Sp. Bi et al., Modeling the distribution of aluminum speciation in acid soil solution equilibria with the mineral phase alunite, ENVIR GEOL, 41(1-2), 2001, pp. 25-36
This paper reports the modeling of the distribution of aluminum (Al) specia
tion in acid soil solution equilibria with the mineral phase alunite. It is
based on thermodynamic calculation using Turbo C++ language to write the c
omputer program. Dependence of distribution of Al speciation on pH was inve
stigated, including Al3+, Al(OH)(2+), Al(OH)(2)(+), Al(OH)(4)(-), Al-F, Al-
SO4, Al-Org, Al-PO4, and Al-ploy, as well as total Al concentrations. Influ
ences of the various factors such as C*(SO4), C*(K), C*(F), and DOC (dissol
ved organic carbon) on Al speciation were also inspected. Comparisons with
gibbsite and other Al oxysulfate minerals such as jurbanite/basaluminite we
re performed. Some unique characteristics were discovered: for example, the
SO42- concentration has a remarkable influence on the distribution of Al s
peciation, and the toxicity of Al is not a major factor in the soil solutio
ns' equilibria with alunite. Results for application to the practical analy
sis of Al speciation in real soil solutions are reported.