Sufficient quantity of trace metals is essential for a well performing anaerobic digestion (AD) process. Among the essential trace elements in active sites of multiple important enzymes for AD are iron and nickel ions. In the present study, iron and nickel in the form of Fe₂O₃ and NiO were coated on TiO₂ nanoparticles to be used in batch and continuous operation mode. The effect of TiO₂, Fe₂O₃–TiO₂, and NiO–TiO₂ nanoparticles on each step of AD process was assessed utilizing simple substrates (i.e. cellulose, glucose, acetic acid, and mixture of H₂–CO₂) as well as complex ones (i.e. municipal biopulp). The hydrolysis rate of cellulose substrate increased with higher dosages of the coated TiO₂ with both metals. For instance, the hydrolysis rate was increased up to 54% at Fe₂O₃–TiO₂ and at a concentration of 23.5 mg/L for NiO–TiO₂ it was increased up to 58%, while higher dosage suppressed the hydrolytic activity. Experimental results revealed that low dosages of NiO–TiO₂ increased the accumulated methane production up to 24% probably by increasing the enzymatic activity of acetoclastic methanogenesis. NiO–TiO₂ showed positive effect on batch and continuous AD of biopulp and improved methane yield up to 8%.

足够数量的微量金属对于良好执行厌氧消化 (AD) 过程至关重要。AD 的多种重要酶的活性位点中的必需微量元素是铁和镍离子。在本研究中，铁和镍以 Fe ₂ O ₃和 NiO 的形式涂覆在 TiO ₂纳米颗粒上，以分批和连续操作模式使用。TiO ₂、Fe ₂ O ₃ -TiO ₂和NiO-TiO ₂纳米粒子对AD 工艺每个步骤的影响通过使用简单的基质（即纤维素、葡萄糖、乙酸和H ₂ -CO _{2 的}混合物）进行评估。) 以及复杂的（即市政生物纸浆）。纤维素底物的水解速率随着两种金属包覆的TiO ₂用量的增加而增加。例如，Fe ₂ O ₃ -TiO ₂的水解率提高了54%，NiO-TiO ₂浓度为23.5 mg/L 时，水解率提高了58%，而较高的剂量抑制了水解活性。实验结果表明，低剂量的 NiO-TiO ₂可能通过增加乙酰碎屑产甲烷的酶活性将累积的甲烷产量增加了 24%。NiO-TiO ₂对生物纸浆的间歇式和连续式 AD 显示出积极的影响，并将甲烷产率提高到 8%。