Rapid and efficient activated sludge treatment by electro-Fenton oxidation

Chen, Yasong; Chen, Huiping; Li, Jie; Xiao, Lin

doi:10.1016/j.watres.2018.12.035

Cited by 88 publications

(20 citation statements)

References 59 publications

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“…The physicochemical characteristics of WAS before and after EF pretreatment, provided in Table 1, point to the improvement of sludge quality after subsequent anaerobic treatments, both in terms of pH and organic matter solubilization (COD, VFA). On one hand, the increase of pH can be explained by the generation of hydroxyl radicals by electrochemical reactions and by the decrease in H + production [21]. On the other hand, after 2 h of treatment, residual flocs precipitated with iron, which was continuously dissolved from the iron anode as governed by the law of Faraday.…”

Section: Discussionmentioning

confidence: 99%

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

et al. 2020

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Anaerobic digestion (AD), being the most effective treatment method of waste activated sludge (WAS), allows for safe disposal. The present study deals with the electro-Fenton (EF) pretreatment for enhancing the WAS biogas potential with low-cost iron electrodes. The effect of pretreatment on the physicochemical characteristics of sludge was assessed. Following EF pretreatment, the pH, conductivity, soluble chemical oxygen demand (SCOD), and volatile fatty acids (VFA) increased to 7.5, 13.72 mS/cm, 4.1 g/L, and 925 mg/L, respectively. Capillary suction time (CST) analysis highlighted the dewaterability effect of EF on WAS, as demonstrated by the decrease in CST from 429 to 180 s following 30 min of pretreatment. Batch digestion assays presented an increase in the biogas yield to 0.135 L/g volatile solids (VS) after 60 min of EF pretreatment in comparison to raw sludge (0.08 L/g VS). Production of biogas was also found to improve during semi-continuous fermentation of EF-pretreated sludge conducted in a lab-scale reactor. In comparison to raw sludge, EF-pretreated sludge produced the highest biogas yield (0.81 L biogas/g VS) with a high COD removal rate, reaching 96.6% at an organic loading rate (OLR) of 2.5 g VS/L. d. Results revealed that the EF process could be an effective WAS disintegration method with maximum recovery of bioenergy during AD.

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Section: Discussionmentioning

confidence: 99%

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

et al. 2020

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“…The electro-Fenton pretreatment significantly reduced the water content and capillary suction time compared to untreated sludge due to •OH radicals attack on extracellular polymeric substances (EPS) that broke the bound water. Chen, Chen, Li, and Xiao (2019) reported a similar study on the dewatering and digestion of waste activated sludge using electro-Fenton treatment. Electro-Fenton treatment effectively enhanced the dewaterability of waste activated sludge in 40-60 min, improved the sludge floc disintegration, facilitated the humification process, and increased the EPS solubilization.…”

Section: Fenton/fenton Like Processesmentioning

confidence: 96%

Hazardous wastes treatment technologies

Shih

et al. 2020

Water Environment Research

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“…The electrochemical advanced oxidation processes have the advantages of high safety, strong oxidation ability of pollutants, and low toxicity [7]. The main principle of EAOP is that the hydroxyl (•OH) produced in the electrochemical process is the active and most aggressive, oxygen-based species that can react with almost all types of biomolecular, organic, or inorganic substances [8]. It has a very strong oxidizing electrode potential (2.8 V) [9], which is the most active inorganic oxidant except fluorine and their oxidizing ability far exceeds that of ordinary chemical oxidants.…”

Section: Introductionmentioning

confidence: 99%

Process optimization and mechanism study of acid red G degradation by electro-Fenton- Feox process as an in situ generation of H2O2

Sun¹,

Yao²,

Wei³

et al. 2021

Turk J Chem

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Dye contaminated wastewaters are industrial wastewaters that are difficult to be treated using traditional biochemical and physicochemical methods. In the present work, the acid red G was removed as a model pollutant by the Electro-Fenton Process for the first time. The anode and cathode used by the Electro-Fenton Process were iron plate and graphite felt, respectively. Optimizing the process, it was concluded that under the conditions of current density= 20 mA cm-2 , pH= 3 and initial Na2SO4 concentration= 0.2 M, the removal rate of acid red G with an initial concentration of 300 mg L-1 could reach 94.05% after 80 min of electrolysis. This reveals that the EF-Feox Process used in this work has an excellent removal efficiency on acid red G. The required reagents (Fe 2+ , H2O2) were generated by the electrode reaction, while the optimal generation conditions and mechanism of •OH, H2O2 and Fe 2+ were investigated. By testing •OH, H2O2, and Fe 2+ agents at different pH and current densities, it was revealed that the Electro-Fenton reaction was most efficient when the current density was 20 mA cm-2, and the pH was 3. Moreover, the removal rate of ARG is consistent with first-order reaction kinetics.

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Rapid and efficient activated sludge treatment by electro-Fenton oxidation

Cited by 88 publications

References 59 publications

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

High-Rate Anaerobic Digestion of Waste Activated Sludge by Integration of Electro-Fenton Process

Hazardous wastes treatment technologies

Process optimization and mechanism study of acid red G degradation by electro-Fenton- Feox process as an in situ generation of H2O2

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