Phytoremediation of Cr(III) by Ipomonea aquatica (water spinach) from water in the presence of EDTA and chloride: effects of Cr speciation.
Wastewater is often co-contaminated with chromium, chelating agents, and chloride. Influences of Cr(3+) speciation on Cr phytoremediation by Ipomonea aquatica were investigated. MINEQL+ was employed to estimate Cr speciation. Statistic regression was used to investigate the relationships between Cr speciation and accumulation. I. aquatica accumulated high Cr concentration (13,217 mg kg(-1)) in the root at Cr(3+) of 10 mg l(-1) and EDTA of 10(-4) M after 14 d growth. Pearson correlation analysis indicates that root Cr concentration significantly correlated with Cr-EDTA speciation (r = 0.67, p < 0.05) and Cr-Cl speciation (r = 0.91, p < 0.01). Shoot Cr concentration also significantly correlated with Cr-Cl speciation (r = 0.97, p < 0.01). An increase in Cl(-) concentration to 1.72 x 10(-4) M enhanced root Cr concentration; however, the accumulation of root Cr was inhibited at high Cl(-) concentration (5.76 x 10(-5) M). Microscopic image showed that a high portion of Cr(3+) accumulated on the root surface.
Chen
Jung-Chun
JC
Department of Soil and Water Conservation, National Chung-Hsing University, Taichung 402, Taiwan, ROC.
Wang
Kai-Sung
KS
Chen
Hsien
H
Lu
Chi-Yuan
CY
Huang
Lung-Chiu
LC
Li
Heng-Ching
HC
Peng
Tzu-Huan
TH
Chang
Shih-Hsien
SH
D001673:Biodegradation, Environmental / Q000187:drug effects; D002712:Chlorides / Q000737:chemistry* / Q000494:pharmacology; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D004492:Edetic Acid / Q000737:chemistry* / Q000494:pharmacology; D027741:Ipomoea / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012044:Regression Analysis; D012995:Solubility / Q000187:drug effects; D012996:Solutions; D014867:Water / Q000378:metabolism*
D002712:Chlorides; D012996:Solutions; D014867:Water; D002857:Chromium; D004492:Edetic Acid