Sand and water can be separated by any of the following methods:
1. Sedimentation and decantation: This method involves the mixture being kept undisturbed for some time. After some time, sand being heavier and insoluble in water, settles down at the bottom of container. Now, water is poured into another container to separate it from sand.
2. Filtration: This method involves the mixture being passed through a filter paper (a filter with very fine pores). Sand particles being larger in size are retained by the filter paper and get separated from water.
I hope this helps! :D