Sustainability, Vol. 9, Pages 1845: Assessment of Phosphorus Recovery from Swine Wastewater in Beijing, China (Sustainability)

The nutrient management of phosphorus (P) contained in swine wastewater is an important challenge to enhance P use efficiency. In the present study, assessment of P recovery from swine wastewater in Beijing was performed. P amounts of swine wastewater increased from 11,687 tons in 1980 to 16,237 tons in 2014. Without treatment of swine wastewater, P concentration will reach a maximum 1.20 mg/L. The maximum P recovery was 99.36% under the condition of crystallization coupled BPR (biological phosphorus removal) when the operating conditions were 60.6 mg/L for Cp (initial P concentration (mg/L)), 1.2 for Mg/P (magnesium-to-P molar ratio), 9.7 for pH of crystallization process, and 8.0 for pH, 1.6 h for anaerobic stage time, 15 days for sludge retention time of BPR. The P concentration for water quality was 0.03 mg/L to meet the water regulation standard. Under this situation, if the target P concentration were set as Grade II and III, pig breeding numbers reached 42.07 and 95.90 million heads. Construction investments for the crystallization, BRP, and coupled methods are 411 (104 Yuan, 604,307 USD), 301 (104 Yuan, 442,580 USD), and 551 (104 Yuan, 810,170 USD), respectively. The running costs are 15.205 (104 Yuan/year, 22,360 USD/year), 28.907 (104 Yuan/year, 42,500 USD/year) and 44.112 (104 Yuan/year, 64,860 USD/year). To manage non-point pollution, swine wastewater treatment facilities should be used and pig breeding numbers should be managed within reasonable ranges.