Study On The Advanced Treatment For Coking Plant Wastewater With Coagulating And Fenton's Reagent

The study mainly aims at treatments of coking wastewater in which the concentration of COD, colority and turbidity is higher than the nation discharge standard after biochemical treatment. On the foundation of investigation the methods of advanced treatment for coking wastewater, the methods such as Fenton reagent,coagulanting and combined process have been put forward. This study tries to find out a reasonable advanced process to dispose coking wastewater in an efficient and lower cost manner.The experiment results indicated that the concentration of H₂O-2 and Fe²⁺ , initial pH and reaction time are the major influencing factors, when the coking wastewater is treated by Fenton reagent, the removal efficiency of COD can reach to 68% and the removal efficiency of the colority and turbidity can both exceed 88%; Comparing with traditional coagulants and other polysilicate-metal coagulants, a new type coagulant PFASS (poly-ferric-aluminum sulfate silicate) which has been self-prepared in laboratory had superior capability. In the course of preparation, the moral ratio of Al/SiO₂ and Fe/SiO₂, activation pH and activation time are the major influencing factors. At the optimum condition, the stabilization time of PFASS would exceed 19d, the removal efficiency of COD, the colority and turbidity can reach to 75%, 80% and 92%, respectively. When the coking wastewater is treated by the combined method of coagulanting and Fenton reagent, the removal efficiency of COD can reach to 88% and the removal efficiency of the colority and turbidity can both achieve over 90%; the outflow of coking wastewater can meet nation discharge standard.