Hazardous water pollution caused by pure or chemically refined hydrocarbons – e.g., crude oil, nano- and microplastics, or herbicides – can be removed by rust. Nanoscience combined with chemical recognition motifs on surfaces enables an efficient and sustainable technique. Water is essential for all life on earth – yet the supply of clean water in sufficient quantities is at risk. While our need for clean water is certified as a human right, recognised as such through UN Resolution 64/292 in 2010, almost all water pollution is human-made. A crucial class of contaminants relate to the excessive use of hydrocarbons including fossil fuels and al...