Due to light it does not transmit the depth and the bed of the improvement mannered null pollution waters of the bottom material and the deep environment which utilize

摘要

PROBLEM TO BE SOLVED: To clean water in a polluted water area by constituting 'hollow of water area' to transmit solar rays to a deep layer or the bottom of the water and to supply a large amt. of dissolved oxygen by accelerating photosynthetic action in the deep water layer or on the bottom of the water to preserve ecological environment or bottom material environment. ;SOLUTION: A sunlight hole system cleans water in 'hollow of water area' being a water area surrounded by a bank structure or a membrane structure to enhance the transparency of water and to transmit solar rays to the deep layer under a thermocline 9 to accelerate the photosynthetic action of the deep layer and supplies a large amt. of dissolved oxygen to a bottom material layer 3. By this constitution, in the system utilizing a large amt. of natural solar rays, running cost is reduced and the preserving effect of ecological environment or bottom material environment is large.;COPYRIGHT: (C)1999,JPO