WATER PURIFYING METHOD AND DEVICE IN SHALLOW WATER REGION

PURPOSE: To efficiently purify contaminated matters under water by providing oystershells in a shallow water region and forcibly causing water to flow in the neighborhood thereof so that oxygen is supplied to microorganisms attached to the oystershells to activate them. CONSTITUTION: A great number of oyster shelves 3 each supporting many oystershells are installed at regular intervals at proper locations in a shallow water region 1. An intermittent air lift device 4 is provided at the middle point of each oyster shelf 3. Further, in the device 4, a large number of water lift cylinders are parallelly provided and a common floating room 6 is engaged with the upper parts of the cylinders and an air room 7 is engaged with a lower bubble collecting cylinder. Air bubbles are discharged from the room 7 to lift the water near the bottom 39 of the water so that the water 27 lifted is mixed with the water near the surface 28 of the water to diffuse it and the mixed water is caused to flow against the the seashore 30 and flow reversely so as to flow near the shelves 3 and then the water is lifted. As a result, microorganisms attached to the oystershells are activated, thereby efficiently purifying contaminated matters under water.