Effect of available nitrogen on phytoavailability and bioaccumulation of hexavalent and trivalent chromium in hankow willows (Salix matsudana Koidz)

TY - JOUR

T1 - Effect of available nitrogen on phytoavailability and bioaccumulation of hexavalent and trivalent chromium in hankow willows (Salix matsudana Koidz)

AU - Yu, Xiao Zhang

AU - Gu, Ji Dong

N1 - Funding Information: This work was supported by a Ph.D. studentship from The University of Hong Kong. We thank Tian-Peng Li and Li-Qun Xing for their technical assistance.

PY - 2008/6

Y1 - 2008/6

N2 - The effect of available nitrogen in nutrient solution on removal of two chemical forms of chromium (Cr) by plants was investigated. Pre-rooted hankow willows (Salix matsudana Koidz) were grown in a hydroponic solution system with or without nitrogen, and amended with hexavalent chromium [Cr (VI)] or trivalent chromium [Cr (III)] at 25.0±0.5 °C for 192 h. The results revealed that higher removal of Cr by plants was achieved from the hydroponic solutions without any nitrogen than those containing nitrogen. Although faster removal of Cr (VI) than Cr (III) was observed, translocation of Cr (III) within plant materials was more efficient than Cr (VI). Substantial difference existed in the distribution of Cr in different parts of plant tissues due to the nitrogen in nutrient solutions (p<0.05): lower stems were the major sink for both Cr species in willows grown in the N-free nutrient solutions and more Cr was accumulated in the roots of plants in N-containing ones. No significant difference was found in the removal rate of Cr (VI) between willows grown in the N-free and N-containing solutions (p>0.05). Removal rates of Cr (III) decreased linearly with the strength of nutrient solutions with or without N addition (p<0.01). Translocation efficiencies of both Cr species increased proportionally with the strength of N-containing nutrient solutions and decreased with the strength of N-free nutrient solutions. Results suggest that uptake and translocation mechanisms of Cr (VI) and Cr (III) are apparently different in hankow willows. The presence of easily available nitrogen and other nutrient elements in the nutrient solutions had a more pronounced influence on the uptake of Cr (III) than Cr (VI). Nitrogen availability and quantities in the ambient environment will affect the translocation of both Cr species and their distribution in willows in phytoremediation.

AB - The effect of available nitrogen in nutrient solution on removal of two chemical forms of chromium (Cr) by plants was investigated. Pre-rooted hankow willows (Salix matsudana Koidz) were grown in a hydroponic solution system with or without nitrogen, and amended with hexavalent chromium [Cr (VI)] or trivalent chromium [Cr (III)] at 25.0±0.5 °C for 192 h. The results revealed that higher removal of Cr by plants was achieved from the hydroponic solutions without any nitrogen than those containing nitrogen. Although faster removal of Cr (VI) than Cr (III) was observed, translocation of Cr (III) within plant materials was more efficient than Cr (VI). Substantial difference existed in the distribution of Cr in different parts of plant tissues due to the nitrogen in nutrient solutions (p<0.05): lower stems were the major sink for both Cr species in willows grown in the N-free nutrient solutions and more Cr was accumulated in the roots of plants in N-containing ones. No significant difference was found in the removal rate of Cr (VI) between willows grown in the N-free and N-containing solutions (p>0.05). Removal rates of Cr (III) decreased linearly with the strength of nutrient solutions with or without N addition (p<0.01). Translocation efficiencies of both Cr species increased proportionally with the strength of N-containing nutrient solutions and decreased with the strength of N-free nutrient solutions. Results suggest that uptake and translocation mechanisms of Cr (VI) and Cr (III) are apparently different in hankow willows. The presence of easily available nitrogen and other nutrient elements in the nutrient solutions had a more pronounced influence on the uptake of Cr (III) than Cr (VI). Nitrogen availability and quantities in the ambient environment will affect the translocation of both Cr species and their distribution in willows in phytoremediation.

KW - Accumulation

KW - Chromium

KW - Translocation

KW - Uptake

KW - Willows

UR - http://www.scopus.com/inward/record.url?scp=42049103655&partnerID=8YFLogxK

U2 - 10.1016/j.ecoenv.2007.11.010

DO - 10.1016/j.ecoenv.2007.11.010

M3 - 文章

C2 - 18192014

AN - SCOPUS:42049103655

SN - 0147-6513

VL - 70

SP - 216

EP - 222

JO - Ecotoxicology and Environmental Safety

JF - Ecotoxicology and Environmental Safety

IS - 2

ER -