| The high COD concentration,high salinity,high pollution and the poor biodegradability of coal-chemical engineering wastewater have become the bottleneck of the development of coal chemical industry.In order to achieve the near zero discharge of coal chemical wastewater,it is necessary to add advanced treatment unit after biochemical treatment.Catalytic ozonation is a kind of AOPs which uses catalysts induce ozone transformed into hydroxyl radicals(·OH).It has the advantages of strong oxidation ability,weak selectivity and no secondary pollution,which is an effective advanced treatment technology.The mechanism of activated carbon catalytic ozonation was preliminarily analyzed.A bench scale catalytic ozonation membrane reactor was built.The results of batch test indicate that the catalytic oxalic acid degradation effect of activated carbon is much better than that of metal oxides.The best TOC removal rate was 97.6% in 10 minutes.Activated carbon is cheap and free of the secondary pollution caused by metal ion leakage.It is suitable for advanced treatment of coal chemical wastewater.In all samples,the smaller the particle size,the more hydroxyl on the surface,the better its catalytic ozonation degradation effect.However,the smaller the particle size is,the higher the cost of catalyst manufacturing and recycle is.When the particle size is less than 7.4 micron,the reduction of particle size does not improve the catalytic degradation efficiency.A bench scale catalytic ozonation membrane reactor was built,and the operation parameters of the reactor were determined.On the basis of this,the COD degradation rate of continuous operation of catalytic ozonation membrane reactor was 68%. |
