Method for solidifying island reef calcareous sand through indigenous microorganisms

Abstract

The invention provides a method for solidifying island reef calcareous sand through indigenous microorganisms. The method for solidifying the island reef calcareous sand through the indigenous microorganisms comprises the specific steps: firstly a calcareous sand sample is adopted through a sterile measure, and growth promotion fluid and consolidating fluid are prepared; when the growth promotionfluid with 1.2 times of the pore volume is injected into the calcareous sand till the concentration of carbonate ions in an effluent is equal to or larger than 70% of the concentration of urea in thegrowth promotion fluid, the growth promotion fluid stops being injected; when the consolidating fluid is injected for the first time, a Tris-HCl buffer solution with 1.2 times of the pore volume of sandy soil is injected into the sandy soil firstly, then the consolidating fluid with the equal pore volume is injected into the calcareous sand, the fluid is injected in the direction from bottom to top, the fluid is continuously injected for 7-9 days, and consolidating is completed; and then demolding and drying are conducted, and a consolidated sample is obtained. Operation is easy, the cost is low, the homogeneity of the solidification effect of the calcareous sand can be effectively improved, and meanwhile the adverse impact on the ecological environment due to introduction of exogenous microorganisms is avoided.

Description

technical field [0001] The invention relates to the field of calcareous sandstone soil reinforcement, in particular to a method for using native microorganisms to solidify calcareous sand of islands and reefs. Background technique [0002] The surface of natural and artificial islands and reefs in the South my country Sea is almost entirely covered by calcareous sand, which is calcareous debris formed by the long-term physical fragmentation of porous coral reefs. Different from quartz sand with similar particle size, calcareous sand has poor roundness, many pores and low dry density in appearance. In addition, the calcareous sand has a high degree of looseness and a large effective force-bearing area, which makes it easy to start and carry under the action of waves, currents or wind. Long-term physical transportation will cause the loss of calcareous sand, and even aggravate the coastal erosion of islands and reefs. It is of great significance to study and solve the immobi...

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Problems solved by technology

Although this method is simple and efficient, the long-term impact on marine ecology is difficult to ignore

Laying vegetation can also achieve the effect of fixing calcareous sand, but considering the high salt content of calcareous sand, poor water retention, limited freshwater resources on islands and reefs, and frequent occurrence of bad weather, it is difficult to build vegetation, which easily leads to waste of resources

[0004] Disadvantages of the prior art: the cost of exogenous microorganism preparation and storage is high, which increases the cost of engineering practice; the artificial introduction of exogenous microorganisms will have a potential impact on the ecological environment of sandy soil, and the environmental tolerance of introduced bacteria is also worthwhile. further research

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