Insights into the mechanism of sludge-based biochar in electro-dewatering and energy consumption optimization

IF 6.3 2区工程技术 Q1 ENGINEERING, CHEMICAL

Journal of water process engineering Pub Date : 2024-10-20 DOI:10.1016/j.jwpe.2024.106328

Yahong Yang , Pengjin Ma , Yangying Li , Yirong Chen , Huining Zhang

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引用次数: 0

Abstract

Electro-dewatering (EDW) technology allows for deep dewatering of sludge. Its synergistic effect with other dewatering techniques significantly improves dewatering efficiency. Sludge-based biochar (SBB) acts as an environmentally friendly physical conditioner with electrical conductivity. It has the potential to enhance the dewatering performance of EDW and reduce energy consumption. This study prepared Fe-loaded SBB at three different temperatures and treated the sludge using an EDW at a constant voltage of 30 V for 20 min under optimal conditions of 12 % g/g dry solids (DS). The results indicate that the presence of Fe ions on the SBB surface significantly enhances the electrical conductivity and Zeta potential during the EDW process, effectively neutralizing the negative charges of sludge flocs and promoting the disintegration of sludge cells. During dehydration, the migration of Fe ions from the anode to the cathode forms a loose, porous structure at the cathode, enhancing its filterability. SBB@800 significantly promotes the degradation of sludge extracellular polymeric substances (EPS), effectively releasing bound water. The degree of damage to fluorescent organic matter in the three-layer EPS increases, significantly reducing the content of proteins (PN) and polysaccharides (PS). The anode layer sludge treated with SBB@800 shows higher PN degradation efficiency. Protein secondary structure and hydrogen bond analysis indicate increased hydrophobicity and weakened binding forces in sludge EPS. Moreover, SBB@800 with 12 % DS significantly reduces the overall energy consumption of the EDW system and slows the rate of increase in dewatering energy consumption, demonstrating favorable economic benefits. This study elucidates the mechanism of enhanced EDW by sludge SBB, providing technical guidance for energy-saving and consumption-reduction in EDW processes.

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洞察污泥基生物炭在电脱水中的作用机理及能耗优化

电脱水（EDW）技术可对污泥进行深度脱水。它与其他脱水技术的协同作用可显著提高脱水效率。污泥基生物炭（SBB）是一种具有导电性的环保型物理调节剂。它具有提高 EDW 脱水性能和降低能耗的潜力。本研究在三种不同的温度下制备了含铁的 SBB，并在 12 % g/g 干固体（DS）的最佳条件下使用 EDW 在 30 V 的恒定电压下处理污泥 20 分钟。结果表明，在 EDW 过程中，SBB 表面铁离子的存在显著提高了导电性和 Zeta 电位，有效中和了污泥絮体的负电荷，促进了污泥细胞的解体。在脱水过程中，铁离子从阳极迁移到阴极，在阴极形成疏松的多孔结构，增强了其可过滤性。SBB@800 能明显促进污泥胞外聚合物物质 (EPS) 的降解，有效释放结合水。三层 EPS 中荧光有机物的破坏程度增加，蛋白质（PN）和多糖（PS）的含量明显降低。经 SBB@800 处理的阳极层污泥显示出更高的 PN 降解效率。蛋白质二级结构和氢键分析表明，污泥 EPS 中的疏水性增加，结合力减弱。此外，含有 12% DS 的 SBB@800 能显著降低 EDW 系统的整体能耗，并减缓脱水能耗的增长速度，显示出良好的经济效益。该研究阐明了污泥SBB增强EDW的机理，为EDW工艺的节能降耗提供了技术指导。

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来源期刊

Journal of water process engineering Biochemistry, Genetics and Molecular Biology-Biotechnology

CiteScore

10.70

自引率

8.60%

发文量

846

审稿时长

24 days

期刊介绍： The Journal of Water Process Engineering aims to publish refereed, high-quality research papers with significant novelty and impact in all areas of the engineering of water and wastewater processing . Papers on advanced and novel treatment processes and technologies are particularly welcome. The Journal considers papers in areas such as nanotechnology and biotechnology applications in water, novel oxidation and separation processes, membrane processes (except those for desalination) , catalytic processes for the removal of water contaminants, sustainable processes, water reuse and recycling, water use and wastewater minimization, integrated/hybrid technology, process modeling of water treatment and novel treatment processes. Submissions on the subject of adsorbents, including standard measurements of adsorption kinetics and equilibrium will only be considered if there is a genuine case for novelty and contribution, for example highly novel, sustainable adsorbents and their use: papers on activated carbon-type materials derived from natural matter, or surfactant-modified clays and related minerals, would not fulfil this criterion. The Journal particularly welcomes contributions involving environmentally, economically and socially sustainable technology for water treatment, including those which are energy-efficient, with minimal or no chemical consumption, and capable of water recycling and reuse that minimizes the direct disposal of wastewater to the aquatic environment. Papers that describe novel ideas for solving issues related to water quality and availability are also welcome, as are those that show the transfer of techniques from other disciplines. The Journal will consider papers dealing with processes for various water matrices including drinking water (except desalination), domestic, urban and industrial wastewaters, in addition to their residues. It is expected that the journal will be of particular relevance to chemical and process engineers working in the field. The Journal welcomes Full Text papers, Short Communications, State-of-the-Art Reviews and Letters to Editors and Case Studies