The phenomenology and the mathematical modeling of the silicone-supported chemical oxidation of aqueous sulfide to elemental sulfur by ferric sulphate
✍ Scribed by Andy de Smul; Willy Verstraete
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1999
- Tongue
- English
- Weight
- 176 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0268-2575
No coin nor oath required. For personal study only.
✦ Synopsis
When pumping a sul®de solution through a silicone cylinder immersed in a solution of ferric sulfate, a cloud of elemental sulfur is formed in the ferric sulfate if the pH of the sul®de solution is below about 8.5. The elemental sulfur subsequently sediments as orthorhombic a-sulfur particles. H 2 S(aq) diffuses through the pores of the hydrophobic silicone membrane and simultaneously reacts to become sulfur. This was con®rmed by a mass balance between the amount of sul®de removed from the sul®de solution and the amount of solid product formed in the ferric solution. During the experiment, the pH of the non-buffered sul®de solution rises up to a maximum of 8.5; this is explained by the continuous protonation of HS caused by the removal of H 2 S(aq). The pH of the strongly acidic (pH 1.5) ferric sulfate solution hardly decreased. A mathematical model has been developed to quantify the phenomena related to the removal of H 2 S(aq). The model has been succesfully validated with the data of batch experiments. An Arrhenius-like relationship was found between the process temperature and the overall mass transfer coef®cient K. A sul®de oxidation rate of 2.5 g S dm À3 day À1 was predicted for a plug ¯ow reactor. The integration of the novel process with biological sulfate reduction was studied.