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You X.-Y.,Central South University | You X.-Y.,National Engineering Research Center for Pollution Control of Heavy Metals | You X.-Y.,Chinese Research Academy of Environmental Sciences | Chai L.-Y.,Central South University | And 7 more authors.
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2013

Activated carbon after saturated adsorption of EDTA was used as particle electrode in a three-dimensional electrode reactor to treat EDTA-containing wastewater. Electrochemical method was used to regenerate activated carbon after many times of electrolysis. Based on the analysis of infrared spectra of activated carbon after adsorption and repeated electrolysis, EDTA was degraded into glycine, and then non-catalytic activated associated complex was formed with N - H bond on the activated carbon. The catalytic ability of the activated carbon vanished and the EDTA degradation efficiency was dropped. Activated carbon could be effectively regenerated by electrochemical method in the three-dimensional reactor. Effects of electric current, conductivity and pH on activated carbon regeneration were investigated, and the optimum conditions were concluded as follows: 100-300 mA of current intensity, 1.39 mS/cm of electric conductivity, 60 min of electrolysis time and pH 6.0-8.0. Under the optimized conditions, the activity of the activated carbon can be recovered and the residual total organic carbon (TOC) was below 10 mg/L (the initial TOC was 200 mg/L) in the three-dimensional electrode reactor. © 2013 The Nonferrous Metals Society of China.

Yang J.,Central South University | Yang J.,National Engineering Research Center for Pollution Control of Heavy Metals | You X.-Y.,Central South University | You X.-Y.,National Engineering Research Center for Pollution Control of Heavy Metals | And 6 more authors.
Zhongguo Youse Jinshu Xuebao/Chinese Journal of Nonferrous Metals | Year: 2012

The degradation technology of phenol in wastewater via three-dimensional electrode reactor was proposed, and then the degradation mechanism of phenol was investigated by the electrochemical methods. The results show that the removal efficiency of total organic carbon (TOC) can reach 95% under conditions of pH 6-7, influent flow rate of 180 mL/min, 25°C, NaCl dosage of 1 g/L, electric density of 100 mA and electrolysis time for 1.5 h, and using the pretreated activated carbon as particle electrode. The hydroxyl radicals are generated and adsorbed on the surface of activated carbon electrode during the process of electrochemical degradation. Meanwhile, the micro-batteries are formed by the radicals and adsorbed phenol. In the micro-cell, firstly phenol is degraded into the intermediates, such as catechol, resorcinol and hydroquinone, and then those intermediates are mineralized into CO 2 and H 2O. Furthermore, the anodic polarization curves show that phenol can be oxidized at the anode surface. However, the hydroxyl radical is the major contributor for phenol degradation.

Hu W.,Central South University | Hu W.,National Engineering Research Center for Pollution Control of Heavy Metals | Min X.,Central South University | Min X.,National Engineering Research Center for Pollution Control of Heavy Metals | And 8 more authors.
RSC Advances | Year: 2016

In this study, we developed a novel selective method for copper quantification based on gold nanoclusters (GNCs) and DNAzyme. The GNCs were used as the sensing interface to immobilize with the DNAzyme capturing Cu2+ ions. The DNAzyme could be activated to cleave the substrate strand into two DNA fragments in the presence of Cu2+, and produce changes in the interfacial properties of the electrode. The difference in the interfacial electron-transfer resistance was probed in the presence of the reversible redox couple, Fe(CN)6 3-/4-, as a marker using electrochemical impedance spectroscopy (EIS). A Randles equivalent circuit was employed to evaluate the EIS results. The charge transfer resistance (RCT) of the Fe(CN)6 3-/4- redox indicator decreased remarkably after hybridization with Cu2+. The difference in RCT values before and after hybridization with Cu2+ showed a linear relationship with the concentration of Cu2+ in a range of 0.1-400 nM, with a detection limit of 0.0725 nM (S/N = 3). Furthermore, with the application of Cu2+ dependent DNAzyme, the proposed sensing system exhibited high selectivity. This biosensor demonstrated promising potential for Cu2+ detection in real samples. © The Royal Society of Chemistry 2016.

Zhang L.,Central South University | Wang Y.,Central South University | Peng B.,Central South University | Peng B.,National Engineering Research Center for Pollution Control of Heavy Metals | And 10 more authors.
Green Chemistry | Year: 2014

A new sustainable microorganism-based route is reported for the synthesis of carbon-fiber monolith through using filamentous fungi as feedstock. The fungi are cultured in solution within three days with biomass as nutrient, and fungi concentration reaches as high as 11 mg mL-1 on an average. Based on the rational control of fungi filtration and drying, fungi membrane or aerogel was obtained. Through pyrolysis in an inert atmosphere, intact carbon-fiber monolith (membrane or aerogel) was formed and its conductivity was more than 1 S cm-1. The carbon-fiber aerogel and membrane synthesized at 800 °C was doped by N (∼2.4 at%) and O (∼1.3 at%) and displayed a BET surface area of ∼305 and ∼20 m2 g-1, respectively. Mesopores and macropores were detected in the carbon materials. The carbon-fiber monolith showed promising capability to improve the cyclability and capacity of lithium-sulphur (Li-S) batteries, and are expected to be used as versatile electrode in energy storage. This journal is © the Partner Organisations 2014.

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