Dephosphorization device in riverway

The invention discloses a dephosphorization device in a riverway, which comprises at least one box body arranged in a riverway water body; water permeable holes are formed in the side wall of the box body, and a plurality of vertically arranged dephosphorization columns are arranged in the box body; a plurality of dephosphorization chains and a plurality of dephosphorization boxes which are sequentially connected in series are arranged in the dephosphorization column at intervals in the vertical direction; a floating block is connected above a dephosphorization box at the top in the dephosphorization column through a dephosphorization chain, the upper end of the floating block is connected to the top of the dephosphorization column through a flexible piece, and the dephosphorization box at the lower part of the floating block is connected to the bottom of the dephosphorization column through the dephosphorization chain; water permeable holes are formed in the side wall of the dephosphorization box, and a deph