Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4410560 | Chemosphere | 2011 | 6 Pages |
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.
► P flows through food consumption were explored in two megacities of China. ► Around 72% and 64% of the P inflow remained in Beijing and Tianjin, respectively. ► P in uncollected and treated sewage contributes greatly to water eutrophication. ► Solving sanitation problem is urgent for megacities to improve P recycling efficiency.