Thermally treated aluminium waste-filings, a low cost and efficient adsorbent for phosphorus removal from water

A facile strategy toward modification of aluminium filings (AF), a waste material from aluminium manufacturing industry, into a highly efficient adsorbent was examined. AF was simply treated with thermal modification to form a cheap adsorbent for Phosphorus (P) removal from aqueous solutions. The results showed that increasing the calcination temperature from 500 to 900 ˚C improved the P removal. P adsorption occurred quite fast and 70% of P removal observed in 15 minutes. Adsorption efficiency was increased by increasing pH, decreasing P initial concentration as well. The presence of coexisting anions, except HCO3-, showed a negligible effect on P adsorption by AF. Thermodynamic studies revealed that P adsorption onto AF was endothermic in nature. Kinetic modelling demonstrated that the adsorption rate was controlled by the chemisorption. The process also fitted well with the Langmuir isotherm model, indicating that the process proceeds via monolayer coverage with 49.97 mg g-1 maximum monolayer capacity. Overall, in addition to beneficial environmental and economic aspects, the results demonstrated excellent adsorption characteristics which make thermally treated AF a promising adsorbent material for phosphorus removal from polluted streams.