title: Nitrogen and phosphorus removal from tertiary wastewater in an osmotic membrane photobioreactor.
abstract: An osmotic membrane photobioreactor (OMPBR) was designed and operated for 162days for nitrogen and phosphorus removal from wastewater using Chlorella vulgaris. The removal efficiency for NH4(+)-N, NO3(-)-N and PO4(3-)-P reached as high as 95%, 53% and 89%, whereas the maximum removal rates were 3.41 mg/L-day, 0.20 mg/L-day and 0.8 mg/L-day, respectively. The microalgae exhibited high tendency to aggregate and attached to the bioreactor and membrane surfaces, and total biomass accumulation in the OMPBR was over 5 g/L. Salt accumulation and biofouling had adverse effects on membrane filtration, but the performance could be recovered through periodic backwashing of the membranes. Extracellular polymeric substances characterization indicated higher fraction of polysaccharides as compared to proteins. The biomass in the OMPBR accumulated higher levels of carbohydrates and chlorophyll. These results indicate the suitability of OMPBR in wastewater treatment and in high-density microalgae cultivation.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
authors: Prashant
authors: P
authors: Praveen
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore. Electronic address: chelohkc@nus.edu.sg.
authors: Kai-Chee
authors: KC
authors: Loh
mesh_terms: D057219:Biofouling; D018533:Biomass; D048408:Chlorella vulgaris / Q000378:metabolism; D005374:Filtration; D008567:Membranes, Artificial; D058086:Microalgae / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification*; D009995:Osmosis; D010758:Phosphorus / Q000302:isolation & purification*; D058433:Photobioreactors / Q000382:microbiology; D013997:Time Factors; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D008567:Membranes, Artificial; D009584:Nitrogen; D010758:Phosphorus; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Biofouling; Forward osmosis; Membrane bioreactor; Microalgae; Wastewater treatment