title: Long-term impact of primary domestic sewage on metal/loid accumulation in drainage ditch sediments, plants and water: Implications for phytoremediation and restoration.
abstract: We evaluate the long-term performance of a vegetated drainage ditch (VDD) treating domestic sewage with respect to heavy metal/metalloid (HM/M) accumulation in sediments, plants and water. VDD sediment contained significantly higher macro and trace elements compared to an agricultural ditch (AD) sediment. However, concentrations of HM/Ms in VDD sediment were below the ranges considered toxic to plants. Most HM/Ms were efficiently removed in the VDD, whereby removal efficiencies varied between 11% for Al and 89% for K. Accumulation of HM/Ms varied among species and plant parts, although sequestration by plants represents only a small proportion (<1%) of the inflow load. Accumulation of Al, As, Cd, Pb, Cr, Fe and Ni in VDD plants were mostly distributed in the roots, indicating an exclusive strategy for metal tolerance. The opposite was found for Zn, Cu, K, Ca, P, K, Na, N and Mg, which were accumulated either in the stems or leaves. Overall, concentrations of metals in sediment showed significant positive correlations with those in ditch plants. None of the studied species were identified as metal hyper-accumulators (i.e. >10,000mgkg-1of Zn or Mn). Nevertheless, the high translocation factor (TF) values for Mn, Ni, Cu, Zn, Na, Mg, P, K and Ca in the ditch plants make them suitable for phytoextraction from water/soil, while the low TF values for Pb, Cd, As, Fe, Cr and Al make them suitable for their phytostabilization.
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, 610041 Chengdu, PR China; Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041 Chengdu, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Faculty of Agronomy, Department of Natural Resources and Environmental Management, University of Lubumbashi, PO Box 1825, Democratic Republic of the Congo. Electronic address: kumwimbamatthieu@yahoo.fr.
authors.forename: Mathieu Nsenga
authors.initials: MN
authors.lastname: Kumwimba
authors.affiliation: Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, 610041 Chengdu, PR China; Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041 Chengdu, PR China. Electronic address: bzhu@imde.ac.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors.forename: Fidèle
authors.initials: F
authors.lastname: Suanon
authors.affiliation: School of Life Science and Engineering, Southwest Jiaotong University, Chengdu 610031, PR China.
authors.forename: Diana Kavidia
authors.initials: DK
authors.lastname: Muyembe
authors.affiliation: Key Laboratory of Northwest Water Resources, Environment and Ecology, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Mawuli
authors.initials: M
authors.lastname: Dzakpasu
mesh_terms: D001673:Biodegradation, Environmental; D002681:China; D052918:Environmental Restoration and Remediation; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D010944:Plants / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D012987:Soil; D014867:Water / Q000737:chemistry
chemical_list: D019216:Metals, Heavy; D012722:Sewage; D012987:Soil; D014867:Water
keywords: Ditch plants; Heavy metal and metalloid; Phytoremediation and restoration; Untreated domestic sewage; Vegetated drainage ditch