Rainwater bioretention facility for synchronized nitrogen and phosphorus removal in rainfall conditions

Abstract

A stormwater bioretention facility, including a pool body. The pool body includes an overflow layer, a cover layer, a filtration layer, an upper drainage layer, a biochar layer, a submerged layer, and a lower drainage layer from top to bottom. An upper drainage pipe is disposed in the upper drainage layer; a lower drainage pipe is disposed in the lower drainage layer. The upper drainage pipe and the lower drainage pipe include side walls including a plurality of inlet holes. The lower drainage pipe includes a water outlet raised to be level with the top surface of the submerged layer, and the submerged layer is filled with iron shavings and quartz sand material. The pool body further includes an overflow well having an opening covered by a manhole cover. The water outlets of the upper drainage pipe and the lower drainage pipe are connected to the overflow well.