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Articles 1 - 21 of 21
Full-Text Articles in Physical Sciences and Mathematics
Simultaneous Redox Conversion Of Chromium(Vi) And Arsenic(Iii) Under Acidic Conditions, Zhaohui Wang, Richard Bush, Leigh Sullivan, Jianshe Liu
Simultaneous Redox Conversion Of Chromium(Vi) And Arsenic(Iii) Under Acidic Conditions, Zhaohui Wang, Richard Bush, Leigh Sullivan, Jianshe Liu
Dr Zhaohui Wang
Arsenic and chromium are often abundant constituents of acid mine drainage (AMD) and are most harmful as arsenite (As(III)) and hexavalent (Cr(VI)). To simultaneously change their oxidation state from As(III) to As(V), and Cr(VI) to Cr(III), is a potentially effective and attractive strategy for environmental remediation. The coabundance of As(III) and Cr(VI) in natural environments indicates their negligible direct interaction. The addition of H2O2enables and greatly accelerates the simultaneous oxidation of As(III) and reduction of Cr(VI). These reactions are further enhanced at acidic pH and higher concentrations of Cr(VI). However, the presence of ligands (i.e., oxalate, citrate, pyrophosphate) greatly retards …
Dynamic Changes Of Nitrogen In Saline-Alkaline Paddy Field And Its Potential Environmental Impacts, Jieqiong Ye, Ruixia Yuan, Zhaohui Wang
Dynamic Changes Of Nitrogen In Saline-Alkaline Paddy Field And Its Potential Environmental Impacts, Jieqiong Ye, Ruixia Yuan, Zhaohui Wang
Dr Zhaohui Wang
No abstract provided.
Photocatalytic Oxidation Of Organic Pollutants Catalyzed By An Iron Complex At Biocompatible Ph Values: Using O2 As Main Oxidant In A Fenton-Like Reaction, Xi Chen, Wanhong Ma, Jing Li, Zhaohui Wang, Chungcheng Chen, Hongwei Ji, Jincai Zhao
Photocatalytic Oxidation Of Organic Pollutants Catalyzed By An Iron Complex At Biocompatible Ph Values: Using O2 As Main Oxidant In A Fenton-Like Reaction, Xi Chen, Wanhong Ma, Jing Li, Zhaohui Wang, Chungcheng Chen, Hongwei Ji, Jincai Zhao
Dr Zhaohui Wang
A red iron(II) 4,4′-dicarboxy-2,2′-bipyridine complex ([FeII(dcbpy)3]) was investigated as an extraordinary Fenton catalyst capable of activating much more molecular O2 to mineralize organic pollutants in water at biocompatible pH values under visible irradiation. Eight representative organic pollutants were effectively degraded in the presence of this catalyst with high turnover number (368−2000). The flexible bifunctional coordination mode (N donor for ferrous ion and O donor for ferric form) devoted by the ligand dcbpy should be responsible for the preservation of iron(II/III) catalysis in such a neutral pH condition, whereas any substitution of the 4,4′-carboxylic groups in …
Sensitization Of Titania Semiconductor: A Promising Strategy To Utilize Visible Light, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Sensitization Of Titania Semiconductor: A Promising Strategy To Utilize Visible Light, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Dr Zhaohui Wang
No abstract provided.
Comparative Study Of Interaction Between Pyrite And Cysteine By Thermogravimetric And Electrochemical Techniques, Zhaohui Wang, Xuehui Xie, Shengmu Xiao, Jianshe Liu
Comparative Study Of Interaction Between Pyrite And Cysteine By Thermogravimetric And Electrochemical Techniques, Zhaohui Wang, Xuehui Xie, Shengmu Xiao, Jianshe Liu
Dr Zhaohui Wang
Adsorption mechanism of l-cysteine on pyrite was investigated by thermogravimetric and electrochemical techniques. TG curves provided the direct evidence for chemisorption of cysteine on pyrite surface. Once cysteine adsorbed to pyrite surface, Ecorr (corrosion potential) sharply lowered whereas Icorr (corrosion current) increased rapidly. Pyrite became more susceptible to be oxidized even at lower potential as cysteine was added. However, the mechanism for pyrite oxidation does not fundamentally change, although cysteine can obviously accelerate oxidation rate of pyrite. These findings have important implications for understanding the mechanism of bacterial adhesion to pyrite and even metal sulfide bioleaching.
Dynamic Variation Characteristics Of Phosphorus In Paddy Field Runoff In Saline Land And Its Potential Environmental Effect, Ruixia Yuan, Jieqiong Ye, Zhaohui Wang, Jianshe Liu
Dynamic Variation Characteristics Of Phosphorus In Paddy Field Runoff In Saline Land And Its Potential Environmental Effect, Ruixia Yuan, Jieqiong Ye, Zhaohui Wang, Jianshe Liu
Dr Zhaohui Wang
No abstract provided.
Numerical Modelling Of Potential Profiles In Electrical Double Layer Of Acidithiobacillus Ferrooxidans Cell Surface, Zhaohui Wang, X Xie, J Liu
Numerical Modelling Of Potential Profiles In Electrical Double Layer Of Acidithiobacillus Ferrooxidans Cell Surface, Zhaohui Wang, X Xie, J Liu
Dr Zhaohui Wang
No abstract provided.
Effects Of Chloride Ion On Degradation Of Acid Orange 7 By Sulfate Radical-Based Advanced Oxidation Process: Implications For Formation Of Chlorinated Aromatic Compounds, Ruixia Yuan, Sadiqua Ramjaun, Zhaohui Wang, Jianshe Liu
Effects Of Chloride Ion On Degradation Of Acid Orange 7 By Sulfate Radical-Based Advanced Oxidation Process: Implications For Formation Of Chlorinated Aromatic Compounds, Ruixia Yuan, Sadiqua Ramjaun, Zhaohui Wang, Jianshe Liu
Dr Zhaohui Wang
Sodium chloride is a common salt used during textile wet processes. Here a dual effect of chloride (i.e. inhibitory and accelerating effect) on azo dye (Acid Orange 7, AO7) degradation in an emerging cobalt/peroxymonosulfate (Co/PMS) advanced oxidation process (AOP) was reported. Compared to OH-based AOPs, high concentrations of chloride (>5 mM) can significantly enhance dye decoloration independent of the presence of the Co2+ catalyst, but did greatly inhibit dye mineralization to an extent which was closely dependent upon the chloride content. Both UV–vis absorbance spectra and AOX determination indicated the formation of some refractory byproducts. Some chlorinated aromatic compounds, …
Light-Assisted Decomposition Of Dyes Over Iron-Bearing Soil Clays In The Presence Of H2o2, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Light-Assisted Decomposition Of Dyes Over Iron-Bearing Soil Clays In The Presence Of H2o2, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Dr Zhaohui Wang
Four types of soil clays from different sites in China have been chosen to simulate chemical remediation of soils contaminated with dyes by light-assisted Fenton-like method. X-Ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS) and electron spin resonance (ESR) measurements indicated that these soil clays contain iron oxides such as magnetite and hematite, where nondistorted iron active sites (ESR spectra, g = 2.3) predominate. Upon visible or UV irradiation, the soil clays were very effective for the degradation of nonbiodegradable cationic dyes such as Rhodamine B (RhB) by activating H2O2 at neutral pH. The photodegradation rates of RhB …
Photochemical Cycling Of Iron Mediated By Dicarboxylates: Special Effect Of Malonate, Zhaohui Wang, Chen Xi, Hongwei Ji, Wanghong Ma, Chuncheng Chen, Jincai Zhao
Photochemical Cycling Of Iron Mediated By Dicarboxylates: Special Effect Of Malonate, Zhaohui Wang, Chen Xi, Hongwei Ji, Wanghong Ma, Chuncheng Chen, Jincai Zhao
Dr Zhaohui Wang
Photochemical redox cycling of iron coupled with oxidation of malonate (Mal) ligand has been investigated under conditions that are representative of atmospheric waters. Malonate exhibited significantly different characteristics from oxalate and other dicarboxylates (or monocarboxylates). Both strong chelating ability with Fe(III) and strong molar absorptivities, but much low efficiency of Fe(II) formation (ΦFe(II) = 0.0022 ± 0.0009, 300−366 nm) were observed for Fe(III)−Mal complexes (FMCs). Fe(III) speciation calculation indicated that Mal is capable of mediating the proportion between two photoactive species of Fe(III)−OH complexes and FMCs by changing the Mal concentration. Spin-trapping electron spin resonance (ESR) experiments proved the formation …
Adsorption Behavior Of Glucose On Pyrite Surface Investigated By Tg, Ftir And Xrd Analyses, Zhaohui Wang, Xuehui Xie, Shengmu Xiao, Jianshe Liu
Adsorption Behavior Of Glucose On Pyrite Surface Investigated By Tg, Ftir And Xrd Analyses, Zhaohui Wang, Xuehui Xie, Shengmu Xiao, Jianshe Liu
Dr Zhaohui Wang
The interaction of glucose with pyrite has been investigated by a series of surface analyses, such as amounts adsorbed, TG, FTIR and XRD measurements. The adsorption experiment reveals that glucose would rapidly adsorb on the pyrite surface within 60 min. However, physical adhesion characterized as multi-molecular layer adsorption may occur based on adsorption isotherm type. All results obtained by TG and FTIR suggest that no adsorption took place after several times of washing. XRD results indicate that crystal structure of pyrite was not obviously destructed after glucose was added. The interplane distances of (111), (400) after interaction between glucose and …
Photodegradation Mechanism Of Chlorophenols Pollutants By Tio2 Photocatalysis, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Hongwei Ji, Jincai Zhao
Photodegradation Mechanism Of Chlorophenols Pollutants By Tio2 Photocatalysis, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Hongwei Ji, Jincai Zhao
Dr Zhaohui Wang
No abstract provided.
Photodegradation Of Persistent Toxic Organic Pollutants And Their Mechanism, Zhaohui Wang, Wanhong Ma, Jianshe Liu, Jincai Zhao
Photodegradation Of Persistent Toxic Organic Pollutants And Their Mechanism, Zhaohui Wang, Wanhong Ma, Jianshe Liu, Jincai Zhao
Dr Zhaohui Wang
No abstract provided.
Epr Application In Environmental Chemistry, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Epr Application In Environmental Chemistry, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Dr Zhaohui Wang
No abstract provided.
Photochemical Coupling Reactions Between Fe(Iii)/Fe(Ii), Cr(Vi)/Cr(Iii) And Polycarboxylates: Inhibitory Effect Of Cr Species, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Photochemical Coupling Reactions Between Fe(Iii)/Fe(Ii), Cr(Vi)/Cr(Iii) And Polycarboxylates: Inhibitory Effect Of Cr Species, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Jincai Zhao
Dr Zhaohui Wang
The roles of chromium species on photochemical cycling of iron and mineralization of polycarboxylates are examined in the presence of Cr(VI) or Cr(III) at pH 2.2−4.0. Under UV irradiation, Cr(III) altered the redox equilibrium of iron species, leading to the shift of the photosteady state toward Fe(II). After a longer time of illumination, total organic carbon (TOC) approached a steady state in the presence of Cr(III) or Cr(VI), whereas oxalate was thoroughly mineralized in the absence of Cr species. The TOC of steady state was closely related to the kind of polycarboxylates, Cr species dosages, pH and O2 atmosphere, but …
Treatment Of Acid-Alkali Mixed Mine Wastewater With Oxidation Process, Cheng Zhang, Jianshe Liu, Huiping Wang, Zhaohui Wang
Treatment Of Acid-Alkali Mixed Mine Wastewater With Oxidation Process, Cheng Zhang, Jianshe Liu, Huiping Wang, Zhaohui Wang
Dr Zhaohui Wang
Acid mine drainage(AMD) in a copper mine is characterized as low pH and high concentrations of metal ions such as Fe3+,Fe2+ and Cu2+,while flotation wastewater often contains amounts of residual flotation reagents,which lead to high COD(chemical oxygen demand) value.AMD and flotation wastewater were firstly pre-mixed at a ratio of 1∶1 and then were treated by use of NaClO,O3 and Fe2+/H2O2 oxidation techniques respectively.The experimental results indicate that H2O2 as the oxidants is feasible and effective for the treatment of the mixed wastewater,while NaClO and O3 oxidation exhibites poor degradation efficiency towards COD removal.91.6% COD of the mixed wastewater can be …
Probing Paramagnetic Species In Titania-Based Heterogeneous Photocatalysis By Electron Spin Resonance (Esr) Spectroscopy- A Mini Review, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Hongwei Ji, Jincai Zhao
Probing Paramagnetic Species In Titania-Based Heterogeneous Photocatalysis By Electron Spin Resonance (Esr) Spectroscopy- A Mini Review, Zhaohui Wang, Wanhong Ma, Chuncheng Chen, Hongwei Ji, Jincai Zhao
Dr Zhaohui Wang
Many paramagnetic species such as active surface sites, reactive oxygen species (ROS) and organic radicals derived from the photodegradation of organics were involved in the heterogeneous photocatalysis. Identification and characterization of these paramagnetic species are essentially conducted using electron spin resonance (ESR) techniques, which can provide a detailed understanding of the radical composition and structure on the basis of the unique feature of g, hyperfine, and superhyperfine tensors for each kind of radicals of interest. In the present review, the basic theoretical principles of the ESR technique and its application in the field of TiO2-based heterogeneous photocatalysis are generally summarized. …
Degradation Of Reactive Dyes By Contact Glow Discharge Electrolysis In The Presence Of Cl− Ions: Kinetics And Aox Formation, Sadiqua Ramjaum, Ruixia Yuan, Zhaohui Wang, Jianshe Liu
Degradation Of Reactive Dyes By Contact Glow Discharge Electrolysis In The Presence Of Cl− Ions: Kinetics And Aox Formation, Sadiqua Ramjaum, Ruixia Yuan, Zhaohui Wang, Jianshe Liu
Dr Zhaohui Wang
The plasma generated around the anode during contact glow discharge electrolysis (CGDE) is a rich source of hydroxyl (OH) radicals that can efficiently degrade organic contaminants in aqueous solutions. The degradation of textile azo dyestuffs, Reactive Yellow 176 (Y3RS), Reactive Red 239 (R3BS) and Reactive Black 5 (B5), by anodic CGDE was investigated in the presence of chloride (Cl−) ions. The degradation kinetics of the dyes was dependent on the concentration of Cl− ions and on the respective dye being treated. R3BS degradation was inhibited by Cl− ions in the range of 0–0.01 M. When the …
Effects Of Chloride Ions On Bleaching Of Azo Dyes By Co2+/Oxone Regent: Kinetic Analysis, Zhaohui Wang, Ruxia Yuan, Yaoguang Guo, Lei Xu, Jinashe Liu
Effects Of Chloride Ions On Bleaching Of Azo Dyes By Co2+/Oxone Regent: Kinetic Analysis, Zhaohui Wang, Ruxia Yuan, Yaoguang Guo, Lei Xu, Jinashe Liu
Dr Zhaohui Wang
Orange II (Org II), one of the most common used azo dyes, was taken as a model to investigate the effects of chloride ion on dye decoloration in cobalt/peroxymonosulfate (Co/PMS) system. A significant decrease in the rate of Org II decoloration was observed upon addition of Cl− (0.05–10 mM), but further addition of Cl− (>50 mM) apparently accelerated dyes degradation. This dual effect of chloride on dyes bleaching was also observed as other halide ions (e.g. Br−, I−) or other azo dyes were present in Co/PMS system. In the Co-free PMS solutions, the …
Industrial Experiments For Treatment Of Mine Wastewater From Dexing Copper Mine, Zhang Cheng, Jianshe Liu, Pan Bin, Zhaohui Wang, Youhong Zhang, Wugang Zhang
Industrial Experiments For Treatment Of Mine Wastewater From Dexing Copper Mine, Zhang Cheng, Jianshe Liu, Pan Bin, Zhaohui Wang, Youhong Zhang, Wugang Zhang
Dr Zhaohui Wang
Taking the mine wastewater from the industrial waste-water treatment station of Dexing Copper Mine as research target,and the index of Chemical Oxygen Demand(COD),heavy metals ion and SO2-4 and suspended solid(SS) as water quality monitoring index,the feasibility of applying the integrated Fenton oxidation-neutralization-PAM flocculation techniques to attain standard discharge is studied.The industrial experiments for 48 h indicated that with the rational addition of H2O2,calcium carbide and PAM,a high removal rate of COD,SO2-4,the heavy metal ion and SS was realized.Then each index of the treated water can meet I-class criteria specified in Integrated Wastewater
Environmental Photochemistry Of Iron Complexes And Their Involvement In Environmental Chemical Processes, Zhaohui Wang, Wenjing Song, Wanhong Ma, Jincai Zhao
Environmental Photochemistry Of Iron Complexes And Their Involvement In Environmental Chemical Processes, Zhaohui Wang, Wenjing Song, Wanhong Ma, Jincai Zhao
Dr Zhaohui Wang
Iron is one of the most abundant metals in the continental crust, while most of dissolved iron is complexed with organic ligands. The irradiated iron complexes in the environment undergo direct photolysis and secondary (photo)chemical reactions, generating Fe(Ⅱ), organic radicals and some reactive oxygen species (ROS). Environmental photochemistry of iron complexes can greatly affect ROS dynamics, organics degradation and redox cycling of other elements. Therefore, it is becoming a hot topic in the international field of environmental sciences research. This review firstly summarizes three types of iron complexes including inorganic Fe complexes, simple organic Fe complexes and macrocyclic organic Fe …