Preparation And Properties Of Clay-based Polymer Soil Fixation Materials

In recent years,the destruction of the earth on which human beings live for survival has become more and more serious with the rapid development of human society.The excessive grazing,mining,deforestation,land reclamation,large-scale development and a construction,rapidly population expand have caused shortage of resources and a deterioration of the ecological environment.Ecological and environmental problems,such as soil erosion,instability of slopes,mudslides,desertification,sandstorms and other environmental problems,have also followed,and affected people’s lives seriously.Among them,water erosion and wind erosion intensity are very serious.Northwestern China,especially the Loess Plateau,has a dry climate,scarce vegetation,concentrated and heavy rainfall,poor soil erosion resistance and serious soil erosion.Severe soil erosion cause thousands of ravines,destruction of fertile fields,a large number of silt deposition in the river channel,rise of the river bed,reduction of the ability of flood control dam,a serious threat to the survival and development of human beings.It has brought great harm to the national economy and social sustainable development.Domestically and internationally,there are mainly engineering measures,biological measures and agricultural measures to prevent and control soil erosion,slope protection and soil protection.However,the current measures have many problems,such as large dosage,large investment,long cycle,slow effect and environmental pollution.In this thesis,inorganic loess,laterite and palygorskite(attapulgite)with abundant natural reserves were used as raw materials,and natural polymer biogel,cellulose and starch were added respectively.Soil-based polymer soil-fixing materials were prepared with pure water as solvent,and their watercorrosion resistance was investigated.Added natural polymer biogel,cellulose and starch.Used pure water as the solvent.Slope surface erosion test was carried out according to indoor simulated artificial rainfall or flood to test the water erosion resistance of the material.The main contents are as follows:1.Loess and laterite were used as raw materials,and different kinds and different mass fractions of polymer biogel(water soluble xanthan gum,artemisia sphaerocephala krasch gum,locust bean gum,guar gum,flaxseed gum,sesbania gum,seaweed gum,fenugreek gum,konjac gum,arabic gum,carrageenan)were added.Used pure water as the solvent,the reaction is controlled to obtain clay-based biogel soil fixation material.The structure of the material was analyzed and characterized by scanning electron microscopy(SEM),fourier transform infrared spectroscopy(FTIR),particle size analyzer(DTS)and X-ray diffraction(XRD).The effects of preparation conditions,biogel types and addition amounts on the water erosion resistance of the materials were investigated.The results showed that the addition of biogel(0.3%-0.4%)greatly improved the water erosion resistance of loess and laterite.Among them,the biogel with excellent water erosion resistance were xanthan gum,artemisia sphaerocephala krasch gum,flaxseed gum,fenugreek gum.The maximum resistance to water erosion time was more than 12 h,the maximum water erosion resistance time increased by 144 times compared with pure soil;the second most effective biogel were sesbania gum,locust bean gum and guar gum.The maximum resistance to water erosion time is over 8 h,the maximum water erosion resistance time can be increased by 96 times compared with pure soil.2.Loess and laterite were used as raw materials,and different kinds and different mass fractions of polymer cellulose(water soluble sodium carboxymethyl cellulose,carboxymethyl cellulose sodium,sodium hydroxyethyl cellulose,sodium hydroxypropyl cellulose,sodium hydroxypropyl methyl cellulose,methyl ceulose,ethyecellulose)were added.Used pure water as the solvent,the reaction is controlled to obtain clay-based cellulose soil fixation material.The structure of the material was analyzed and characterized by SEM,FTIR,DTS,XRD.The effects of preparation conditions,cellulose types and addition amounts on the water erosion resistance of the material were investigated.The results showed that the addition of cellulose(0.4%-0.5%)greatly improved the water erosion resistance of loess and laterite.Among them,the cellulose with excellent water erosion resistance were sodium carboxymethyl cellulose,sodium hydroxypropyl methyl cellulose.The maximum resistance to water erosion time was more than 12 h,the maximum water erosion resistance time increased by 144 times compared with pure soil;the second most effective cellulose were sodium hydroxymethylcellulose and sodium hydroxyethylcellulose.The maximum resistance to water erosion time was over 6 h,the maximum water erosion resistance time increased by 72 times compared with pure soil.3.Loess and laterite were used as raw materials,different kinds and different mass fractions of polymer starch(water soluble oxidized starch,corn starch,soluble starch,sodium carboxymethyl starch,potato starch,modified corn starch,sweet potato starch,tapioca starch)and gelatinized starch were added.Used pure water as the solvent,the reaction was controlled to obtain clay-based starch soil fixation material.The structure of the material was analyzed and characterized by SEM,FTIR,DTS,XRD.The effects of different starch types and different gelatinized starches on the water erosion resistance of the material were investigated.The results showed that the gelatinized starch(1%)with better water erosion resistance are tapioca starch,potato starch and sodium carboxymethyl starch.The maximum water erosion resistance time was more than 10 h.Compared with pure soil,the maximum water erosion resistance time was improved 120 times.And compared with ungelatinized starch,the maximum water erosion resistance time increased by 10 times.The gelatinized starch soil fixation material had good resistance to water erosion.