Fahmi Ridwan

A highly efficient single chambered up-flow membrane-less microbial fuel cell for treatment of azo dye Acid Orange 7-containing wastewater.

Single chambered up-flow membrane-less microbial fuel cell (UFML MFC) was developed to study the feasibility of the bioreactor for decolorization of Acid Orange 7 (AO7) and electricity generation simultaneously. The performance of UFML MFC was evaluated in terms of voltage output, chemical oxygen demand (COD) and color removal efficiency by varying the concentration of AO7 in synthetic wastewater. The results shown the voltage generation and COD removal efficiency decreased as the initial AO7 concentration increased; this indicates there is electron competition between anode and azo dye. Furthermore, there was a phenomenon of further decolorization at cathode region which indicates the oxygen and azo dye are both compete as electron acceptor. Based on the UV-visible spectra analysis, the breakdown of the azo bond and naphthalene compound in AO7 were confirmed. These findings show the capability of integrated UFML MFC in azo dye wastewater treatment and simultaneous electricity generation.

Evaluation on the molecular structure of azo dye in photocatalytic mineralization under solar light irradiation

AbstractThe aim of this study was to investigate the effects of number of sulphonic groups on solar photocatalytic degradation of Acid Orange 7 (AO7), Orange G (OG), New Coccine (NC), Reactive Black 5 (RB5) and Reactive Green 19 (RG19) in aqueous solution. The data obtained for photocatalytic degradation of AO7, OG, NC, RB5 and RG19 were well fitted with the Langmuir–Hinshelwood kinetic model. The pseudo-first-order rate constant of RG19 with six sulphonic groups was the highest among the dyes in this study. Results showed that photocatalytic degradation rate of the azo dyes increased following the increase of the number of sulphonic groups of the dyes in the sequence of: AO7 < OG < NC < RB5 < RG19.

Comparison on solar photocatalytic degradation of orange g and new coccine using zinc oxide as catalyst

The mineralization of azo dyes could be realized through solar photocatalytic degradation that is a green method where non-harmful end products are produced. The aim of this study was to investigate the mineralization of Orange G (OG) and New Coccine (NC) using ZnO as catalyst. The degradation of the azo dyes was conducted at different experimental conditions, and parameters such as effect of sunlight to the degradation rate, initial azo dye concentration, amounts of catalyst dosage, pH and effect of aeration to the decolorization of azo dye were investigated. Photocatalytic mineralization of the azo dyes was evaluated through the analysis of UV-Vis spectra, chemical oxygen demand (COD) and ion chromatography (IC) for residual ionic species analysis. The results showed that solar photocatalytic degradation using ZnO was effective for colour removal and the photodegradation rate followed Langmuir-Hinshelwood kinetic model. It was observed that the degradation rate of NC was higher than OG which may be due to the different number of sulphonate ions that are attached on to the azo dye molecule.

Sustainable green technology on wastewater treatment: The evaluation of enhanced single chambered up-flow membrane-less microbial fuel cell

This study demonstrated the potential of single chamber up-flow membrane-less microbial fuel cell (UFML-MFC) in wastewater treatment and power generation. The purpose of this study was to evaluate and enhance the performance under different operational conditions which affect the chemical oxygen demand (COD) reduction and power generation, including the increase of KCl concentration (MFC1) and COD concentration (MFC2). The results showed that the increase of KCl concentration is an important factor in up-flow membrane-less MFC to enhance the ease of electron transfer from anode to cathode. The increase of COD concentration in MFC2 could led to the drop of voltage output due to the prompt of biofilm growth in MFC2 cathode which could increase the internal resistance. It also showed that the COD concentration is a vital issue in up-flow membrane-less MFC. Despite the COD reduction was up to 96%, the power output remained constrained.

Pilot scale single chamber up-flow membrane-less microbial fuel cell for wastewater treatment and electricity generation

Pilot scale up-flow membrane-less microbial fuel cell (UFML-MFC) was constructed to study feasibility of the bioreactor for simultaneous degradation of organic substance and electricity generation. The performance of the UFML-MFC was evaluated with different anode electrode (cube carbon felt and stacked carbon felt) in terms of voltage output, chemical oxygen demand (COD) and Coulombic efficiency (CE). Carbon flake were used as cathode in the UFML-MFC. UFML-MFC was operated in three stages where included batch-fed, end of batch fed and semi-continuous. The Cube carbon felt as anode have the better performance in terms of voltage output and electricity generation in all 3 stages. Maximum voltage output was 0.311 ± 0.004 V at 75% of COD reduction and thus CE was 0.15%. The result shows the operational mode is the key to improve the voltage output and also COD reduction.