GOALI: Field Monitoring and Performance Evaluation of Four Bioreactor Landfills

生物反应器填埋技术是实现垃圾加速稳定化的新途径。这项技术涉及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弃体的岩土稳定性，从而影响了各种设计的可行性。这项研究描述和量化了生物反应器垃圾填埋场生命周期中的动态水平衡及其对岩土稳定性的影响。具体地说，这项工作的目标是：(1)在生物反应器运行期间，将水的动态平衡与废物的工程性质同时量化；(2)开发适用于评估生物反应器垃圾填埋场性能的现场验证的流动-力学耦合模型；以及(3)扩大和开发创新的、具有成本效益的地球物理方法，用于现场监测生物反应器的性能。这些目标将通过以下方式实现：(1)在四个生物反应器垃圾填埋场全面监测和测试水分和工程性质的瞬时和空间变化，包括渗透性和剪切强度；(2)流体流动-力学耦合模型，以量化动态水平衡与岩土稳定性之间的关系；(3)为生物反应器垃圾填埋场的设计、建造、操作和监测制定实用指南。选定的生物反应器垃圾填埋场包括：(1)伊利诺伊州罗克福德附近的Orchard Hills生物反应器垃圾填埋场；(2)宾夕法尼亚州杜布瓦附近的格林特里生物反应器垃圾填埋场；(3)法国南特附近的La Vergne生物反应器示范项目；以及(4)澳大利亚布里斯班附近的钛树生物反应器垃圾填埋场。将使用密集的现场监测数据来确定垃圾成分、单元设计、渗滤液循环和其他操作参数对生物反应器性能的影响。除了渗滤液产生、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测试计划，以确定液体分布的时空变异性和可降解废物的现场性质。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。岩土测试将包括在不同时间段对废物进行钻孔，并对挖掘出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特性。总体而言，这项研究将实施新的地球物理和岩土技术仪器和监测，并对生物反应器垃圾填埋场进行全面的流动-力学耦合模拟，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基础。为与威立雅环境公司(通过Creed、Onyx France、Onyx North America和Collex Australia)和垃圾填埋场+公司(一家美国咨询公司)成功完成并直接应用这项研究，学术界和工业界建立了独特的合作伙伴关系。实地活动将为本科生和研究生提供地质环境工程方面的真实世界体验。

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.