Jianmeng Chen

Zhejiang University of Technology, Hang-hsien, Zhejiang Sheng, China

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Publications (115)334.65 Total impact

  • Shijin Wu · Yuan Li · Penghua Wang · Li Zhong · Lequan Qiu · Jianmeng Chen
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    ABSTRACT: The environmental risk of fluoride and chloride pollution is pronounced in soils adjacent to solar photovoltaic sites. The elevated levels of fluoride and chloride in these soils have had significant impacts on the population size and overall biological activity of the soil microbial communities. The microbial community also plays an essential role in remediation of these soils. Questions remain as to how the fluoride and chloride contamination and subsequent remediation at these sites have impacted the population structure of the soil microbial communities. We analyzed the microbial communities in soils collected from close to a solar photovoltaic enterprise by pyrosequencing of the 16S rRNA tag. In addition, we used multivariate statistics to identity the relationships shared between sequence diversity and heterogeneity in the soil environment. The overall microbial communities were surprisingly diverse, harboring a wide variety of taxa and sharing significant correlations with different degrees of fluoride and chloride contamination. The contaminated soils harbored abundant bacteria that were probably resistant to the high acidity, high fluoride and chloride concentration, and high osmotic pressure environment. The dominant genera were Sphingomonas, Subgroup_6_norank, Clostridium sensu stricto, Nitrospira, Rhizomicrobium, and Acidithiobacillus. The results of this study provide new information regarding a previously uncharacterized ecosystem and show the value of high-throughput sequencing in the study of complex ecosystems.
    No preview · Article · Dec 2015 · Applied Microbiology and Biotechnology
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    Zhiqiao He · Jie Shen · Zhili Ni · Juntao Tang · Shuang Song · Jianmeng Chen · Li Zhao
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    ABSTRACT: Surface-roughened Pb electrodes were prepared through a facile oxidation-reduction cycle. Compared with their smooth surface counterparts, the electrodes exhibited significantly higher activity, selectivity, and energy utilization in the electrocatalytic reduction of CO2 to HCOOH using water under ambient temperature and pressure. Furthermore, the modified electrodes maintained high activities after operating repeatedly for five batches. The enhanced performance of these electrodes is attributed to the enlarged active surface area and increased number of reactive species associated with the three-dimensional structure of the surface. Both the hydrogenation mechanism and the hydrogencarbonate mechanism were affected during the electrochemical CO2 reduction.
    Full-text · Article · Dec 2015 · Catalysis Communications
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    Zhiqiao He · Juntao Tang · Jie Shen · Jianmeng Chen · Shuang Song
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    ABSTRACT: TiO2 nanosheets modified with various concentrations of sulfuric acid have been synthesized through hydrothermal treatment at 240 °C followed by heat treatment at 105 °C. Compared with untreated TiO2 nanosheets, the H2SO4-modified samples exhibited markedly improved quantum yield (QY), energy returned on energy invested (EROEI), and turnover number (TON) for CO2 reduction to CH4 under visible-light irradiation. As supported by physical-chemical characterization, the enhanced photocatalytic activities can be attributed to acidification promoting the formation of hydroxyl groups (Brønsted acidic sites) and oxygen vacancies/Ti3+ species. Thus, efficient charge separation and transfer to the TiO2 surface for both CO2 reduction and the accompanying H2O oxidation is facilitated. The highest activity for CO2 photoreduction to CH4 was obtained with TiO2 nanosheets with 0.5 mol L−1 H2SO4, with QY, EROEI, and TON of 0.726‰, 0.335‰, and 83.124, respectively. Furthermore, the catalyst maintained stable performance throughout five successive recyclability test runs.
    Full-text · Article · Dec 2015 · Applied Surface Science
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    ABSTRACT: A novel molybdenum modified PbO2 electrode was successfully prepared with the method of electrodeposition. The SEM and XRD were employed to study the surface morphology of electrodes, which indicated that the modified PbO2 electrode had a larger effective area and more compact film. Electrochemical degradation of cinnamic acid (CA) in aqueous solution with Mo–PbO2 electrode and PbO2 electrode were investigated. The results showed that the Mo–PbO2 electrode had a better effect of CA removal. The operational parameters influencing the electrochemical degradation of CA with Mo–PbO2 electrode were optimized and the results revealed that the electrochemical degradation of CA followed the pseudo-first-order kinetics and the optimal removal of CA and COD were 85.51% and 25.79% after 120 min on condition of the electrolyte concentration, initial concentration of CA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 10 mA/cm2 and 3.4, respectively. The degradation mechanism of CA in electrochemical oxidation with Mo–PbO2 electrode was analyzed and the main degradation pathway of CA was proposed based on the intermediates identified by IC and GC–MS.
    No preview · Article · Dec 2015
  • Yiming Sun · Jiguo Qiu · Dongzhi Chen · Jiexu Ye · Jianmeng Chen
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    ABSTRACT: Recently, the biodegradation of volatile organic sulfur compounds (VOSCs) has become a burgeoning field, with a growing focus on the reduction of VOSCs. The reduction of VOSCs encompasses both organic emission control and odor control. Herein, Alcaligenes sp. SY1 was isolated from active sludge and found to utilize dimethyl sulfide (DMS) as a growth substrate in a mineral salt medium. Response surface methodology (RSM) analysis was applied to optimize the incubation conditions. The following conditions for optimal degradation were identified: temperature 27.03°C; pH 7.80; inoculum salinity 0.84%; and initial DMS concentration 1585.39μM. Under these conditions, approximately 99% of the DMS was degraded within 30h of incubation. Two metabolic compounds were detected and identified by gas chromatography-mass spectrometry (GC-MS): dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS). The DMS degradation kinetics for different concentrations were evaluated using the Haldane-Andrews model and the pseudo first-order model. The maximum specific growth rate and degradation rate of Alcaligenes sp. SY1 were 0.17h-1 and 0.63gs gx-1h-1. A possible degradation pathway is proposed, and the results suggest that Alcaligenes sp. SY1 has the potential to control odor emissions under aerobic conditions.
    No preview · Article · Nov 2015 · Journal of hazardous materials
  • Runye Zhu · Yubo Mao · Liying Jiang · Jianmeng Chen
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    ABSTRACT: A nonthermal plasma catalysis reactor was developed as pretreatment technology for a biotrickling filter (BTF), which was adopted to enhance removal of poorly soluble and recalcitrant volatile organic compounds. The performance of this pretreatment process was evaluated under various technological parameters, including discharge voltage, initial concentration, and residence time. Experimental results show that the system afforded higher efficiency of removal and selectivity to CO2 compared with those obtained with the control plasma process at discharge voltages of 5-9 kV and residence times of 3-15 s. Increasing the discharge voltage and residence time increased the removal efficiency. The activity of catalysts followed the order CeO2/HZSM-5 > CuO/MnO2 > Ag/TiO2. Furthermore, the solubility and biodegradability of degradation products were examined and analyzed. The main products of chlorobenzene degradation were O3, COx, benzene derivatives, and nitrogenous organics. The amounts of nitrogenous byproducts and O3 concentration during the reaction decreased significantly in the plasma catalysis reactor. This pretreatment technology greatly enhanced the solubility and biodegradability of byproducts. The results provide fundamental data for a feasible plasma catalytic system used as pretreatment technology for a BTF.
    No preview · Article · Nov 2015 · The Chemical Engineering Journal
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    ABSTRACT: Bacteria and fungi are often utilized for the biodegradation of organic pollutants. This study compared fungal and/or bacterial biofiltration in treating toluene under both steady and unsteady states. Fungal biofilter (F-BF) removed less toluene than both bacterial biofilters (B-BF) and fungal & bacterial biofilters (F&B-BF) (<20% vs >60% vs >90%). The mineralization ratio was also lower in F-BF-levels were 2/3 and 1/2 of those values obtained by the other biofilters. Microbial analysis showed that richer communities were present in B-BF and F&B-BF, and that the Hypocreales genus which Trichoderma viride belongs to was much better represented in F&B-BF. The F&B-BF also supported enhanced robustness after 15-day starvation episodes; 1 day later the performance recovered to 80% of the original removal level. The combination of bacteria and fungi makes biofiltration a good option for VOC treatment including better removal and performance stability versus individual biofilters (bacteria or fungi dominated).
    No preview · Article · Oct 2015 · Journal of hazardous materials
  • Qizhou Dai · Yijing Xia · Jianmeng Chen

    No preview · Article · Oct 2015
  • Liying Jiang · Lu Liu · Shaodan Xiao · Jianmeng Chen
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    ABSTRACT: A novel modified diatomite was prepared by chemical treatment by impregnating diatomite into an acidic permanganate solution after calcination to remove aniline. Material characterization by Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed the presence of manganese dioxide (MnO2) on the diatomite surface with an increased surface area. Various adsorption conditions, such as contact time, adsorbent dosage, pH and interaction effect were investigated. It was shown that the equilibration removal capacity of aniline from solution for MnO2 coated-diatomite (Mn-D) was 42.9mg/g. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) results revealed that aniline was adsorbed by O-H (such as Si-OH and Mn-OH) on the diatomite surface and then oxidized by MnO2. Oxidation and adsorption therefore existed during MnO2 removal. Products obtained during removal were studied by gas chromatography-mass spectroscopy (GC-MS) to confirm that azobenzene and phenol were the main intermediates and to propose a possible degradation pathway for aniline. MnO2 on the Mn-D surface played a role in oxidation and adsorption to degrade aniline. Mn-D can be used as a low-cost adsorbent to remove aniline under mild conditions.
    No preview · Article · Sep 2015
  • Liying Jiang · Shaodan Xiao · Jianmeng Chen
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    ABSTRACT: An amorphous Fe–Mn binary oxide adsorbent was developed using simultaneous oxidation and coprecipitation, and characterized by Brunauer–Emmett–Teller analysis, X-ray diffractometry, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The removal behavior of the prepared absorbent for cobalt (II) was studied. Results showed that iron and manganese in adsorbent existed mainly in the +III and +IV oxidation states, respectively. The adsorbent exhibited the best depletion of Co(II) at pH 6–8, and the best removal ability at an ionic strength of 0.01 mmol L−1. The Freundlich isotherm model fitted the Co(II) adsorption data best. The FTIR spectra of the absorbent before and after Co(II) adsorption showed that the surface hydroxyl groups, Mn–OH and Fe–OH, existed at the surface and formed Mn–O–Co or Fe–O–Co. The iron oxide was the main adsorbent, and the manganese oxide also showed adsorption and oxidation ability. The XPS spectra confirmed that the Mn in the absorbent was reduced whereas the Fe showed no difference after reaction with Co(II). The XPS measurements of cobalt adsorbed on the adsorbent indicate that Co(II) has been oxidized to Co(III).
    No preview · Article · Aug 2015 · Colloids and Surfaces A Physicochemical and Engineering Aspects
  • Yijing Xia · Qizhou Dai · Jianmeng Chen
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    ABSTRACT: The novel nickel modified PbO2 electrodes were successfully prepared via electrodeposition in nitrate solution. The influence of nickel content on the physico-chemical properties and electrocatalytic performance of PbO2 electrodes was investigated. The electrodes were characterized by SEM, EDX and XRD techniques. A limited amount of doping nickel could produce a more compact PbO2 film and diminish the size of the crystal grains. The steady-state polarization curves and the cyclic voltammetry analysis showed that the 1% Ni–PbO2 electrode had the highest oxygen evolution potential and the optimal electrochemical oxidation ability. The cyclic voltammograms with various scan rates showed that the oxidation of aspirin on these PbO2 electrodes was a typical diffusion-controlled electrochemical process. Stability tests of different PbO2 electrodes showed that 1% Ni–PbO2 electrode had the highest electrochemical stability. In addition, nickel modified PbO2 electrodes were used to degradation aspirin in aqueous solution, which gave the direct evidence of the electrocatalytic capabilities of these electrodes. The results showed that 1% Ni–PbO2 electrode obtained the highest kinetic rate constant, chemical oxygen demand (COD) and total organic carbon (TOC) removals, which were 1.41, 1.22, 1.20 times than those of undoped PbO2 electrode, respectively. Moreover, the energy required for the treatment of 1 m3 aspirin solution significantly decreased and the hydroxyl radical utilization rate was enhanced after appropriate nickel doping. As a result, the 1% Ni–PbO2 electrode is a promising anode for the treatment of organic pollutants.
    No preview · Article · May 2015 · Journal of electroanalytical chemistry
  • Qizhou Dai · Liling Chen · Wei Chen · Jianmeng Chen
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    ABSTRACT: This study aims to investigate degradation mechanisms and kinetics of phenoxyacetic acid by ozonation in aqueous solution. The optimized operating condition was achieved by phenoxyacetic acid and total organic carbon (TOC) removal based on the studies of the effects of various parameters, such as pH value (4–12), the initial concentration of phenoxyacetic acid (100–2000 mg L−1) and the ozone dosage (16–48 mg min−1). A series of intermediates were formed in the ozonation process and detected by GC/MS and HPLC analysis, such as phenyl formate, salicylic acid, phenol, oxalic acid and small molecule acids. A possible degradation pathway of phenoxyacetic acid was proposed. The kinetic analysis showed that phenoxyacetic acid degradation was in slow kinetic regime based on the results of Ha. This paper can provide basic data and theoretical reference for pharmaceutical wastewater treatment by ozonation.
    No preview · Article · Mar 2015 · Separation and Purification Technology
  • Jun Chen · Lei Wang · Ji Zheng · Jianmeng Chen
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    ABSTRACT: Chemical absorption-biological reduction (BioDeNOx), which uses Fe(II)(EDTA) as a complexing agent for promoting the mass transfer efficiency of NO from gas to water, is a promising technology for removing nitric oxide (NO) from flue gases. The carbon source and pH are important parameters for Fe(II)(EDTA)-NO (the production of absorption) reduction and N2O emissions from BioDeNOx systems. Batch tests were performed to evaluate the effects of four different carbon sources (i.e., methanol, ethanol, sodium acetate, and glucose) on Fe(II)(EDTA)-NO reduction and N2O emissions at an initial pH of 7.2 ± 0.2. The removal efficiency of Fe(II)(EDTA)-NO was 93.9 %, with a theoretical rate of 0.77 mmol L(-1) h(-1) after 24 h of operation. The highest N2O production was 0.025 mmol L(-1) after 3 h when glucose was used as the carbon source. The capacities of the carbon sources to enhance the activity of the Fe(II)(EDTA)-NO reductase enzyme decreased in the following order based on the C/N ratio: glucose > ethanol > sodium acetate > methanol. Over the investigated pH range of 5.5-8.5, the Fe(II)(EDTA)-NO removal efficiency was highest at a pH of 7.5, with a theoretical rate of 0.88 mmol L(-1) h(-1). However, the N2O production was lowest at a pH of 8.5. The primary effect of pH on denitrification resulted from the inhibition of nosZ in acidic conditions.
    No preview · Article · Feb 2015 · Bioprocess and Biosystems Engineering
  • Qizhou Dai · Liling Chen · Shijie Zhou · Jianmeng Chen
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    ABSTRACT: In this study, the kinetics and mechanism study of direct ozonation organics in aqueous solution was explored. Phenoxyacetic acid was selected as the model pollutant and ozonation experiments were performed in the bubble batch reactor in order to determine the rate constants for the direct reaction. Two kinetic methods were used for the determination of different kinetic rate constants (kapp and ki). The first group of the results showed the degradation of phenoxyacetic acid followed the pseudo-first-order kinetics. A simplified model related to the operational parameters on phenoxyacetic acid degradation was derived and the apparent rate constant kapp was obtained. The reaction was proved in the slow kinetics of gas-liquid reaction and the kinetic constant ki was built. The kapp and ki influenced by the pH value, the O3 dosage and the initial phenoxyacetic acid concentration were carefully analyzed.
    No preview · Article · Feb 2015 · RSC Advances
  • Jianmeng Chen · Yijing Xia · Qizhou Dai
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    ABSTRACT: This study presents an electrochemical method for the degradation of chloramphenicol (CAP) in aqueous solution with a novel Al doped PbO2 electrode. The Al-doped PbO2 electrode showed high electrochemical activity, oxygen evolution potential, radical utilization rate, reusability and safety. The influence factors on CAP degradation with the Al-doped PbO2 electrode were investigated in detail, and under the optimal conditions the removal rates of CAP and TOC reached 87.30% and 52.06% in acid conditions after 2.5 h electrolysis with a 0.2 mol dm−3 Na2SO4 at a current density of 30 mA cm−2, respectively. The electrochemical degradation of CAP at Al-doped PbO2 electrode electrode followed pseudo-first-order kinetics. The degradation mechanism was proposed by cyclic voltammograms tests and it was deduced that hydroxyl radicals generated in the electrochemical process played a key role in oxidizing CAP. Finally, based on the reaction products identified, a possible degradation pathway including radical reaction, ring open and mineralization was proposed.
    No preview · Article · Feb 2015 · Electrochimica Acta
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    Zhiqiao He · Lixian Jiang · Da Wang · Jianping Qiu · Jianmeng Chen · Shuang Song
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    ABSTRACT: A series of fluorinated anatase TiO2 nanosheets with dominant {001} facets were synthesized to oxidize p-chlorophenol (PCP) and reduce Cr(VI) simultaneously under visible light. The {001}/{101} surface facets ratio of TiO2 was controlled by varying the initial HF concentration, and fluorine-free samples were obtained by alkaline-washing. A synergistic effect among TiO2, Cr(VI), and PCP was observed, which is ascribed to effective trapping of photogenerated electrons and holes by Cr(VI) and PCP, respectively. A maximum synergistic effect was obtained at a molar ratio of [PCP] to [Cr(VI)] of one. Using X-ray diffraction, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller analyses, the optimum ratio of exposed {001} to {101} facets for TiO2 was determined to be 80:20 because of selective transfer and charge balance of photogenerated carriers. Surface fluorination facilitates the formation of oxygen vacancies and unsaturated Ti atoms, which is useful for visible light activity induction, extending the lifetime of photogenerated electron-hole pairs, and enhancing the rate of PCP oxidation and Cr(VI) reduction.
    Full-text · Article · Jan 2015 · Industrial & Engineering Chemistry Research
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    Liying Jiang · Runye Zhu · Yubo Mao · Jianmeng Chen · Liang Zhang
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    ABSTRACT: The combination of chemical oxidation methods with biotechnology to removal recalcitrant VOCs is a promising technology. In this paper, the aim was to identify the role of key process parameters and biodegradability of the degradation products using a dielectric barrier discharge (DBD) reactor, which provided the fundamental data to evaluate the possibilities of the combined system. Effects of various technologic parameters like initial concentration of mixtures, residence time and relative humidity on the decomposition and the degradation products were examined and discussed. It was found that the removal efficiency of mixed VOCs decreased with increasing initial concentration. The removal efficiency reached the maximum value as relative humidity was approximately 40%-60%. Increasing the residence time resulted in increasing the removal efficiency and the order of destruction efficiency of VOCs followed the order styrene > o-xylene. Compared with the single compounds, the removal efficiency of styrene and o-xylene in the mixtures of VOCs decreased significantly and o-xylene decreased more rapidly. The degradation products were analyzed by gas chromatography and gas chromatography-mass spectrometry, and the main compounds detected were O3, COx and benzene ring derivatives. The biodegradability of mixed VOCs was improved and the products had positive effect on biomass during plasma application, and furthermore typical results indicated that the biodegradability and biotoxicity of gaseous pollutant were quite depending on the specific input energy (SIE).
    Preview · Article · Jan 2015 · International journal of environmental research and public health
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    ABSTRACT: A novel Al-doped PbO2 electrode with high oxygen evolution potential and electrochemical oxidation performance is prepared by electrodeposition technique. The Al-doped PbO2 electrode has significant improvements in electrochemical oxidation ability and electrode stability. From the morphological point of view, the introduction of Al3+ limits crystal particles and produces compact films. The films have better electrochemical oxidation ability and we demonstrated that by oxidizing aspirin. We found that the energy saving (using EE/O calculations) can be up to 34% after Al3+ doping. Meanwhile, Al-doped PbO2 electrode showed higher reusability and stability than undoped PbO2 electrode.
    No preview · Article · Jan 2015 · Journal of The Electrochemical Society
  • Xiangqian Wang · Chao Wu · Nan Liu · Sujing Li · Wei Li · Jianmeng Chen · Dongzhi Chen
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    ABSTRACT: A Pseudomonas sp. strain WL2 that is able to efficiently metabolize ethyl mercaptan (EM) into diethyl disulfide (DEDS) through enzymatic oxidation was isolated from the activated sludge of a pharmaceutical wastewater plant. One hundred percent removal of 113.5 mg L−1 EM and 110.3 mg L−1 DEDS were obtained within 14 and 32 h, respectively. A putative EM degradation pathway that involved the catabolism via DEDS was proposed, which indicated DEDS were further mineralized into carbon dioxide (CO2), bacterial cells, and sulfate (SO4 2−) through the transformation of element sulfur and ethyl aldehyde. Degradation kinetics for EM and DEDS with different initial concentrations by strain WL2 were evaluated using Haldane-Andrews model with maximum specific degradation rates of 3.13 and 1.33 g g−1 h−1, respectively, and maximum degradation rate constants of 0.522 and 0.175 h−1 using pseudo-first-order kinetic model were obtained. Results obtained that aerobic degradation of EM by strain WL2 was more efficient than those from previous studies. Substrate range studies of strain WL2 demonstrated its ability to degrade several mercaptans, disulfides, aldehydes, and methanol. All the results obtained highlight the potential of strain WL2 for the use in the biodegradation of volatile organic sulfur compounds (VOSCs).
    No preview · Article · Nov 2014 · Applied Microbiology and Biotechnology
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    ABSTRACT: A reactor model was established to describe the electrochemical hydrodechlorination of 2-chlorobiphenyl (2-ClBP) in a plug flow reactor. This model was based on the pseudo-first-order reaction rate constants obtained under various temperatures (T), current densities (J), initial concentrations of 2-ClBP (C2-ClBP,0), and Pd loadings (M). The simple global power-law rate (r2-ClBP) equation, with Arrhenius dependency, was determined to be r2-ClBP = -1.0982 × 106 C2-ClBP,00.0141 M0.9307 J1.3461 e-34615/RT C2-ClBP. Results predicted by using the model are in good agreement with experimental values, showing deviation of <8.9%.
    Full-text · Article · Nov 2014 · International journal of electrochemical science