Now showing 1 - 9 of 9
  • Publication
    Hybrid system of photocatalytic fuel cell and Fenton process for electricity generation and degradation of Reactive Black 5
    ( 2017-01-01)
    Noradiba Nordin
    ;
    ; ; ; ;
    Lee Sin Li
    ;
    Oon Yoong Sin
    ;
    Oon Yoong Ling
    A novel hybrid system composed of a photocatalytic fuel cell (PFC) and Fenton reactor was developed with the aim to degrade the azo dye Reactive Black 5 (RB5) and generate electricity. Compared to previously established system of bioelectro-Fenton system, microbial fuel cell (MFC) system has significant challenge in the development and operation system. Therefore, PFC is used instead of MFC to generate electrons for the Fenton system. The effect of azo dye (RB5) on each PFC and Fenton reactor was investigated. The experimental results showed that maximum power output was achieved in the absence of dye in the Fenton reactor of this hybrid system. Furthermore, higher degradation efficiency of RB5 could also be observed in the PFC reactor in this hybrid system.
  • Publication
    Reactive Green 19 degradation using O3/S2 O8(2-) process: Intermediates and proposed degradation pathway
    ( 2022-01-01)
    Mohd Razali N.A.
    ;
    ; ; ; ;
    Siti Nasuha Sabri
    ;
    Kow Su Huan
    ;
    Safya Abdul Malik
    The massive drawbacks of conventional wastewater treatment have led to a demand investigation about new advanced wastewater treatment technology. The issue can be addressed via advanced oxidation processes (AOPs) as witnessed recently. Therefore, the objective of this study was to investigate the performance of ozone/persulfate ((Formula presented.)) process to assess its use as potential degradation of diazo dye which is Reactive Green 19 (RG19). In this work, efficiency, color, and COD removal were investigated over a range of initial pH, persulfate concentration and initial concentration of RG19. The amount of sodium persulfate ((Formula presented.)) was varied at different levels (20–100 mM) relative to precursor radical to assess the optimum usage of persulfate concentration for RG19 degradation. Evidence that RG19 could degrade efficiently had occurred at 100 mg/L, initial pH 9, 60 mM persulfate concentration was identified by FTIR and GC/MS analysis. The results revealed that RG19 could achieve complete decolorization easily as compared to mineralization. In addition, RG19 degradation pathway gave the best representation of level degradation. The GC/MS and FTIR results exhibited the proposed RG19 degradation pathway that involved the characteristic of sulfonic group, (Formula presented.) accompanied with (Formula presented.) became as an indicator of their structure broken down one by one. The degradation products such as oxalic acid, formic acids and others were analyzed and finally converted to carbon dioxide and water. The diazo dye structure itself aided with (Formula presented.) has its superior characteristic as an aid for the efficient degradation process.
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  • Publication
    Influence of leachate matrix on oxidation performance of ozonation and aops
    Landfill leachate is a critical environmental issue that should be adequately treated to prevent it from spreading to the environment. This study explored the influence of raw leachate matrix and treated leachate matrix on O3, O3/H2O2, and O3/PS performance. O3 and AOPs were conducted in a laboratory-scale batch reactor. The findings showed the degradation of p-cresol, COD, and humic substances was much slower in treated leachate matrix than in raw leachate matrix. However, color was found easier to remove in treated leachate. The results revealed a synergic effect between molecular O3 and dissolved organic matter in the raw leachate as the O3 performance was enhanced in the presence of raw leachate matrix, except for color removal. The highest degradation of more than 90% was achieved in O3 /H2 O2 to remove COD, p-cresol, and humic substances, although it is the most affected by the leachate matrix. This study provides vital insight into the notable performance of O3 /PS in color removal regardless of the influence of leachate matrix, suggesting that the sulfate radical-induced oxidation outperformed O3 and O3 /H2 O2 in reducing nitrogen-containing compounds.
      1  39
  • 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.
      6  23
  • Publication
    Influence of leachate matrix on oxidation performance of ozonation and aops
    Landfill leachate is a critical environmental issue that should be adequately treated to prevent it from spreading to the environment. This study explored the influence of raw leachate matrix and treated leachate matrix on O3, O3/H2O2, and O3/PS performance. O3 and AOPs were conducted in a laboratory-scale batch reactor. The findings showed the degradation of p-cresol, COD, and humic substances was much slower in treated leachate matrix than in raw leachate matrix. However, color was found easier to remove in treated leachate. The results revealed a synergic effect between molecular O3 and dissolved organic matter in the raw leachate as the O3 performance was enhanced in the presence of raw leachate matrix, except for color removal. The highest degradation of more than 90% was achieved in O3 /H2 O2 to remove COD, p-cresol, and humic substances, although it is the most affected by the leachate matrix. This study provides vital insight into the notable performance of O3 /PS in color removal regardless of the influence of leachate matrix, suggesting that the sulfate radical-induced oxidation outperformed O3 and O3 /H2 O2 in reducing nitrogen-containing compounds.
      2  47
  • 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%.
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  • 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.
      1  6
  • Publication
    UVA-irradiated dual photoanodes and dual cathodes photocatalytic fuel cell: Mechanisms and Reactive Red 120 degradation pathways
    ( 2022-11-01)
    Ong Yong Por
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    ; ; ; ;
    Thor Shen Hui
    ;
    Lee Sin Li
    ;
    Teoh Tean Peng
    To enhance dye removal and energy recovery efficiencies in single-pair electrode photocatalytic fuel cell (PFC-AC), dual cathodes PFC (PFC-ACC) and dual photoanodes PFC (PFC-AAC) were established. Results revealed that PFC-AAC yielded the highest decolorization rate (1.44 h−1) due to the promotion of active species such as superoxide radical (•O2−) and hydroxyl radical (•OH) when the number of photoanode was doubled. The results from scavenging test and UV-Vis spectrophotometry disclosed that •OH was the primary active species in dye degradation of PFC. Additionally, PFC-AAC also exhibited the highest power output (17.99 μW) but the experimental power output was much lower than the theoretical power output (28.24 μW) due to the strong competition of electron donors of doubled photoanodes to electron acceptors at the single cathode and its high internal resistance. Besides, it was found that the increments of dye volume and initial dye concentration decreased the decolorization rate but increased the power output due to the higher amount of sacrificial agents presented in PFC. Based on the abovementioned findings and the respective dye intermediate products identified from gas chromatography-mass spectrometry (GC-MS), the possible degradation pathway of RR120 was scrutinized and proposed.
      1  31
  • Publication
    Influence of Amaranth dye concentration on the efficiency of hybrid system of photocatalytic fuel cell and Fenton process
    ( 2017-10-01)
    Noradiba Nordin
    ;
    ; ; ; ;
    Sin Li Lee
    ;
    Oon Yoong Sin
    ;
    Oon Yoong Ling
    A novel sustainable hybrid system of photocatalytic fuel cell (PFC) and Fenton process is an alternative wastewater treatment technology for energy-saving and efficient treatment of organic pollutants. The electrons generated from PFC photoanode are used to produce H2O2 in the Fenton reactor and react with the in situ generation of Fe2+ from sacrificial iron for hydroxyl radical formation. In this study, the effect of different initial Amaranth dye concentrations on degradation and electricity generation were investigated. ZnO/Zn photoanode was prepared by anodizing method and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Results revealed that the maximum power density (9.53 mW/m2) and current density (0.0178 mA/m2) were achieved at 10 mg/L of Amaranth. The correlation between dye degradation, voltage output, and kinetic photocatalytic degradation were also investigated and discussed.
      1  36