COLUMN SORPTION OF TOXIC IONS IN VARIOUS QUARTZ SAND - PACKED COLUMNS

Abstract

In this study the adsorption of As(V), Cu(II) and Zn(II) ions from multi-species model solution was tested in dynamic conditions in sand columns containing a thin layer of bentonite (B), iron-based sludge (IS) and synthetic magnetic particles (MP). Adsorption experiments were performed in order to evaluate the removal efficiency and selectivity of the individual layers in the column. The model solution with concentration of 10 mg/L Cu(II), Zn(II) and As(V) ions of each representing the real wastewater concentration was percolated through the columns of different beddings. In columns filled only with QS/B and QS/IS the removal effect for Cu(II) and Zn(II) ions was comparable while for As(V) ions more efficient column was IS bearing. The columns with B/IS and B/MP layer showed opposite effect for removal of individual ions. While IS layer showed higher affinity towards Cu(II) and Zn(II) the MP layer enhanced the removal of As(V). The highest removal effect for all ions was obtained by QS/B/MP column. For As(V) the removal effect achieved 90 % after 4 percolation cycles. After the third percolation cycle the removal effect of QS/B/IS column decreased from 100% to 58, 90 and 77 %, for As(V), Cu(II) and Zn(II) ions, respectively. By repeating of the percolation cycles the removal of As(V) by QS/B/MP column slight decreased, up to 90 % after four runs. In spite that after the third cycle almost 100 % of As(V) was removed. For Cu(II) and Zn(II) the decrease from 100 % to 76 and 62 % was detected after four cycles, respectively.