Activation of sodium percarbonate with ferrous ions for degradation of chlorobenzene in aqueous solution: mechanism, pathway and comparison with hydrogen peroxide

2017 ◽  
Vol 14 (8) ◽  
pp. 486 ◽  
Author(s):  
Sai Zhang ◽  
Xuebin Hu ◽  
Li Li ◽  
Xiaoliu Huangfu ◽  
Yingzhi Xu ◽  
...  
Keyword(s):  
Degradation Process ◽  
Degradation Pathway ◽  
Chemical Oxidation ◽  
Molar Concentration ◽  
Contaminated Groundwater ◽  
Ferrous Ions ◽  
Paramagnetic Resonance ◽  
In Situ Chemical Oxidation ◽  
Wide Range ◽  
Initial Ph

Environmental contextIt is practicable to remediate chlorobenzene-contaminated groundwater by in situ chemical oxidation. This study shows highly efficient degradation of chlorobenzene by an Fe-based process in a wide range of pH values. The technology is feasible for the removal of chlorobenzene from aqueous solutions and is appropriate for remediation of groundwater. AbstractSodium percarbonate (SPC) could be applied as a strong oxidant to degrade organic compounds activated by transition metals. In this study, the degradation performance of chlorobenzene (CB) in the Fe2+-catalysed SPC system was investigated at different Fe2+ and SPC concentrations and pH conditions. Fe2+/Fe3+ conversion was also studied, and the SPC system was compared with the H2O2 and H2O2/Na2CO3 systems. Free radicals were identified through scavenging tests and electron paramagnetic resonance (EPR) experiments, and the reaction intermediates and by-products were determined as well. The results show that CB was completely removed when the molar concentration ratio of Fe2+/SPC/CB was 8 : 8 : 1 and that the decomposition of CB increased as the initial Fe2+/SPC dosage increased. The optimal molar concentration of Fe2+/SPC/CB was 2 : 1 : 1, and the degradation rate was inhibited when increasing or decreasing Fe2+ or SPC. CB degradation was not significantly affected by variation of initial pH, and the variation of pH during the degradation process corresponded well with the degree of Fe2+ to Fe3+ conversion and the formation of •OH. It was confirmed that •OH, O2•− and 1O2 participate in the degradation process. Moreover, not all the •OH takes part in the degradation process, as some transforms into O2•− and 1O2. The same degradation efficiency was obtained when replacing SPC by equal stoichiometric amounts of H2O2, compared with inhibition with the addition of Na2CO3. Further, a likely degradation pathway for CB is proposed based on the identified products. These results show that the Fe2+/SPC system can form the basis of a promising technology for the remediation of CB-contaminated groundwater.

Application of in situ chemical oxidation to remediate sulfolane-contaminated groundwater: batch and pilot-scale studies

2021 ◽  
Vol 223 ◽  
pp. 136-145
Author(s):  
Zong-Han Yang ◽  
Ya-Lei Chen ◽  
Francis Verpoort ◽  
Cheng-Di Dong ◽  
Chiu-Wen Chen ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Chemical Oxidation ◽  
Contaminated Groundwater ◽  
In Situ Chemical Oxidation

Development of KMnO4-releasing composites for in situ chemical oxidation of TCE-contaminated groundwater

2014 ◽  
Vol 54 ◽  
pp. 149-158 ◽  
Author(s):  
S.H. Liang ◽  
K.F. Chen ◽  
C.S. Wu ◽  
Y.H. Lin ◽  
C.M. Kao
Keyword(s):  
Chemical Oxidation ◽  
Contaminated Groundwater ◽  
In Situ Chemical Oxidation

scholarly journals In Situ Chemical Oxidation of RDX-Contaminated Groundwater with Permanganate at the Nebraska Ordnance Plant

2010 ◽  
Vol 30 (3) ◽  
pp. 96-106 ◽  
Author(s):  
Jeffrey Albano ◽  
Steve D. Comfort ◽  
Vitaly Zlotnik ◽  
Todd Halihan ◽  
Mark Burbach ◽  
...  
Keyword(s):  
Chemical Oxidation ◽  
Contaminated Groundwater ◽  
In Situ Chemical Oxidation ◽  
Ordnance Plant

scholarly journals Photocatalytic Degradation of Phenol Using Chemical Vapor Desposition Graphene Column

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1251
Author(s):  
Juhee Kim ◽  
Baekwon Park ◽  
Dong Heon Shin ◽  
Je Min Yoo ◽  
Hyukjin Lee ◽  
...  
Keyword(s):  
Advanced Oxidation Process ◽  
Uv Light ◽  
Graphene Film ◽  
Chemical Vapor ◽  
Degradation Process ◽  
Chemical Oxidation ◽  
Cvd Graphene ◽  
In Situ Chemical Oxidation ◽  
Activation Conditions

In the field of wastewater treatment, the advanced oxidation process (AOP) is a widely employed method. It uses reactive oxygen species (ROS) to degrade harmful organic and inorganic chemicals. Metal catalysts are the conventional standard when using these methods. However, they have drawbacks such as harsh activation conditions and poor recyclability. We previously suggested chemical vapor deposition (CVD) graphene film as an alternative metal-free catalyst. In this study, we enhanced the catalytic activity of the CVD graphene film by synergistically adding UV light irradiation. The result was complete degradation of phenol on a wafer-scale in a reduced timeframe. To further enhance the degradation process, we devised a graphene-based column for continuous in situ chemical oxidation and analyzed the intermediates over time, proving the potential of graphene-assisted AOP in industrial wastewater applications.

scholarly journals Biodegradation of Tetrahydrofuran by the Newly Isolated Filamentous Fungus Pseudallescheria boydii ZM01

2020 ◽  
Vol 8 (8) ◽  
pp. 1190 ◽  
Author(s):  
Hao Ren ◽  
Hanbo Li ◽  
Haixia Wang ◽  
Hui Huang ◽  
Zhenmei Lu
Keyword(s):  
Filamentous Fungus ◽  
Degradation Rate ◽  
Incubation Temperature ◽  
Dry Weight ◽  
Degradation Process ◽  
Pseudallescheria Boydii ◽  
Metabolic Intermediate ◽  
Wide Range ◽  
Initial Ph ◽  
High Concentrations

Tetrahydrofuran (THF) is widely used as a precursor for polymer syntheses and a versatile solvent in industries. THF is an environmental hazard and carcinogenic to humans. In the present study, a new THF-degrading filamentous fungus, Pseudallescheria boydii ZM01, was isolated and characterized. Strain ZM01 can tolerate a maximum THF concentration of 260 mM and can completely degrade 5 mM THF in 48 h, with a maximum THF degradation rate of 133.40 mg THF h−1 g−1 dry weight. Growth inhibition was not observed when the initial THF concentration was below 150 mM, and the maximum THF degradation rate was still maintained at 118.21 mg THF h−1 g−1 dry weight at 50 mM THF, indicating the great potential of this strain to degrade THF at high concentrations. The initial key metabolic intermediate 2-hydroxytetrahydrofuran was detected and identified by gas chromatography (GC) analyses for the first time during the THF degradation process. Analyses of the effects of initial pH, incubation temperature, and heavy metal ions on THF degradation revealed that strain ZM01 can degrade THF under a relatively wide range of conditions and has good degradation ability under low pH and Cu2+ stress, suggesting its adaptability and applicability for industrial wastewater treatment.

scholarly journals Degradation of Norfloxacin in an Aqueous Solution by the Nanoscale Zero-Valent Iron-Activated Persulfate Process

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yanchang Zhang ◽  
Lin Zhao ◽  
Yongkui Yang ◽  
Peizhe Sun
Keyword(s):  
Degradation Process ◽  
High Reactivity ◽  
Degradation Efficiency ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Paramagnetic Resonance ◽  
Promising Alternative ◽  
Quenching Effect ◽  
Nanoscale Zero Valent Iron ◽  
Initial Ph

In this study, nanoscale zero-valent iron (nZVI) was synthesized and used to activate persulfate (PS) for the degradation of norfloxacin (NOR). The nZVI/PS system exhibited a high reactivity towards NOR, and the degradation efficiency of NOR (100 mg/L) reached 93.8% with 0.1 g/L nZVI, 12 mM PS, and an initial pH of 7.0 within 7 min. The NOR degradation followed a pseudo-first-order kinetic model, and the effects of parameters such as nZVI dosage, PS concentration, initial pH, and temperature were investigated systematically. Overloading of nZVI lowered the degradation efficiency owing to the quenching effect of excessive Fe2+. The higher PS concentration and temperature favored the degradation of NOR. The influence of pH was not obvious, and the degradation was effective in a wide pH range. In addition, the radical quenching experiments and electron paramagnetic resonance (EPR) indicated that both sulfate radical (SO4⋅-) and hydroxyl radical (OH⋅) were the dominant radicals in the degradation process, in which the latter played a more important role. Finally, three degradation pathways were proposed based on the result of intermediates identified by liquid chromatography-mass spectrometry. Overall, this study indicated that the nZVI/PS system could provide a promising alternative for NOR wastewater treatment.

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