Kinetics and Adsorption Isotherm Studies of Methylene Blue Photodegradation Under UV Irradiation Using reduced Graphene Oxide- TiO2 Nanocomposite in Different Wastewaters Effluents.

Abstract

Keywords:Photodegradation COD Nanoparticles reduced graphene oxide MB dye Wastewaters In this study TiO2@rGO nanoparticles was synthesized as an effective photocatalyst. Reduced graphene oxide (rGO) was mixed with TiO2 with different doping ratio (1%, 3% and 5% wt) and utilized to remove MB dye as organic pollutants from different wastewater effluents and also from aqueous solution. The impacts of different factors, e.g. pH of solution, contact time, photocatalyst dose and initial MB dye concentration on the removal efficiency were studied. The results showed that the highest MB degradation occurred at pH 9, contact time = 120 min, dose of photocatalyst of 0.75 g/L at 30 mg/l dye concentration. Also, the prepared nanocomposites success in reducing COD values of wastewater in the range of 30 -89.1 %. Moreover, the data of kinetics studies indicated that the adsorption process well obeys the pseudo-second order reaction model with qe values ranged between 14.28 -19.37 mg/L. Langmuir isotherm model well describes the behavior of adsorption behavior than Freundlich Model.

Synthesis of different types of nano-hydroxyapatites for efficient photocatalytic degradation of textile dye (Congo red): a crystallographic characterization

“…In the previously mentioned formulas, the unit cell is indicated by plane (h,k,l) and a,b,c reects as lattice variable, X c = crystallinity degree, q = angles of the diffraction (in degree), b = FWHM (full width at half maximum) in radian, D c = dimension of repeating unit, d = dislocation density, K = shape factor (arbitrary constant)/Scherrer's constant = 0.94, H (hkl) = peak height of the respective plane, K a = 0.24, for HAp, as well as CI XRD = crystallinity index. The specic surface area of the synthesized HAp was estimated through eqn (8). Where density as well as crystallite dimensions of HAp were denoted by r (3.16 g cm −3 ) as well as D c .…”

“…Considering the above-mentioned criteria, the photocatalytic phenomena became a prominent innovation for the deterioration of synthetic dye along with various inorganic compounds like phenol and their derivatives. 8,9 However, the degradation efficiency of dyes depends on the nature of the photocatalyst used. Because of this, several photocatalysts have been developed to estimate their performance in synthetic dye degradation.…”