As mobilisation by liming-implications for remedial site management
Since liming is a commonly suggested method for the remeditation of shooting range sites the aim of our work was to investigate the influence of a pH increase in a sesquioxide-rich and an organic-rich shooting range topsoil under special consideration of the valency of the counterion. We conducted batch experiments and increased the pH of the suspensions to ranges between 6 and 7 by adding a monovalent (KOH) or a divalent base (Ca(OH)2). We determined dissolved and colloidal As, Al, Fe, Mn, and Corg concentrations in the filtered (1.2μm) suspensions. Besides, the amount of dispersed colloids, particle charge and size were determined. In the sesquioxide-rich soil, a pH increase lead to a decrease in dissolved As concentrations irrespective of the counterion. Colloid-associated As concentrations increased in the presence of the monovalent cation, whereas the presence of the divalent cation reduced colloid-associated As concentrations. In comparison to monovalent cations, bivalent cations lead to the coagulation of sesquioxides and therefore reduce the quantity of dispersed colloids significantly. In the organic-rich soil, dissolved As concentrations increased with increasing pH in the presence of the monovalent ion and remained constant in the presence of the divalent ion. Colloid-associated As could not be detected in both treatments.
Keywords: Arsenic batch experiment colloid mobilization liming
S. Kltzke F. Lang
Berlin University of Technology, Department of Soil Science, Salzufer 11-12, D-10587 Berlin
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
840-841
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）