Khan Sohaib Z, Zaidi Asad A, Naseer Muhammad Nihal, AlMohamadi Hamad
Department of Mechanical Engineering, Faculty of Engineering, Islamic University of Madina, Madinah, Saudi Arabia.
Department of Mechanical Engineering, Faculty of Engineering Science and Technology, Hamdard University, Karachi, Pakistan.
Front Bioeng Biotechnol. 2022 Sep 2;10:868454. doi: 10.3389/fbioe.2022.868454. eCollection 2022.
Nanotechnology is considered one of the most significant advancements in science and technology over the last few decades. However, the contemporary use of nanomaterials in bioenergy production is very deficient. This study evaluates the application of nanomaterials for biogas production from different kinds of waste. A state-of-the-art comprehensive review is carried out to elaborate on the deployment of different categories of nano-additives (metal oxides, zero-valent metals, various compounds, carbon-based nanomaterials, nano-composites, and nano-ash) in several kinds of biodegradable waste, including cattle manure, wastewater sludge, municipal solid waste, lake sediments, and sanitary landfills. This study discusses the pros and cons of nano-additives on biogas production from the anaerobic digestion process. Several all-inclusive tables are presented to appraise the literature on different nanomaterials used for biogas production from biomass. Future perspectives to increase biogas production via nano-additives are presented, and the conclusion is drawn on the productivity of biogas based on various nanomaterials. A qualitative review of relevant literature published in the last 50 years is conducted using the bibliometric technique for the first time in literature. About 14,000 research articles are included in this analysis, indexed on the Web of Science. The analysis revealed that the last decade (2010-20) was the golden era for biogas literature, as 84.4% of total publications were published in this timeline. Moreover, it was observed that nanomaterials had revolutionized the field of anaerobic digestion, methane production, and waste activated sludge; and are currently the central pivot of the research community. The toxicity of nanomaterials adversely affects anaerobic bacteria; therefore, using bioactive nanomaterials is emerging as the best alternative. Conducting optimization studies by varying substrate and nanomaterials' size, concentration and shape is still a field. Furthermore, collecting and disposing nanomaterials at the end of the anaerobic process is a critical environmental challenge to technology implementation that needs to be addressed before the nanomaterials assisted anaerobic process could pave its path to the large-scale industrial sector.
纳米技术被认为是过去几十年来科学技术领域最重要的进步之一。然而，纳米材料在生物能源生产中的当代应用非常不足。本研究评估了纳米材料在利用各种废物生产沼气中的应用。开展了一项最新的全面综述，以阐述不同类别的纳米添加剂（金属氧化物、零价金属、各种化合物、碳基纳米材料、纳米复合材料和纳米灰）在几种可生物降解废物中的应用，这些废物包括牛粪、废水污泥、城市固体废物、湖泊沉积物和卫生填埋场。本研究讨论了纳米添加剂在厌氧消化过程中对沼气生产的利弊。给出了几个综合性表格，以评估关于用于从生物质生产沼气的不同纳米材料的文献。提出了通过纳米添加剂提高沼气产量的未来展望，并基于各种纳米材料得出了关于沼气生产率的结论。首次在文献中使用文献计量技术对过去50年发表的相关文献进行了定性综述。本分析纳入了约14000篇在科学网上索引的研究文章。分析表明，过去十年（2010 - 2020年）是沼气文献的黄金时代，因为84.4%的出版物是在这个时间段发表的。此外，观察到纳米材料已经彻底改变了厌氧消化、甲烷生产和废弃活性污泥领域；并且目前是研究界的核心焦点。纳米材料的毒性会对厌氧细菌产生不利影响；因此，使用生物活性纳米材料正成为最佳选择。通过改变底物以及纳米材料的尺寸、浓度和形状来进行优化研究仍是一个领域。此外，在厌氧过程结束时收集和处置纳米材料是技术实施面临的一项关键环境挑战，在纳米材料辅助的厌氧过程能够迈向大规模工业领域之前，这一挑战需要得到解决。
