The effect of pH and temperature on the isotopic fractionation of boron between saline brine and sediments

The effects of pH and temperature on the adsorption distribution of boron in sediment and the boron isotopic fractionation factor between saline brine and sediment were studied. The results show that the adsorption and isotopic fractionation of boron between saline brine and sediment are similar to that between seawater and marine or pure sediments in a certain pH range. The adsorption distribution factor (Kd) and isotopic fractionation factor ( α) of boron are controlled by the pH of the saline brine. Kd increases with pH, while α decreases. An unusual aspect of this study was that 11B enrichment in the solid was seen during boron adsorption by clay at high pH. These results have been used to study the distribution of boron isotopes in salt lakes of Qaidam Basin.