Batch Sorption Experiments on Recycling Building Waste to Treat Total Iron in Landfill – Leachate

Building waste, namely Concrete Waste (CW), Brick and Mortar Waste (BMW), Flooring Waste (FW), and Roofing Waste (RW), was used as an adsorbent of total iron contained in landfill-leachate. First, kinematic batch sorption experiments were conducted to optimize the contact time, and thereafter adsorption isotherm experiments were conducted to optimize the adsorbent mass. Next, the effects of the initial iron concentration, initial pH of the landfill-leachate and temperature on the removal efficiency of total iron was studied. About 90% removal of total iron was possible in about 12 h, 2 h, 8 h and 8 h for CW, FW, BMW and RW, respectively, under batch test conditions. The maximum adsorption of total iron occurred at adsorbent dosages of 8 g, 10 g, 6 g and 10 g for CW, FW, BMW and RW with the removal efficiencies 99.6%, 97.8%, 97.9% and 95.3%, respectively. The removal efficiency was proportional to the initial total iron concentration and decreased with increase of temperature. The adsorption data follows the Langmuir adsorption isotherm model the best. The adsorption capacity of total iron on CW, BMW, FW and RW were 0.43, 0.84, 0.17 and 0.43 mg/g, respectively.