An Experimental Study On Adsorption Of NO And Adsorption Of NO And SO₂ Together Over Modified Activated Carbon Fibers

NOx do great harm to mankind health and the environment .In China,NOx coming from the coal-fired plants increase year by year. Therefore,it is very urgent to control the emission of NOx.The paper adopt lots of methods to modify activated carbon fibers,have the adsorption experiment on the self-made small adsorpton reactor. Analysis on the change of surface structure and functional groups,discuss the possible mechanism of modification and adsorption,and the effect of various surface factors to adsorption performance of NO over ACF.Finally fix the best modidication method.The paper use two ways to modidy the rayon-based activated carbon fiber.One is to modify the ACF through oxidation,the other is through high temperature heat treatment and immersion of KOH.The oxidation modification include two methods,one is the oxidation of ordinary oxidant,the other is the oxidation by hydroxyl radical in the use of system-UV/H2O₂/Fe2+。The results of adsorption experiments show that,the KMnO4 /NaOH modification when the concentration ratio is 0.03/0.1 mol/L has the best adsorption efficiency in ordinary oxidation.The advanced oxidation processes-UV/H2O₂/Fe2+ has general adsorption efficiency;Of all modidication methods,The high temperature heat treatment and immersion of KOH bring the best adsorption efficiency.Combining with the analysis of the surface struture and functional groups,we can assume that,the adsorption process of NO is firstly adsorption then oxidation.The factors to adsorption is various,among them ,the acid-base properties of surface and average pore diameter is the most important.The less of average pore diameter and the higher basicity lead to better initial adsorption efficiency.The structure C-O and C=O play a great role in the oxidation of NO,and the effect of C-O is more obvious. The experiment on the adsorption of NO and SO₂ together show that,NO and SO₂ cause competitive adsorption,SO₂ will preempt the adsorption sites of NO.And the H2O will promote the adsorption of SO₂,decrease the adsorption of NO.