title: The effect of mixed liquor suspended solids (MLSS) on biofouling in a hybrid membrane bioreactor for the treatment of high concentration organic wastewater.
abstract: Biofouling is a crucial factor in membrane bioreactor (MBR) applications, particularly for high organic loading operations. This paper reports a study on biofouling in an MBR to establish a relationship between critical flux, Jc, mixed liquor suspended solids (MLSS) (ranging from 5 to 20 g L-1) and volumetric loading rate (6.3 kg COD m-3 h-1) of palm oil mill effluent (POME). A lab-scale 100 L hybrid MBR consisting of anaerobic, anoxic, and aerobic reactors was used with flat sheet microfiltration (MF) submerged in the aerobic compartment. The food-to-microorganism (F/M) ratio was maintained at 0.18 kg COD kg-1 MLSSd-1. The biofouling tendency of the membrane was obtained based on the flux against the transmembrane pressure (TMP) behaviour. The critical flux is sensitive to the MLSS. At the MLSS 20 g L-1 the critical flux is about four times lower than that for the MLSS concentration of 5 g L-1. The results showed high removal efficiency of denitrification and nitrification up to 97% at the MLSS concentration 20 g L-1. The results show that the operation has to compromise between a high and a low MLSS concentration. The former will favour a higher removal rate, while the latter will favour a higher critical flux.
authors.affiliation: Institute of Environmental & Water Resource Management (IPASA), Universiti Teknologi Malaysia (UTvl), 81310 Skudai, Johor Bahru, Malaysia.
authors.forename: A
authors.initials: A
authors.lastname: Damayanti
authors.forename: Z
authors.initials: Z
authors.lastname: Ujang
authors.forename: M R
authors.initials: MR
authors.lastname: Salim
authors.forename: G
authors.initials: G
authors.lastname: Olsson
mesh_terms: D000641:Ammonia / Q000737:chemistry; D019149:Bioreactors; D008567:Membranes, Artificial; D009566:Nitrates / Q000737:chemistry; D009573:Nitrites / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D009566:Nitrates; D009573:Nitrites; D000641:Ammonia