Effect of Particle Size and Mass of Longan Peel (Euphoria Longan L.) as Adsorbent on The Adsorption of Rhodamine B and Methylene Blue Dyes Using the Column Method

Abstract

Dyes are a mixture of organic compounds that are synthesized in complex forms and are often used in the process of coloring products in various types of industries, so that this complex structure will be difficult to decompose naturally. Therefore, this dye will accumulate in the liquid waste. The accumulation of these dyes will cause harm to living things and the surrounding environment. Therefore, an effective method is needed to overcome this problem, a method that can be used to reduce the dye content in a simple and environmentally friendly way such as the adsorption method. In this study, the adsorption method using a column was used to absorb dyes from the cationic group, namely methylene blue and rhodamine B with adsorben derived from longan peel waste. In this study, the results obtained were the identification of longan peel containing several functional groups, namely O-H, C-H, C=O, -C-NO2, C=C, C-O-C, and C-N derived from alcohol, carboxylic acid, ester, ether, aromatic nitro compounds, and amines. By using a adsorbent particle size of 106 µm, it can absorb methylene blue and rhodamine B at 30.31 mg/g and 28.28 mg/g, respectively. The absorption of methylene blue with 0.1 gram of adsorbent resulted in an absorption capacity of 59.97 mg/g while 0.2 gram of adsorbent could absorb rhodamine B of 32.40 mg/g.