title: Attempts to improve nitrogen utilization efficiency of aquaponics through nitrifies addition and filler gradation.
abstract: Aquaponics has attracted worldwide attention in recent years and is considered as an alternative technology for conventional aquaculture. In this study, common carp (Cyprinus carpio) and pakchoi (Brassica chinensis) were cultured in lab-scale aquaponics, and attempts were conducted to enhance its nitrogen utilization efficiency (NUE) through two optimization methods, i.e., nitrifies addition (NA) and filler gradation (FG). Results showed that NA and FG could improve the NUE of aquaponics by 8.8 and 16.0%, respectively, compared with control. The total ammonia (TAN) and nitrite (NO2(-)) concentrations in NA and FG systems were maintained at relatively low level (TAN < 0.5 mg/L, NO2(-) < 0.1 mg/L), which demonstrated that both the NA and FG could provide non-toxic water environment for fish culture. Nitrous oxide conversion ratio of the control, NA, and FG were 0.8, 1.2, and 1.7%, respectively, indicating that media-based aquaponics also contributed to global warming. Although the two proposed attempts in this study caused more N2O emission, they made new breakthrough in improving the NUE of aquaponics.
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Yina
authors.initials: Y
authors.lastname: Zou
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China. huzhen885@sdu.edu.cn.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Environmental Research Institute, Shandong University, Jinan, 250100, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Xie
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liang
authors.affiliation: School of City Planning and Environmental Engineering, Shandong Construction University, Jinan, 250100, China.
authors.forename: Jinhe
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Runxin
authors.initials: R
authors.lastname: Yan
mesh_terms: D000641:Ammonia / Q000032:analysis; D000818:Animals; D017756:Aquaculture / Q000379:methods*; D001937:Brassica / Q000254:growth & development* / Q000378:metabolism; D002347:Carps / Q000254:growth & development* / Q000378:metabolism; D005374:Filtration / Q000379:methods*; D058465:Nitrification; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000032:analysis* / Q000378:metabolism; D009609:Nitrous Oxide / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D009573:Nitrites; D000641:Ammonia; D009609:Nitrous Oxide; D009584:Nitrogen
keywords: Aquaponics; N2O emission; Nitrogen utilization efficiency; System optimization