Preparation and study of medical grade activated carbon prepared from locally available fruits

Activated carbons were prepared using papaya seeds as raw materials. The present study aims to demonstrate and illustrate the following aspects: first the development of activated carbon; second the impact of different thennal treatment condition on the physical and chemical characteristic of the activated carbon; third the corresponding liquid phase adsorption test as evaluated by iodine and methylene blue as adsorbates. The dried papaya seeds were SUbjected to semi carbonized at 200°C for 15 minutes and activation at elevated temperature of 40ifC, 500°C and 600°C under self generated atmosphere. Different activation durations were attempted to activate the semi charred samples. All heating process proceeded in preset temperature to neglect the effect of different progressing heating rate, and also for the cost and time effective perspective. Developed activated carbons were characterized by BET surface area analysis, SEM and FTIR. Increasing burn-off of the samples raised the BET surface area, iodine uptake and methylene blue removal efficiency. These were clearly illustrated by SEM micrographs that porous structures were progressively developed. However, the surface chemistry of the activated carbon under different thermal treatment had neglected variance due to the pH controlled during the preparation process. Activated carbon prepared at 600°C and 4S minutes had the highest BET . surface area, iodine number and methylene blue removal efficiency. The BET surface area was 219.056 m2/g and the iodine number was 196.85 mglg. The methylene blue adsorption results were well fitted in the Langmuir isotherm, with the highest removal efficiency recorded at 62%. Higher activation temperature tends to produce optimum result than longer activation time, suggested that papaya seeds derived activated carbon with higher surface area and better adsorption capacity can be developed by considering higher activation temperature