Stability In Seawater Research Articles

Stability and microtox response of butenyltin compounds

AbstractTributenyltin bromides containing double bonds at carbon atoms C‐1, C‐2 or C‐3 were synthesized from symmetrical tetrabutenyltins. Although all three tetrabutenyltin compounds were stable, only the tributenyltin bromides with double bonds at C‐1 and C‐3 were sufficiently stable for further studies. In aqueous sodium bromide (NaBr) solution containing 1% acetone, tri‐1‐butenyltin bromide was more stable in sunlight than tri‐3‐butenyltin bromide, yet neither compound was as stable as tributyltin bromide. Stability in seawater, in the absence of ultraviolet (UV) light, was less for both tri‐1‐butenyltin bromide and tri‐3‐butenyltin bromide than for tributyltin bromide. The relative toxicities of the tributenyltin bromides were determined using a bioluminescent bacteria assay. The concentrations of tributenyltin bromides necessary to produce a toxic response were three to six times greater than for tributyltin bromide.

A Comparative Experimental Study of Glass Stability in Seawater and Distilled Water

AbstractBoth PNL76−68 and ABS-118 glasses show greater stability in seawater (SW) than in distilled and deionized water (DDW), in the MCC-1 90°C corrosion test. After 180 days of corrosion, the boron release from PNL76- 68 and ABS-118 glasses is about five and two times lower respectively in SW than in DDW. Seawater leachates show less increase in pH than DDW leachates. Glass corroded in SW shows little or no total weight loss. Significant amounts of Mg from SW have been added to the surface layers of both types of glass. Mg-silicates were found in surface layers formed in SW, whereas Zn- and Fe-silicates in surface layers formed in DDW. Shortterm leaching tests in D2O, NaCl and MgCl2 solutions suggested that high salt content in leachant can impede glass hydration. Both silica saturation and Mg diffusion may be responsible for greater stability of the glasses in SW than in DDW.

Development of Sorbers for the Recovery of Uranium from Seawater. 1. Assessment of Key Parameters and Screening Studies of Sorber Materials

Abstract At an average uranium content of 3.3 ppb the oceans can be considered as a very low-grade but practically unlimited source of uranium. Some essential chemical aspects of a large-scale sorptive recovery of uranium from seawater are discussed with special emphasis on required sorber properties such as high physical and chemical stability in seawater, fast and selective uptake of uranium, as well as a sufficient loading capacity. Systematic screening tests, including about 200 sorber materials on the basis of organic ion-exchange resins, identified cross-linked poly(acrylamidoximes) as the most promising candidate sorbers. Their uranium uptake closely approaches the uranium content of actually explored uranium ores.