Sediment metal bioavailability in Lake Taihu, China: evaluation of sequential extraction, DGT, and PBET techniques.
The European "Community Bureau of Reference" (BCR) sequential extraction procedure, diffusive gradient in thin-films technique (DGT), and physiologically based extraction test were applied to assess metal bioavailability in sediments of Lake Taihu (n = 13). Findings from the three methods showed that Cd was a significant problem in the western lake whereas Cu, Zn, and Ni pollution was most severe in the northern lake. Results from the sequential extraction revealed that more than 50 % of the Cu and Zn were highly mobile and defined within the extractable fraction (AS1 + FM2 + OS3) in the majority of the sediments, in contrast extractable fractions of Ni and Cd were lower than 50 % in most of the sampling sites. Average Cu, Zn, Ni, and Cd bioaccessibilities were <50 % in the gastric phase. Zn and Cd bioaccessibility in the intestinal phase was ∼50 % lower than the gastric phase while bioaccessibilities of Cu and Ni were 47-57 % greater than the gastric phase. Linear regression analysis between DGT and BCR measurements indicated that the extractable fractions (AS1 + FM2 + OS3) in the reducing environment were the main source of DGT uptake, suggesting that DGT is a good in situ evaluation tool for metal bioavailability in sediments.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, 210023, People's Republic of China.
Jinghua
J
Ren
Paul N
PN
Williams
Jun
J
Luo
Hongrui
H
Ma
Xiaorong
X
Wang
D002104:Cadmium / Q000032:analysis; D002681:China; D003300:Copper / Q000032:analysis; D019015:Geologic Sediments / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry; D009532:Nickel / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality; D015032:Zinc / Q000032:analysis
D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; D009532:Nickel; D015032:Zinc