SusChemE 2015
International Conference on Sustainable Chemistry & Engineering
October 8-9, 2015, Hotel Lalit, Mumbai
Degradation of Reactive Black 5 Azo Dye Using Catalytic Ozonation with MgO
Nikita P. Chokshi1, Bhargav Mehta2, J. P. Ruparelia3
1, 2, 3
Chemical Engineering Department, Institute of Technology, Nirma University
nikita.chokshi@nirmauni.ac.in, 13mche05@nirmauni.ac.in, jr@nirmauni.ac.in
Abstract:
Water pollution is a one of the major problem in all over the world. One of the major source of water pollution is untreated sludge
and that it accounts for the death of more than 14000 people daily. Water is a substance necessary for life, without water no one
can imagine the life. Only few percentage of fresh water is available for living being out of which some percentage is in the form
of ice. Sea water and sea ice constitutes of the 97% of the total remaining water. Due to scarcity of Water, it has become a necessary
means to Re-Cycle and Re-Use water. [1-3]
Micro pollutants in wastewater are a challenge to wastewater professionals. The presence of contaminants in WWTP effluents may
cause a severe risk for the drinking water preparation. Upon discharge of the effluent into the receiving water body dilution and
further degradation will occur. Nevertheless, some of the compounds might enter the drinking water treatment process, especially
the process of those drinking water companies which produce drinking water from surface water. [4, 5]. Advanced Oxidation
processes are widely used in treatment of wastewater because it generates •OH radical. This radical tend to be highly unstable and,
therefore, highly reactive because one of their electrons is unpaired. Oxidation reactions that produce radicals tend to be followed
by additional oxidation reactions between the radical oxidants and other reactants (both organic and inorganic) until
thermodynamically stable oxidation products are formed. The ability of an oxidant to initiate chemical reactions is measured in
terms of its oxidation potential. The most powerful oxidants are fluorine, hydroxyl radicals (•OH), ozone, and chlorine with
oxidation potentials of 2.85, 2.70, 2.07 and 1.49 electron volts, respectively. The end products of complete oxidation (i.e.,
mineralization) of organic compounds are carbon dioxide (CO2) and water (H2O) [6, 7, 8].
Catalytic ozonation has gained highly increasing attention during past years, because of its good effectiveness in the degradation
of organic pollutants. Organics can be oxidized by catalytic ozonation in the room temperature and pressure, which are hard to
dissociate by single ozonation. Catalytic ozonation shows great advantages in refractory organics in water, and is expected to be
the powerful and valuable technology in water treatment [9-11]. In this paper the catalytic ozonation of Reactive Black 5 (RB5)
solution in the presence of MgO catalysts was investigated in a laboratory scale batch reactor. The effects of solution pH (3–12),
reaction time, MgO dosage (0.05-1 g/L), and initial dye concentration (100–500 ppm) on color and TOC removal were evaluated,
and the findings were compared to those of ozonation without a catalyst. The results indicate that addition of MgO crystals greatly
accelerate the degradation of RB5 dye.
Figure 1 Catalytic ozonation experiment set up
1. Oxygen cylinder 2. Ozonator 3. Reactor 4. Magnetic stirrer 5. KI solution
References:
[1] Guo, Y., Yang, L., Cheng, X., Wang, X., Environmental & Analytical Toxicology, 2012, 2-7.
[2] Lucas, M.S., Mouta, M., Pirre, A., Peres, J.A., Water and Science Technology, IWA Publishing, 2009.
[3] Eric, S.E., “Municipal Waste Water Treatment Plant (WWTP) Effluents”, RIWA, 2007, 5-8.
[4] Sperling, M.V., “Wastewater characteristics, Treatment and Disposal”, IWA publishing, 2007, vol. 1, 6-11.
[5] Abdel-Raouf, N., Al-Homaidan, A.A., Ibraheem, I.B.M., Saudi Journal of Biological Sciences, 2012, 19, 257-275
[6] Kommineni, S., Zoeckler, J., Stocking, A., Sun Liang., Flores, A., Kavanaugh M., Rodriguez, R., Browne, T., Roberts, R.,
Brown, A., Stocking, A., “Advanced Oxidation Processes”, Chap. 3, 111-113.
[7] Advanced Oxidation Processes for Wastewater Treatment, International Journal of Photo-energy, Volume 2013 (Article
ID 683682).
[8] Grote, B., Skills Tech TAFE, Parklands, Gold Coast, 2012, 17-19.
[9] Polat, D., Yucel, H., Ozbelge, T., Yilmazer, U., Catalytic Ozonation Of Industrial Textile Wastewaters In A Three Phase
Fluidized Bed Reactor, Middle East Technical University, 2010, 4-12.
[10] Hordern, B.K., Ziolek, M., Nawrocki, J., Applied Catalysis B: Environmental 46, 2003, 639–669.
[11] Nawrocki, J., Applied Catalysis B: Environmental 142– 143, 2013, 465– 471.