Desorption of Tributyltin, Dibutyltin and Zinc from Resuspended Sediment

✍ Scribed by N. Watanabe; H. Takatsuki; S. Sakai

• Book ID: 101280236
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 165 KB
• Volume: 11
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/(sici)1099-0739(199704)11:4<273::aid-aoc580>3.0.co;2-q

✦ Synopsis

Adsorption-desorption equilibrium and desorption kinetic studies were conducted in order to assess desorption of tributyltin (TBT), dibutyltin (DBT) and zinc from resuspended sediment. Equilibria were described in terms of linear adsorption. Desorption kinetics were represented by a two-site model which assumed that desorption consisted of rapid desorption and first-order kinetic desorption. TBT desorbed the most easily. Desorption kinetic parameters were related to adsorption mechanisms. Some experimental results did not correspond with the theoretical model. This was thought to be caused by natural organic ligands originally held in the sediment. Zinc deviated the most, because it was affected by the natural organic ligands more strongly than butylins. For example the partition coefficient of zinc varied by up to 1000-fold, and re-adsorption to sediment of the zinc that had been discharged to the water took place. Release of chemicals induced by remedial dredging was assessed. Desorbed TBT may pose a high risk. Among remediation alternatives, capping or leaving the sediment to stand prior to in situ degradation are preferred.