| 摘要 |
PURPOSE:To reduce COD and make heavy metals insoluble to remove said metals by adding hydrogen peroxide and a solution of ferrous sulfate to the pickling waste liquor containing an inhibitor, copper ion sequestering agent and heavy metals, while controlling the pH. CONSTITUTION:To the pickling waste liquor wich washes the piping of a boiler, heat exchanger, etc., and contains an inhibitor, copper ion sequestering agent, and heavy metals such as iron and copper, alkali is added firstly to adjust about 7.2- 7.5pH, which is weak alkaline. Then, hydrogen peroxide generating oxygen corresponding to the COD value of the waste liquor is added. Next, caustic alkali is added to adjust about >=10pH and the solu. of ferrous sulfate is rapidly mixed to make the heavy metals insoluble, thereby settling the heavy metals. Thus, the heavy metals are treated by being made insoluble after COD is decreased by using iron ion in the waste liquor. |
