An exemplary apparatus (20), for removing pollutants atop a body of coolant, includes a filter (21), a pollutant removing structure (22), and a pump (23). The filter includes a housing (210), and a filtering unit (211) positioned in the housing for removing the pollutants from the coolant. The filtering unit is separated into a first cavity (2112) and a second cavity (2113) by a partition sheet (213). The partition sheet is spaced apart from a bottom surface of the housing to define a communicating gap (2131) for the first cavity and the second cavity to communicate with each other. The pollutant removing structure is positioned on the filter. The pollutant removing structure includes a removing member (221) for removing the pollutants out of the filter. The pump is configured for pumping the coolant into the first cavity of the filter.