Characterisation and Kinetic Studies on Activated Carbon Derived from Rubber Seed Shell for the Removal of Methylene Blue in Aqueous Solutions

The aim of this research is to investigate and identify the absorption capacity of activated carbon derived from a rubber seed shell (RSS). An RSS was prepared through the conduction of a chemical activation process primarily using potassium hydroxide at a ratio of 1:1 followed by carbonisation at 400°C with N2 under a steady flow rate of 1 ml min–1 for 3 h. The produced RSS activated carbon (RSSAC) was characterised using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopyenergy dispersive X-ray (SEM-EDX) spectroscopy, Brunauer-Emmet-Teller (BET) analysis and thermogravimetric analysis (TGA). The SEM image obtained revealed the presence of a highly porous RSSAC surface, with an average pore diameter of 3.35 nm, indicating a mesoporous structure. EDX analysis depicted that C and K were major elements found in RSSAC with a compound percentage of 99.73% and 0.27%, respectively. Batch adsorption studies were conducted to investigate the adsorption properties of RSSAC towards the removal of methylene blue (MB) dye. The optimum dosage of RSSAC was determined to be 5.0 g per 100 ml. Effect of contact time revealed that the highest percentage removal of MB (99.62%) by RSSAC was obtained at a concentration of 100 mg l–1 during a time period of 1 h. In comparison, the effect of pH study affirmed that RSSAC achieved an average removal of 99% of MB in both acidic and basic media at 100 mg l–1. Kinetic studies revealed that the adsorption process abides by the pseudosecond-order kinetic model. Based on the findings by utilising multiple approaches Activated Carbon from Rubber Seed 2 as mentioned, it can be proposed that RSSAC is a viable alternative to act as a green alternative adsorbent.