Shanshan Zhang1, Chun Yong Lim2, Chia-Lung Chen3, He Liu4, Jing-Yuan Wang5. 1. School of Environmental and Civil Engineering, Jiangnan University, No. 1800 Lihu Road, Wuxi, Jiangsu, PR China; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, #06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141. 2. School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, #06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141. Electronic address: limc0146@ntu.edu.sg. 3. Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, #06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141. 4. School of Environmental and Civil Engineering, Jiangnan University, No. 1800 Lihu Road, Wuxi, Jiangsu, PR China. Electronic address: liuhe@jiangnan.edu.cn. 5. School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, #06-08 CleanTech One, 1 Cleantech Loop, Singapore 637141. Electronic address: jywang@ntu.edu.sg.
Abstract
High rate food consumption in urban cities causes vast amounts of nitrogen and phosphorus used in agriculture to end up in urban wastewaters. To substantially recover these nutrients, source-separated human urine should be targeted. The present study was to investigate the feasibility of recovering nitrogen and phosphorus in urine via microalgae cultivation. In concentrated urine, urea hydrolysis and precipitation occur rapidly, making microalgal growth difficult and nutrient recovery ineffective. However, when fresh urine was added as nutrient stock for 1-day growth requirement, biomass of Chlorella sorokiniana grew from 0.44 to 0.96 g L(-1) utilising 62.64 mg L(-1) of N and 10.64 mg L(-1) of P, achieving 80.4% and 96.6% recoveries, respectively in a 1-day non-sterile cultivation cycle. Overall, microalgae grown with urine added as nutrient supplement show no signs of inferiority as compared to those grown in recipe medium BG11 in terms of mass and chlorophyll a growth rates as well as resulting lipids (36.8%) and energy contents (21.0 kJ g(-1)).
High rate food consumption in urban cities causes vast amounts of nitrogen and n>an class="Chemical">phosphorus used in agriculture to end up in urban wastewaters. To substantially recover these nutrients, source-separated human urine should be targeted. The present study was to investigate the feasibility of recovering nitrogen and phosphorus in urine via microalgae cultivation. In concentrated urine, urea hydrolysis and precipitation occur rapidly, making microalgal growth difficult and nutrient recovery ineffective. However, when fresh urine was added as nutrient stock for 1-day growth requirement, biomass of Chlorella sorokiniana grew from 0.44 to 0.96 g L(-1) utilising 62.64 mg L(-1) of N and 10.64 mg L(-1) of P, achieving 80.4% and 96.6% recoveries, respectively in a 1-day non-sterile cultivation cycle. Overall, microalgae grown with urine added as nutrient supplement show no signs of inferiority as compared to those grown in recipe medium BG11 in terms of mass and chlorophyll a growth rates as well as resulting lipids (36.8%) and energy contents (21.0 kJ g(-1)).