Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control

Guangzhou, China

Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control

Guangzhou, China
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Huang B.,Hunan University | Huang B.,Guangdong Provincial Key Laboratory of Atmospheric environment and Pollution Control | Zhu Y.,Hunan University | Li J.,Hunan University | And 2 more authors.
Electrochimica Acta | Year: 2017

The relationship between electrocatalysis and molecular electrochemistry for the reductive dechlorination of organic chlorides has been a central topic for decades. Herein, we try to reveal the catalytic property of silver electrode by investigating the thermodynamics of dissociative electron transfer (DET) to C–Cl bonds of polychloroethanes (PCAs) on both inert (GC) and catalytic (Ag) electrodes. By extending the “sticky” DET model reported by Savéant, we show that the catalyzed DET model can well describe the activation-driving force relationships for the electrocatalytic dechlorination on Ag, where in addition to the possible ion-dipole interations, the adsorption of chlorinated species onto Ag surface, which is found to play a fundamental role in the electrocatalysis process in this study, is introduced in the new developed DET model. In this work, we firstly report that the catalytic property of Ag electrode characterizing with drastically postive shift of reduction potential is ascribed to the lower of intrinsic barrier free energy, rather than the activation free energy, for the reductive dechlorination. Moreover, the intrinsic relationship of electrocatalysis and molecular electrochemistry is clearly indicated and quantitatively developed. These results may provide new insights in uncovering both the nature of catalytic property of Ag and the relationship of electrocatalysis and molecular electrochemistry for PCAs and other halocarbons. © 2017 Elsevier Ltd

Huang B.,Hunan University | Huang B.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Qi C.,Hunan University | Yang Z.,Hunan University | And 4 more authors.
Journal of Catalysis | Year: 2017

The widespread presence of humic acids (HAs) and chromium (Cr) in aquatic systems and drinking water sources is a serious threat to the environment and human being. However, no studies on the potential interaction and simultaneous removal of these two types of contaminants have been conducted. Here, a novel electro-Fenton process was reported for the effective and simultaneous removal of HAs and Cr(VI), where H2O2 was in situ produced from the electro-generated H2 and O2 on the Pd/Fe3O4 nanocatalyst surface and Fe(II) was provided from the support. We show that HAs exhibit as reductants and sorbents as well as electron shuttles for the removal of Cr(VI); HAs were efficiently mineralized, as revealed by a total organic carbon removal efficiency of beyond 90%, and Cr(VI) was completely reduced with 90% of total Cr removal. The Pd/Fe3O4 nanocatalysts, as electron transfer and hydrogen atom transfer carriers, were found to play fundamental roles for the removal of HAs and Cr(VI). The HAs degradation was driven by the sequentially involved O2 - and OH radicals during electro-Fenton process. The reduction of Cr(VI) was primarily attributed to the contributions from Pd/Fe3O4 nanoparticles and atomic hydrogen on the catalyst surface. In a similar manner, a good recycle of Fe3+ to Fe2+ was accelerated, which favored the Fenton reaction to generate reactive oxidizing species. Importantly, the energy consumption of this electro-Fenton process for HAs degradation was almost 2 orders of magnitude lower than those of reported electrochemical oxidation. The Pd/Fe3O4 nanocatalysts showed excellent removal performances for HAs and Cr(VI) after eight times repeated treatment. This work reports a cost-effective methodology for simultaneous removal of HAs and Cr(VI) and provides a new insight into efficient elimination of complex contaminants by heterogeneous catalysis. © 2017 Elsevier Inc.

Liu B.,Guangdong University of Technology | Liu B.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Chen H.,Northwest University, China | Oh S.C.,University of Maryland University College | Fang Y.,Guangdong University of Technology
Microporous and Mesoporous Materials | Year: 2017

Multifunctional porous hybrid materials have recently received a lot of attentions because they combine the advantages of incorporating both inorganic oxides and organic species into the structure to solve the limitation of sole component material. This paper reports a type of model of organic pillared MFI zeolite catalyst, in which the full-atom mimetic model is constructed by using molecular modeling technique. Dreiding force field is used to calculate the interactions between sorbate–sorbate and sorbate–sorbent in the organic pillared MFI zeolite. The optimized model is characterized by calculating low-angle and high-angle X-ray diffraction patterns. Besides, the adsorption behavior of benzene and toluene is also investigated through the mimetic model. Simulated adsorption isotherms of benzene and toluene are agreement with the experimental data at low pressure. Density distributions of benzene and toluene show that toluene adsorbs preferentially in the region of interlayer space of lamellar MFI zeolite while benzene tends to adsorb in the area of micropores at low pressure. With increasing pressure, the guest molecules gradually fill in the area of micropores and mesopores of the organic pillared MFI zeolite. Moreover, the developed strategy in the present work can be applied to build other model for organic pillared zeolite catalyst by arranging different zeolite frameworks or organic species. © 2017 Elsevier Inc.

Li H.,South China University of Technology | Huang S.,South China University of Technology | Huang S.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Zhang Y.,South China University of Technology
Journal of Microbiology | Year: 2016

Cr(VI) pollution is increasing continuously as a result of ongoing industrialization. In this study, we investigated the thermophilic denitrifying bacterium Chelatococcus daeguensis TAD1, isolated from the biofilm of a biotrickling filter used in nitrogen oxides (NOX) removal, with respect to its ability to remove Cr(VI) from an aqueous solution. TAD1 was capable of reducing Cr(VI) from an initial concentration of 10 mg/L to non-detectable levels over a pH range of 7–9 and at a temperature range of 30–50°C. TAD1 simultaneously removed both Cr(VI) and NO3 −-N at 50°C, when the pH was 7 and the initial Cr(VI) concentration was 15 mg/L. The reduction of Cr(VI) to Cr(III) correlated with the growth metabolic activity of TAD1. The presence of other heavy metals (Cu, Zn, and Ni) inhibited the ability of TAD1 to remove Cr(VI). The metals each individually inhibited Cr(VI) removal, and the extent of inhibition increased in a cooperative manner in the presence of a combination of the metals. The addition of biodegradable cellulose acetate microspheres (an adsorption material) weakened the toxicity of the heavy metals; in their presence, the Cr(VI) removal efficiency returned to a high level. The feasibility and applicability of simultaneous nitrate removal and Cr(VI) reduction by strain TAD1 is promising, and may be an effective biological method for the clean-up of wastewater. © 2016, The Microbiological Society of Korea and Springer-Verlag Berlin Heidelberg.

Zhang Q.,Kunming University of Science and Technology | Zhang Q.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Xu L.,Kunming University of Science and Technology | Ning P.,Kunming University of Science and Technology | And 2 more authors.
Applied Surface Science | Year: 2014

A series of CuO-CeO2-ZrO2 catalysts were prepared by different methods and applied to the selective catalytic reduction of NO with NH3 reaction at low temperature. The results showed that the SCR activities, morphology, particles dimension, and the surface chemical state of CuO-CeO2-ZrO2 catalysts were obviously influenced by the preparation method. The SCR performance results showed that the CuO-CeO2-ZrO2 catalyst prepared by co-precipitation method presented the best activity in the temperature range of 125-180 °C. The characterization results showed that the Ce4+, Ce3+, Cu2+ and Cu+ species were coexistence in the CuO-CeO2-ZrO2 catalysts, and the Cu species mainly existed as Cu2+. It was also found that the high surface area, the synergistic effect between copper and ceria, enhanced acidity and the highly dispersed copper species were responsible for the high SCR activity of the CuO-CeO2-ZrO2 catalyst. © 2014 Elsevier B.V. All rights reserved.

Liang H.-Y.,South China University of Technology | Zhang Y.-Q.,South China University of Technology | Zhang Y.-Q.,Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology | Zhang Y.-Q.,The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | And 3 more authors.
Chemical Engineering Journal | Year: 2013

Oxidation of p-chloroaniline (PCA) by persulfate (PS) performed with a novel supported copper oxidate catalyst in an aqueous solution at ambient temperature (i.e. 20°C) was investigated in this study. This study focused mainly on determining the proportions of heterogeneous catalysis in the copper oxidate/PS combined system. There existed a more remarkable effect on the degradation of PCA in the copper oxidate/PS combined system than in the Cu2+/PS or only PS system. The effects of copper oxidate dosage, persulfate concentration, and initial solution pH on the oxidation of PCA were also evaluated. Higher copper oxidate dosage and persulfate concentration resulted in higher PCA degrading rates, the optimal initial pH was determined as 7.0. Moreover, the change in the degradation of PCA by pH was also investigated in terms of the contribution of dissolved copper ion in leaching solution. We inferred that homogeneous catalysis was of increasing importance and the copper ion dissolved from the copper oxidate was regarded as the key factor activating the persulfate under acidic conditions (pH 3.0), heterogeneous catalysis played the main role in the oxidation of PCA at pH 5-7. However, both heterogeneous catalysis and base-activated persulfate contributed to the degradation of PCA under alkaline conditions (pH 11). In addition, the radical mechanism was studied and three radical scavengers (phenol, methanol (MA) and Tert-butanol (TBA)) were used to determine the kind of major active areas taking part in the PCA degradation at pH 7. © 2012 Elsevier B.V.

Li L.,Guangdong Power Grid Corporation | Wang L.,South China University of Technology | Wang L.,U.S. National Center for Atmospheric Research | Pan S.,Guangdong Power Grid Corporation | And 4 more authors.
Cuihua Xuebao/Chinese Journal of Catalysis | Year: 2013

A series of manganese and cerium oxides supported on multi-walled carbon nanotubes (MWCNTs) catalysts for low-temperature NH3 selective catalytic reduction (SCR) of NOx were prepared by the pore volume impregnation method. The SCR activity of Mn-Ce/MWCNTs catalysts was compared with that of Mn/MWCNTs catalyst. The effects of Ce were characterized by transmission electron microscopy, N2 adsorption-desorption, H2 temperature-programmed reduction, X-ray photoelectron spectroscopy and X-ray powder diffraction. The results show that the addition of ce-rium oxides could improve the SCR activity of Mn/MWCNTs catalysts. Mn-Ce/MWCNTs catalyst with a Ce/Mn ratio of 0.6 was found to have the highest activity. The addition of cerium oxides enhanced the dispersion of metal oxides on the MWCNTs. It could also increase the specific surface area and total pore volume, and decrease the average pore size of the catalysts. Ce would improve the concentration of oxygen and the valence of manganese. Furthermore, from the XRD results, it was obvious that the crystalline MnOx disappeared because of the introduction of Ce to the catalyst. MnOx mainly existed in an amorphous state or microcrystal structure in the Mn-Ce/MWCNTs catalysts. CeO2 was found to be the main phase for CeOx. © 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Peng D.,South China University of Technology | Peng D.,Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | Lan Z.,South China University of Technology | Lan Z.,Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters | And 7 more authors.
Bioresource Technology | Year: 2013

In this work, a new biotechnological procedure was developed using cellulase as a modifier to produce oil sorbent from corn stalk (CMCS). Cellulase treatment of raw corn stalk (RCS) with enzyme loading of 100 U/g at 45 °C for 6 h resulted in high oil sorption capacity. The sorption capacities of vegetable oil, diesel and crude oil by CMCS were 18.47, 16.15 and 27.23 g/g, respectively, which were found to be much higher than RCS. XRD, BET and SEM were applied to characterize RCS and CMCS. The effects of sorbent dose (0.1-0.5 g), initial oil amount (5-30 g), and the sorption kinetics were also studied. This work demonstrated that corn stalk modified by cellulase is an efficient and environment-friendly biosorbent for the removal of spilled oil. © 2013 Elsevier Ltd.

Hussain I.,South China University of Technology | Zhang Y.,South China University of Technology | Zhang Y.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Huang S.,South China University of Technology | Huang S.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control
RSC Advances | Year: 2014

Zero valent iron (ZVI) can activate persulfate to generate sulfate free radicals which are a strong oxidant to degrade organic pollutants. The oxidative degradation of aniline in aqueous solution by persulfate activated with zero valent iron was studied under laboratory conditions. Batch experiments were conducted to investigate the effects of different parameters such as pH, ZVI concentration, aniline concentration, persulfate concentration and reaction temperature on aniline degradation. The results showed that aniline degradation increased with increasing temperature. The optimum dosage of ZVI was 0.4 g L-1 and 85% aniline degradation was observed. Maximum aniline degradation was observed at pH 4.0, whereas at pH above or below 4.0, aniline degradation efficiency was decreased. In the persulfate-ZVI system, the apparent energy of activation for aniline degradation was 14.85 kJ mol-1. The existence of persulfate radicals and hydroxyl radicals produced during the degradation of aniline were identified with scavenger ethanol and tert-butyl alcohol. The reaction intermediates nitrobenzene, nitroso-benzene and p-benzoquinone were detected by gas chromatography-mass spectrometry and based on these intermediates obtained a probable pathway for aniline degradation has been proposed.

Lin J.-M.,South China University of Technology | Fu M.-L.,South China University of Technology | Fu M.-L.,Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control | Zhu W.-B.,South China University of Technology | And 3 more authors.
Journal of Molecular Catalysis | Year: 2014

Citric acid complex method and coprecipitation method were utilized for the preparation of MnOx(0.4)-CeO2 catalysts towards model soot oxidation. The structure properties and surface reactive species on the catalysts were characterized by XRD, BET, Raman, H2-TPR, O2-TPD and XPS. The soot catalytic oxidation mechanism was investigated by in situ Raman spectra. The results showed that MnOx(0.4)-CeO2-CA catalyst synthesized with citric acid complex method, with more Mn ions incorporated into the ceria lattice, possessed larger specific surface area, more oxygen vacancies, Mn4+ and Ce4+. Thus, MnOx(0.4)-CeO2-CA exhibited better redox properties and higher soot oxidation activities. O- was found to play a key role in soot oxidation. Mn4+ and Ce4+ favored to the redox reaction, and the increase of oxygen vacancies were propitious to the adsorption, migration and transformation of oxygen species, boosting soot oxidation. The reaction path was O- spilled from the catalyst and reacted with soot firstly, oxygen vacancy was formed simultaneously, and then part of the lattice oxygen O2- replenish the consumed O-. Gaseous oxygen O2 adsorbed to the oxygen vacancy and activated to O2 -, and then changed to O-(can transformed to O2- in the further step), O- migrated to the soot surface and oxidizes it very efficiently in the next cycle, CO2 was formed subsequently.

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