ABSTRACT Wheat straw and animal wastes are important feedstock for biogas production in Europe. Yet, the high content of lignocellulosic and refractory materials causes the process to be relatively slow. Therefore, pretreatment methods have been proposed to shorten the hydrolysis phase. The present study examined the effectiveness of alkali pre-treatment (AP), ultrasonic pre-treatment (UP), and alkali-ultrasonic pre-treatment (AUP) applied on wheat straw (WS), solid fraction of cattle manure (SCM) and solid fraction of slaughterhouse waste (SSHW), by monitoring solubilisation ratio, anaerobic biodegradability and methane yield. The results indicate that the solubilisation ratio of the substrates improved regardless of the types of pre-treatment applied. Though, AP was more effective on WS and SSHW than other pre-treatments (UP and AUP), with approximately 47% and 17% extra methane, respectively. Moreover, AP of SCM caused an increased in methane production rate by 100% and minimised lag phase from 16 days to 1 day during anaerobic digestion. Based on Danish conditions, only AP of WS was economical prior to the biogas process due to high extra methane yield. A positive energy budget of 8 € t−1 VS was calculated. High-energy consumption during UP and AUP in laboratory scale hindered the positive benefits of these pre-treatments. GRAPHICAL ABSTRACT

中文翻译：

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通过碱、超声波和碱-超声波预处理提高麦秸、固体牛粪和固体屠宰场的厌氧生物降解性

摘要 小麦秸秆和动物粪便是欧洲沼气生产的重要原料。然而，木质纤维素和耐火材料的高含量导致该过程相对缓慢。因此，已提出预处理方法以缩短水解阶段。本研究考察了碱预处理 (AP)、超声波预处理 (UP) 和碱超声波预处理 (AUP) 对麦秆 (WS)、牛粪固体部分 (SCM) 和屠宰场废物 (SSHW) 的固体部分，通过监测溶解率、厌氧生物降解性和甲烷产量。结果表明，无论采用何种类型的预处理，基材的溶解率都得到了提高。尽管 AP 对 WS 和 SSHW 比其他预处理（UP 和 AUP）更有效，分别含有约 47% 和 17% 的额外甲烷。此外，SCM 的 AP 使甲烷产率提高了 100%，并将厌氧消化过程中的滞后期从 16 天缩短到 1 天。根据丹麦的条件，由于额外的甲烷产量高，只有 WS 的 AP 在沼气过程之前是经济的。计算出 8 € t−1 VS 的正能量预算。实验室规模的 UP 和 AUP 期间的高能耗阻碍了这些预处理的积极好处。图形概要 计算出 8 € t−1 VS 的正能量预算。实验室规模的 UP 和 AUP 期间的高能耗阻碍了这些预处理的积极好处。图形概要 计算出 8 € t−1 VS 的正能量预算。实验室规模的 UP 和 AUP 期间的高能耗阻碍了这些预处理的积极好处。图形概要