title: Quantification of phosphorus flows throughout the consumption system of Bangkok Metropolis, Thailand.
abstract: Due to unequal distribution of the world's Phosphorus (P) sources for fertilizer production, an evaluation of P flows throughout the consumption system of a city is needed. The prime objective of this paper is to assess and prioritize P recovery options as to bring about, as much as possible, a close-looped P-for-food system. Using the Bangkok Metropolitan Administration (BMA) as a case study, the aim of this work is to quantify the potential mass flow of P for four major types of urban wastes: domestic wastewater (DWW), septage sludge (SS), food waste (FW) and green garbage (GB) and to determine the recoverable stock of P available. The consumption of food and supplements such as cleansing products and fertilizer is estimated at a rate of 1146.4 g P·cap(-1)·year(-1). P contained in wastes being discarded from its average 7.9 million population plus 33.8 million Bangkok-visiting tourists per annum is determined to be 8.01 kt P annually. Only 4% of the above quantity is recycled and used internally for cultivating plants grown in public parks. An annual amount of 7.68 kt P was found to be disposed of in landfills (6.23 kt P) and in the river systems (1.45 kt P). From the findings of this study, therefore, it is recommended that P recovery efforts from BMA's urban wastes should be focused on wastes enrouted to landfills since these constitute 81% of P discarded. As a consequence, solid waste combustion coupled with energy recovery from P-binding organics may be an appropriate means of P recovery. This technology has the potential to reduce waste volume, generate electricity, and produce P-containing ash that can be used for further application on farm lands.
authors.affiliation: Department of Sanitary Engineering, Faculty of Public Health, Mahidol University, Rajvithee Road, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, Bangkok 10400, Thailand. Electronic address: b.thitanuwat@gmail.com.
authors.forename: Bussarakam
authors.initials: B
authors.lastname: Thitanuwat
authors.affiliation: Department of Sanitary Engineering, Faculty of Public Health, Mahidol University, Rajvithee Road, Bangkok 10400, Thailand; Center of Excellence on Environmental Health and Toxicology, Bangkok 10400, Thailand. Electronic address: chongchin.pol@mahidol.ac.th.
authors.forename: Chongchin
authors.initials: C
authors.lastname: Polprasert
authors.affiliation: Department of Global Environmental Health Sciences, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112, USA. Electronic address: aenglan@tulane.edu.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Englande
keywords: Food consumption; Human excreta; Landfill; Phosphorus recovery; Urban wastes; Wastewater treatment