ISSN 1000-3665 CN 11-2202/P

    新型固化剂对新疆荒漠矿区露天采场边坡复垦土壤抗侵蚀能力的影响研究

    The effect of new curing agent on the erosion resistance of reclaimed soil in open pit slope of desert mining area in Xinjiang

    • 摘要: 新疆天山北麓矿产资源丰富,但生态环境相对脆弱,自我恢复能力差,多风沙、短时强降雨的气候导致土壤侵蚀问题严重。在土壤固化剂的种类中,聚合物作为一种非传统的化学土壤稳定材料,由于其环境友好、有效和低剂量,其使用越来越受到关注。因此将聚丙烯酰胺(PAM)和纳米二氧化硅(nano - SiO2)作为提高复垦土壤抗侵蚀能力的添加剂,采用物理边坡模型试验在不同冻融—干湿循环次数下(0、1、3、6、9、12、15次),对掺入不同PAM与nano - SiO2掺量(2∶1、1∶1、0∶1、1∶0、1∶2、0∶0)的复垦土壤进行抗侵蚀能力测试,结合扫描电子显微镜试验(SEM)探究改良机理,并进行植被对照试验。研究结果表明:(1)对边坡模型表面进行三维激光扫描发现,PAM和nano - SiO2掺量在1∶1时,三维色阶图表面更加平滑,异常的色彩和形态变化最少,而其余掺量的色阶图色彩和形态多变,说明掺量在1∶1时边坡模型产生的裂隙最少;随着循环次数的增加,色阶图中形成了新的色彩区域,说明边坡内部形成了更多的孔隙和裂缝,这些区域在扫描时可能呈现不同的色彩,从而增加了色阶图的色彩丰富度。(2)PAM改良复垦土壤的机理主要为吸附作用、絮凝作用、保水作用,nano - SiO2改良机理主要为填充作用、表面能效应。(3)植物生长试验中,在第28天,素土土壤中的植物趋于枯萎,而改良土壤中的植株继续茁壮成长,说明添加PAM和nano - SiO2不仅提高了发芽率,而且延长了植株的寿命。综合以上试验结果,PAM和nano - SiO2在1∶1的配比下对天山北麓复垦土壤的抗侵蚀性改良效果最佳。通过添加环境友好型的新型固化剂为天山北麓矿山生态修复提供了新思路,且价格低廉,具有良好的应用前景。

       

      Abstract: The northern foothills of the Tianshan Mountains in Xinjiang are rich in mineral resources. However, the ecological environment is relatively fragile and has a poor self-recovery capacity. Characterized by frequent wind-blown sand and short-duration heavy rainfall, the climate has led to severe soil erosion. As a non-traditional chemical soil stabilization material, polymers among various types of soil stabilizers are receiving increasing attention due to their environmental friendliness, effectiveness, and low dosage requirements. Therefore, the erosion resistance of reclaimed soil was enhanced using polyacrylamide and nano - SiO2 as additives. A physical slope model test was conducted under different freeze–thaw and dry–wet cycle counts (0, 1, 3, 6, 9, 12, and 15 cycles) to evaluate the erosion resistance of reclaimed soil mixed with various ratios of polyacrylamide and nano - SiO2 (2∶1, 1∶1, 0∶1, 1∶0, 1∶2, and 0∶0). The improvement mechanism was investigated using scanning electron microscopy (SEM), accompanied by a vegetation comparison experiment. The results showed that: (1) Three-dimensional laser scanning of the slope model surface indicated that with the fewest abnormal color and morphological variations, the surface of the 3D color scale map appeared smoother when the ratio of polyacrylamide to nano - SiO2 was 1∶1. In contrast, the color scale maps of other mixing ratios showed more varied colors and surface morphologies, indicating that the 1∶1 ratio resulted in the fewest cracks on the slope model. New color regions appeared in the color scale maps as the number of cycles increased. This indicates that more pores and cracks developed within the interior of the slope. During scanning, these regions may exhibit different colors , thereby increasing the color diversity of the scale map. (2) The mechanism by which polyacrylamide improves reclaimed soil primarily involves adsorption, flocculation, and water retention. The improvement mechanism of nano - SiO2 mainly involves the filling effect and surface energy effect. In the plant growth experiment, the plants in the untreated soil showed signs of withering by day 28, while those in the improved soil continued to grow vigorously. This indicates that the addition of polyacrylamide and nano - SiO2 not only improved the germination rate but also extended the lifespan of the plants. The combination of polyacrylamide and nano - SiO2 at a 1∶1 ratio, based on the above experimental results, showed the best improvement effect on the erosion resistance of reclaimed soil in the northern foothills of the Tianshan Mountains. A new approach for ecological restoration of mines in the northern foothills of the Tianshan Mountains is provided by adding environmentally friendly novel stabilizers. In addition, it is low in cost and holds great potential for practical application.

       

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