title: The forms and bioavailability of phosphorus in integrated vertical flow constructed wetland with earthworms and different substrates.
abstract: A sequential extraction method was utilized to analyze seven forms of P in an integrated vertical-flow constructed wetland (IVFCW) containing earthworms and different substrates. The aluminum-bound P (Al-P) content was found to be lower, and the occluded P (Oc-P) content was higher in the IVFCW. The addition of earthworms into the influent chamber of IVFCW increased the exchange P (Ex-P), iron-bound P (Fe-P), calcium bound P (Ca-P), Oc-P, detritus-bound (De-P) and organic P (Org-P) content in the influent chamber, and also enhanced P content uptake by wetland plants. A significantly positive correlation between P content of above-ground wetland plants and the Ex-P, Fe-P, Oc-P and Org-P content in the rhizosphere was found (P<0.05), which indicated that the Ex-P, Fe-P, Oc-P and Org-P could be bio-available P. The Ex-P, Fe-P, De-P, Oc-P and Ca-P content of the influent chamber was higher where the substrate contained a mixture of Qing sand and river sand rather than only river sand. Also the IVFCW with earthworms and both Qing sand and river sand had a higher removal efficiency of P, which was related to higher P content uptake by wetland plants and P retained in IVFCW. These findings suggest that addition of earthworms in IVFCW increases the bioavailable P content, resulting in enhanced P content uptake by wetland plants.
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China. Electronic address: defuxu1@163.com.
authors.forename: Defu
authors.initials: D
authors.lastname: Xu
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Yingxue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Geography and Environmental Science, University of Reading, Reading RG6 6AB, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Howard
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Yidong
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Jiuhai
authors.initials: J
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing 210044, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
mesh_terms: D000818:Animals; D001682:Biological Availability; D006863:Hydrogen-Ion Concentration; D009835:Oligochaeta / Q000187:drug effects*; D010758:Phosphorus / Q000737:chemistry*; D010944:Plants / Q000378:metabolism; D058441:Rhizosphere; D045483:Rivers; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D014872:Water Movements; D014873:Water Pollutants / Q000032:analysis*; D053833:Wetlands
chemical_list: D012987:Soil; D012989:Soil Pollutants; D014873:Water Pollutants; D010758:Phosphorus
keywords: Bio-available; Eisenia fetida; Phosphorus forms; Substrates