高分子多肽衍生物防治风蚀的风洞试验

Wind tunnel experiment on polypeptide derivatives in controlling wind erosion

利用高分子化学材料改善地表结构进行化学固沙,是防治风蚀的重要措施之一。为寻找有效的高分子化学材料防治黄土高原北部水蚀风蚀交错区风积沙及沙黄土风蚀,将不同剂量(0(喷清水为对照)、0.4、0.6及1.2 g/m^2)的4种高分子化学材料聚丙烯酰胺(polyacrylamide,PAM)、阳离子羟丙基多糖(cationic hydroxypropyl quito sugar,Jag C162)、羧甲基纤维素(carboxymethyl cellulose,CMC)及羟丙基化多糖(hydroxypropyl polysaccharide,HP-120)喷施于沙黄土及风积沙表面,进行室内风洞试验,测定其风蚀率及表面固积层硬度。结果表明:喷施不同剂量的高分子化学材料PAM、Jag C162、CMC及HP-120于沙黄土及风积沙表面均能显著降低松散扰动沙黄土及风积沙的风蚀率(P<0.05)。总体而言,在相同条件下,与其他3种材料相比,PAM防治沙黄土表面风蚀的效果最好,而CMC在防治风积沙风蚀效果最好。喷施4种化学材料于沙黄土和风积沙表面均能显著增加固结层的硬度(0.4 g/m^2 Jag C162除外),且PAM对提高沙黄土表面硬度效果较好,Jag C162、CMC及HP-120对提高风积沙结皮硬度效果较好,其中CMC效果最显著;使用4种高分子化学材料防治风积沙和沙黄土风蚀时,当施用剂量控制在1.2 g/m^2时,几乎可以抵御14 m/s的大风,历时20 min的吹蚀而不产生风蚀。

The utilization of macromolecular polymers that can improve soil structure to fix sand is one of important measures for controlling soil wind erosion.Indoor wind tunnel experiments were conducted to study the effect of macromolecular polymers and polypeptide derivatives on wind erosion control in drift-sand and sandy loess.The soils used in this study were collected from the wind-water erosion crisscross region on the Loess Plateau.Four macromolecular polymers or polypeptide derivatives were used and they were polyacrylamide（PAM）,cationic hydroxypropyl quito sugar（Jag C162）,carboxymethyl cellulose（CMC）and hydroxypropyl polysaccharide（HP-120）.The application doses of the polymers were 0（CK）,0.4,0.6and 1.2 g/m^2.All the tests were repeated for 3 times.The wind tunnel had a length in 24 m.The wind speed could be adjusted in a range of 0-16 m/s.The wind speed was measured by using an AZ-8902 Anemobiagraph with a range of 0.6-35 m/s.The soil tank had the width of 98 cm,the length of 126 cm and the depth of 5 cm.The soil density of the drift-sand and sandy loess was 1.36 and 1.29 g/cm^3,respectively.The water content of air-dried sandy loess and drift-sand was 0.25%and 0.21%,respectively.During the experiment,the wind speed was adjusted to 14 m/s for 20 min.The wind erosion rate was calculated and the consolidation layer hardness was determined.The results showed that all the materials with different doses could significantly reduce wind erosion rate（P〈0.05）on the disturbed drift-sand and sandy loess surface.Compared with the others,PAM was the best in decreasing wind erosion rate on the surface of sandy loess.Averagely,PAM,Jag C162,CMC and HP-120 on the surface of sandy loess could decrease the wind erosion rate by 65.47%,51.78%,62.34%and 50.29%（P〈0.05）,respectively;On the surface of drift-sand,PAM,Jag C162,CMC and HP-120 could decrease the wind erosion rate by 62.56%,92.58%,98.45%and 92.88%（P〈0.05）,respectively.The CMC had the best effect in reducing wind erosion rate on the surface of drift-sand among the polymers.Compared with the CK,the polymers could increase the consolidation layer hardness of the sandy loess significantly except for the 0.4 g/m^2 Jag C162 treatment.For the most treatments,the hardness increased with application doses.At the application dose of 1.2 g/m^2,the hardness was the highest after spraying PAM and the least after spraying HP-120 on the surface of sandy loess.Compared with the CK,the hardness could be increased by 356%using the PAM.On the drift-sand,the CMC had the best effect in increasing consolidation layer hardness and the hardness could be increased by 746.15%using the CMC.Overall,the PAM had the best effect in decreasing wind erosion rate and increasing hardness on the surface of sandy loess while the CMC was the best for the drift-sand.At the application dose of 1.2 g/m^2,all the polymers showed good wind erosion control capacity to resist against 14 m/s wind for 20 min with little wind erosion.