Affiliations: Centre for Environmental Studies, Anna University
Chennai – 600 025, India | School of Environment Resource and Management Asian
Institute of Technology (AIT), Pathumthani, Thailand
Abstract: The impact of feed starvation condition on the biological
characteristics and the performance of an aerobic submerged Membrane Bioreactor
(MBR) system was investigated. The synthetic wastewater treated in MBR under
steady-state condition showed 95% removal of COD, 98% removal of TOC and
suspended solids, 88% of TKN removal and 30% removal of phosphate. The system
was subjected to a feed starvation shock load for five days and the response of
the system in the process of recovering back to pre-shock steady-state
condition was studied. After five days of shock loading, the effluent quality
deteriorated showing traces of substrate leakage in effluent, large fraction of
biomass wash off and reduction in microbial activity inside the reactor. The
biological solids in the reactor reduced gradually from 15 g/L to 6 g/L, which
took around a month for the biomass to revert back to its normal growth phase.
The system required seven days to recover back to steady condition. Overall,
the study showed a faster recovery of organic, solid, nutrients removal;
however, the system took a month to regain the amount of biomass lost during
feed starvation shock load.
