GOALI: Field Monitoring and Performance Evaluation of Four Bioreactor Landfills

生物反应器填埋技术是实现城市生活垃圾加速稳定化的新途径。该技术包括向废物中注入渗滤液或其他液体，以加速厌氧微生物的生物降解。含水率的变化极大地影响了废土的岩土稳定性，从而影响了各种设计的可行性。本研究描述并量化了生物反应器填埋场生命周期内的动态水平衡及其对岩土稳定性的影响。具体来说，这项工作的目标是：(1)量化生物反应器运行期间废物的动态水平衡和工程特性；(2)开发一个现场验证的耦合流动力学模型，适用于评估生物反应器垃圾填埋场的性能；(3)扩展和开发创新的、具有成本效益的地球物理方法，用于生物反应器性能的原位监测。这些目标将通过以下方式实现：(1)对四个生物反应器填埋场的水分和工程特性（包括渗透性和抗剪强度）的瞬态和空间变化进行全面监测和测试；(2)建立流体力学耦合模型，量化动态水平衡与岩土稳定性之间的关系；(3)制订生物反应器堆填区的设计、建造、运作及监察的实用指引。选定的生物反应器填埋场包括：(1)伊利诺伊州罗克福德附近的Orchard Hills生物反应器填埋场；(2)宾夕法尼亚州杜波依斯附近的格林特里生物反应器填埋场；(3)法国南特附近的La Vergne生物反应器示范项目；(4)澳大利亚布里斯班附近的钛树生物反应器填埋场。将使用密集的现场监测数据来确定废物组成、池设计、渗滤液再循环和其他操作参数对生物反应器性能的影响。除了诸如渗滤液产生、液体注入和沉降等常规监测外，还将实施一项全面的地球物理和岩土工程测试计划，以确定液体分布的时空变化以及降解废物的原位特性。地球物理测试将包括电阻率测深、二维电阻率剖面、电磁剖面和废物降解不同阶段的测井。岩土工程测试将包括在不同的时间钻孔穿过废物，并对挖掘出来的样本进行井下测试和测试，以确定废物在不同分解状态下的关键岩土工程特性。总体而言，该研究将实施新的地球物理和岩土工程仪器和监测，并对生物反应器垃圾填埋场进行全面的耦合流动力学建模，这将为改进生物反应器垃圾填埋场的设计、运行和监测提供合理的依据。学术界和工业界之间建立了独特的合作伙伴关系，与威立雅环境（通过CReeD， ONYX法国，ONYX北美和Collex澳大利亚）和Landfills+， Inc（美国咨询公司）成功完成并直接应用了这项研究。实地活动将为本科生和研究生提供地球环境工程的实际经验。

Bioreactor landfill technology is being explored as a new approach to achieve accelerated stabilization of MSW. This technology involves injecting leachate or other liquids into the waste in order to accelerate anaerobic microbial biodegradation. The changing moisture contents greatly influence the geotechnical stability of the waste mass and hence the viability of various designs. This research characterizes and quantifies the dynamic water balance and its implications on geotechnical stability during the life cycle of a bioreactor landfill. Specifically, the objectives of the work are: (1) to quantify the dynamic water balance concurrently with the engineering properties of the waste during bioreactor operations, (2) to develop a field-validated coupled flow-mechanical model suitable to assess the performance of bioreactor landfills; and (3) to expand and develop innovative and cost-effective geophysical approaches for in situ monitoring of bioreactor performance. These objectives will be accomplished through: (1) comprehensive monitoring and testing at four bioreactor landfills of both transient and spatial changes in moisture and engineering properties, including permeability and shear strength; (2) coupled fluid flow-mechanical modeling to quantify relationships between dynamic water balance and geotechnical stability; (3) development of practical guidelines for the design, construction, operation and monitoring of bioreactor landfills. The selected bioreactor landfills include: (1) Orchard Hills Bioreactor Landfill, near Rockford, Illinois; (2) Greentree Bioreactor Landfill, near Dubois, Pennsylvania; (3) La Vergne Bioreactor Demonstration Project, near Nantes, France; and (4) Ti Tree Bioreactor Landfill, near Brisbane, Australia. Intensive field monitoring data will be used to determine the effects of waste composition, cell design, leachate recirculation, and other operational parameters on bioreactor performance. In addition to routine monitoring such as leachate production, liquid injection, and settlement, a comprehensive geophysical and geotechnical testing program will be implemented to define the spatial and temporal variability of liquid distribution and in situ properties of the degrading waste mass. The geophysical testing will consist of resistivity soundings, 2D resistivity profiles, electromagnetic profiles and well logging at various stages of waste degradation. Geotechnical testing will include drilling boreholes through the waste at different time periods and conducting both downhole testing and testing of the exhumed samples to determine the critical geotechnical properties of waste at various states of decomposition. Overall, the research will implement novel geophysical and geotechnical instrumentation and monitoring as well as perform a comprehensive coupled flow-mechanical modeling of the bioreactor landfills that will lead to a rational basis for the improved design, operation and monitoring of bioreactor landfills. A unique partnership between academia and industry has been established for the successful completion and direct application of this research with Veolia Environment (through CReeD, ONYX France, ONYX North America, and Collex Australia) and Landfills+, Inc (a U.S. consultancy). Field campaigns will give undergraduate and graduate students real-world experience in geoenvironmental engineering.