Biosorption of Cd2+ Metal Ions using Longan Peels Modified with Cationic Surfactant CTAB (Cetyltrimethylammonium Bromide)
Desy Kurniawati1*, Popi Patricia1, Sherly Kusuma Warda Ningsih1, Deski Beri1, Linda Hevira2

1Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Negeri Padang, Padang, West Sumatera
2Department of Pharmacy, Faculty of Health Science, Universitas Mohammad Natsir Bukittinggi, Bukittiinggi, West Sumatera

Abstract

Heavy metal pollution of aquatic ecosystems poses a significant health risk to humans and endangers ecosystems. One of the harmful heavy metals is the Cd2+ ion. The threshold for cadmium ions allowed in water is 0.01 mg/L. Biosorption is one effective method for mitigating the impact of metal pollution, using biosorbents derived from agricultural and plantation waste. Biosorbent from longan peels, modified with the cationic surfactant CTAB, aims to increase the sorption capacity of biomass for heavy metal ions. This research was conducted using the batch method. The results from various conditions identified the optimum state of Cd2+ ion sorption at pH 5 and a concentration of 400 ppm, with an absorption capacity of 12.5 mg/g. An adsorption isotherm study was conducted, yielding a Langmuir equation with a regression coefficient value (R2 = 0.6862) and a Freundlich isotherm with a regression value (R2 = 0.9594). The Freundlich isotherm produced a regression coefficient value closer to one, indicating it is a better fit, with a maximum sorption capacity of 25.906 mg/g.

Keywords: Biosorption, Cadmium, Longan peels, Surfactant, Waste

Topic: Chemistry