Abstract: Disclosed is a modified activated sludge-based two-compartment treatment method for processing nitrate-contaminated drinking water. Raw water is firstly sent to a first TiO2-modified denitrifying activated sludge bioreactor (2), wherein organic carbon source is added in a controlled amount, and nitrate is partly reduced with nitrite being accumulated. Then, the effluent from the first bioreactor is sent to a second TiO2-modified denitrifying activated sludge bioreactor (3), wherein organic carbon source and hydrogen gas are supplemented, and remaining nitrate and accumulated nitrite are reduced to nitrogen gas. The denitrified effluent from the second bioreactor is sent to a settling tank (4), and TiO2-containing precipitates collected from the settling tank receive sequential alkaline and acidic treatment before being injected into the first bioreactor (2) for TiO2 recycling.