somayeh hosseinpoor

One of the best methods for managing coal wastes to prevent their accumulation in nature and reduce environmental pollution is their application as the sorbents of pollutants. The objective of this study was to investigate the capability and behavior of the coal wastes in three forms of pristine powder (cp), nanoparticles (cnp) and FeCl3 modified nanoparticles (mcnp) for phosphorous (P) sorption from aqueous solution. Characterization of the sorbents was carried out using XRD, SEM-EDS and FTIR analyses. Equilibrium sorption experiments were done in batch systems and the effects of pH, initial P concentration and contact time were studied. The results showed that the P sorption process was pH dependent and the maximum P sorption occurred at 2-6 pH ranges. The maximum P removal efficiency of the sorbents obtained in the range of 0-50 mg/L of initial P concentration and it was increased with time and reached equilibrium after 2 hours. The P removal efficiencies of the sorbents were determined to be 3.3, 18 and 78.8 % for cp, cnp and mcnp, respectively. The pseudo-first and pseudo-second order kinetic models and Langmuir isotherm described the P sorption data well. The maximum P sorption capacities were calculated to be 0.37, 3.97 and 30.39 mg/g for cp, cnp and mcnp, respectively. Results revealed that the modified coal wastes have the potential to use as cost-effective and environmental-friendly sorbents.