Preparation and Evaluation of Terminalia catappa Shell-Based Activated Carbon for Methylene Blue Dye Removal

Tropical almond (Terminalia catappa) is a large tree that is widely distributed in coastal environments throughout the tropics. In this study the feasibility of using Terminalia catappa shells as a cheap adsorbent for removing methylene blue dye in aqueous solutions was investigated. Two separate samples of activated carbon were prepared from the fruit shells of Terminalia catappa via physical and chemical activation, respectively. The specific surface area of the activated carbon prepared using physical activation was found to be 1095 m2/g, while that prepared via chemical activation was 1613.4 m2/g. The changes were due to different contact times and the dosage of the adsorbent in the adsorption process were investigated for both samples. The results showed that for both samples, increasing the contact time and adsorbent dosage resulted in a greater percentage of methylene blue dye being removed. The highest percentage removal was achieved using the chemically activated carbon, which showed an exponential increase from 68.25% to 87.41% at 0 to 40 minutes and a small increment from 89.00% to 90.12% in the last 20 minutes. Similarly, the percentage removal also rose with an increase in the adsorbent dosage from 59.65% to 90.69% at 0.1 to 0.6g of the adsorbent. These findings suggest that Terminalia catappa shells is an efficient and cheap adsorbent that be used for the removal of methylene blue dye from aqueous solutions.