title: Trophic mode conversion and nitrogen deprivation of microalgae for high ammonium removal from synthetic wastewater.
abstract: In this study, a well-controlled three-stage process was proposed for high ammonium removal from synthetic wastewater using selected promising microalgal strain UMN266. Three trophic modes (photoautotrophy, heterotrophy, and mixotrophy), two N sufficiency conditions (N sufficient and N deprived), two inoculum modes (photoautotrophic and heterotrophic), and different NH4(+)-N concentrations were compared to investigate the effect of trophic mode conversion and N deprivation on high NH4(+)-N removal by UMN266. Results showed that photoautotrophic inoculum with trophic mode conversion from heterotrophy to photoautotrophy and N deprivation in Stage 2 turned was the optimum plan for NH4(+)-N removal, and average removal rates were 12.4 and 19.1mg/L/d with initial NH4(+)-N of 80 and 160mg/L in Stage 3. Mechanism investigations based on algal biomass carbon (C) and N content, cellular composition, and starch content confirmed the above optimum plan and potential of UMN266 as bioethanol feedstock.
authors: Center for Biorefining, Bioproducts and Biosystems Engineering Department, University of Minnesota, Saint Paul, United States; Research Institute of Environmental Planning and Management, College of Environmental Science & Engineering, Tongji University, Shanghai, China.
authors: Jinghan
authors: J
authors: Wang
authors: Center for Biorefining, Bioproducts and Biosystems Engineering Department, University of Minnesota, Saint Paul, United States; School of Resources, Environmental & Chemical Engineering and MOE Biomass Engineering Research Center, Nanchang University, Nanchang, China. Electronic address: zhouw@umn.edu.
authors: Wenguang
authors: W
authors: Zhou
authors: Research Institute of Environmental Planning and Management, College of Environmental Science & Engineering, Tongji University, Shanghai, China.
authors: Haizhen
authors: H
authors: Yang
authors: Research Institute of Environmental Planning and Management, College of Environmental Science & Engineering, Tongji University, Shanghai, China.
authors: Feng
authors: F
authors: Wang
authors: Center for Biorefining, Bioproducts and Biosystems Engineering Department, University of Minnesota, Saint Paul, United States; School of Resources, Environmental & Chemical Engineering and MOE Biomass Engineering Research Center, Nanchang University, Nanchang, China. Electronic address: ruanx001@umn.edu.
authors: Roger
authors: R
authors: Ruan
mesh_terms: D064751:Ammonium Compounds / Q000302:isolation & purification*; D058086:Microalgae / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D009584:Nitrogen / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D064751:Ammonium Compounds; D009584:Nitrogen; D062065:Wastewater
keywords: Ammonium removal; Microalgae; Nitrogen deprivation; Nitrogen starvation; Trophic mode conversion