BOD Reduction of Grey Water by utilizing Sequencing Batch Reactor (SBR)

Presently, Universiti Teknologi PETRONAS (UTP) obtains water supply from the
treatment plant in Parit, Perak. All the wastewater produced in the student village is sent
to the university treatment plant. To save cost on water supply, better quahty of
wastewater like grey water can be treated and reused for toilet flushing purposes. This
project is done to study on the grey water treatment which mainly focuses on the
process for BOD removal only. The BOD treatment facility must be incorporated in
order to meet the water reuse for toilet flushing standard to ensure safe usage. The
standard BOD level taken from NSW Health Department's Publication for toilet
flushing is 20 mg/L. Grey water samples are taken from sumps which are located at the
ground floor of student village. BOD5 and COD test analysis was conducted to study
the relationship between BOD5 and COD. COD:BOD5 ratio is 2.5. Sequencing Batch
Reactor (SBR) was set up to study the parameter used for the BOD treatment. SBR
cycle consists of 5 phases: FELL, REACT, SETTLE, DECANT and IDLE. The
optimum react time for the treatment is obtained in this research project with the
reaction time of 3 hours is required to remove 65% of influent COD. Besides, this
literature reviews on the alternative ways ofBODreduction of greywater are included:
Multistage Rotary Biological Contractor (RBC), Membrane Bioreactor (MBR), and
Biologically Aerated Filter (BAF).