| 摘要 |
<p>PURPOSE:To prevent the elution of N and P from bottom mud or to remove agricultural chemicals and purify water by generating the flow of downward current in the bottom layer water of a pond, river, etc. CONSTITUTION:This method purifies the water by forming a gravel 4 layer in the bottom of the pond 1, etc., further forming a sand layer atop this gravel 4 layer and inducing the downward current at all times within the pond 1 by means of a pipe 3 provided with suction holes 2 therethrough and a pump 7.</p> |
