Techniques for Enhancing Anaerobic Digestibility of Municipal Solid Waste

目前，废水处理的目标正在从公共卫生和环境保护转向营养和能量回收，这是由高昂的能源成本和营养价值推动的。城市固体废物能源被认为是未来最有前途的可再生能源之一。厌氧消化(AD)是将有机废物生物转化为可再生能源和生物燃料的默认过程。AD是一个多步骤的过程，在这个过程中，复杂的有机化合物被转化为氧化和还原程度最高的形式，如单原子二氧化碳和甲烷。近年来，AD在有机废物处理中的应用迅速兴起。AD的吸引力来自于该工艺的各种好处：(A)产生的沼气是高效能源和环境友好的，(B)产生的泥浆(沼渣)富含氮，可在农业中用作营养肥和/或有机改良剂，(C)最近的应用是将沼渣转化为生物炭，可进一步用作土壤改良剂或用于净化废水或烟气的吸附剂。AD的主要缺点是停留时间长(典型的20-30天)和有机物的整体降解率低，部分原因是厌氧微生物不能有效地降解某些有机物。尽管在城市生活垃圾的AD领域做出了所有的努力，但其过程还没有得到充分的了解，仍然需要进一步发展和优化现有的技术，特别是在上述领域。 这项研究建议开发新的技术来提高城市固体废物的厌氧消化能力，以用于可再生能源的生产和养分回收。这项研究计划将针对三个关键的短期计划：(3)开发一种新型的实验室规模的集成微生物电化学电池工艺的厌氧消化器，(2)开发一种简单的工具，可用于优化AD的两种或多种基质的混合，以及(3)研究新的预处理技术，以提高AD的性能。 这项研究提案将解决学术文献中的几个关键空白。这将有助于我们更好地了解基片特性(改性前后)与AD性能之间的关系。此外，通过改进技术和培训高素质的人员，这项研究的结果将为加拿大带来可观的经济和环境效益。具体地说，我们的社会将受益于可再生能源的替代可持续技术以及从二氧化碳和有机废物中回收养分，这将对我们的环境产生直接影响。

The goals of wastewater treatment are currently changing from public sanitation and environmental protection towards nutrient and energy recovery, which are driven by the high cost of energy and value in nutrients. Energy from municipal solid waste is considered to be one of the most promising future renewable energy sources. Anaerobic digestion (AD) is the default process for the biological conversion of organic waste to renewable energy and biofuel. AD is a multi-steps process in which the complex organic compounds are converted to the most oxidized and reduced form such as mono-atomic carbon dioxide and methane. In recent years, the application of AD for the treatment of organic waste has emerged dramatically. The attractiveness of AD is due to the various benefits of the process: (a) the produced biogas is energy efficient and environmentally friendly, (b) the produced slurry (digestate) is nitrogen rich and can be utilized in agriculture as a nutrient fertilizer and/or organic amendment, (c) a more recent application is to transform the digestate into biochar, which can be further employed as soil enhancer or an adsorbent for the purification of wastewater or flue gas. The major drawbacks of AD are its long retention time (typical 20-30 days) and the low overall degradation efficiency of organic matter, which is partly caused by the inability of the anaerobic microorganisms to degrade certain organic compounds efficiently. In spite of all the efforts in the AD of municipal solid waste sector, the process is not yet fully understood, and further development and optimization of the current technology, especially in the above-mentioned areas, is still needed. This research proposal is to develop novel techniques to improve the anaerobic digestibility of municipal solid wastes for renewable energy production and nutrient recovery. This research proposal will address three key short-term programs: (3) develop a novel integrated lab-scale anaerobic digester with microbial electrochemical cell process, (2) develop a simple tool which can be used to optimize the mixing of two- or multi-substrates for AD, and (3) investigate new pretreatment techniques to enhance the AD performance. This research proposal will address several key gaps in the academic literature. It will help us better understand the correlation between the substrate characteristics (before and after modification) and the AD performance. Furthermore, through improved techniques and the training of highly qualified personnel, the findings of this study will bring substantial economic and environmental benefits to Canada. Specifically our society will benefit from alternative sustainable technologies for renewable energy and nutrient recovery from carbon dioxide and organic wastes, which will have a direct effect on our environment.