, and bioaccumulative. Ferrous-based persulfate stimulation methods are a potential approach for soil restoration, however they have limitations with ferrous accumulation. Citrate (CA) and ethylenediaminetetraacetic acid (EDTA) were used in the current investigation to enhance the efficiency of Fe(II)-activated persulfate (PS) reactions in the decomposition of 4-chlorophenol (4-CP) and 3-chlorobenzoic acid (3-CB) in soil. The combination of organic ligands with Fe(II) increased the overall iron content in the organic ligands/Fe(II)/PS systems and inhibited Fe(II) accumulation. Organic ligands absorbed Fe oxides in soil and facilitated to stimulate persulfate. The optimal concentration of organic ligands/Fe(II)/PS is 50:50:50, and around 74.11%, 70.05%, and 77.67%, 72.92% of the 4-CP and 3-CB were decomposed within 30 minutes, in contrast to 34.14% and 38.14% in the Fe(II)/PS system. The degradation percentage of 4-CP and 3-CB raised with increasing PS and Fe(II) levels, whereas high PS and Fe(II) concentrations prevented 4-CP and 3-CB degradation, most likely because of sulfate radical absorption. Furthermore, the 4-CP and 3-CB decomposition mediated by the citrate/Fe(II)/PS and EDTA/Fe(II)/PS systems were effective over a wide range of pH values (2.0–10). The organic ligands combined with Fe(II) catalyzed PS degradation showed a strong ability on enduring the effects of HCO3, Cl, and HA anions in soil on 4-CP and 3-CB decontamination. In addition, SO4 •- and OH • produced from citrate/Fe(II)/PS and EDTA/Fe(II)/PS systems were identified as the primary reactive oxygen species for 4-CP and 3-CB degradation. In conclusion, the organic ligands coupled with Fe(II) stimulated PS activation are potentially useful technique for the restoration of 4-CP and 3-CB contaminated soils.
研究领域:
环境科学
·
污染治理
✓ 已验证
产品关联
DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2021
·Vol. 87
·期 6
·
IF 4.792
Minggen Cheng,Dongmei Pei,Xiangrong He,Yongchuang Liu,Pingping Zhu,Xin Yan
The bacterial hydrolytic dehalogenation of 4-chlorobenzoate (4CBA) is a coenzyme A (CoA)-activation-type catabolic pathway that is usually a common part of the microbial mineralization of chlorinated aromatic compounds. Previous studies have shown that the transport and dehalogenation genes for 4CBA are typically clustered as an fcbBAT1T2T3C operon and inducibly expressed in response to 4CBA. However, the associated molecular mechanism remains unknown. In this study, a gene (fcbR) adjacent to the fcb operon was predicted to encode a TetR-type transcriptional regulator in Comamonas sediminis strain CD-2. The fcbR knockout strain exhibited constitutive expression of the fcb cluster. In the host Escherichia coli, the expression of the Pfcb-fused green fluorescent protein (gfp) reporter was repressed by the introduction of the fcbR gene, and genetic studies combining various catabolic genes suggest that the ligand for FcbR may be an intermediate metabolite. Purified FcbR could bind to the Pfcb DNA probe in vitro, and the metabolite 4-chlorobenzyl-CoA (4CBA-CoA) prevented FcbR binding to the Pfcb DNA probe. Isothermal titration calorimetry (ITC) measurements showed that 4CBA-CoA could bind to FcbR at a 1:1 molar ratio. DNase I footprinting showed that FcbR protected a 42-bp DNA motif (5′-GGAAATCAATAGGTCCATAGAAAATCTATTGACTAATCGAAT-3′) that consists of two sequence repeats containing four pseudopalindromic sequences (5′-TCNATNGA-3′). This binding motif overlaps with the −35 box of Pfcb and was proposed to prevent the binding of RNA polymerase. This study characterizes a transcriptional repressor of the fcb operon, together with its ligand, thus identifying halogenated benzoyl-CoA as belonging to the class of ligands of transcriptional regulators.IMPORTANCE The bacterial hydrolytic dehalogenation of 4CBA is a special CoA-activation-type catabolic pathway that plays an important role in the biodegradation of polychlorinated biphenyls and some herbicides. With genetic and biochemical approaches, the present study identified the transcriptional repressor and its cognate effector of a 4CBA hydrolytic dehalogenation operon. This work extends halogenated benzoyl-CoA as a new member of CoA-derived effector compounds that mediate allosteric regulation of transcriptional regulators.
研究领域:
微生物学
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分子生物学
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环境科学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Jiasheng Zhou,Zimo Lou,Jiang Xu,Xiaoxin Zhou,Kunlun Yang,Xiaoyu Gao,Yilin Zhang,Xinhua Xu
In this study, a novel approach was developed for the dechlorination of 2,4-dichlorobenzoic acid (2,4-DCBA) via the combination of the moveable activated carbon (AC) supported palladium (Pd) nanoparticles and nickel (Ni) foam electrode. The morphology and chemical structure of Pd/AC catalyst was investigated by various characterization techniques, including SEM, TEM, EXS-mapping, XRD, and XPS. Pd nanoparticles was successfully loaded and dispersed on the AC, accompanied with the significantly enhanced reactivity. The removal rate of 2,4-DCBA by Ni electrode with moveable Pd/AC catalyst was 222, 25, and 5 folds higher than dispersed AC and Ni electrode system, chemical deposited Pd/Ni electrode, and electrodeposited Pd/Ni electrode, respectively. Compared with the conventional electrocatalytic reductive approach which deposited Pd on the Ni foam electrode, moveable Pd/AC catalyst possesses higher surface area, more atomic H ∗ production and more active sites, favored mass transfer, and enhanced reactivity, without the consideration of catalyst loss and deactivation. The effects of Pd:AC mass ratio, constant current, initial solution pH, and electrolyte concentration on the dechlorination of 2,4-DCBA were studied. Generally, high Pd loading, constant current, and acidity favored the dechlorination of 2,4-DCBA, while excessive electrolyte would inhibit the dechlorination of 2,4-DCBA. Good longevity and recyclability of moveable Pd/AC catalyst was confirmed via consecutive experiments. The findings of the present study show that making the catalyst moveable is a promising strategy for electrocatalytic remediation technology.
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
ACS Applied Nano Materials
·
2025
·
IF 5.5
Xingsheng Wang,Guojun Wen,Siyi Cheng,Xianhua Tan,Xingyue Liu
The all-inorganic wide-bandgap CsPbCl3 perovskite is drawing increasing attention in the ultraviolet detection field due to its salient optoelectronic property and ultraviolet durability. However, the abundant intrinsic defects in polycrystalline CsPbCl3 nanofilms limit the UV detection performance of self-powered CsPbCl3 photodetectors. In this study, an efficient low-pressure annealing technique and a 4-chlorobenzoic acid (ClBA) modification strategy are proposed to suppress both the bulk and surface defects of evaporated CsPbCl3 nanofilms. It is found that low-pressure annealing can effectively ameliorate the crystallization dynamics of the CsPbCl3 nanocrystal, yielding a more homogeneous film with higher crystallinity and UV absorption capability as well as larger grain sizes and lower trap density. These are favorable for the photoelectric conversion process, thus contributing to a much enhanced UV detection performance. The multifunctional ClBA is further introduced to passivate the surface defects of the CsPbCl3 nanofilm. The electron-accepting end group of carboxyl in ClBA can effectively coordinate with the positively charged Pb2+, helping to suppress the Cl– vacancy defect and trap-assisted nonradiative carrier recombination. The ClBA passivation can also alleviate the interfacial energy barrier and enhance the charge transfer driving force, which is beneficial for improving the sensitivity and reducing the dark current level of the device. The best-performing photodetector achieves an excellent on/off ratio of 1.33 × 106, a responsivity R of 0.26 A/W, and a detectivity D* of 1.14 × 1013 Jones at 0 V bias, more superior than those of the previously reported self-powered CsPbCl3 counterparts. Additionally, our photodetector exhibits salient operational and ambient stability, conducive to their practical applications.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2017
·
IF 4.9
Hao Li,Yanbei Cao,Di Zhang,Bo Pan
The dominant adsorption mechanism of ionizable organic chemicals (IOCs) on carbonaceous materials is still unclear. This study used benzoic acid (BA), o -chlorobenzoic acid (2-CBA) and p -chlorobenzoic acid (4-CBA) as representatives of IOCs to investigate the dominant adsorption mechanism on graphene oxide (GO) and graphite (GP), with a specific emphasis on the impact of pH-dependent K OW . The order of apparent adsorption of the investigated chemicals changed with pH, which could not be explained by their constant K OW . According to our measurement, K OW varied greatly with pH. The pH-dependent adsorption of BA, 2-CBA and 4-CBA were significantly correlated with pH-dependent K OW for both GO and GP. Our observations indicated that the hydrophobic effects may dominate the apparent adsorption of BA, 2-CBA and 4-CBA on GO and GP. Electrostatic repulsion played a minor role in their reduced adsorption at high pH. Negative charge-assisted H-bond and π-π interactions may explain the adsorption of negatively charged BA, 2-CBA and 4-CBA on negatively charged GO. This study implied that pH-dependent K OW rather than constant K OW should be incorporated to understand IOC adsorption as affected by pH.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLoS One
·
2015
·Vol. 10
·期 4
·e0122740
·
IF 3.234
Jinxing Hu,Mingrong Qian,Qian Zhang,Jinglan Cui,Chunna Yu,Xiaomei Su,Chaofeng Shen,Muhammad Z. Hashmi,Jiyan Shi
Biphenyl and polychlorinated biphenyls (PCBs) are typical environmental pollutants. However, these pollutants are hard to be totally mineralized by environmental microorganisms. One reason for this is the accumulation of dead-end intermediates during biphenyl and PCBs biodegradation, especially benzoate and chlorobenzoates (CBAs). Until now, only a few microorganisms have been reported to have the ability to completely mineralize biphenyl and PCBs. In this research, a novel bacterium HC3, which could degrade biphenyl and PCBs without dead-end intermediates accumulation, was isolated from PCBs-contaminated soil and identified as Sphingobium fuliginis . Benzoate and 3-chlorobenzoate (3-CBA) transformed from biphenyl and 3-chlorobiphenyl (3-CB) could be rapidly degraded by HC3. This strain has strong degradation ability of biphenyl, lower chlorinated (mono-, di- and tri-) PCBs as well as mono-CBAs, and the biphenyl/PCBs catabolic genes of HC3 are cloned on its plasmid. It could degrade 80.7% of 100 mg L −1 biphenyl within 24 h and its biphenyl degradation ability could be enhanced by adding readily available carbon sources such as tryptone and yeast extract. As far as we know, HC3 is the first reported that can degrade biphenyl and 3-CB without accumulation of benzoate and 3-CBA in the genus Sphingobium , which indicates the bacterium has the potential to totally mineralize biphenyl/PCBs and might be a good candidate for restoring biphenyl/PCBs-polluted environments.
研究领域:
环境微生物学
·
污染治理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Jingxin Yang,Ji Li,Wenyi Dong,Jun Ma,Tingting Li,Yi Yang,Jiayin Li,Jia Gu
This study proposed deethylatrazine (DEA) as the OH probe compound during ozonation and compared with the widely used p -chlorobenzoic acid ( p CBA) for the first time. Results showed the ozone decay was not affected by DEA, but largely accelerated by p CBA as compared to the control. The DEA degradation was exclusively attributed to OH formation from ozonation of the tested waters, while p CBA was partially degraded by OH formation from the p CBA-derived propagation reactions. In synthetic waters with different OH scavenging capacities, the ozone decay rates with DEA were almost consistent with the control. The ozone decay rates with p CBA remained consistent with the control only in the synthetic waters with high OH scavenging capacities. For the synthetic waters with low OH scavenging capacities, p CBA led to higher ozone decay rates and OH exposures, and thus gave overestimated R ct values. The two OH probe compounds were also investigated in four authentic waters with different OH scavenging capacities. DEA exhibited no detectable effect on the ozone decay in all four authentic waters as compared to the control. The enhancing effects of p CBA on the ozone decay and OH formation were observed in the tap and reservoir water, which led to an overestimation of R ct as compared to the presence of DEA. In the ground water and wastewater, similar values were observed in ozone decay rates and R ct for the presence of p CBA and DEA. Thus, the use of p CBA as the OH probe compound should be carefully examined or avoided to prevent its interrupts in determining the R ct during ozonation of waters with different OH scavenging capacities. DEA is a more appropriate OH probe compound during ozonation.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Zimo Lou,Jiasheng Zhou,Mei Sun,Jiang Xu,Kunlun Yang,Dan Lv,Yaping Zhao,Xinhua Xu
A Pd/MnO 2 /Ni foam electrode with hierarchical structure was synthesized via electrodeposition for efficient electrocatalytic hydrodechlorination. Compared with the ordinary Pd/Ni foam electrode, the introduction of MnO 2 greatly enhanced the catalytic reactivity and reduced the dose of precious metal Pd. Only a quarter of Pd was required for the Pd/MnO 2 /Ni foam compared to the Pd/Ni electrode to achieve complete dechlorination of 2,4-dichlorobenzoic acid (2,4-DCBA) within 120 min. Various characterizations suggested that MnO 2 covered the surface of the Ni foam and increased the specific surface area of the electrode, while Pd nanoparticles were subsequently deposited on MnO 2 . The atomic H ∗ -based indirect dechlorination was the dominant pathway while only approximately 13% of 2,4-DCBA was removed by direct electron transfer. Atomic H ∗ adsorbed on Pd acted as the key active species for the dechlorination of 2,4-DCBA by the Pd/MnO 2 /Ni foam electrode in this study. The introduction of MnO 2 would promote the water dissociation and the hydrogen evolution reaction, and provide Pd with more atomic H ∗ . Pd/MnO 2 /Ni foam exhibited good stability and reusability according to the XPS spectra and consecutive electrocatalytic experiments, which suggested its long-term potential for efficient removal of chlorinated contaminants. This work demonstrated a new strategy to design efficient electrocatalysts with less precious metal.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIODEGRADATION
·
2017
·Vol. 29
·期 1
·1-10
·
IF 2.018
Wang Hui,Hu Jinxing,Xu Kai,Tang Xianjin,Xu Xinhua,Shen Chaofeng
Two biphenyl-degrading bacterial strains, SS1 and SS2, were isolated from polychlorinated biphenyl (PCB)-contaminated soil. They were identified as Rhodococcus ruber and Rhodococcus pyridinivorans based on the 16S rRNA gene sequence, as well as morphological, physiological and biochemical characteristics. SS1 and SS2 exhibited tolerance to 2000 and 3000 mg/L of biphenyl. And they could degrade 83.2 and 71.5% of 1300 mg/L biphenyl within 84 h, respectively. In the case of low-chlorinated PCB congeners, benzoate and 3-chlorobenzoate, the degradation activities of SS1 and SS2 were also significant. In addition, these two strains exhibited chemotactic response toward TCA-cycle intermediates, benzoate, biphenyl and 2-chlorobenzoate. This study indicated that, like the flagellated bacteria, non-flagellated Rhodococcus spp. might actively seek substrates through the process of chemotaxis once the substrates are depleted in their surroundings. Together, these data provide supporting evidence that SS1 and SS2 might be good candidates for restoring biphenyl/PCB-polluted environments.
研究领域:
环境微生物学
·
生物修复
·
微生物生态学
·
趋化性
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Conghao Sun,Yin Li,Yong Ke,Zhiyan Zeng,Weizhen Liu,Zhang Lin,Liyuan Chai
Beryllium is a very important strategic metal and has been applied in high-tech industries. Since the low beryllium content in minerals, the enrichment technique is a vital aspect of beryllium smelting. In this study, we present a novel protic ionic liquid, 4-Hydroxymethyl-5-methylimidazolium p-Chlorobenzoate ([Hymim][pCb]), as an efficient and environmentally friendly extraction solvent for beryllium preconcentration in aqueous solution. Our research demonstrates that BeII can be captured rapidly with high efficiency, reaching nearly 99.6% within 2 h. By controlling the initial metal concentration and pH condition, we could achieve the selective extraction of beryllium in the presence of other heavy metal ions. Our findings also shed new light on the extraction mechanism established by the material characterizations and density functional theory (DFT) calculation, revealing that metal ions disrupt the proton transfer between the cation and anion in the ionic liquid, leading to metal chelation with the cation and subsequent translation of the anion into an aqueous solution. Overall, our research presents a novel method for the enrichment of beryllium in the smelting process while also expanding the scope of protic ionic liquid applications. The efficient and selective extraction of beryllium demonstrated in this study holds great promise for the advancement of beryllium-related industries.
研究领域:
化学
·
材料科学
·
环境科学
·
冶金学
✓ 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）