Advanced oxidation process based on hydroxyl and sulfate radicals to degrade refractory organic pollutants in landfill leachate

Li, Shuo; Yang, Yalun; Hong, Zheng; Zheng, Yongjie; Tao, Jing; Nan, Jun; Leong, Yoong Kit; Chang, Jo‐Shu

doi:10.1016/j.chemosphere.2022.134214

Cited by 95 publications

(23 citation statements)

References 109 publications

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“…The above difference was mainly caused by the different process mechanisms of Fenton and ozone oxidation. • OH, which generates from the Fenton reaction, mainly degrades organic pollutants through attacking double bonds in order to form carbocation, or by combining with carbocation intermediate to form additional product, capturing H + by the C-H bond fracture of organic pollutants (Equation ( 4)) and degrading organic pollutants by electron transfer [31]. By contrast, O 3 degrades organic pollutants through reacting with organic compounds containing unsaturated bonds or receiving electrons to replace some functional groups of organic pollutants [32].…”

Section: Biodegradability Improvement Analysismentioning

confidence: 99%

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

et al. 2022

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Cost-effective pretreatment of highly concentrated and bio-refractory petrochemical wastewater to improve biodegradability is of significant importance, but remains challenging. This study compared the pretreatment of petrochemical wastewater by two commonly used chemical advanced oxidation technologies (Fenton and ozone oxidation), and the mechanisms of biodegradability improvement of pretreated wastewater were explored. The obtained results showed that in the Fenton oxidation system, the COD removal of petrochemical wastewater was 89.8%, BOD5 decreased from 303.66 mg/L to 155.49 mg/L, and BOD5/COD (B/C) increased from 0.052 to 0.62 after 60 min under the condition of 120 mg/L Fe2+ and 500 mg/L H2O2, with a treatment cost of about 1.78 $/kgCOD. In the ozone oxidation system, the COD removal of petrochemical wastewater was 59.4%, BOD5 increased from 127.86 mg/L to 409.28 mg/L, and B/C increased from 0.052 to 0.41 after 60 min at an ozone flow rate of 80 mL/min with a treatment cost of approximately 1.96 $/kgCOD. The petrochemical wastewater treated by both processes meets biodegradable standards. The GC–MS analysis suggested that some refractory pollutants could be effectively removed by ozone oxidation, but these pollutants could be effectively degraded by hydroxyl radicals (•OH) produced by the Fenton reaction. In summary, compared with ozone oxidation, petrochemical wastewater pretreated with Fenton oxidation had high COD removal efficiency and biodegradability, and the treatment cost of Fenton oxidation was also lower than that of ozone oxidation.

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Section: Biodegradability Improvement Analysismentioning

confidence: 99%

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

et al. 2022

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“…This wastewater can cause serious harm to soil and groundwater when discharged directly [3]. Currently, the sanitation industry commonly adopts a combination of biological and membrane treatment processes to treat landfill leachate [4,5]. However, this treatment method has high costs, and the landfill leachate concentrate produced after membrane treatment causes secondary pollution [6].…”

Section: Introductionmentioning

confidence: 99%

“…However, this problem can be effectively solved by using ZVI in this system instead of Fe 2+ activation of PS, in combination with an electrochemical oxidation reaction. ZVI can gradually release Fe 2+ under acidic conditions, and Fe 3+ can also be reduced to Fe 2+ on the surface of ZVI, according to (4) and (5) [13,14]. Furthermore, excessive Fe 2+ consumption of SO 4…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on the Treatment of Landfill Leachate by Electro-Assisted ZVI/UV Synergistic Activated Persulfate System

et al. 2022

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To solve the problem of the poor treatment of high concentration landfill leachate, an electro-assisted ultraviolet (UV)/zero-valent iron (ZVI) synergic activated persulfate (PS) system was used to treat landfill leachate. The effects of PS and ZVI dosage, initial pH value, and current density on the removal efficiency of COD and NH3-N in landfill leachate were investigated. The treatment effects of single PS, single electrochemical, UV/PS, electro-assisted ZVI activated PS, and electro-assisted ZVI/UV co-activated PS were compared. At the same time, UV-visible and three-dimensional fluorescence spectroscopy were performed on the landfill leachate before and after treatment. The results show that under the optimal conditions of initial pH = 3, the dosage of PS/12COD = 1, ZVI = 1.5 g/L, current density 62.5 mA/cm2, and t = 6 h, most of the macromolecular organic substances such as humic acid and fulvic acid were removed. Removal efficiencies of COD, NH3-N, and Chroma reached 81.99%, 89.90%, and 99.75%, respectively. The BOD5/COD value increased from 0.23 to 0.46. In addition, the radical identification results showed that the degradation of COD was due to the combined action of sulfate radicals (SO4•−) and hydroxyl radicals (•OH) and that SO4•− was dominant. The combined means of synergistic activation of PS for landfill leachate treatment was significantly better than that of single means of PS activation, confirming that electrically assisted ZVI/UV synergistic activation of PS is a promising method for landfill leachate treatment.

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“…Fenton processes, as classical AOPs, have been widely used in landfill leachate treatment (Brasil et al, 2021; Traid et al, 2022; Wu et al, 2021). The principle is that hydrogen peroxide (H 2 O 2 ) is activated by ferrous ions (Fe 2+ ) to generate a large amount of HO • (Li et al, 2022). HO • has a high redox potential of 2.7 V, and so can oxidize organic pollutants in wastewater non-selectively and thus mineralize organic matter (Chen et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Removal of refractory organics from landfill leachate by in situ electrogenerated H₂O₂ combined with an Fe⁰ Fenton-like process

Bai

et al. 2022

Waste Manag Res

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Landfill leachate contains a large amount of refractory organic matter, which will cause harm to the environment if not appropriately treated. In this study, the refractory organic matter in landfill leachate has been treated by in situ electrogenerated H2O2 combined with an Fe0 Fenton-like process, aiming to explore a cleaner and more efficient process for leachate treatment. The results showed that the current, initial pH and oxygen flow rate have significant influences on H2O2 production. The current and oxygen flow rate are positively correlated with H2O2 production, and neutral conditions are more favourable. Under the conditions of a current of 200 mA, an initial pH of 7.0 and an oxygen flow rate of 0.3 L/min, H2O2 production reached 2.81 mM, the current efficiency was close to 80% and the highest removal efficiency of organic matter reached 40.70%. The absorbance at 280 nm ( E280) decreased from 0.1669 to 0.1180, and the ratios E240/ E420, E250/ E365 and E300/ E400 in the UV and visible regions changed from 0.7825, 5.4492 and 0.2422 to 1.3135, 7.3745 and 0.2966, respectively. The maximum fluorescence intensities due to humic-like acid and fulvic-like acid substances decreased from 1275 and 1246 to 595.9 and 711.0, respectively. Spectral analysis further showed that the complex structure of refractory organic matter in the landfill leachate was obviously destroyed, and the relative content of humus decreased significantly. This study may provide a theoretical basis for the effective treatment of refractory organic matter in landfill leachate by in situ electrogenerated H2O2 combined with a Fenton-like process.

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Advanced oxidation process based on hydroxyl and sulfate radicals to degrade refractory organic pollutants in landfill leachate

Cited by 95 publications

References 109 publications

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

Experimental Study on the Treatment of Landfill Leachate by Electro-Assisted ZVI/UV Synergistic Activated Persulfate System

Removal of refractory organics from landfill leachate by in situ electrogenerated H₂O₂ combined with an Fe⁰ Fenton-like process

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Advanced oxidation process based on hydroxyl and sulfate radicals to degrade refractory organic pollutants in landfill leachate

Cited by 95 publications

References 109 publications

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

Comparison of Fenton and Ozone Oxidation for Pretreatment of Petrochemical Wastewater: COD Removal and Biodegradability Improvement Mechanism

Experimental Study on the Treatment of Landfill Leachate by Electro-Assisted ZVI/UV Synergistic Activated Persulfate System

Removal of refractory organics from landfill leachate by in situ electrogenerated H2O2 combined with an Fe0 Fenton-like process

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Removal of refractory organics from landfill leachate by in situ electrogenerated H₂O₂ combined with an Fe⁰ Fenton-like process