To provide a general process of performing water improvement by means of the purification function buildup through soil improvement of dry beach, the facilitation of the conventional sediment scum decomposition and, in addition, the suppression of blue tide through the dissolution of red tide.

With a view to association with nature, biomass material is utilized. The action of biomass material is slow, however, is reliable and causes no side reaction. The purification function buildup through soil improvement of dry beach is performed by using equipment of carbon belt line CBR and the facilitation of the conventional sediment scum S decomposition is performed through the concentrated installment of functional carbonized water purification material FCWR and the scattering of bamboo carbon C2, chip C3, and the like. The dissolution of red tide RT is brought about through the adsortion of phytoplankton to smoked carbon C1, bamboo carbon C2, chip C3, and the like, and the thermal destruction treatment according to heat absorption of carbon C and solar light rays.