title: Striking the balance between nutrient removal, greenhouse gas emissions, receiving water quality, and costs.
abstract: This Water Environment Research Foundation study considered the relationship between varying nutrient-removal levels at wastewater treatment plants, greenhouse gas emissions, receiving water quality (measured by potential algal production), and costs. The effluent nutrient concentrations required by some U.S. permits are very low, approaching the technology-best-achievable performance. This study evaluated five different treatment levels at a nominal 40 ML/d (10 mgd) flow. Greenhouse gas emissions and costs increase gradually up to the technologies' best-achievable performance, after which they increase exponentially. The gradual increase is attributed to additional biological treatment facilities, increased energy and chemical use, and additional tertiary nitrogen and phosphorus removal processes. Within the limited focus of this study, the evaluation shows that a point of diminishing return is reached as nutrient-removal objectives approach the technology-best-achievable performance, where greenhouse gas emissions and cost of treatment increases rapidly while the potential for algal growth reduce marginally.
authors.affiliation: HDR Engineering, Folsom, CA 95630, USA. Michael.Falk@hdrinc.com
authors.forename: Michael W
authors.initials: MW
authors.lastname: Falk
authors.affiliation: HDR Engineering, Folsom, CA 95630, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Reardon
authors.affiliation: HDR Engineering, Folsom, CA 95630, USA.
authors.forename: J B
authors.initials: JB
authors.lastname: Neethling
authors.affiliation: HDR Engineering, Boise, ID 83706, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Clark
authors.affiliation: Water Environment Research Foundation, Alexandria, VA 22314, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Pramanik
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*; D060753:Water Quality
chemical_list: D002245:Carbon Dioxide; D010758:Phosphorus; D009584:Nitrogen