Modification Of Activated Carbon Fiber And Its Study On The Adsorption Of Triazole Fungicide

Activated carbon fiber(ACF)has the special pore-structure and surface chemistry properties,having the ability of absorbing pesticides.In order to improve its adsorption capacity,ACF was modified by oxidation and alkalization,meanwhile,the triazole fungicides adsorption properties of ACF before and after modification was studied.Oxidized by the mass fraction of 10% hydrogen peroxide and alkalized by the mass fraction of 5% sodium hydroxide to obtain two modified absorbents,ACF-O10 and ACF-OH5,respectively.The results of Boehm titration analysis showed that the acidic group amount of oxidized ACF increased obviously,of which the amount of acidic group increased to about 4.7 times.It is also proved by FT-IR.However,sodium hydroxide can counteract surface acidic group so that the total content of acidic group was 21% lower.Under the varies experiment conditions,three kinds of the representative triazole fungicide(Flusilazole ? Myclobutanil ?Triadimenol)as adsorbates,absorbed by the different modification of ACF.In the experiment,the adsorbents dosage ? initial concentration ? temperature ? time and other factors wasinvestigated to study the effect of the absorption efficiency of the absorbents on pesticide,the experiment data were fitted and the adsorption mechanism were analyzed.The research results indicated that the different adsorbents on the adsorption effect of the triazole fungicide is ACF-O10>ACF-0>ACF-OH5,the adsorption efficiency that adsorption of ACF-O10 against this pesticide is best,namely.The results showed blow:(1)Removal effect of ACF-O10 on the triazole fungicide is best for lower concentration;(2)Adsorption reaction of ACF-O10 on the trizole fungicide belongs to the spontaneous?exothermic and entropy increased reaction;(3)Both Langmuir model and Temkin model can simulate well the adsorption thermodynamics process of these pesticides.Meanwhile,Langmuir saturated adsorption amount that adsorption on triazole fungicides is very large at 25?,which show that ACF-O10 for the wastewater treatment of triazoles fungicides has great practical vaule;(4)Through the longitudinal comparison of three kinds of absorbents for the triazole fungicides adsorption isotherm and related data fitting results find that the main influence factor of adsorption performance of activated carbon fiber is surface chemical properties besides associated with microporous content and poresize distribution;(5)Dynamic fitting results show that quasi secondary adsorption dynamic model is far better than the first order kinetics model on simulating the adsorption process of ACF-O10.The analysis results of activation energy know that chemical adsorption is viewed as the main control process in the whole adsorption process.