Problems on Yellow-Colouring of the Wastewater Treated with the Coagulant, Ferrous Salt
亚铁盐混凝处理水的“泛黄”问题

When ferrous salt is used as a coagulant to treat wastewater, if there exists superfluity in the process of coagulation to sedimentation, purged water will be clear. However, When the purged water is laid aside, it becomes turbid and turns to yellow-colouring. The reason is that oxygen in the air has dissolved in it as time goes on. The authors have proposed a measure to control the phenomenon that a higher pH or at optimal quantity of the mixed coagulant paralleled with tests can avoid color changing.