Integrated approach to enhance excess sludge degradation in microbial electrolysis cell: Role of ozone pretreatment

IF 4.8 2区化学 Q1 BIOCHEMISTRY & MOLECULAR BIOLOGY

Bioelectrochemistry Pub Date : 2025-06-14 DOI:10.1016/j.bioelechem.2025.109028

Kai Hu , Xin-yue Zhang , Xing Sun , Hang Xu , Wei Chen , Wei Wang

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引用次数: 0

Abstract

Microbial electrolysis cell (MEC) is an alternative to conventional sludge treatment process with great energy-recovery potential. However, hydrolysis is considered as a rate-limiting step in MEC. In this study, ozone (O₃) pretreatment was successfully applied to disintegrate sludge matrix and accelerate microbial electrolysis. At 100–250 mg·g⁻¹ (O₃/SS), rapid SCOD increment and SS reduction rates were observed with increased O₃ dosage. Afterwards, the mass transfer from gas to liquid was inhibited and oxidation reactions between O₃ and organics occurred, which resulted in a declining disintegration rate. At favorable dosage of 250 mg·g⁻¹ (O₃/SS), the degree of disintegration was 17 % and SS reduction reached 44.9 %. A lab-scale MEC experiment was performed by feeding ozonated sludge. Results showed that O₃ pretreatment yielded 8.3-times increment in biogas production rate. In addition, O₃ pretreatment improved the organics removal and bioelectrochemical efficiency during microbial electrolysis, achieving 74.50 % of VSS removal rate and 77.56 % of TCOD removal rate, with gas yield increased by 7.5 times and cathodic hydrogen recovery increased by 7.40 %. The FT-IR spectra indicated negligible difference between influent extracellular biological organic matter (EBOM) and effluent EBOM, which suggested the function of O₃ pretreatment was to accelerate microbial electrolysis reactions due to sludge disintegration. Furthermore, the ozonation pretreatment facilitated the enrichment of exoelectrogens and collaborative bacteria in MEC, collectively enhancing MEC performance. This study provides a theoretical reference for enhanced bioelectrochemical treatment of complex heterogeneous mixture with soluble/insoluble organic matters.

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提高微生物电解池剩余污泥降解的综合方法：臭氧预处理的作用

微生物电解池（MEC）是一种替代传统污泥处理工艺，具有很大的能量回收潜力。然而，水解被认为是MEC中的限速步骤。本研究成功地将臭氧（O3）预处理应用于污泥基质分解和加速微生物电解。在100 ~ 250 mg·g−1 （O3/SS）浓度下，随着O3用量的增加，SCOD的快速增加和SS的减少速率加快。之后，气体向液体的传质受到抑制，O3与有机物发生氧化反应，导致分解速率下降。在最佳投加量为250 mg·g−1 （O3/SS）时，崩解度为17%，SS还原率达44.9%。通过投喂臭氧化污泥进行了实验室规模的MEC实验。结果表明，O3预处理后沼气产率提高8.3倍。此外，O3预处理提高了微生物电解过程中有机物的去除率和生物电化学效率，VSS去除率达到74.50%，TCOD去除率达到77.56%，产气量提高7.5倍，阴极氢回收率提高7.40%。FT-IR光谱显示，进水和出水EBOM的差异可以忽略不计，说明O3预处理的作用是加速污泥分解引起的微生物电解反应。此外，臭氧化预处理促进了MEC中外电菌和协同菌的富集，共同提高了MEC的性能。本研究为强化生物电化学处理含可溶性/不溶性有机物的复杂非均相混合物提供了理论参考。

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来源期刊

Bioelectrochemistry 生物-电化学

CiteScore

9.10

自引率

6.00%

发文量

238

审稿时长

38 days

期刊介绍： An International Journal Devoted to Electrochemical Aspects of Biology and Biological Aspects of Electrochemistry Bioelectrochemistry is an international journal devoted to electrochemical principles in biology and biological aspects of electrochemistry. It publishes experimental and theoretical papers dealing with the electrochemical aspects of: • Electrified interfaces (electric double layers, adsorption, electron transfer, protein electrochemistry, basic principles of biosensors, biosensor interfaces and bio-nanosensor design and construction. • Electric and magnetic field effects (field-dependent processes, field interactions with molecules, intramolecular field effects, sensory systems for electric and magnetic fields, molecular and cellular mechanisms) • Bioenergetics and signal transduction (energy conversion, photosynthetic and visual membranes) • Biomembranes and model membranes (thermodynamics and mechanics, membrane transport, electroporation, fusion and insertion) • Electrochemical applications in medicine and biotechnology (drug delivery and gene transfer to cells and tissues, iontophoresis, skin electroporation, injury and repair). • Organization and use of arrays in-vitro and in-vivo, including as part of feedback control. • Electrochemical interrogation of biofilms as generated by microorganisms and tissue reaction associated with medical implants.