Soil degradation is a global challenge that is intrinsically linked to climate change and food security. Soil degradation has many causes, but all degraded soils suffer from poor soil structure. The increasing global production of water treatment residual (WTR), an organo-mineral waste product from clean water treatment, means that the sustainable reuse of this waste provides a potential timely opportunity, as research has shown that WTR application to soil can improve soil health. Recycling or reuse of WTR to land is commonplace across the world but is subject to limitations based on the chemical properties of the material. Very little work has focused on the physical impacts of WTR application and its potential to rebuild soil structure, particularly improving its ability to hold water and resist the effects of flooding. This paper presents novel research in which the use of Fe WTR and Fe WTR $/$ compost [1 : 1] co-amendment has shown to be beneficial for a soil's water retention, permeability, volume change, and strength properties, all critical in soil health. Application rates of WTR were 10 %–30 % by dry mass. Compared with the control sandy loam soil, co-amended samples have 5.7 times the hydraulic conductivity (570 % improvement), 54 % higher shear strength, and 25 % greater saturated water content. Single WTR-amended soil had 26 times the saturated hydraulic conductivity (2600 % improvement), 129 % higher shear strength, and 13.7 % greater saturated water content. Data indicate that Fe WTR can be added as a single amendment to significantly improve soil physical characteristics where shear strength and hydraulic conductivity are the most important factors in application. Although the co-application of Fe WTR with compost provides a lesser improvement in shear strength and hydraulic conductivity compared with single WTR amendment, the co-amendment has the best water retention properties and provides supplementary organic content, which is beneficial for environmental applications where the soil health (i.e. ability to sustain ecosystem functions and support plants) is critical.

中文翻译：

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再利用铁水处理残渣作为土壤改良剂，以提高身体机能和抗洪能力

土壤退化是一项全球性挑战，与气候变化和粮食安全有着内在联系。土壤退化有很多原因，但所有退化的土壤都受到土壤结构不良的影响。残留水处理（WTR）的全球产量不断增加，这是一种来自清洁水处理的有机矿物废物，这意味着这种废物的可持续再利用提供了一个潜在的及时机会，因为研究表明，将 WTR 应用于土壤可以改善土壤健康. WTR 的回收或再利用在世界各地都很普遍，但受到基于材料化学性质的限制。很少有工作关注 WTR 应用的物理影响及其重建土壤结构的潜力，特别是提高其保水能力和抵抗洪水影响的能力。 $/$ 堆肥 [1 : 1] 共同修正已证明有利于土壤的保水性、渗透性、体积变化和强度特性，所有这些对土壤健康都至关重要。WTR 的施用率为 10%-30%（按干重计）。与对照砂壤土相比，共同修正的样品具有 5.7 倍的导水率（提高 570%），抗剪强度提高 54%，饱和含水量提高 25%。单一 WTR 改良土壤的饱和导水率提高了 26 倍（提高了 2600%），抗剪强度提高了 129%，饱和含水量提高了 13.7%。数据表明，Fe WTR 可以作为单一改良剂添加，以显着改善土壤物理特性，其中剪切强度和导水率是应用中最重要的因素。