MUDDY WATER TREATMENT DEVICE AND METHOD OF TREATING MUDDY WATER

PROBLEM TO BE SOLVED: To provide a muddy water separating device capable of keeping constant the quality of muddy water by maintaining the fine fraction ratio of the muddy water within a predetermined range and also provide a method of separating the muddy water. SOLUTION: This muddy water treatment device 10 is used to control the fine fraction ratio of muddy water in a circulation tank 73 used in a cast-in-place pile method. The muddy water treatment device comprises: at least a set of electrodes 11a, 11b so disposed in the circulation tank 73 as to be opposed to each other; a hydrometer 12a and a viscometer 12b used for detecting the fine fraction ratio of the muddy water in the circulation tank 73; an electrode position moving part 16 for moving the position of the electrode 11b; and a fine fraction ratio control part 13 for controlling the coagulated amount of fine fraction by applying a current to the electrode and adjusting the position of the electrode by an electrode position moving part 16 to bring the fine fraction ratio within a predetermined range when the fine fraction ratio is larger than the target value. COPYRIGHT: (C)2009,JPO&INPIT