Effect of biogenic iron species and copper ions on the reduction of carbon tetrachloride under iron-reducing conditions

Chemosphere ◽  
2008 ◽  
Vol 70 (8) ◽  
pp. 1405-1413 ◽  
Author(s):  
R.A. Maithreepala ◽  
Ruey-an Doong
2004 ◽  
Vol 50 (8) ◽  
pp. 161-168 ◽  
Author(s):  
R.A. Maithreepala ◽  
R.-A. Doong

The effect of Cu(II) ion on the dechlorination of carbon tetrachloride (CT) by Fe(II) associated with various iron oxides was investigated. Iron oxides including goethite, hematite, ferrihydrite and magnetite were selected as the model compounds. CT was dechlorinated to chloroform (CF) by 3 mM Fe(II) in iron oxide suspensions at pH 7.2. The dechlorination followed pseudo first-order kinetics and the pseudo firstorder rate constants (kobs) were 0.048 h−1, 0.0836 h−1, 0.0609 h−1 and 0.0144 h-1 in goethite-, hematite-, ferrihydrite- and magnetite-amended systems, respectively. Addition of Cu(II) into systems increased the kobs for CT dechlorination significantly. A 3- to 120-fold increase in kobs relative to the systems without Cu(II) was observed when 0.5 mM Cu(II) was added to the Fe(II)-Fe(III) suspensions. The pH of the system is an important factor controlling the dechlorination rate of CT. The increase in concentrations of Fe(II) and iron oxides also enhanced the dechlorination efficiency and rate of CT. Moreover, a linear relationship between the kobs and Cu(II) concentration ranging between 0 and 0.4 mM was observed. Results obtained demonstrate the feasibility of using surface-bound iron species with Cu(II) for the detoxification of chlorinated solvents in the contaminated aquifers.


2007 ◽  
Vol 20-21 ◽  
pp. 631-634
Author(s):  
Alena Luptakova ◽  
E. Macingova

Biogenic iron sulphides are excellent adsorbents for various heavy metals ions. Consequently, they have practical application for the elimination of heavy metals from waste waters. One of the principles for the iron sulphides preparation is the application of sulphatereducing bacteria. This biological-chemical method is based on the ability of these bacteria to reduce sulphates to hydrogen sulphide, which binds with the ferrous cations to form insoluble precipitates – iron sulphides. Under certain bacterial growth conditions biogenic iron sulphides can be magnetic. The aim of this work is to study the possibility of using SRB for the preparation of iron sulphides, which were used subsequently in the framework of sorption tests to eliminate copper ions from model solutions.


2000 ◽  
Vol 87 (5) ◽  
pp. 229-233 ◽  
Author(s):  
Beatrice Arosio ◽  
Nicoletta Gagliano ◽  
Lorena Maria Pia Fusaro ◽  
Luciano Parmeggiani ◽  
Jacopo Tagliabue ◽  
...  

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