Electronic International Standard Serial Number (EISSN)
Basaluminite precipitation may play an importantrole in the behavior of trace elements in water and sedimentsaffected by acid mine drainage and acid sulfate soils. In this study,the affinity of basaluminite and schwertmannite for arsenate andselenate is compared, and the coordination geometries of theseoxyanions in both structures are reported. Batch isothermexperiments were conducted to examine the sorption capacity ofsynthetic schwertmannite and basaluminite and the potentialcompetitive effect of sulfate. In addition, synchrotron-basedtechniques such as differential pair distribution function (d-PDF)analysis and extended X-ray absorptionfine structure (EXAFS)were used to determine the local structure of As(V) and Se(VI)complexes. The results show that oxyanion exchange with structuralsulfate was the main mechanism for removal of selenate, whereasarsenate was removed by a combination of surface complexes and oxyanion exchange. The arsenate adsorption capacity ofbasaluminite was 2 times higher than that of schwertmannite and 3 times higher than that of selenate in both phases.