Study On The Treatment For Coking Plant Wastewater With Heterogeneous Fenton-type Catalyst

The coking plant wastewater, which is mainly composed of phenol, is a kind of organic wastewater with high concentration. Its ingredient is complicated; therefore, coking plant wastewater is difficult to be treated. It has been a difficult problem to figure out efficient methods in treating coking plant wastewater because the degradation is difficult.Homogeneous Fenton reagent is one of oxidation methods which applies H₂O₂ as oxidation and Fe²⁺ as catalyst. In reaction,·OH is one of free radicals with excellent oxidizability. Therefore, it can oxidize organic compounds in order to reduce chroma and COD value in the wastewater. However, homogeneous Fenton reagent is hard to be separated from reaction medium, and it is vulnerable to cause secondary pollution after running off. If a new heterogeneous catalyst which is easy to be separated from reaction medium and recycled, it will have good perspective in application.According to principle of Fenton, author has prepared a new, high efficient, economical, and recycled heterogeneous Fenton catalyst and has gotten good results in treating organic wastewater by using the catalyst. The article focuses on the perspectives in technics of catalyst, condition of catalyst preparation, selection in optimal reaction condition, and catalyst performance evaluation, and comparison in results that simulant wastewater is treated by homogeneous Fenton reagent and heterogeneous Fenton catalyst. In addition, author has done research that heterogeneous Fenton reagent can be applied in treatment of coking phenol acetone wastewater. The major processes are as follows:1. By steeping, three kinds of catalysts of Fe³⁺ were made by different carriers. Experiment proves that Fe³⁺ supported on activated carbon, as carrier, can help make more efficient catalyst.2. Man-made Fe³⁺ supported on activated carbon is used to catalyze H₂O₂ in order to degrade phenol wastewater. Orthogonal and single factor experiments are used to decide the dose of catalyst, concentration of H₂O₂ and pH value. According to experimental results, under the optimum reaction condition(catalyst of 1.5g, H2O2 of 2% and pH of 5), Fe³⁺ supported on activated carbon can make the removal efficiency of COD_cr over 95% in the diluted coking plant wastewater.