حذف آرسنيك از پساب هاي صنعتي با استفاده از نانو ذرات دي اكسيد تيتانيوم ﴿TiO2)

چكيده انگليسي :

Removal of Arsenic From Industrial Wastewaters Using Titanium Dioxide Nanoparticles Hajar Sharifi Forushani h sharififorushani@na iut ac ir 1May 2011 Department of Natural Resources Isfahan University of Technology Isfahan 84156 83111Degree M Sc Language FarsiDr Norolah Mirghaffari mnorolah@cc iut ac irDr Alimorad Rashidi rashidiam@gmail com AbstractArsenic is one of the most toxic environmental pollutants This element enter the water resources via differentways such as rocks weathering or direct discharge of industrial wastewater from mining metal melting glassand ceramics paint and pesticide manufacturing oil refineries and organic chemical industries It causes aserious threat to human health worldwide especially in developing countries where the supply of drinking waterfor a high proportion of the population depends on groundwater resources Various processes such asprecipitation ion exchange chemical oxidation adsorption etc have been used for removing arsenic fromaqueous solutions Adsorption by biological and mineral materials has appeared to be an effective technologyfor removal of arsenic from aqueous solutions especially at low concentration Simple design no sludgeproduction and relatively low cost are known as the advantages of adsorption processes Choosing anappropriate sorbent is one of the important principles of sorption process In this study the nanoparticles oftitanium dioxide anatase Anatase TiO2 and a hybrid combination of anatase nanoparticles with single wallcarbon nanotubes SWNT were used for adsorption of AsIII arsenite and AsV arsenate from water andindustrial wastewater using batch and column methods Some of physical chemical and morphologicalproperties of sorbents were characterized by the X ray diffraction XRD Fourier transform infraredspectroscopy FTIR and scanning electron microscopy SEM The different parameters affecting adsorptionincluding equilibrium time pH initial arsenic concentration amount of adsorbent and the presence of disturbedions were investigated The adsorption isotherms were described by Langumir and Freundlich models Theadsorption kinetics showed that arsenite and arsenate sorption by both nano adsorbents is fast Arsenicadsorption was dependent on the initial pH of solution so that the optimum pH for arsenite and arsenate removalby both nano adsorbents was in the range of 7 0 9 5 and 3 0 8 0 respectively Arsenate adsorption by nanodioxide titanium and the hybrid as well as arsenite adsorption by the nano dioxide titanium were fitted by theLangmuir model R2 0 95 while the arsenite adsorption by hybrid did not follow the two models Themaximum arsenite adsorption by anatase and hybrid was 79 6 and 75 8 mg g at pH 7 and for arsenate were113 0 and 92 4 mg g at pH 4 respectively The increase of sorbent amount had no significant effect onadsorption of arsenite and arsenate The presence of copper lead zinc chromium cadmium and nickel cationsin the solution at the concentration of one hundred times of arsenic was not influenced on the arsenite andarsenate adsorption Arsenate desorption by the solutions of 0 1 0 2 and 0 4 M NaOH was higher thanhydrochloric acid and the maximum desorption 0 4 M NaOH for anatase and hybrid was 69 5 and 87 9 respectively This shows that the adsorbed arsenate on nano adsorbent is not fully reversible Arsenitedesorption on both nano adsorbents by acid and base was almost similar about 100 Removal of arsenic fromtwo industrial wastewaters battery factory and metal finishing indicated that theses nanomaterials have a highefficiency and could be used for wastewater treatment Key Words Arsenic Adsorption Nano Titanium Dioxide Carbon Nanotubes Langmuir and Frundlich Isotherm

شريفي فروشاني، هاجر

حذف آرسنيك از پساب هاي صنعتي با استفاده از نانو ذرات دي اكسيد تيتانيوم ﴿TiO2)

جذب سطحي , نانو لوله هاي كربني , همدماي لانگمويرو فروندوليچ