Adsorption of Lead from Aqueous Solution using Activated Carbon from Sawdust as Adsorbent.

Activated carbon is a well known as porous material, with large specific surface area use for adsorption purposes. The preparation of activated carbon from agricultural by-products such rice-husk, yam peels, cassava peels, orange peels, to remove and recover metal ions namely lead, cadmium, zinc, selenium from the waste water is one of the most environmental friendly solutions and economical (Akissi, Adouby, Wandan, Yao, & Kotchi, 2010). Wood sawdust from Meranti was used to prepare activated carbon using potassium hydroxide (KOH) and phosphoric acid (H3PO4) as activating agent. From FESEM characterization, results showed that the sawdust activated by KOH exhibit fine smaller pores at 1000 times magnification which can be the mesopores. While the sawdust activated using H3PO4 has irregular surface with fewer pores. Thus, KOH promote the formation of pores inside activated carbon better than H3PO4. This is supported by the EDX spectroscopy that analyzed the carbon content after activation done using KOH is 78.48% while for H3PO4 is 69.47%. By using N2 adsorption-desorption isotherm analysis, Sample E which is prepared at IR of 1:3 with KOH solution, activation temperature of 500oC and activation time of 30 minutes yields the highest value of SBET (2.5613 m2g-1), total pore volume, VT (0.005280 cm3g-1) and pore diameter, D (8.246 nm). Lead adsorption study also been done and it was found that the material is capable to removing up to 89.3% of lead in aqueous solution, suggesting that it can be effectively used as an adsorption material.