A novel method to improve methane generation from waste sludge using iron nanoparticles coated with magnesium hydroxide
A novel method to improve methane generation from waste sludge using iron nanoparticles coated with magnesium hydroxide
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DOI：
10.1016/j.rser.2022.112192
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发表时间：
2022-04
影响因子：
15.9
通讯作者：
Ramadan Eljamal;I. Maamoun;K. Bensaida;G. Yilmaz;Yuij Sugihara;O. Eljamal
中科院分区：
文献类型：
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作者：
Ramadan Eljamal;I. Maamoun;K. Bensaida;G. Yilmaz;Yuij Sugihara;O. Eljamal
针对厌氧消化（AD）工艺产生甲烷气体效率低的问题，我们首次应用包覆/Fe0+Mg(OH)2来提高废污泥降解甲烷气体的产率。一系列批量测试研究了几个操作因素，随后进行了半连续操作系统，检查了在涂层/FeO存在下甲烷气体的长期生产。对Mg(OH)2/Fe0的包覆比和包覆/Fe0的用量进行优化，获得最高的甲烷产率，分别为0.5%和25mg/gVS。在这些最佳条件下，与对照反应器相比，间歇试验中甲烷产量增加了46.6%，半连续操作系统中甲烷产量增加了120%。结果表明，Fe0和Mg(OH)2在不同剂量下单独使用时，并没有显着提高甲烷产量，而甲烷产量的提高源于这两种材料组合的协同效应。 Mg(OH)2涂层的关键作用与Fe0的受控反应性释放有关，这通过生物反应器中Fe2+和Fe3+的缓慢释放表明了这一点。此外，涂层/Fe2O的添加刺激了细菌生长，增加了甲烷含量，并将生物反应器中的pH值维持在最佳范围内。在AD过程的四个阶段对涂层/Fe0的投加时间进行了研究，发现最佳投加时间是在产甲烷阶段（第4天）。总体而言，根据实验和预测的甲烷产量，涂层/Fe0在AD的实际应用中具有巨大的潜力。
In response to the low efficiency of the anaerobic digestion (AD) process in generating methane gas, we apply for the first time the use of coated/Fe0with Mg(OH)2to enhance the production rate of methane gas from the degradation of waste sludge. A series of batch tests investigated several operations factors followed by a semi-continuous operation system examined the long-term production of methane gas in the presence of the coated/Fe0were performed. The coating ratio of Mg(OH)2/Fe0and the dosage of coated/Fe0were optimized to acquire the highest production rate of methane as 0.5% and 25mg/gVS, respectively. Under these optimum conditions, the methane production increased by 46.6% in the batch tests and 120% in the semi-continuous operation system compared to the control reactor. The results revealed that both Fe0and Mg(OH)2did not significantly improve the production of methane when each one was used alone at different dosages, and the improved methane production originated from the synergetic effect of combining these two materials. The crucial role of Mg(OH)2coating layer was associated with the controlled reactivity release of Fe0, which was indicated by the slow release of Fe2+and Fe3+in the bioreactors. Furthermore, the addition of coated/Fe0stimulated bacterial growth, increased methane content, and maintained the pH within the optimum range in the bioreactors. The dosing time of coated/Fe0was investigated during the four stages of AD process, and the best dosing time was found in the methanogenic stage (on Day 4). Overall, based on the experimental and predicted methane production, the coated/Fe0has a great potential for the practical applications of AD.