Simultaneous removal of organic matter and nitrate from aqueous solutions using a bio-electrochemical reactor / Mook Wei Tze

In this research an up-flow undivided bio-electrochemical reactor is used for treating simultaneously organic matter and nitrates in aqueous solutions. Nitrate elimination takes place at the cathode while organic substance is oxidized at the anode. The cathode material is palm shell granular acti...

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Bibliographic Details
Main Author: Mook, Wei Tze
Format: Thesis
Published: 2014
Subjects:
Online Access:http://studentsrepo.um.edu.my/7994/
http://studentsrepo.um.edu.my/7994/1/Final_dissertation.pdf
Description
Summary:In this research an up-flow undivided bio-electrochemical reactor is used for treating simultaneously organic matter and nitrates in aqueous solutions. Nitrate elimination takes place at the cathode while organic substance is oxidized at the anode. The cathode material is palm shell granular activated carbon coated with a film of autohydrogenotrophic bacteria. A nano-crystalline PbO2 coated carbon combination was compared against various anodic materials namely stainless steel, titanium, graphite and carbon felts. The results showed that PbO2 provided better performance in the elimination of both pollutants. As such PbO2 was used to study the effects of major operating parameters such as electrodes spacing, electric current and hydraulic retention time (HRT) on the performance of the reactor to treat organic matter and nitrates. Response surface methodology (RSM) was used to evaluate the interactions between these operating parameters and to optimize the reactor performance. The optimum conditions for the simultaneous elimination of organic matter and nitrate are an electrodes spacing of 3.2 cm, electric current of 18 mA and HRT of 45h that provided organic matter removal efficiency of 83% along with 99% elimination of nitrate. It was found that the current efficiency (CE) is unaffected by electrode spacing and is higher at low electric current and HRT. The control of pH is important to minimize nitritenitrogen accumulation.