title: Calcium water treatment residue reduces copper phytotoxicity in contaminated sandy soils.
abstract: Calcium water treatment residue (Ca-WTR), an industrial by-product, was found to be effective in decreasing Cu availability in contaminated soils and transport to the environment. In this study, a greenhouse study was conducted to test the ability of Ca-WTR to reduce the toxicity and uptake of Cu by ryegrass (Lolium perenne L.) and lettuce (Lactuca sativa L.) as indicator crop plants in Cu-contaminated sandy soils. Eight weeks growing period was observed in Alfisol and Spodosol amended with different levels of Ca-WTR (5-100 g kg(-1) soil). Plant biomass yields increased with WTR application rates at the low levels (5-20 g kg(-1) for Alfisol, pH 5.45 and 5-50 g kg(-1) for Spodosol, pH 4.66), and decreased at the high levels (>20 g kg(-1) for Alfisol and >50 g kg(-1) for Spodosol). The maximum growth of ryegrass with Ca-WTR was 133% and 149% of the control (without Ca-WTR) for the original Alfisol and Spodosol (without spiked Cu), respectively, while the corresponding values for lettuce was 145% and 206%. Copper concentrations in ryegrass shoots decreased significantly with increasing Ca-WTR application rates. For lettuce, Cu concentration decreased only at high Ca-WTR rates (>50 g kg(-1)). In addition, ryegrass had a greater potential for Cu uptake and translocation than lettuce in both soils.
authors.affiliation: Indian River Research and Education Center, Institute of Food and Agricultural Sciences, University of Florida, Fort Pierce, FL 34945, USA.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Fan
authors.forename: Zhenli
authors.initials: Z
authors.lastname: He
authors.forename: Lena Q
authors.initials: LQ
authors.lastname: Ma
authors.forename: Thiago A R
authors.initials: TA
authors.lastname: Nogueira
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhanbei
authors.initials: Z
authors.lastname: Liang
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stoffella
mesh_terms: D018533:Biomass; D002118:Calcium / Q000737:chemistry*; D003300:Copper / Q000032:analysis / Q000633:toxicity*; D010944:Plants / Q000737:chemistry / Q000187:drug effects*; D012989:Soil Pollutants / Q000032:analysis / Q000633:toxicity*; D014867:Water / Q000737:chemistry*
chemical_list: D012989:Soil Pollutants; D014867:Water; D003300:Copper; D002118:Calcium