High-solid anaerobic digestion (HSAD) is a promising technology for treating livestock manure and agricultural waste; however, the wide application has been limited due to homogenization problems. This study established a novel HSAD system by integrating liquid and biogas recirculation (RBL), aiming to enhance the biogas conversion efficiency of high-solid substrates at low costs. Results showed that the highest methane yield was 357 mL/gVSadded in the novel HSAD system (RBL), 30.7 % and 251.7 % higher than those with only liquid recirculation (RL) or with no recirculation (RNo). Biogas recirculation helped enhance dissolution and degradation of organic matter, and prevented the VFAs accumulation, contributing to the enhanced methane production in the novel HSAD system. The net electric energy benefit of RBL was 301.2 kWh for treating 1-ton raw materials, suggesting the high economic feasibility of the novel HSAD system for the sustainable treatment of high-solid organic wastes.

中文翻译：

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沼气和液体再循环的整合提高了猪粪和稻壳高固体厌氧消化中的甲烷产量


高固体厌氧消化 （HSAD） 是一种很有前途的技术，用于处理牲畜粪便和农业废弃物;然而，由于同质化问题，广泛的应用受到限制。本研究通过集成液体和沼气再循环 （RBL） 建立了一种新型 HSAD 系统，旨在以低成本提高高固体分基质的沼气转化效率。结果表明，新型 HSAD 系统 （RBL） 中的甲烷产量最高，为 357 mL/gVSadd，比仅液体再循环 （RL） 或无再循环 （RNo） 的系统高 30.7 % 和 251.7 %。沼气再循环有助于增强有机物的溶解和降解，并防止 VFA 积累，有助于提高新型 HSAD 系统中的甲烷产量。RBL 处理 1 吨原材料的净电能效益为 301.2 kWh，表明新型 HSAD 系统在可持续处理高固体有机废物方面具有很高的经济可行性。