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Mô tả chi tiết
Optimized sequential extraction arsenic in
sediment and Application for evaluating
mobilization of arsenic from sediment
into groundwater
Nguyen Thi Thu Trang
Hanoi University of Science, VNU
Major: Analytical Chemistry; Code: 60.44.29.
Supervisors: Pham Hung Viet, Prof. PhD
Date of Presenting Thesis: 2011
Abstract. - Optimized time of sequential extraction arsenic in sediment, experiments
performed in closed systems with five extractants.
- Carried out experiment at different time of optimal process : 0.167h; 0.33h; 0.66h; 1h;
2h; 3h; 6h; 12h;18h;24h. Carried out at 6h for extraction and application of extraction
with five sediment samples.
Table 1.Sequential extraction scheme for sediments
Target Extractants Concentration pH
RRS
(g:ml)
(g:mL)
Analysis
Nonspecifically
bound NaHCO3 0.5M 8.5 1:10 Fe(II), As(III)
As(V),PO4
Solubility
acid HCOOH 0.5M 3 1:10
Fe tổng,
Fe(II),As(III),
As(V)
Active Iron
– bound As Ascorbic 0.1M 3 1:10 Fe tổng,
Fe(II),As(III),As(V)
Crystalline
Fe and
oxides
bound As
Đệm NH4-
oxalate +
axit ascorbic
0.2 M NH4
oxalate + 0.1M
ascorbic
3 1:10 Fe, As
As in
Sulfides
minerals
HNO3 (65%) Digestion 1:10 Fe, As