Water infiltration into granular soils and the associated pore water pressure increase and reduction in shear strength can trigger landslides, instability of vertical cuts and failure of retaining walls. Water-repellent soils can reduce infiltration to maintain soil suction. Recent research has demonstrated the creation of synthetic water-repellent soils using chemical methods. This paper investigates a biological treatment for creating water-repellent sand by way of the growth of the fungus Pleurotus ostreatus. Water repellency was assessed using: (a) the water drop penetration test; (b) the molarity of ethanol drop test; and (c) the modified sessile drop method with contact angle (θ) determination by way of image analysis. Fungal-induced water repellency was found to be ‘extreme’ (θ > 110°) up to 4 weeks and ‘severe’ (θ > 105°) up to 12 weeks, even with no further supply of moisture or nutrients. A water-repellent layer was formed and maintained in saturated conditions, which is difficult to achieve using chemical methods.

中文翻译：

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真菌引起的沙子拒水性

水渗入粒状土壤以及相关的孔隙水压力增加和剪切强度降低会引发滑坡、垂直切口的不稳定和挡土墙的破坏。拒水土壤可以减少渗透以保持土壤吸力。最近的研究表明，可以使用化学方法制造合成防水土壤。本文研究了一种通过真菌Pleurotus ostreatus的生长来制造防水砂的生物处理方法。使用以下方法评估防水性： ( a ) 水滴渗透试验；( b ) 乙醇滴试验的摩尔浓度；( c ) 带有接触角 ( θ) 通过图像分析的方式确定。真菌引起的拒水性被发现在 4 周内是“极端”（θ > 110°）和“严重”（θ  > 105°）长达 12 周，即使没有进一步提供水分或营养。防水层形成并保持在饱和条件下，这是使用化学方法难以实现的。