The water source of Jiangyin Waterworks is a long river, which needs to be purified from the Yangtze River to domestic water. The process is as follows: water inflow → precipitation → filtration → ads

The water source of Jiangyin Waterworks is a long river, which needs to be purified from the Yangtze River to domestic water. The process is as follows: water inflow → precipitation → filtration → adsorption → A, taking water only changes the position of water, and no new substance is generated, which is a physical change, so A is wrong;

B, filtration is only a method to separate insoluble solids from liquids, and it is only the separation of mixtures, and no new substances are produced, which belongs to physical changes, so B is wrong;

C, adsorption only uses the adsorption of activated carbon to adsorb impurities on the surface, and no new substances are generated, which belongs to physical changes, so C is wrong;

D, disinfection is generally the use of chlorine gas, chlorine gas reacts with water to generate hydrochloric acid and hypochlorous acid, hypochlorous acid has the effect of sterilization and disinfection, so disinfection belongs to chemical changes, so D is correct.

So choose D.