title: Influence of carbohydrate addition on nitrogen transformations and greenhouse gas emissions of intensive aquaculture system.
abstract: Aquaculture is one of the fastest-growing segments of the food economy in modern times. It is also being considered as an important source of greenhouse gas (GHG) emissions. To date, limited studies have been conducted on GHG emissions from aquaculture system. In this study, daily addition of fish feed and soluble starch at a carbon-to-nitrogen (C/N) ratio of 16:1 (w/w) was used to examine the effects of carbohydrate addition on nitrogen transformations and GHG emissions in a zero-water exchange intensive aquaculture system. The addition of soluble starch stimulated heterotrophic bacterial growth and denitrification, which led to lower total ammonia nitrogen, nitrite and nitrate concentrations in aqueous phase. About 76.2% of the nitrogen output was emitted in the form of gaseous nitrogen (i.e., N2 and N2O) in the treatment tank (i.e., aquaculture tank with soluble starch addition), while gaseous nitrogen accounted for 33.3% of the nitrogen output in the control tank (i.e., aquaculture tank without soluble starch addition). Although soluble starch addition reduced daily N2O emissions by 83.4%, it resulted in an increase of daily carbon dioxide (CO2) emissions by 91.1%. Overall, starch addition did not contribute to controlling the GHG emissions from the aquaculture system.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-ro 2511, Sejong 339-700, South Korea.
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Earth and Environmental Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA.
authors.forename: Kartik
authors.initials: K
authors.lastname: Chandran
authors.affiliation: Department of Environmental Engineering, College of Science and Technology, Korea University, Sejong-ro 2511, Sejong 339-700, South Korea.
authors.forename: Sungpyo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Advanced Water Management Centre, University of Queensland, St. Lucia, QLD 4072, Australia.
authors.forename: Keshab
authors.initials: K
authors.lastname: Sharma
authors.affiliation: Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822, USA. Electronic address: khanal@hawaii.edu.
authors.forename: Samir Kumar
authors.initials: SK
authors.lastname: Khanal
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis*; D002244:Carbon / Q000032:analysis; D004784:Environmental Monitoring; D017752:Greenhouse Effect; D009584:Nitrogen / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D002241:Carbohydrates; D002244:Carbon; D009584:Nitrogen
keywords: Carbohydrate addition; Greenhouse gases; Intensive aquaculture system; Nitrogen transformations; Nitrous oxide