TREATMENT OF WASTE WATER OF COAL THERMAL POWER PLANT OR THE LIKE

摘要

PURPOSE:To considerably decrease the amt. of the sludge to be discharged and to simplify the treatment stage over the entire part by making combination use of the effect possessed by a heavy metal capturing agent and high-polymer flocculating agent and the flocculation effect of the Al contained in water to be treated. CONSTITUTION:The water to be treated after fly ash removal is supplied to a first reaction vessel T1 and while slaked lime and the heavy metal capturing agent are injected to the water in the 1st reaction vessel, the pH of the water to be treated is increased up to the conditions under which the flocculation effect is high. The high-polymer flocculating agent is further injected to the water, then the water is fed into a 1st setting tank T2. The gypsum and metal hydroxide in the water to be treated are settled in the 1st settling tank. After respective treatments for the recovery of the gypsum rough sepn. of fluorine and removal of heavy metals are simultaneously executed, and the residual fluorine treatment in the water to be treated is executed. More specifically, the treatment for removing the heavy metals which is heretofore executed in a second reaction vessel is efficiently and simultaneously executed in the 1st reaction vessel by making combination use of the effect possessed by the heavy metal capturing agent and the high-polymer flocculating agent and the flocculation effect of the Al (eluted from fly ashes) contained in the water to be treated. The amt. of the sludge to be discharged is thereby considerably decreased.