title: Environmental Comparison of Biochar and Activated Carbon for Tertiary Wastewater Treatment.
abstract: Micropollutants in wastewater present environmental and human health challenges. Powdered activated carbon (PAC) can effectively remove organic micropollutants, but PAC production is energy intensive and expensive. Biochar adsorbents can cost less and sequester carbon; however, net benefits depend on biochar production conditions and treatment capabilities. Here, life cycle assessment was used to compare 10 environmental impacts from the production and use of wood biochar, biosolids biochar, and coal-derived PAC to remove sulfamethoxazole from wastewater. Moderate capacity wood biochar had environmental benefits in four categories (smog, global warming, respiratory effects, noncarcinogenics) linked to energy recovery and carbon sequestration, and environmental impacts worse than PAC in two categories (eutrophication, carcinogenics). Low capacity wood biochar had even larger benefits for global warming, respiratory effects, and noncarcinogenics, but exhibited worse impacts than PAC in five categories due to larger biochar dose requirements to reach the treatment objective. Biosolids biochar had the worst relative environmental performance due to energy use for biosolids drying and the need for supplemental adsorbent. Overall, moderate capacity wood biochar is an environmentally superior alternative to coal-based PAC for micropollutant removal from wastewater, and its use can offset a wastewater facility's carbon footprint.
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: Kyle A
authors.initials: KA
authors.lastname: Thompson
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: Kyle K
authors.initials: KK
authors.lastname: Shimabuku
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.|Department of Civil, Construction, and Environmental Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Kearns
authors.affiliation: Department of Civil, Construction, and Environmental Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors.forename: Detlef R U
authors.initials: DRU
authors.lastname: Knappe
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Summers
authors.affiliation: Department of Civil, Environmental, and Architectural Engineering, University of Colorado Boulder , Boulder, Colorado 80309, United States.
authors.forename: Sherri M
authors.initials: SM
authors.lastname: Cook