Water treatment system and method

The water treatment system of 13, wherein the first and/or second reactor is modular, at least one of the plurality of cell units being removeably attachable.

A water treatment system comprising:

• a first reactor and a second reactor arranged to be placed in series in a body of water between an inlet of the body of water and an outlet of the body of water, the first and/or second reactor arranged to house biomedia,
• a settling zone between the first reactor and the second reactor,
• at least one baffle positioned across a flow path in the body of water and around at least one of the first reactor and the second reactor for directing water through the at least one of the first reactor and the second reactor, and for providing a water treatment chain from the inlet to the outlet, through the first reactor, the settling zone, and the second reactor, without recirculation of the water.

A water treatment system comprising a first reactor and a second reactor arranged to be placed in series in a body of water between an inlet of the body of water and an outlet of the body of water, the first and/or second reactor arranged to house biomedia, a mid-settling zone between the first and second reactors for separating solids in the water, the system arranged to form a water treatment chain from the inlet to the outlet through the first reactor, the mid-settling zone, and the second reactor without recirculation of the water, the first and/or second reactor being adapted to float in the body of water, and the biomedia having a surface area of about 160 to about 330 m2 per cubic meter.