title: Nutrient removal efficiency in a rice-straw denitrifying bioreactor.
abstract: Rice straw was used as a carbon source in a denitrifying bioreactor, for the removal of nutrients from agricultural drainage. Nutrient removal efficiency was evaluated by: (a) nutrient loading rates (low, medium, and high); (b) hydraulic retention time, and (c) comparison with another carbon source (woodchip). The results show that concentrations of nitrate nitrogen (NO3(-)-N), ammonia nitrogen (NH4(+)-N), total nitrogen (TN), and orthophosphate phosphorus (PO4(3-)-P) in the rice-straw bioreactor effluents were reduced by 53%, 25%, 40%, and 35%, respectively, compared with influents at the medium nutrient loading rate (NO3(-)-N: 10-15 mg N L(-1), NH4(+)-N: 10-15 mg N L(-1), PO4(3-)-P: 1.0-1.5 mg P L(-1)) and long hydraulic retention time (HRT, 24h), with a corresponding denitrification rate (DR) of 0.40 mg N L(-1)h(-1). Moreover, the rice-straw bioreactor showed significantly higher (p<0.05) nutrient removal efficiency than the woodchip bioreactor at the medium nutrient loading rate and 24h HRT.
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory for Water Pollution Control and Environmental Safety, Zhejiang Province, Hangzhou 310058, China. Electronic address: liang410@zju.edu.cn.
authors.forename: Xinqiang
authors.initials: X
authors.lastname: Liang
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Lin
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ye
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jiatao
authors.initials: J
authors.lastname: Gu
authors.affiliation: Key Laboratory for Water Pollution Control and Environmental Safety, Zhejiang Province, Hangzhou 310058, China.
authors.forename: Zhibo
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Lixian
authors.initials: L
authors.lastname: Xu
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Jin
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Qiukai
authors.initials: Q
authors.lastname: Ru
authors.affiliation: College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Tian
mesh_terms: D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D058440:Denitrification; D005068:Eutrophication; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D014876:Water Pollution / Q000517:prevention & control; D014934:Wood / Q000378:metabolism
chemical_list: D009566:Nitrates; D010710:Phosphates; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
keywords: Agricultural drainage water; Denitrifying bioreactor; Nitrogen and phosphorus removal; Nutrient removal; Rice straw