Cost-effectiveness of nitrogen mitigation by alternative household wastewater management technologies

JOURNAL OF ENVIRONMENTAL MANAGEMENT

卷:150

Article

Wood, Alison¹  Blackhurst, Michael²  Hawkins, Troy³  Xue, Xiaobo³  Ashbolt, Nicholas⁴  Garland, Jay⁵ 

[1] Univ Texas Austin, Dept Civil Architectural & Environm Engn, Austin, TX 78712 USA

[2] Univ Texas Austin, Austin, TX 78712 USA

[3] US EPA, Off Res & Dev, Natl Risk Management Res Lab, Cincinnati, OH 45268 USA

[4] US EPA, Off Res & Dev, Natl Exposure Res Lab, Cincinnati, OH 45268 USA

[5] US EPA, Off Res & Dev, Microbiol & Chem Exposure Assessment Res Div, Cincinnati, OH 45268 USA

关键词: Household wastewater;    Nitrogen;    Compost toilet;    Diversion toilet;    Advanced septic;    Blacicwater digestion;    Cost-effectiveness;   

DOI  :  10.1016/j.jenvman.2014.10.002

来源: Elsevier

【 摘 要 】

Household wastewater, especially from conventional septic systems, is a major contributor to nitrogen pollution. Alternative household wastewater management technologies provide similar sewerage management services but their life cycle costs and nitrogen flow implications remain uncertain. This paper addresses two key questions: (1) what are the total costs, nitrogen mitigation potential, and cost-effectiveness of a range of conventional and alternative municipal wastewater treatment technologies, and (2) what uncertainties influence these outcomes and how can we improve our understanding of these technologies? We estimate a household nitrogen mass balance for various household wastewater treatment systems and combine this mass balance with life cycle cost assessment to calculate the cost-effectiveness of nitrogen mitigation, which we define as nitrogen removed from the local watershed. We apply our methods to Falmouth, MA, where failing septic systems have caused heightened eutrophication in local receiving water bodies. We find that flushing and dry (composting) urine-diversion toilets paired with conventional septic systems for greywater management demonstrate the lowest life cycle cost and highest cost-effectiveness (dollars per kilogram of nitrogen removed from the watershed). Composting toilets are also attractive options in some cases, particularly best-case nitrogen mitigation. Innovative/advanced septic systems designed for high-level nitrogen removal are cost-competitive options for newly constructed homes, except at their most expensive. A centralized wastewater treatment plant is the most expensive and least cost-effective option in all cases. Using a greywater recycling system with any treatment technology increases the cost without adding any nitrogen removal benefits. Sensitivity analysis shows that these results are robust considering a range of cases and uncertainties. (C) 2014 The Authors. Published by Elsevier Ltd.

【 授权许可】

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