Please use this identifier to cite or link to this item:
Title: Modeling decentralized source-separation systems for urban waste management
Authors: Chang, Victor Wei-Chung
Stegmann, Rainer
Wang, Jing-Yuan
Ng, Bernard Jia Han
Giannis, Apostolos
Issue Date: 2012
Source: Ng, B. J. H., Giannis, A., Chang, V. W. C., Stegmann, R., & Wang, J.-Y. (2012). Modeling Decentralized Source-Separation Systems for Urban Waste Management. International Journal of Engineering and Applied Sciences, 6, 283-287.
Series/Report no.: International journal of engineering and applied sciences
Abstract: Decentralized eco-sanitation system is a promising and sustainable mode comparing to the century-old centralized conventional sanitation system. The decentralized concept relies on an environmentally and economically sound management of water, nutrient and energy fluxes. Source-separation systems for urban waste management collect different solid waste and wastewater streams separately to facilitate the recovery of valuable resources from wastewater (energy, nutrients). A resource recovery centre constituted for 20,000 people will act as the functional unit for the treatment of urban waste of a high-density population community, like Singapore. The decentralized system includes urine treatment, faeces and food waste co-digestion, and horticultural waste and organic fraction of municipal solid waste treatment in composting plants. A design model is developed to estimate the input and output in terms of materials and energy. The inputs of urine (yellow water, YW) and faeces (brown water, BW) are calculated by considering the daily mean production of urine and faeces by humans and the water consumption of no-mix vacuum toilet (0.2 and 1 L flushing water for urine and faeces, respectively). The food waste (FW) production is estimated to be 150 g wet weight/person/day. The YW is collected and discharged by gravity into tank. It was found that two days are required for urine hydrolysis and struvite precipitation. The maximum nitrogen (N) and phosphorus (P) recovery are 150-266 kg/day and 20-70 kg/day, respectively. In contrast, BW and FW are mixed for co-digestion in a thermophilic acidification tank and later a decentralized/centralized methanogenic reactor is used for biogas production. It is determined that 6.16-15.67 m3/h methane is produced which is equivalent to 0.07-0.19 kWh/ca/day. The digestion residues are treated with horticultural waste and organic fraction of municipal waste in co-composting plants.
ISSN: 2010-3980
Rights: © 2012 World Academy of Science, Engineering and Technology. This is the author created version of a work that has been peer reviewed and accepted for publication by International journal of engineering and applied sciences, World Academy of Science, Engineering and Technology. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at official URL: [
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:CEE Journal Articles
NEWRI Journal Articles

Files in This Item:
File Description SizeFormat 
Modeling Decentralized Source-Separation Systems for Urban Waste Management.pdf590.51 kBAdobe PDFThumbnail

Google ScholarTM


Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.