Study On Regeneration And Mechanism Of2,4,6-Tcp-satured Activated Carbon Modified With Iron And Manganese By Using Microwave Irradiation

In recent years, with the rapid development of industry and economy, theenvironmental pollution problems caused by the chlorophenol organic chloride isgetting worse.This paper selected a typical pollutant of chlorophenols--2,4,6-TCP as the targetpollutant, and the surface modification method is used on the activated carbon forpreparation of modified activated carbon ferromanganese ion loaded, apply it to thewater treatment technology to remove the2,4,6-TCP. Design the orthogonalexperimental to obtain the optimal condition for the microwave regeneration, andstudy the changes of iron and manganese modified activated carbon regeneration andsurface chemical composition, surface microstructure and pore structure, to explainthe mechanism of regeneration by analysing the characterization results, the researchresults are as follows:1、The orthogonal experiment were analyzed, the best process combination formicrowave regeneration of modified activated carbon loaded with2,4,6-TCP were:microwave power550W, microwave irradiation time8min, activated carbon loading7g, nitrogen flow rate0.1m3/h.2、After three cycles of regeneration of modified activated carbon, regenerationrate can reach higher than100%. After that, removal rate, regeneration rate andadsorption capacity all decreased, but after9times regeneration rate remained at75%,and the overall carbon loss rate is very small. This shows that the microwave multipleregeneration is a very effective means of regeneration of activated carbon.3、The experimental data show that, during re adsorption of modified activatedcarbon after regeneration, it did not occur when the iron and manganese ion leakagephenomenon; in the microwave regeneration process, material which loaded on thesurface of activated carbons (mainly Fe2O3and MnO2by XRD spectrumanalysis)during modifying process, would move and desorb, and it can be prove bySEM, XRD characterization and iron manganese ion leakage experiment, and thephenomenon is more obvious in the first three regeneration processes. 4、To regenerate the activated carbon Modified with Iron and Manganese byusing microwave irradiation after adsorption, was similar to Modify activated carbonby using microwave irradiation, and the metal ions, which loaded on the surface ofactivated carbon, were equivalent to the regeneration of the catalyst in the process,because the iron and manganese ion on the absorption of microwave more stronglythan activated carbon, and the move will produce holes, which made the reactionmove toward the favorable direction.5、Microwave irradiation can change obturator into microporous, then big holes,and the adsorption capacity of big holes is way worse than microporous holes. Afterseventh times, regeneration cavity melt collapse phenomenon is more obvious, thenumber of microporous structure is very small. So the first regeneration efficiency isvery high, and with the increasing times of microwave regeneration, the efficiencywill be decreased.6、Activated carbon with iron and manganese modified acidic groups willincrease, regenerated acid group on the surface of the rapidly decreasing, while thenumber of basic groups increased, while alkaline comes mainly from the hydrophobicC=O. It makes the hydrophobic active carbon enhanced, thus the hydrophobic organic2,4,6-TCP better adsorption effect. This is why even the hole which on surface ofactive carbon melt after subsidence, the active carbon can still maintain the goodadsorption performance.