生物矿化技术固化风积沙试验与应用

Experiment and application of biomineralization technology solidifying aeolian sand

为了改善沙漠地区的生态环境,采用生物矿化技术进行风积沙固化.首先,从土壤中分离并培养类芽孢杆菌,提取脲酶溶液.然后,通过风蚀测试试验、表面强度测试试验和植物适生性测试试验,研究生物矿化的室内固沙效果.最后,在乌玛高速公路中卫段进行了面积为5×10^(4)m^(2)现场试验,验证生物矿化固沙技术的现场应用效果.结果表明,生物矿化可以有效胶结风积沙并在试样表面形成强度大于400 kPa的硬化层,可抵御11级风的风蚀作用,且不影响植物种子的萌发.虽然降雨对生物矿化固沙效果存在影响,但是固化7 d时硬化层强度超过500 kPa, 2 a内固化区高程无明显变化,表现出较好的抗风蚀性.固化区植物成活率超过50%,说明固化区具有良好的生态恢复功能.

To improve the ecological environment in desert areas, a biomineralization technology was used to solidify aellian sand. Firstly, urease-producing Paenibacillus was isolated from soil, and the urease enzyme was extracted after culturing Paenibacillus species. Then, the wind tunnel test, surface strength test, and plant fitness test were used to study the solidification effects of specimens treated by biomineralization in doors. Finally, a field test of 5×10^(4) m^(2) of sand fixation was carried out in the Zhongwei section of Wuma highway to verify the field application effect of biomineralization sand fixation technology. The results show that the aeolian sand can be effectively cemented to form a hardened layer with a strength higher than 400 kPa on the surface of the specimens by the biomineralization technology, which can resist the wind erosion of the 11th grade wind and does not affect the germination of plant seeds. Although the solidification effect can be influenced by rainfall, the 7 d strength of the cured layer is higher than 500 kPa, and little elevation change is shown in the cured area within 2 a, which demonstrates a good resistance to wind erosion. Moreover, the survival rate of plants in the solidified area exceeds 50%, exhibiting a good ecology restoration function in the solidified area.