SLURRY WASTE LIQUID TREATMENT METHOD

PROBLEM TO BE SOLVED: To provide a proper slurry waste liquid treatment method large in treatment capacity and low in cost. SOLUTION: A predetermined chemical liquid is injected in a pH adjusting tank 3 into which a slurry waste liquid is sent so that the pH of the slurry waste liquid becomes a pH value in the vicinity of the isoelectric point of one particles dispersed in the waste liquid. Since the solubility of one particles shows the minimum value at the isoelectric point, particles exceeding solubility are precipitated. The slurry waste liquid mixed under stirring and adjusted in its pH is sent to a charging treatment tank 5 in which an electrode plate group is arranged. Relatively large particles attracted to the electrode plates by coulomb force gathers to the peripheries of the electrodes and loose zeta potential to be coarsely fluocculated by intermolecular force and precipitated heavy particles are sedimented and separated. After definite time treatment, the flocculated solid is discharged from the lower part of the tank and a supernatant liquid is sent to a drain treatment process from the upper part of the tank.