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Hybrid system of photocatalytic fuel cell and Fenton process for electricity generation and degradation of Reactive Black 5

2017-01-01 , Noradiba Nordin , Ho Li Ngee , Ong Soon An , Abdul Haqi Ibrahim , Wong Yee Shian , 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.

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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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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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Influence of Amaranth dye concentration on the efficiency of hybrid system of photocatalytic fuel cell and Fenton process

2017-10-01 , Noradiba Nordin , Ho Li Ngee , Ong Soon An , Abdul Haqi Ibrahim , Wong Yee Shian , 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.

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Explicating the importance of aeration and pH for Amaranth degradation and electricity generation in a viable hybrid system of photocatalytic fuel cell and electro-Fenton process

2020-05-15 , Thor Shen Hui , Ho Li Ngee , Ong Soon An , Noradiba Nordin , Ong Yong Por , Yap Kea Lee

Hybrid system of photocatalytic fuel cell (PFC) and electro-Fenton (EF) process emerges as an environmentally sustainable technology for wastewater treatment and energy recovery. The established dual-cell hybrid system can reduce the recombination of electron and hole in photoanode and PFC acts as the power source for EF process. Hence, the optimal conditions for dye degradation synchronized with electricity generation in the dual-cell hybrid system should be determined. The in-situ generation of hydroxyl radicals was the key factor for dye degradation in the system. Hence, the operating parameters such as aeration and initial pH of dye were assessed. Higher decolourization efficiency was attained in aerated PFC (76.6%) and aerated EF process (84.5%). Enhanced power density (1.493 μW cm−2) was achieved in aerated hybrid system through the elevated transfer of electrons from photoanode in PFC to the cathode of EF process. Acidic environment was favoured for the dye degradation in both PFC and EF process. At optimal pH 3, PFC and EF process attained highest colour removal efficiency which were 88.5% and 84.5%, respectively. Consequently, largest power density (2.221 μW cm−2) and maximum current density (0.012 mA cm−2) were achieved in the hybrid system under pH 3 condition in both PFC and EF process.