基于煤矸石基质充填的重构土壤多变量因子协同响应特征研究

The reconstructed soil of reclaimed land which filled with coal gangue is different from undisturbed soil. The characteristic of matrix-soil -crops system is controlled and influenced by the properties of coal gangue. The system is selected as research object to study the fllowing works through the simulation expeiment ,field experiments and theoretical methods.(1) The influence rule of reconstructed soil properties and physiological and ecological properties of crop are proved which influenced by mineral composition and size graduation of coal gangue.(2) The influence rule of migration characteristic of reconstructed soil moisture, salinity and nutrient is revealed which influenced by temperature field variation of coal gangue during the weathering process. The coupling migration mechanism of reconstructed soil moisture, salinity, nutrient and temperature which influenced by temperature gradient change also is revealed.(3) for improving the capacity of holding water and fertilizer of coal gangue, the multi-layer structure of filling reclamation is studied and the mechanism is revealed.(4) The migration mechanism of heavy metal migrated from coal gangue to soil and crops is revealed, the pollution risk of heavy metals is evaluated and the spatial-time distribution characteristic of heavy metal in the systme also is revealed. The collaborative response characteristic of variable factors in reconstructed soil is revealed through the research work.

煤矸石充填复垦重构土壤不同于原状土壤，煤矸石直接关系到基质-土壤-作物系统的特性，影响到重构土壤水分、盐分、养分的保持力及重金属的释放与作物吸收。项目以煤矸石基质-土壤-作物系统为研究对象，采用实验室模拟实验、田间小区较大规模监测试验及理论研究方法，开展如下工作:(1)研究煤矸石基质不同矿物成分及粒径级配结构对重构土壤性质及作物生理生态性质的影响规律；(2)研究煤矸石基质风化过程中温度场变化对重构土壤水盐及养分运移影响特征，揭示温度势梯度作用下重构土壤水、盐、养分、热耦合运移机理；(3) 针对煤矸石基质持水保肥能力弱的特性，实验研究煤矸石基质与土层结合的多层复垦结构并揭示其机理。(4) 研究煤矸石基质中重金属元素向土壤及作物中迁移机理，评价重金属污染风险性，分析基质-土壤-作物系统中重金属时空分布特征。探寻煤矸石充填基质-土壤-作物系统水盐、养分及重金属等多变量因子协同作用的规律和特点。

煤炭在我国乃至全世界能源消费结构中占重要比重，但煤炭地下开采不仅造成地表大面积沉陷变形，破坏耕地资源，还产生大量废弃物。其中，煤矸石就是煤炭开采和加工过程中产生的一种主要的固体废弃物。以往，煤矸石在煤炭开采后通常就近堆放在地表，不仅压占土地资源，还在风化和淋溶作用下对大气、土壤和水体造成污染。利用煤矸石对采煤沉陷区进行充填复垦，不仅解决了煤矸石露天堆放污染环境、占用土地的问题，还增加了耕地资源。但是，煤矸石充填复垦重构土壤，不同于原状土壤，煤矸石充填基质在长期风化过程中理化性质发生改变，如释放作物生长所需养分、析出重金属元素、基质层温度场变化等，并通过基质-土壤-作物系统，对上覆土壤的理化性质和作物生长产生影响。因此，对煤矸石充填复垦重构土壤多变量因子协同响应特征进行研究具有重要意义。. 项目主要研究内容包括：(1)充填基质温度场作用下重构土壤水、盐、养分、热耦合迁移规律；(2)充填基质矿物成分与粒径结构对覆土及作物的影响规律；(3)充填基质与土层结合的多层结构重构土壤水盐养分运移规律；(4)充填基质-土壤-作物系统中重金属时空分布特征及迁移规律。. 项目通过土柱模拟实验和田间小区试验，对重构土壤水分和养分运移、水热盐耦合响应，以及煤矸石粒径级配和覆土厚度对重构土壤理化性质的影响等问题进行了研究，并利用高光谱技术对重构土壤中的重金属含量进行了反演。项目组已发表相关研究论文19篇，其中SCI1篇，EI7篇，CSCD5篇，另有3篇SCI在投；申请发明专利14项，已获批10项；出版专著2部。培养博士研究生2人，硕士研究生10余人，培养青年教师5人。组织召开一次国际学术会议。相关研究成果经安徽省科技成果转化服务中心组织的专家鉴定，达到国际先进水平。