A complete nitrogen mass balance for all wastewater generated in the Central Arizona-Phoenix ecosystem was developed using data from the 18 largest wastewater treatment plants (99% of flow). Components included total N in raw wastewater, denitrification in wastewater treatment plants, biosolids production, and effluent (reuse, recharge, and discharge). Denitrification and biosolids production remove 81% of wastewater N. Nearly all biosolids are recycled to cotton fields within the ecosystem. Most effluent is recycled within the ecosystem. As the result of wastewater management practices developed to reuse wastewater, wastewater N is either deliberately volatilized or accumulates within the system; only 4% of the original wastewater N is exported via the Gila River. Copyright (C) 2000 Elsevier Science Ltd.
Bibliographical noteFunding Information:
This project was supported by the Women in Science and Engineering (WISE) program and the NSF-supported Central Arizona-Phoenix Long Term Ecological Research (CAP-LTER) project. We would like to thank the many individuals who provided interviews on various aspects of this project, including: Tom Whitmer, Arizona Department of Water Resources; Stan Ashby, Roosevelt Irrigation District; Bill Todd, Ocotillo Golf Course; Mike Palermo, Ocotillo Management Group; Jerry Garner, farmer; Steve Miller, farmer; Randy Butler, Palo Verde nuclear generating station; and the many treatment plant operators who provided data regarding their plants’ operations.
- Nitrogen mass balance