Phenol Degradation Lab Report

Good Essays
The influence of selected variables such as pH of phenol solution, concentration of hydrogen peroxide, concentration and the volume of phenol to be treated was studied to find the degree on the degradation of phenol. The influence of these variables on the degradation of phenol using H2O2 by interpreting the TOC results is presented in the following sections.

3.1 Effect of pH

The phenol degradation with different pH is shown in Figure 3. As it is clearly seen, a higher pH favors the removal of phenol in altered conditions. In Figure 3(a), the phenol was purged in ozone in absence of hydrogen peroxide. The removal rate for the alkaline solution (pH11) at after 40 minutes was at its highest at 7.89%. Direct procedure involves organic
…show more content…
These organic acids include oxalic acids, maleic acids, muconic acids and so on[18, 20, 21]. Because of the selective nature of ozone with regard to formed by-products, whereby acidic conditions produce a low TOC removal rate, direct ozonation rarely yields complete mineralization. [22]. Alternatively, strong alkaline conditions provide an important improvement in the oxidation power of ozonation process, which can be attributed to the prevalent indirect process that incorporates the production of OH radicals by ozone decomposition in aqueous solution, especially that which is catalyzed by OH− (i.e. higher pH) shown below in the following …show more content…
This can also be seen by the value of the rate constants where k1 k2. Additionally the process of phenol decomposition by direct ozonation is different than that of indirect ozonation. Degradation of phenol by OH radicals favors the formation of aromatic by products, following the formation of organic acids and thereafter partial mineralization [26]. Because the OH radical is a powerful and unselective oxidant, raising the initial Ph values increased TOC removals. The alkaline environment presented a higher degradation rate for the whole duration of 80 minutes than that of the initial pH (pH8.9) and acidic pH (pH4). Some studies show that the fastest phenol degradation occurred at pH 12.9. Furthermore, the highest COD removal in the study of the treatment of penicillin formulation effluent by ozone process at pH 12. [27] In general, the degradation of phenol always happens by both direct and indirect mechanisms, which are competitive and dependent of process conditions. It has also been observed that radical mechanism is predominant even at neutral pH .[24] However, due to the slow rate of self-decomposition of ozone initiated by OH− ion at neutral pH, it was established that phenolic compounds themselves must be acting as the promoters of the decomposition of ozone and the formation of free radicals

Related Documents

  • Decent Essays

    DISCUSSION There are three chemical properties will be discussed which are combustion, reaction with bromine and reaction with potassium permanganate. Combustion was used to test the unsaturation of hydrocarbon. The degree of unsaturation refers to the number of the rings and / or multiple bonds present in the hydrocarbon molecule (McMurry, 2015). Hexane was a saturated hydrocarbon, it completely combusted and emitted carbon dioxide plus water. Cyclohexene was an unsaturated hydrocarbon, it undergoes incomplete combustion (Clark, 2003) which showed the great intensity of light compared to hexane due to the higher ratio of carbon and hydrogen in cyclohexene.…

    • 909 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Liquefaction and gasification in supercritical water (SCW) are two processes for transferring substances into liquid and gaseous fuels, which is special for high moisture substances6. Supercritical water, which is serve as the solvent and the reactant in these reactions, mainly decreases mass transition restrictions in ambient condition water; therefore, it helps to accelerate the chemical reactions largely9. However, the vaporization of water along with raw materials is required by traditional pyrolysis and gasification method to convert high-moisture substances, which causes lowering thermal efficiency2. Recent researches have shown that SCW method of gasification produces enormous amount of tar waste water, which have toxic substances such…

    • 1101 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Al, Alloy 1 And Elece

    • 1504 Words
    • 7 Pages

    This oxide film is Al2O3 and Al(OH)3, in neutral solution, based on Pourbaix diagram [20]. The alloy 1 presents OCP value of about -1.30 V whereas that of Alloy 2 was -1.44 V, which are more negative than that of Al in the same medium. The presence of tin and gallium in aluminum matrix as alloying elements increases the adsorption of Cl- ions at the values of negative potential which leads to the alloy dissolution [10]. The surface morphologies of Al, Alloy 1 and Alloy 2 after immersion in 2 M NaCl solution for 1 h were obtained by scanning electron microscopy (SEM) (Fig. 3).…

    • 1504 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    Results and Discussion 3.1. Block copolymer formation using halogen exchange Normal ATRP of styrene was carried out at 90 °C using SNS as the ligand, Cu-Br as the catalyst, and EBIB as the initiator. The end group of the resulting polystyrene (PS-Br) is a bromine atom. The chain extension of PS-Br as a macroinitiator is usually associated with poor control when MMA monomers are used for the second block. To improve the initiation efficiency, we used the technique of halogen exchange.…

    • 802 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    This is achieved through the existence of the equilibrium HA (aq) ⇄ H+ (aq) + A- (aq). When a strong acid or alkali is added the equilibrium shifts to the right or the left adhering to Le Châtelier 's principle, which states that whenever an equilibrium is subject to change of concentration, temperature, volume, or pressure, the system will readjust itself to some extent, to counteract the effect of the change. This means that if a strong acid is introduced to a buffer, the hydrogen ion concentration would increase by less than the amount expected. This is because adding H+ ions lowers the pH which shifts the equilibrium to the left, thus lowering the H+ ion concentration raising the…

    • 1043 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    To optimize the amount of catalyst and the temperature, reaction between β-naphthol (4), benzaldehyde (5) and dimedone (6) as a model one was performed in the presence of varying amounts of catalyst (Table 3). The product yield increased, and the time for reaction completion decreased upon an increase in the amount of tartaric acid up to 15 mol% catalyst and 70 °C. Any further increase in the amount of catalyst or the temperature did not significantly improve the results. It is important to note that in the absence of catalyst a trace of product was observed (Table 3, entry 1). The role of the temperature in the synthesis of 12-(phenyl)-9,9-dimethyl-8,9,10,12-tetrahydrobenzo[α]xanthenes-11-one was investigated in the presence of tartaric acid as the catalyst.…

    • 1155 Words
    • 5 Pages
    Decent Essays
  • Decent Essays

    The Gibb’s free energy change of adsorption was found to be in range of -2.6 to -0.05KJ/mole. These results indicate that the adsorption of stearic acid complex is feasible and spontaneous. The enthalpy(ΔH) and entropy(ΔS) were found negative and positive values respectively. The negative value of enthalpy confirmed that the adsorption of stearic acid complex is an exothermic process. This can be due to energy released after the adsorption process being higher than that need to the solvent molecules.…

    • 793 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    If there’s a decrease in Kc values, that means there is a decrease in solubility. Increase in temperature means an increase in Kc values because solubility increases with temperature, and vice versa. For example, at 323.2 K, the Kc was 4.54*10^-7, which is more than at 303.2 K, which is Kc = 8.19*10^-9. To calculate the sign and value of deltaSrxn: 45.6(8.314 J/mol*K) = +379.12 J/mol. The positive sign of the entropy change makes since because Borax is placed in distilled water to create a Borax solution, the Borax breaks down into particles; the particles of Borax are random in the solution and are very disordered, meaning that the entropy increases; the positive sign of deltaSrxn shows the increase in disorder.…

    • 1418 Words
    • 6 Pages
    Decent Essays
  • Decent Essays

    Cumnox Reaction Lab Report

    • 1018 Words
    • 5 Pages

    4. The optimization in calcination temperature of CuMnOx (CuMn8) precursor The optimum calcination temperature of the CuMnOx catalyst was 300oC and further increasing the calcination temperature the activity of the catalyst was decreases. There was a correlation between the surface area and the calcination temperature of the catalyst. When the calcination temperature of the CuMnOx catalyst was increased above 300oC, the surface area was decreases and its analysis by BET measurement. The crystallinity was also increased as the increasing of the calcination temperature of the precursor, therefore the diffraction peaks at the XRD analysis was more crystalline phases produced by calcination at (200 - 400oC) temperature.…

    • 1018 Words
    • 5 Pages
    Decent Essays
  • Decent Essays

    But no substantial connection was found between the lowered peak temperatures and ratio of SiO2 added. The reaction rate (such as Rmax) is increased during fuel gas-CaSO4 reaction. The addition of SiO2 as a binder promoted the conversion of solid reactant (CaSO4) in the reaction with fuel gas at relatively low temperatures. The maximum reaction rates (Rmax) of pure CaSO4 with CH4, CO, and H2 were 1.97×10-4, 5.01×10-4, and 1.04×10-3 s-1 at 840 ℃, which was considerably lower than the value 1.37 ×10-3 s-1 of CuO-based oxygen carrier at 850 ℃. But for 13.5 wt % SiO2-supported CaSO4, the value of Rmax increased to 1.24 ×10-3, 9.91× 10-3, and 3.95 ×10-3 s-1, respectively.…

    • 1144 Words
    • 5 Pages
    Decent Essays