耐盐微生物-植被共生沙漠土加固机理试验研究

荒漠化不仅造成了我国农耕及森林的土地流失、大气污染，同时不利于我国经济圈及交通圈一体化，因此，治理沙漠化、造就“绿水青山”是国土资源保持和生态绿化的重大战略需求。本项目基于生物改性，提出耐盐微生物-植被共生沙漠治理方法，该方法通过在培养基中加入高浓度盐对微生物进行生物改造，达到一次加固成型，同时利用反应的副产品作为养分进行植被栽培，实现了固沙及绿化一体化。但关于耐盐微生物的驯化、分离及加固机理研究还是空白。通过耐盐微生物加固土体的抗压、抗剪、渗透性、抗侵蚀等系列试验，量化加固后沙漠土的强度、渗透性以及抗侵蚀与生成碳酸钙含量的关系，探究耐盐微生物加固剂的成核与生长机理和以副产品为养分的植被生长机制，最后形成一套有效的耐盐微生物-植被共生沙漠治理方法。本项目是微生物工程、植物工程、岩土工程等多学科交叉项目，预期成果对国家倡导的生态减灾方法具有重要的理论和工程实际意义。

Desertification not only leads to agricultural and forest land loss and air pollution in China, but also is not conducive to the integration of China's economic circle and traffic circle. Therefore, it is a major strategic demand for land resources conservation and ecological greening to control desertification and create "green waters and green mountains". This project based on biological modification, proposed the salt-tolerant symbiotic microorganisms - vegetation desert control method. The salt-tolerant microorganism is obtained by adding high concentrations of salt in the cultivation medium to reach biological modification, which can react with high concentration of cementation solution and form solid sample with one-time treatment. The by-products of MICP process can also be used to produce fertilizer as a nutrient for vegetation cultivation, finally achieving the integration of sand fixation and greening for desert control. However, the research on the domestic cultivation and isolation of salt-tolerant microorganisms and its reinforcement mechanism is still unavailable. This project proposes to use salt-tolerant microorganism for biocementation and conducts a series of experiments to measure the compressive strength, shear strength, permeability, erosion resistance, etc. of biocemented soil, revealing the strength and permeability improvement of desert soil as well as the relationship between the erosion resistance and calcium carbonate content after biotreatment. This project also investigates the nucleation and growth mechanism of salt-tolerant microorganism are also investigated and uses the by-products to provide nutrient for vegetation cultivation, thus forming an integrated method via salt-tolerant microorganism for biocementation and vegetation cultivation for desert control. This project is an interdisciplinary study, including biological engineering, plant engineering, geotechnical engineering, etc. The expected results can provide great theoretical and engineering practical significance for the ecological disaster reduction method encouraged by government.