DETECTING METHOD FOR RATE OF TRANSFORMATION REACTION INTO FERRITE

摘要

PURPOSE:To eliminate the danger of flowing-out of unreacting heavy metals and avoid the wastefulness in processing by a method wherein the electroconductivity of a part of the ferrite-reaction liquid of waste water including heavy metals is measured through titration by acid and the reaction ratio of transformation into ferrite is detected by the difference in the amount of titration between two bending points of the curve of titration. CONSTITUTION:Ferrous sulfate is added to the waste water including heavy metal ions, the water is neutralized by NaOH to produce a complex compound of the heavy metals and Fe, and the precipitation treatment is applied thereto as the ferrite of spinel structure by supplying O2 thereto. On the occasion, a part of the reaction liquid is put in a beaker 3 immersed in the water 2 in a water tank 1 and is titrated with 1n HCl 8 by using a device equipped with a magnetic stirrer rotor 5, a thermometer 6 and an electroconductivity sensor 7, through which the electroconductivity is measured by an conductivity meter 10. Before the completion of reaction, the curve of titration of the electroconductivity of the reaction liquid has the two inflection points, and although the difference between these points is large, it becomes little with the progress of reaction and the points turn into one at the time when the reaction is completed. Accordingly, the completion of the reaction is foreseen with ease and thus complete treatment can be performed without wasteful blasting of air and the loss of time.