Sulfate Retention by Acid Sulfate-Polluted Soils in the Copper Basin Area of Tennessee1
- J. D. Wolt2
The stability of the Al-hydroxy-sulfates, alunite and basaluminite, was investigated as a possible mechanism for sulfate retention by acid sulfate-polluted soils within the Copper Basin area of Tennessee. Representative soils were described and sampled from sites reflecting varied but unknown levels of S input and were subsequently analyzed for total and extractable S contents and soil solution composition. Although in general agreement with an adsorptive mechanism, the retention of sulfate was best explained as the consequence of Al-hydroxy-sulfate solubility. The ion activity product p(K)(Al)3(OH)6(SO4)2 compared favorably to the pKsp of alunite for the majority of displaced soil solutions. When pertinent soil-solution ion activities were expressed as a function of [pAl + 3pOH] and [pAl + pOH + pSO4], most soil solutions indicated apparent stability of solid-phase alunite. The possible existence of alunite in acid sulfate soils is compatible with mechanisms of sulfate retention by acid soils.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .