Biomass adaptation to complex substrate degradation in membrane bioreactors: appropriated operating conditions

Abstract

The aim of this work is to analyse the biological performances of two immersed membranes bioreactors focusing on the biomass adaptation to complex substrate degradation and the performance in term of permeate quality. Two influents were selected: a synthetic complex influent (acetate/Viandox, MBR1) and a real seafood processing wastewater (surimi product, MBR2). The MBR systems were operated for long periods without any sludge extraction except for sampling. Organic matter removal, sludge production and quality of the treated wastewater were analysed and studied. COD removal efficiencies after a period of biomass adaptation were higher than 97% and 95% for the synthetic and real wastewater respectively. In both cases, the COD of the treated wastewater was lower than 50 mg.L(-1). In spite of salt concentration in the real wastewater a biomass adaptation process occurs. In the overall operational period, a 0.058 gCOD P.gCOD T(-1) and a 0.12 gCOD P.gCOD T(-1) observed sludge yields were obtained for the MBR1 and MBR2 respectively. These values are approximately 5 to 10 times lower than those measured in conventional activated sludge process. These results showed that the presence of particular and some of non-easily degradable compounds in the influent of MBR2 didn't limit the performance of MBR in term of COD removal achieved. The results have also confirmed the excellent permeate quality for water reuse from MBRs systems.

Preliminary Study of Hospital Wastewater Treatment with a Submerged Membrane Bioreactor (SMBR): Case Study of Songklanagarind Hospital – Thailand

“…In this 5MBR stalked ciliates were found higher than free swimming ones and only a few Suctoria or Rotifer. These microhials indicated and confirmed that the stahility of studied 5MBR was well performed whatever the permeation of flux values tested [8][9].…”

“…The SVI value was measured and its values reported. to he ahout 103-108 ml/g, This range of SVI values showed the good settling characteristic of sludge that may he expected in the 5MBR, even if the system was not operating for a long enough period of time [8][9]. This result clearly showed that the sludge characteristics ohtained from a short term operation of 30-35 days can represent that of a long term operation as in general AS.…”

“…Moreover, the permeation of flux is recommended in the sub-critical region. Besides, the formation of biomass cake layer on the membrane surface can be observed playing a key factor in the efficiency and performance of 5MBR [6][7][8][9].…”

Food‐Processing Wastes

“…A submerged MBR system successfully treated seafood waste under a range of COD, suspended solids, and saline loadings. Soluble microbial products were found to be the principal fouling agent (Sridang et al, 2008a).…”