Source Separation and Decentralization for Wastewater Management

Larsen, Tove A.; Udert, Kai M.; Lienert, Judit

doi:10.2166/9781780401072

Cited by 197 publications

(166 citation statements)

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“…Decentral alternatives to the incumbent centralized wastewater system have been explored for many years [64]. While the centralized structure comprising water-flushed toilets, sewers and wastewater treatment plants certainly has unquestionable benefits, e.g., in terms of hygiene or economies of scale, it also has various disadvantages such as high water consumption, large infrastructure requirements, and a mixture of household and industrial wastewaters hampering resource recovery or contamination of surface waters after the treatment process [5,65,66].…”

Section: Scenario Backgroundmentioning

confidence: 99%

Transition of the Swiss Phosphorus System towards a Circular Economy—Part 2: Socio-Technical Scenarios

Jedelhauser¹,

Mehr

Binder

2018

Sustainability

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Abstract:A transition towards a circular economy of phosphorus (P) in Switzerland is a multi-faceted challenge as P use is subject to a variety of influencing factors comprising policy interventions, consumption trends, or technological innovations on different spatial scales. Therefore, scenarios for P use that take into account both the social and the technical dimension of change are needed for investigating possible pathways of a transition towards more sustainable P futures. Drawing on the multi-level perspective of transition theory, we develop scenarios on the landscape level, i.e., a balanced and healthy human diet, on the regime level, i.e., P recovery from sewage sludge (ash) and meat and bone meal, and on the niche level, i.e., urine separation. Based on the P system of the year 2015, we assess the quantitative implications of the scenarios for the Swiss P system. While scenario 1 mainly affects the agricultural system by reducing the overall P throughput, scenario 2 significantly changes P use in waste management, because P losses to landfills and cement plants decrease and the production of secondary P increases. Scenario 3 shows little quantitative impact on the national P system. From a qualitative transition perspective, however, urine separation entails fundamental socio-technical shifts in the wastewater system, whereas P recovery from sewage sludge (ash) represents an incremental system adaptation. The combination of flow-and transition-oriented research provides more general insights into how a circular economy of P can be reached. Furthermore, the analysis of P recycling scenarios reveals that transition processes in Switzerland are embedded in a global resource economy. Thus, a sole focus on concepts of national P self-sufficiency and the reduction of Switzerland's P import dependency tend to fall short when analysing the economisation of secondary P materials in the face of transnational resource flows and markets.

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Section: Scenario Backgroundmentioning

confidence: 99%

Transition of the Swiss Phosphorus System towards a Circular Economy—Part 2: Socio-Technical Scenarios

Jedelhauser¹,

Mehr

Binder

2018

Sustainability

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“…The high pH and high P levels in stored urine require only the addition of a magnesium source for spontaneous precipitation of struvite. 12 Struvite precipitation has received much attention due to its process simplicity, but the hygienic quality of the end-product generated in field settings has not been thoroughly evaluated. Source-separated urine collected in Durban, for example, contains a diversity of pathogens and high concentrations of locally prescribed pharmaceuticals.…”

Section: ■ Introductionmentioning

confidence: 99%

Bacteria Inactivation during the Drying of Struvite Fertilizers Produced from Stored Urine

Bischel

Schindelholz

Schoger

et al. 2016

Environ. Sci. Technol.

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Human urine can be processed into market-attractive fertilizers like struvite; however, concerns regarding the microbial safety of such products remain. The present study evaluated the inactivation of in situ heterotrophs, total bacteria as observed by flow cytometry, and inoculated Enterococcus spp. and Salmonella typhimurium during the drying of struvite under controlled temperature (from 5 to 35°C) and relative humidity (approximately 40 and 80%) as well as dynamic field conditions. Bacteria accumulated in the struvite cake during struvite filtration. Despite the use of sublethal temperatures, all bacteria types were subsequently inactivated to some degree during struvite drying, and the inactivation typically increased with increasing drying temperature for a given relative humidity. Heterotrophic bacteria inactivation mirrored the trend in total bacteria during struvite drying. A linear relationship was observed between inactivation and sample moisture content. However, bacteria survivor curves were typically nonlinear when struvite was dried at low relative humidity, indicating bacterial persistence. Weibull model survivor curve fits indicated that a shift in the mechanism of inactivation may occur with changing humidity. For increased efficiency of bacterial inactivation during the production of struvite, initial heating under moist conditions is recommended followed by desiccation.

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“…It can also contain pharmaceutical and pharmaceutical by-products and in individuals with compromised immune systems, pathogens can be present. Urine contributes 80% of nitrogen, 50% of phosphorus, and half of contaminants of emerging concern (CECs) to municipal wastewater treatment plants (WWTP), but only contributes about 1% of flow by volume (Larsen et al 2013). Reducing the influent urine to municipal WWTP by 70% and 90% can eliminate the need biological phosphorus and nitrogen removal (BPNR), respectively and even small decreases can benefit WWTP (Jimenez et al 2015) Urine in the bladder is sterile in healthy individuals, but may be exposed to normal bacterial flora before fully exiting the body through the distal urethra.…”

Section: Introductionmentioning

confidence: 99%

“…Urine, which contributes 80% of nitrogen, 50% of phosphorus, and half of contaminants of emerging concern (CECs) to municipal WWTP, only contributes about 1% of flow by volume (Larsen et al 2013). Therefore meeting effluent nutrient limits determined by the Environmental Protection Agency's (EPA) National Pollutant Discharge Elimination System can be aided by source-separation and alternative treatment of urine.…”

mentioning

confidence: 99%

Struvite Recovery From Source-Separated Urine Utilizing Fluidized Bed Technology

Gagnon¹

2016

proc water environ fed

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Source-separating urine for nutrient recovery may provide multiple benefits with regards to wastewater management, water conservation, and an impending phosphorus fertilizer shortage. Municipal wastewater systems are designed to treat the combination of urine, feces and graywater produced in household applications. Urine accounts for 1% of wastewater by volume, but provides 70-90% of nitrogen, 35-70% of phosphorus and 50% of the contaminants of emerging concern entering municipal wastewater treatment (Larsen and Gujer 1996). Research has shown managing source-separated urine for nutrient recovery is a more cost effective and less treatment intensive method than using traditional systems found in municipal wastewater plants.Phosphorus fertilizer shortages are projected as current sources diminish and become increasingly difficult to extract and refine. Phosphorus based-fertilizer recovery, in the form of 99.9% pure struvite also known as magnesium ammonium phosphate (MgNH 4 PO 4 •6H 2 O), has been demonstrated successfully in full-scale sidestream treatment using dewatering liquor from anaerobically digested solids (centrate) processed through upflow fluidized bed reactor technologies (Britton et al. 2005). Prior research determined the influence of pH, magnesium to phosphorus (Mg:P) molar ratio, and age of urine on purity, pharmaceutical content and pathogen inclusion in struvite precipitated from source-separated urine. This is the first known example of an attempt to produce a commercially viable struvite product from source-separated urine in a fluidized bed reactor of a design that has been used successfully for struvite recovery in conventional wastewater applications.In order to assess the feasibility of nutrient recovery of phosphorus-based fertilizer recovery from source-separated urine, the first office-based urine separation and collection building was implemented in the U.S. Urine was collected, in a 400 gallon capacity underground sealed manhole, from HRSD's Main office building beginning in March 2015 from five men's waterless urinals and one women's separating toilet. Urine was collected from the manhole on a monthly basis in 275 and 330 gallon plastic totes stored at the HRSD Nansemond WWTP in Suffolk, VA. Collected urine was allowed to age while in storage to encourage the precipitation of excess multivalent cations that may interfere with struvite precipitation and inactivation of pathogens that may be present.An upflow fluidized bed reactor (UFBR) was used to precipitate and recover struvite as slowrelease phosphorus based fertilizer (prill); the reactor was loaned to Hampton Roads Sanitation iii District by the University of British Columbia. A magnesium solution was injected at the bottom of the reactor to facilitate precipitation along with the recycle urine stream and feed urine. Prill production design for the reactor was 0.5 kilograms per day, but while using centrate to determine best operations practices, under loading the reactor to 0.25 kilograms per day maximized struvite rec...

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Source Separation and Decentralization for Wastewater Management

Cited by 197 publications

References 1 publication

Transition of the Swiss Phosphorus System towards a Circular Economy—Part 2: Socio-Technical Scenarios

Transition of the Swiss Phosphorus System towards a Circular Economy—Part 2: Socio-Technical Scenarios

Bacteria Inactivation during the Drying of Struvite Fertilizers Produced from Stored Urine

Struvite Recovery From Source-Separated Urine Utilizing Fluidized Bed Technology

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