Answer
Reverse osmosis and active transport are similar in that they both require energy to move substances across a membrane against their concentration gradient. In reverse osmosis, water is forced through a semi-permeable membrane against its concentration gradient, while in active transport, molecules or ions are moved against their concentration gradient with the help of ATP.
Reverse osmosis is an effective method for purifying water because it can remove a wide range of contaminants, including dissolved salts, bacteria, and viruses. The semi-permeable membrane used in reverse osmosis has very small pores that allow only water molecules to pass through, while blocking larger molecules and ions. This process is driven by pressure, which forces water molecules through the membrane and leaves behind contaminants. As a result, reverse osmosis can produce high-quality drinking water from a variety of sources, including seawater and brackish water.