ADSORPTION OF ARSENIC IN AQUEOUS AND SOLID PHASE BY WASTE-RECLAIMED TREATMENT AGENT IN ABANDONED MINE: BATCH AND FIELD STUDIES

The potential of three different waste-reclaimed treatment agents (WRTAs) for removing arsenic was evaluated by laboratory batch scale, column experiments and field tests. WRTA1 was synthesized using acid mine drainage sludge (AMDS), cement and sand. WRTA2 and WRTA3 were synthesized by adding fly ash or Ca(OH)₂, respectively, based on WRTA1. The maximum adsorption capacity of WRTA1, 2 and 3 for As(III) using Langmuir model were 16.6, 14.5, and 20.6 mg g^-1, respectively, and for As(V) were 29.6, 27.3, and 31.3 mg g^-1, respectively. The pseudo-second order equation for adsorption of As(III) and As(V) fitted the kinetics data well model. The column study showed that WRTA are very effective adsorbents, which exhibited >80 % removal of As from the contaminated soil. The inhibition of As accumulation in plants (i.e., rice, chili and sesame) by WRTAs was evaluated, which showed 96% inhibition in As accumulation in chili roots by WRTA2. The suggested WRTAs is a promising agent for the removal of As and heavy metals from the heavily contaminated agricultural soil.