城市化过程中天然沉积土污染演化机理与控制技术研究

With the rapid urbanization and adjustment of industry policy in mega cities of China, a lot of industrial plants have been relocated from urban to suburban areas. During the operation of these plants prior to relocation, a huge number of contaminated lands are emerging in urban areas, which is due to the less-strictly controlled discharge of waste water. The typical contaminants, including multiple heavy metals and volatile organic compounds, not only expose threat to human health, but also seriously suppress the reconstruction of the contaminated lands and sustainable development of the cities. This study aims at environmental and engineering issues in the reuse/reconstruction of the contaminated lands. Combining with laboratory tests, field investigations, and theory analysis, following key points are addressed: .(1) to investigate crucial factors controlling transport of typical industrial contaminants in natural deposited soils. Subsequently, the induced deterioration impacts to physico-chemical and mechanical properties of natural soils are illustrated. The micro-structural parameters are interlinked with macro-related permeability and effective diffusion coefficient. .(2) to propose a characteristic index for contaminated lands and classification method for contaminated soils, based on in-situ RCPTu testing and laboratory investigation. The characteristics index and classification method will take into account for the soil nature, mechanical properties and environmental characteristics. .(3) to present performance-based design theory for solidification/stabilization (S/S), air sparging (AS), and soil vapour extraction (SVE) technology, which are used for remedying multiple-heavy metal and volatile organic compounds contaminated soils, respectively. The design parameters of S/S, AS and SVE technology, will be optimized, based on comprehensive lab tests and theory analysis. .It is expected that the results will well enhance utilization of urban space, mitigate urban pollution, and promote sustainable development of urbanization. Meanwhile, it is believed that the results will considerably promote theory development and practical application of environmental engineering geology in China.

随着我国城市化的快速发展和大城市群区产业调整战略的实施，留下了大面积工业污染场地，严重阻碍了城市可持续发展。本项目针对城市化过程中大量工业污染场地再开发利用的关键科学技术问题，采用室内试验、现场试验、理论与数值模拟分析相结合的技术路线，系统研究典型工业污染物在天然沉积土体中运移与演化规律，阐明污染物对天然土体物理、化学、力学性状的影响规律与机制，分析污染物对天然土体损伤及其灾变影响的基本特征；通过现场电阻率孔压静力触探（RCPTU)测试和室内试验对比，提出评价污染场地的特征指标，建立污染土的工程分类体系；在此基础上，提出复合重金属污染土体的固化稳定处理技术方法，建立有机污染土体的曝气法（AS）与气相抽取法（SVE）控制处理理论与设计方法。研究成果对提高我国城市空间利用、缓解环境污染、实现可持续发展具有重大理论意义和现实意义，同时能提升我国环境工程地质研究的理论和应用水平。

本项目针对我国工业污染场地勘察测试评价与再开发利用的关键科学技术问题，采用室内试验、现场试验、理论与数值模拟分析相结合的技术路线，着重污染土体工程性质演化规律、现场勘察测试评价方法与分类方法，污染土体力学特性变化及其工程影响，典型污染场地的处理技术等四方面进行了深入系统研究。通过5年的研究，取得了系列研究成果：揭示了重金属和有机污染物在天然沉积土体中运移与演化规律及其对天然土体物理、化学、力学性状的影响规律与机制；明确了污染物对天然土体损伤基本特征和变形强度变化规律；提出了基于电阻率孔压静力触探（RCPTU)评价污染场地的特征指标，建立了污染土的工程分类方法；揭示了水泥固化重金属污染土体的强度增长模式；对高难度重金属污染土体，研发了新型固化剂，构建了固化稳定法处理重金属污染土的施工工艺；对有机污染土，揭示了有机污染物曝气法处理的机制，建立了相应的设计方法和施工工艺。这些成果开拓了我国污染场地岩土工程治理技术领域的研究，对我国污染土壤治理技术的发展，促进城市可持续发展具有重要理论意义和工程应用前景。.研究成果已在国内外重要刊物和会议共发表学术论文171篇，其中SCI、EI检索154篇；获得国家科技进步二等奖1项，教育部技术发明二等奖1项；已获授权发明专利33项；培养已毕业博士、硕士研究生13人（其中博士6人），已出版著作1部，正在主编国家行业标准2部（2019年颁布）。