Ong Soon An
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Preferred name
Ong Soon An
Official Name
Ong, Soon An
Alternative Name
Ong, Soon An
Ong, S. A.
Soon An, Ong
Soon-An, Ong
ONG, Soon An
Ong, Soon an
Soon-An, Ong
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Scopus Author ID
57201387782
Researcher ID
B-9255-2012

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Innovative baffled microbial fuel cells for azo dye degradation: Interactive mechanisms of electron transport and degradation pathway

2021-05-01 , Oon Y.S. , Ong Soon An , Ho Li Ngee , Wong Yee Shian , Oon Y.L. , Lehl H.K. , Thung W.E.

Two membrane-less baffled microbial fuel cells (BMFCs) were developed for non-dye (BMFC1) and dye degradation (BMFC2) investigations along with simultaneous bioelectricity generation. The influence of salinity, organic loading, circuit connection, aeration rate, dye concentration and addition of intermediates on BMFCs performances were evaluated systematically. The increase of salinity by 3-fold (0.39 g/L of NaCl) lowered the internal resistance of BMFC1 system by 38%–620 Ω, and the power density increased 49% to 10.55 ± 0.86 mW/m2. While the further increase of salinity (10-fold) adversely affected BMFC1. The power performance of BMFC1 improved with higher organic loading. Whereas, the increment in organic loading enhanced the decolourisation efficiency but deteriorated the power performance of BMFC2 ascribed to the competition between New Coccine (NC) molecules and anode for electrons. This finding corroborates that NC was a preferable electron acceptor than the anode. The addition of 50 mg/L NC increased the power density by 53% to 12.40 ± 1.60 mW/m2, which revealed that NC decolourised intermediates could act as the electron mediator, hence led to the increase of power performance. The electron-mediating mechanism of NC decolourised intermediate, 1-amino-2-naphthol-6,8-disulfonate as electron shuttle was unveiled. The in-depth understanding of the mechanisms involved in dye degradation in MFCs was presented, where a comprehensive degradation pathway of NC was proposed based on the intermediates identified via UV–Visible spectra, Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC) and gas chromatograph-mass spectrometer (GC-MS) analyses.

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Role of macrophyte and effect of supplementary aeration in up-flow constructed wetland-microbial fuel cell for simultaneous wastewater treatment and energy recovery

2017-01-01 , Oon Yoong Ling , Ong Soon An , Ho Li Ngee , Wong Yee Shian , Farrah Aini Dahalan , Oon Yoong Sin , Harvinder Kaur Lehl , Thung Wei Eng , Noradiba Nordin

This study investigates the role of plant (Elodea nuttallii) and effect of supplementary aeration on wastewater treatment and bioelectricity generation in an up-flow constructed wetland-microbial fuel cell (UFCW-MFC). Aeration rates were varied from 1900 to 0 mL/min and a control reactor was operated without supplementary aeration. 600 mL/min was the optimum aeration flow rate to achieve highest energy recovery as the oxygen was sufficient to use as terminal electron acceptor for electrical current generation. The maximum voltage output, power density, normalized energy recovery and Coulombic efficiency were 545.77 ± 25 mV, 184.75 ± 7.50 mW/m3, 204.49 W/kg COD, 1.29 W/m3 and 10.28%, respectively. The variation of aeration flow rates influenced the NO3− and NH4+ removal differently as nitrification and denitrification involved conflicting requirement. In terms of wastewater treatment performance, at 60 mL/min aeration rate, UFCW-MFC achieved 50 and 81% of NO3− and NH4+ removal, respectively. E. nuttallii enhanced nitrification by 17% and significantly contributed to bioelectricity generation.

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Constructed wetland–microbial fuel cell for azo dyes degradation and energy recovery: Influence of molecular structure, kinetics, mechanisms and degradation pathways

2020-06-10 , Oon Y.L. , Ong Soon An , Ho Li Ngee , Wong Y.S. , Farrah Aini Dahalan , Oon Y.S. , Teoh T.P. , Lehl H.K. , Thung W.E.

Complete degradation of azo dye has always been a challenge due to the refractory nature of azo dye. An innovative hybrid system, constructed wetland-microbial fuel cell (CW-MFC) was developed for simultaneous azo dye remediation and energy recovery. This study investigated the effect of circuit connection and the influence of azo dye molecular structures on the degradation rate of azo dye and bioelectricity generation. The closed circuit system exhibited higher chemical oxygen demand (COD) removal and decolourisation efficiencies compared to the open circuit system. The wastewater treatment performances of different operating systems were ranked in the decreasing order of CW-MFC (R1 planted-closed circuit) > MFC (R2 plant-free-closed circuit) > CW (R1 planted-open circuit) > bioreactor (R2 plant-free-open circuit). The highest decolourisation rate was achieved by Acid Red 18 (AR18), 96%, followed by Acid Orange 7 (AO7), 67% and Congo Red (CR), 60%. The voltage outputs of the three azo dyes were ranked in the decreasing order of AR18 > AO7 > CR. The results disclosed that the decolourisation performance was significantly influenced by the azo dye structure and the moieties at the proximity of azo bond; the naphthol type azo dye with a lower number of azo bond and more electron-withdrawing groups could cause azo bond to be more electrophilic and more reductive for decolourisation. Moreover, the degradation pathway of AR18, AO7 and CR were elucidated based on the respective dye intermediate products identified through UV–Vis spectrophotometry, high-performance liquid chromatography (HPLC), and gas chromatograph-mass spectrometer (GC–MS) analyses. The CW-MFC system demonstrated high capability of decolouring azo dyes at the anaerobic anodic region and further mineralising dye intermediates at the aerobic cathodic region to less harmful or non-toxic products.

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Microbial fuel cell operation using nitrate as terminal electron acceptor for simultaneous organic and nutrient removal

2017-11-01 , Yoong Sin Oon , Ong Soon An , Ho Li Ngee , Wong Yee Shian , Yoong Lin Oon , Harvinder Kaur Lehl , Wei Eng Thung

A double-chambered biocathode microbial fuel cell with carbon felt employed as electrodes was developed for wastewater treatment and bioelectricity generation simultaneously. The system was operated in fed-batch mode for over eight batches. The effect of circuit connections on organic and nitrate reduction was investigated. The maximum power density recorded was 21.97 mW/m2 at current density of 88.57 mA/m2. The Coulombic efficiency and internal resistance of the system were 5% and 100 Ω. Up to 89.9 Â± 5.9% of chemical oxygen demand reduction efficiency achieved with an influent of 1123 Â± 28 mg/L. There was no significant difference in the chemical oxygen demand reduction when system operated in either open or closed circuit. This study clearly showed that higher nitrate reduction efficiency obtained in closed circuit (74.7 Â± 7.0%) due to bio-electrochemical denitrification compared to only 41.7% in the open circuit. The result also successfully demonstrated nitrate as terminal electron acceptor for the cathodic nitrate reduction.

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Microbial fuel cell operation using monoazo and diazo dyes as terminal electron acceptor for simultaneous decolourisation and bioelectricity generation

2017-03-05 , Oon Yoong Sin , Ong Soon An , Ho Li Ngee , Wong Yee Shian , Oon Yoong Ling , Harvinder Kaur Lehl , Thung Wei Eng , Noradiba Nordin

Monoazo and diazo dyes [New coccine (NC), Acid orange 7 (AO7), Reactive red 120 (RR120) and Reactive green 19 (RG19)] were employed as electron acceptors in the abiotic cathode of microbial fuel cell. The electrons and protons generated from microbial organic oxidation at the anode which were utilized for electrochemical azo dye reduction at the cathodic chamber was successfully demonstrated. When NC was employed as the electron acceptor, the chemical oxygen demand (COD) removal and dye decolourisation efficiencies obtained at the anodic and cathodic chamber were 73 Â± 3% and 95.1 Â± 1.1%, respectively. This study demonstrated that the decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. The maximum power density in relation to NC decolourisation was 20.64 mW/m 2 , corresponding to current density of 120.24 mA/m 2 . The decolourisation rate and power output of different azo dyes were in the order of NC > AO7 > RR120 > RG19. The findings revealed that the structure of dye influenced the decolourisation and power performance of MFC. Azo dye with electron-withdrawing group at para substituent to azo bond would draw electrons from azo bond; hence the azo dye became more electrophilic and more favourable for dye reduction.

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