Program: Collaborative Research with Industry (CRI)
Field: Environmental Engineering
Principal Investigator: Assoc. Prof. Dr. Chart Chiemchaisri
Sending University: Kasetsart University (KU)
Japanese Co-Investigator: Prof. Dr. Kazuo YAMAMOTO
Japanese University: The University of Tokyo
Year: 2013
Abstract:
The main purpose of this research is to demonstrate the application of membrane bioreactor technology to local
sewage in Bangkok. Typically, sewage in Bangkok is being collected through a combine sewerage system.
Therefore the wastewater has been partially diluted with storm water from street outlets. In addition to its low
organic strength characteristics, it also contains high percentage of non-biodegradable components like sand and
silt which coming together with urban storm water made it difficulty of treat by biological wastewater treatment
processes. The operational difficulties include maintaining active microorganisms in the wastewater treatment
processes under low organic loading and preventing overflow of inactive biomass during gravity separation by
sedimentation. Membrane bioreactor which utilizes membrane filtration in place of gravity separation can
overcome these problems by preventing the loss of biomass with effluent and thus maintaining the biomass
completely within the biological treatment unit. The biological treatment system with membrane separation can
also be operated at higher biomass concentration made it very compact. There is also possibility to reduce the
treatment time within the biological reactor as the organic concentrations in the sewage are low. Nevertheless, the
operation of membrane bioreactor needs to be investigated in the aspect of pre-treatment requirement and
potential fouling of membrane by inorganic constituents of sewage.
In order to implement the wastewater treatment technology properly, pilot-scale membrane bioreactor is installed
at one of the sewage treatment plant in Bangkok. It is therefore receive real sewage that is being collected and
treated at the treatment plant. The main aim for this investigation is to demonstrate the possibility for applying
this technology to local conditions and investigate performance of the system in long term operation. During the
investigation, several operating conditions will be varied to determine optimal condition for the treatment of local
sewage. Moreover, further detail investigation on membrane fouling condition which is quite critical when
applying this technology to wastewater will be carried out in order to determine the extent of membrane fouling
when applied to the treatment of local sewage. This aspect would explore research opportunity for both partners
(university and industry) to work in-depth on research in order to find operating strategies or mitigation measures
to reducing membrane fouling in the membrane bioreactor system. Without field application of such technology
available for operation under real operating conditions, the investigations on these practical aspects which are
important for technology developers such as universities and industries to accumulate scientific knowledge as
well as technical experiences would not be possible. (Source: Application to CRI 2013)