title: Material flow analysis of phosphorus through food consumption in two megacities in northern China.
abstract: The key stocks and flows of phosphorus (P) through food consumption in Beijing and Tianjin, two megacities in northern China, were explored using a material flow analysis (MFA) approach to construct a static model of P metabolism. A total of 4498 t P has accumulated with 72% of P flow imported through food consumption eventually remaining in Beijing in 2008. Around 64% of the total inflow of P (2670 t) remained in Tianjin in 2008. P in the uncollected sewage from both urban and rural residents and the effluents from sewage treatment plants has significant negative effects on water quality. An average of 55% the P flow remained in the sewage sludge through urban food consumption. The key problems in P metabolism and management in megacities are identified based on the quantitative analysis of P cycling through food consumption. Relevant solutions for improving P recycling efficiency are also discussed. It is important to link P flows with environmental regulations and to establish a strong coordination between urban and rural areas for nutrient recycling to attain sustainable development of megacities.
authors.affiliation: State Key Lab of Regional and Urban Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Min
authors.initials: M
authors.lastname: Qiao
authors.forename: Yuan-Ming
authors.initials: YM
authors.lastname: Zheng
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D000383:Agriculture; D002681:China; D002947:Cities / Q000706:statistics & numerical data*; D003247:Conservation of Natural Resources; D055669:Ecological and Environmental Phenomena; D004784:Environmental Monitoring / Q000379:methods*; D005523:Food Supply / Q000706:statistics & numerical data*; D015233:Models, Statistical; D010758:Phosphorus / Q000032:analysis*; D012722:Sewage / Q000737:chemistry
chemical_list: D012722:Sewage; D010758:Phosphorus