In this study, we employed phosphogypsum, an important solid waste of the phosphorus chemical industry, to prepare a superhydrophobic material for oil/water separation using sodium metasilicate and stearic acid as the chemical modifiers through a facile method. This superhydrophobic material has rough micro–nano structure with low surface energy and possesses an average water contact angle of 151.5° as well as an average water sliding angle of 1.8°, showing extremely low adhesion to water. Due to its superhydrophobicity and superoleophilicity, this material can separate various oil/water mixtures with high separation efficiencies in the range from 92% to 97% by means of a simple apparatus driven by gravity. Additionally, the superhydrophobic material has high resistance to acidic solution and repeated separation, showing the reliability for harsh conditions and long-term use. This superhydrophobic material prepared based on industrial solid waste is a good example of waste valorization.

中文翻译：

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一种基于工业固体废弃物的油水分离超疏水材料

本研究采用磷石膏这一重要的磷化工固体废弃物，以偏硅酸钠和硬脂酸为化学改性剂，通过简便的方法制备了一种用于油水分离的超疏水材料。这种超疏水材料具有粗糙的微纳米结构，表面能低，平均水接触角为151.5°，平均水滑角为1.8°，对水的附着力极低。由于其超疏水性和超亲油性，该材料可以通过重力驱动的简单设备以92％至97％的高分离效率分离各种油/水混合物。此外，超疏水材料对酸性溶液和反复分离具有很高的抵抗力，显示了恶劣条件和长期使用的可靠性。这种基于工业固体废物制备的超疏水材料是废物增值的一个很好的例子。