PURIFYING METHOD FOR LAKE AND POND AND DEVICE USED FOR THIS METHOD

PURPOSE:To rationally purify the water in lakes and ponds by artificially generating the flow of water in the lakes and ponds by operation of submersible mixers, adding a flocculating agent to this flow to generate flocs, floating the flocs on air bubbles, capturing the flocs with fence and recovering the flocs. CONSTITUTION:The submersible mixers 1 are installed in the pond 10 to induce the flow of the specified direction in the water in the pond 10 by the operation thereof. A flocculating agent mixing and air bubble generating device 4 having a submersible pump 11 and an ejector is installed in mid-way of the flow of the water to supply the flocculating agent in a service tank 2 installed on land to a water suction port 13 of the submersible pump 11. This flocculating agent is sufficiently mixed with sewage and the mixture is transferred to the ejector where the mixture is mixed with the air sucked from an air intake pipe. The mixture is then blown from diffusion nozzles 15... to bring the flocculating agent and contaminants into reaction. The flocks grown by this reaction are floated by the buoyancy of the fine air bubbles generated by a fine air bubble generator 16 and are captured and recovered by the oil fence 7.