TESTING AN ARTIFICIAL BEACH SYSTEM FOR REMOVAL OF POLLUTION IN A COASTAL ZONE

The developmental activities and utilizations of Japanese coastal seas have been increased recently. Consequently, the production of coastal fisheries, especially of those in enclosed seas, are considerably aff ected by artificial impacts such as reclamation from the sea and incre ased pollution load. The objective of this paper is to propose a new e cotechnological method to recover the polluted coastal environment by using an artificial beach system. An artificial beach (5 m x 10 m) was constructed in the Matsushima Bay facing the Pacific Sea, about 300 k m northeast from Tokyo. The area was polluted by fishery production an d untreated wastewaters from rural district. The major merits of this system are simplicity of the structure, energy-free operation, capabil ity to use tidal current cycle effectively, and ease of maintenance. T he results of field investigation indicated that rapid removals of tur bidity, suspended solids, phosphorus and ammonium nitrogen by the arti ficial beach system were achieved. The removal rate of total organic c arbon was high because of the retention of the particulate matters. Th ese performances were related to physical and biological filtration th rough the artificial beach system. It suggests that restoration of pol luted coastal area may be expected using this artificial beach system. Copyright (C) 1996 IAWQ.