APPARATUS FOR TREATING RAINWATER AND METHOD FOR TREATING RAINWATER

摘要

PURPOSE: An apparatus for treating initial rainwater and a method thereof are provided to prevent blocking of filter medium and extend exchange period of a filter unit because sludge absorbed in the filter medium inside the filter unit is removed by flowing backward target water into the filter unit, thereby reducing costs for maintenance. CONSTITUTION: An apparatus for treating initial rainwater comprises a settling tank(10), a filter tank(20), a filter unit(30), an effluent tank(40), a back washing unit(50), and a sludge storage tank(60). Initial rainwater flows into the settling tank in which earthy materials and concomitant of the initial rainwater flowed in is sunk. The rainwater, removed the earthy materials and the concomitant in the settling tank, flows into the filter tank. The filter unit is installed in the filter tank to filter the rainwater flowed into the filter tank. The water filtered by the filter unit flows into the effluent tank and temporarily stores. If the water level of the effluent tank becomes lower than predetermined level, the back washing unit allows the water in the effluent tank to flow backward into the inside of the filter unit in order to remove sludge in the filter unit. The sludge removed in the filter unit flows into the sludge storage tank.