| China is the main country to producing dye, the quantity of which is the 20% of that in the world. The 2% of dyes were lost in the process of dyestuff producing . So wastewater with dyes becomes pollutants of water sources. Dyes wastewater contain large quantity of unbiodegradable organic substance and inorganic salt. The colority of it is high and the composition in it is complex. Some dye can cause people ill and induce cancer in some conditions. Ecological environment of water may be damaged by discharged dyes wastewater. So the treatment of dyestuff wastewater is important and difficult. Because reactive dyestuffs have great variety of color and are bright in color, cheaper than others, more and more reactive dyestuffs are used. Reactive dyestuffs are hydrophilic, so the treatment of wastewater with reactive dyestuff is the difficult points of the treatment of dye wastewater.This paper studied the removal processes of colority and CODcr of simulated wastewater with reactive Flavine K-4G dyestuff. In exploring experiment manganese ore was used. The effect of the quantity of manganese ore, density of electric current, the dentention time, the electrical conductivity, pH and preliminary concentrations on the removal results of color and CODcr in the water was investigated. It also reviewed the relation between density of electric current, pH, dentention time and the [Mn2+ ] in the solution.On the basis of exploring experiment, granular activated carbon (GAC) that loaded MnO2 was used. The effect of current density, the quantity of GAC,dentention time, the electrical conductivity and pH on the removal results was investigated. In dynamic test the effect of retention time on the removal results and the stability of the processes was investigated. The result showed that:(1) GAC that loaded MnO2 can improve the decoloration rate and removal rate of CODcr notability. Improved range would be enhanced by increasing of current density.(2) The removal rate of colority and CODcr were improved by longer dentention times and the increase of the quantity of GAC that loaded MnO2 in the wastewater.(3) The removal rate of colority and CODcr were slightly effected by electric conductivity and preliminary pH of solution(4) The equation of kinetics of decoloration with GAC that loaded MnO2 is in accord with the first-order kinetic reaction and the reaction rate constant k equals 0.0306-0.0258min~1. The kinetic equation of the removal rate of CODcr with GAC that loaded MnO2 is in accord with the first-order kinetic reaction and the reaction rate constant k equals 0.0181 -0.0149min~'. The equation of reaction rate constant of decoloration reaction and removal CODq reaction were increased 1.69 times and 1.47 times respectively compared with that in the some processes with the GAC that has no MnO2.(5) The supplied voltage enhanced the oxidative ability of MnC>2 in the process and MnO2 would act as a catalyst.(6) The pore's distributing character of GAC that loaded MnO2 had no evidently changes. Adsorption heat of GAC that loaded MnO2 was increased and its adsorption capability was improved.The main innovations of this paper were: (1) The GAC that loaded MnO2 was used as the multi-electrodes to treat simulated dye wastewater. Through the experiment it was found that the catalysis of MnO2 can improved the removal results of colority , CODcr and the reaction speed greatly. (2) Put forward that oxidation ability of MnO2 can enhanced by supplying voltage and the catalyticability of MnO2 loaded on the GAC can be improved by increasing of current density. (3) Bring forward that GAC that loaded MnO2 improved its adsorption ability of dye by increasing its adsorption heat in the process.The research work is creative. The conclusion of this paper can give a new way and provide the theoretic foundation for the removal of dyestuffs from wastewater with multi-electrodes.
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