Magnetization Improved Fine Particle Biochar Adsorption of Lead

Biochar can be an alternative sorbent to the high cost activated carbon for wastewater treatment. Its adsorption capacity for heavy metals can be increased by magnetizing it with iron. In this study, we compared the physiochemical properties and sorption capacity of an iron-coated fine empty fruit bunch biochar (IC-EFBB) for Pb with a commercially available activated carbon (AC) and the uncoated fine empty fruit bunch biochar (EFBB). The results revealed that the AC had greater micropores surface area (671.14 m(2) g(-1)), compared to the IC-EFBB (25.79 m(2) g(-1)) and EFBB (2.57 m(2) g(-1)). On the other hand, the IC-EFBB had the highest pH, and content of functional groups (OH and CO) while the EFBB had the highest total oxygen containing functional groups, CEC, and the lowest PZC. The sorption data of Pb by EFBB, IC-EFBB and AC were better fitted to the Langmuir adsorption as indicated by the R-2 (1.00, 1.00 and 0.98, respectively) and RMSE values (0.009, 0.017 and 0.428, respectively). The IC-EFBB (142.86 mg g(-1)) had the highest adsorption capacity for Pb followed by EFBB (103.09 mg g(-1)) and the lowest was AC (50.51 mg g(-1)). The results indicated that surface area was not an important indicator for Pb sorption by the adsorbents but the amount of oxygen-containing functional groups, pH and CEC were the dominant factors. The IC-EFBB was readily separated from the aqueous solution using an external magnetic force. Therefore, it can be concluded that the IC-EFBB can be a very good alternative sorbent to remove heavy metals from wastewater.