2.2. Activated carbon production
Activated carbon was prepared by following the one step pyrolysis method [21,43]. For this, the test samples were divided into three parts; the first part mixed with 10% phosphoric acid (H3PO4) (100 g sample + 100 mL of H3PO4, wt/v) and the second part mixed with 10% potassium hydroxide (KOH) (100 g sample + 100 mL of KOH, wt/v) and the third part without any addition. Both the treated and untreated samples were pyrolyzed at 450°C (BEFP) and 400°C (DRFP) for 1 h in an electric muffle furnace. After activation, the mixture was removed from the furnace and allowed to cool to room temperature. The pyrolysed carbons were leached with 2% HCl (v/v) for 2 h and washed several times with de-ionized hot water until a neutral pH was achieved. Later the carbon paste was dried in an electric oven at 110°C for 24 h. The activated carbon yield was calculated by applying the formula [44].
X (%) = m/mo × 100,