The use of power plant fly ashes for removal of arsenic from wastewaters

In this study, adsorption of As(V) from wastewaters onto different power plant fly ashes having different physical and chemical properties, obtained from Afşin-Elbistan, Seyitömer and Soma, was examined as a function of initial pH, contact time and adsorbent concentration. Effectiveness of fly ash was compared with a commercial activated carbon. In addition, obtained data were corrected using the linear form of Langmuir and Freundlich equations.Experimental data showed that optimum pH for Afşin-Elbistan, Soma fly ashes and activated carbon was 6, for Seyitömer fly ash was 5 for the highest adsorption of As(V). The equilibrium conditions were reached about 7 hour shaking time at optimum pH for all adsorbents.The maximum arsenic removal for all fly ash types (Afşin-Elbistan, Seyitömer, Soma) and activated carbon was found 71%, 74%, 80% and 87%, respectively. The adsorption data were better fitted to the Langmuir isotherm since the correlation coefficients for Langmuir isotherm were higher than that for the Freundlich isotherm.