Preparation and characterization of activated carbon from paper mill sludge: a direct chemical activation study

Activated carbon is mainly an adsorbent material and for its versatile application in material science, it's received much attention in recent years. Activated carbon can be prepared using different methods such as physical or chemical activation or physicochemical activation. As a precursor Paper Mill Sludge was used to prepare activated carbon by direct chemical activation where H3PO4 was used as an activating agent. Among different activation temperatures (200 degrees C, 250 degrees C, 300 degrees C, 350 degrees C, and 400 degrees C), high yield (49.2%) and iodine number (761.4 mg/g) were obtained at 250 degrees C with 30 min activation time. The decrease in iodine number and yield of activated carbon was observed with increasing temperature due to activation burn off at higher temperature. A higher iodine number indicates higher activation. The obtained product was characterized by using XRD, FTIR, and EDAX-SEM. FTIR indicates the presence of several aliphatic and aromatic carbons and XRD showed the presence of amorphous structure at the produced activated carbon. SEM showed an irregular and highly rough surface of activated carbon. All the studies of characterization reveal that paper mill sludge has been converted into activated carbon successfully. The novelty of this work is that activated carbon can be produced from paper mill sludge by direct chemical activation with less time and energy consumption. The textural properties and potential applications of obtained activated carbon will be done in our future research works.