Now showing 1 - 4 of 4
  • Publication
    Treatment of O3 with Na2S2O8 by ANOVA Interpretation towards degradation of azo dye
    Advanced oxidation processes (AOPs) especially ozonation method is widely studied in the wastewater treatmentfield. In this study, it highlighted about threemainenvironmental issues in the world such as1) proposing a method to overcome uncontrollable effluents from textile industriesby using syntheticdyes; 2)creating an improvementof previous conventional method; 3) reduced process time by using statistical approach.To address with this issue, analysis of variance (ANOVA)from Response Surface Methodology (RSM)to study the performance of O3with the help of persulfate (Na2S2O8) for treating one of azo dyes which is Reactive Green 19.This is due to there isvery limited work done by statistical analysis on this study. Hence, ANOVA data would proposestatistical models tailored to the data in 2D and 3D contour plots by knowing the three influenced parameterswhich is pH(6 to 10),persulfate concentration (30to 70mM) and contact time (4 to 20 min). Through the analysis, the result can be concluded that improvement of ozonation process with persulfate (Na2S2O8) werestatistically significant after allinteractive effectsgave a positive feedback towards responses.The obtained optimum conditions included a persulfate concentration (49mM), initial pH (8.89) and contact time (18 min) with fixed initial concentration 100mg/L. The experimental results were corresponded well with predicted models colour removal rates which is 99%.
  • Publication
    Removal of dyes from industrial effluents using combination of Advanced Oxidation Processes (AOPs) and biological treatment
    Nowadays, the removal of dyes from industrial effluents is still far away to a satisfactory solution. Even though the AOPs are known strong technologies for wastewater treatment, it still requires further advancement and extent. Hence, a new promising treatment is their combination with biological treatment, by taking the advantages of the individual potentials. Therefore, this research evaluated four treatment techniques, namely ozonation, ozone/hydrogen peroxide (O3/H2O2), ultraviolet/hydrogen peroxide (UV/H2O2), and a combination of ozonation-biological for synthetic dyes, consist of monoazo Methyl Orange (MO), disazo Reactive Red 120 (RR120) and anthraquinone Reactive Blue 19 (RB19). Finally, the treatments are evaluated with batik wastewater as a real wastewater sample from industries. The finding revealed that ozonation, O3/H2O2, UV/H2O2, and ozonation-biological become an effective treatment for monoazo, disazo, anthraquinone, and real wastewater. The treatments accomplish, under appropriate conditions, a full decolourization and a substantial mineralization. However, O3/H2O2 and ozonation works well with the dyes, in contrast to UV/H₂O₂. It reveals that complete decolourization by ozonation and O3/H2O2, with less than 20 min contact. Two decolourization curves of ozonation and O3/H2O2 almost overlapped suggesting that H2O2 hardly affects decolourization rate. Contrariwise, it takes more than 60 min for complete decolourization with UV/H₂O₂ for RR120, but requires more than 120 min for MO and RB19. Nevertheless, there was a significant difference for COD and TOC removals. It is apparent that O₃/H₂O₂ showed higher removal, suggesting that the presence of H₂O₂ promote the oxidation reaction. The final COD removal of O₃/H₂O₂ reached 100% within less than 10 min for RR120 and RB19, while 15 min for MO. Likewise, the higher TOC removal was observed for O₃/H₂O₂ in comparison to ozonation and UV/H₂O₂. On the whole, the COD removal was similar to TOC removal for each treatment. It is obvious that high decolourization from the start of biological was contributed from ozonation pre-treatment. In addition, the results indicate that 59.6 and 69.4% COD removal from ozonation and ozonationbiological, respectively for MO. While, resulted about 40.7 and 72.9% removal for RR120, and 51.4 and 59.8% for RB19, respectively. Thus, it represents small organic molecules that contribute considerably to the COD that cannot be completely removed by ozonation-biological treatment. Similar to COD, the results indicate that 49.1 and 73.7% TOC removal from ozonation and ozonation-biological, respectively for MO. While it leads to 39.3 and 64.3% removal for RR120 and 37.5 and 70.8% removal for RB19, respectively. It is clear that the biological further degrades the dyes from ozonation. In addition, each dye shows different decolourization pattern and degradation behaviour according to its chemical structure. The change in UV-vis and FT-IR spectra indicated the evidence of dye structure cleavage and intermediates formation. While, the NO₃-, SO₄2- and Cl- anions formed indicate dye mineralization. The decolourization conform first-order kinetics, with R2 values greater than 0.92. The O₃/H₂O₂ performs better with the batik wastewater, as compared to ozonation and UV/H₂O₂. Therefore, the results for synthetic wastewater support its application for real wastewater, even though the batik wastewater was more difficult to be decolourized and degraded because of its complex composition.
  • Publication
    Study of O3/S2O82- Advanced Oxidation Processes (AOPs) for removal of dye industrial effluents
    This research was carried out to study the efficiency of O3/S2O82- system in removal of Reactive Red 120 (RR120) dye sample. Different operating parameter such as pH, initial dye concentration and persulfate dosage were studied to evaluate the performance on removing colour and COD. The removal of colour and COD achieved higher efficiency at pH 7, 100 mg/L of initial dye concentration and persulfate dosage of 5 g S2O82-/1 g RR120. O3/S2O82- with the most effective conditions experienced effective decolourization and degradation of organic pollutants than O3 only. Furthermore, it achieved faster breakdown of azo bond and aromatic groups than O3 after treatment as observed with UV-Vis absorption spectra. The FT-IR analysis obtained new absorption peak that represents alkenes after 20 min of O3 treatment whereas mostly of the absorption bands of O3/S2O82- flattened.
  • Publication
    Preliminary screening oxidative degradation methyl orange using ozone/ persulfate
    ( 2018)
    Nur Aqilah Razali
    ;
    ; ; ; ;
    Siti Nasuha Sabri
    ;
    Su Huan Kow
    The present study focusing on the performances of advanced oxidation process by using ozonation method towards Methyl Orange based on the efficiency of colour removal and Chemical Oxygen Demand (COD) removal. Factorial design with response surface methodology (RSM) was used to evaluate the interaction between operational conditions, such as pH, initial concentration, contact time and persulfate dosage to obtain the optimum range conditions using a semi-batch reactor. The range of independent variables investigated were pH (3-11), initial concentration (100-500mg/L), contact time (10-50min) and persulfate dosage (20-100mM) while the response variables were colour removal and COD removal of Methyl Orange. The experimental results and statistical analysis showed all the parameters were significant. Thus, from this findings, optimization of operational conditions that had been suggested from the ozone/persulfate RSM analysis were (pH 3, 100 mg/L, 50min, 60mM) that would be produced 99% Colour Removal and 80% COD Removal and help in promoting an efficient ozonation process. The effect list data that showed the most contributed effects to increase the percentages of colour removal were pH and persulfate dosage whereas the contact time and initial concentration had the highest positive effects on the COD removal. Other than that, the interaction between pH, contact time and persulfate dosage were found to be the most influencing interaction. Therefore the least influencing interaction was interaction between persulfate dosage and pH. In this study, the correlation coefficient value R2 for colour removal and COD removal of Methyl Orange were R2= 0.9976 and R2= 0.9924 which suggested a good fit of the first-order regression model with the experimental data.