Biological Characteristics of Bangkok Domestic Wastewater Treatment Using a Pilot Scale Membrane Bioreactor

Abstract

Abstract

This paper presents the biological performance of a pilot scale membrane bioreactor (MBR).  The MBR treated Bangkok domestic wastewater by combining membrane filtration and biological processes in one reactor.  The removal efficiency for chemical oxygen demand (COD) and ammonia was around 90 and 99.7% respectively.  However, efficiency of nitrate and phosphate removal has not been significantly satisfied yet.  The mixed liquor suspended solids (MLSS) was gradually building up from 5,200 mg/L to 6,900 mg/L in the MBR during 45 day period.  Measurements of carbohydrate and protein of the extra cellular polymeric substances (EPS) was investigated.  Protein was predominant in the soluble EPS and the ratios between protein and carbohydrate was around 1.8 by average.  The MLSS and total soluble EPS was found to have a stronger positive potential on membrane fouling than carbohydrate EPS and protein EPS alone.