The presence of nano-nutrients can be stimulatory for the anaerobic digestion (AD) of hardly degradable wastes and thus enhance process performance. One of the essential trace elements, nickel (Ni), is involved in multiple important enzymes necessary for efficient AD. This study investigated the effects of Ni nanoparticles (NPs) with different concentrations on cattle manure AD performance and effluent chemical composition. The results showed that the highest specific biogas production was attained with 4 mg/L Ni NPs (p<0.05) and was 792.00 mL/g VS compared with cattle manure-only which yielded only 589.20 mL/g VS. Moreover, the addition of 2 mg/L Ni NPs significantly increases the methane yield (p<0.05) by 70.46% compared with cattle manure-only. Besides, H₂S production decreased by 16.50%, 90.47%, and 51.89% compared with cattle manure-only when the cattle manure was treated by 1, 2, and 4 mg/L Ni NPs, respectively. The supplementation of bio-digester with 2 mg/L Ni NPs improved the total and volatile solids removal efficiencies by 19.2% and 12.1% and maintained pH at a suitable level (6.8–7.3). FTIR spectrum of effluent presented the addition of Ni NPs changed the intensity and shift of peaks compared with cattle manure-only peak. Moreover, all of the effluent samples from the AD systems using Ni NPs showed stronger fertilizer values, as well as the effluent with 2 mg/L Ni NPs, had the highest sulfide content (31.2%, increase), leading to higher H₂S removal efficiency by 47.5%. A first-order kinetic model showed an increase up to 1.88-fold in the hydrolysis rate constant (K), in 4mg/L Ni NPs compared to cattle manure-only, leading to higher biogas yield.

纳米营养物的存在可以促进难降解废物的厌氧消化（AD），从而提高工艺性能。必需的微量元素之一，镍（Ni），参与了有效AD所必需的多种重要酶。这项研究调查了不同浓度的镍纳米颗粒（NPs）对牛粪AD性能和废水化学成分的影响。结果表明，与仅牛粪粪便仅产生589.20 mL / g VS相比，使用4 mg / L镍NPs可获得最高的比沼气产量（p <0.05），为792.00 mL / gVS。此外，与仅使用牛粪相比，添加2 mg / L Ni NPs可使甲烷产量显着提高（p <0.05），增幅为70.46％。此外，H ₂仅当分别用1、2和4 mg / L Ni NP处理牛粪时，S产量与牛粪相比就减少了16.50％，90.47％和51.89％。补充2 mg / L Ni NP的生物消解剂可使总固体和挥发性固体的去除效率分别提高19.2％和12.1％，并将pH维持在适当的水平（6.8-7.3）。废水的FTIR光谱表明，与仅使用牛粪的峰相比，添加Ni NP改变了峰的强度和峰位移。此外，AD系统使用Ni NPs的所有废水样品均显示出更强的肥料价值，以及使用2 mg / L Ni NPs的废水具有最高的硫化物含量（31.2％，增加），从而导致更高的H _2。脱硫效率提高了47.5％。一阶动力学模型显示，与仅牛粪相比，4mg / L Ni NPs的水解速率常数（K）增加了1.88倍，从而导致更高的沼气产量。