Application of AMDS mortar as a treatment agent for arsenic in subsurface environment
Tuesday, 16 December 2014
Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.