Degradation of Brilliant Green by Using a bentonite Clay- Based Fe Nano Composite Film as a Heterogeneous Photo- Fenton Catalyst

This paper aims to study the chemical degradation of Brilliant Green in water via photo-Fenton (H2O2/Fe 2+ /UV) and Fenton (H2O2/Fe 2+ ) reaction. FeB nano particles are applied as incrustation in the inner wall surface of reactor. The data form XRay diffraction (XRD) analysis that FeB nanocomposite catalyst consist mainly of SiO2 (quartz) and Fe2O3 (hematite) crystallites. B.G dye degradation is estimated to discover the catalytic action of FeB synthesized surface in the presence of UVC light and hydrogen peroxide. B.G dye solution with 10 ppm primary concentration is reduced by 99.9% under the later parameter 2ml H2O2, pH= 7, temperature =25°C within 10 min. It is clear that pH of the solution affects the photocatalytic degradation of B.G dye. All the conditions above have been studied to reach the optimum operation condition for the two processes Fenton and photoFenton. The B.G degradation process follows firstorder reaction rules. PhotoFenton process causes a more efficient oxidation rate than the Fenton process. So, the photoFenton degradation is an effective and economic process by producing higher percentage of degradation and mineralization in short radiation time.


Introduction:
All dyes molecules are stable and difficult to degrade biologically [1], so they lead to pollution problems like a form of colored waste water discharged; into environmental water bodies [2].The adsorption procedure is the most efficient method for removing the pollutant dyes form waste water [3][4][5].
The dye will be transferred to solid phase thereby keeping the effluent volume to a minimum [6][7][8].Also the adsorbent can be used more than one time by being regenerated and stored in a dry place [4][5][6][7][8].The brilliant green dye as used in this study is triphenyl nitrogen containing cationic dye.The Open Access exact structure of the brilliant green dye is given in Figure (1).Brilliant green is chemically described as ammonium, 4(diethylamino)-alphaphenylbenzylidene) (C 27 H 34 N 2 O 4 S) with λ max =625 nm and molecular weight 482 g. mol -1 .The use of brilliant green (B.G) dye has been banned in many countries due to its carcinogenic nature [1].It is used as a dye to color synthetic fibers and silk biological stain, dermatological agent, veterinary medicine, and as an additive to poultry feed to inhibit propagation of mold, intestinal parasites and fungus.It is also extensively used in textile dying and paper printing.It is considered highly toxic for humans and animals because it can cause permanent injury to eyes.It also causes irritation to the respiratory tract that leads to cough and shortness of breath.It can cause irritation to the gastrointestinal tract, which also results in nausea, vomiting and diarrhea in human beings [9].

Preparation of Dye Sample:
Standard stock solutions of 500 mg/L of brilliant green are prepared by diluting the corresponding mass of brilliant green in de-ionized water and protected from light.A different initial concentration of brilliant green is prepared by further diluting the standard stock solutions.G which is determined in λ max = 624 nm that obeys the (Lambert beer ' s law) at specific concentrations prepared for each compound.After that, the absorption has been recorded and a calibration curve is plotted between adsorption and concentration, the best line between the points has been drawn.To study the discoloration of B.G dye, the UV-visible absorption spectra of (10 ppm) B.G dye solution at a pH=7.0 before and after treatment with photo-Fenton catalyst in the presence of 8W UVC are measured and presented in Figure 6.To study the effect of initial dye concentration on the degradation efficiency, the experiments are carried out by using different initial
X-Ray) X-ray diffraction is used to analyze Fe-B nanocomposite, and the result is shown in Figure (3).The strong diffraction peaks at 2ϴ of (25.5°, 26.2°) indicate that the Fe-B nanocomposite mainly consists of SiO 2 (quartz) and (33.15°, 39.28°) Fe 2 O 3 (hematite).The increasing in particle size lead, to higher intensity of diffraction pattern[13].

Fig. ( 6 )
Fig. (6): UV-Visible Spectra of The 10 ppm of B.G Solution Before and After Treatment with Photo-Fenton Catalyst At pH=7.0 and 298.15KFor 20 min.
Figure (11) shows the effect of pH on percentage degradation of B.G dye at temperature 298.15K, and in presence of (2*10 -4 M H 2 O 2 + catalyst+ 8W Befor e After UVA).It is clear that the photo-Fenton degradation depends strongly on pH of the reaction medium, whereas the degradation percentage of B.G increases with increasing pH up to 7.0 and then percentage degradation of B.G decreases with increasing pH to pH= 14.The effect of temperature on the degradation of B.G dye is investigated in three different temperatures (298.15,308.15, 318.15)K at the following condition pH=7, with different initial concentration (10, 20, 30, 40, 60, 80, 100) ppm of B.G.The results in Figure (12) show that, the degradation 10ppm of B.G decreases as temperature increases indicating an anti-Arrhenius relation.Then after increasing the temperature more than 318.15K, the R% stays with in the same level.Removal percentage for (20, 30, 40, 60, 80, 100) ppm increases when temperature increases until 320K the R% does not change for 320 to 330K.The degradation B.G dye by Fenton is a first order reaction.This is determined from the slope of the linear plot of logarithmic remaining B.G concentration versus treatment time t as shown in the following Figure (13).