Indonesian Journal of Chemical Science and Technology (IJCST-UNIMED) , 2023, Volume 06, No. 2, pp 143-152 143 e-ISSN : 2622-4968, p-ISSN : 2622-1349 © 2023 State University of Medan Indonesian Journal of Chemical Science and Technology (IJCST) State University of Medan, https://jurnal.unimed.ac.id/2012/index.php/aromatika IJCST-UNIMED 2023, Vol. 06, No. 2 Page; 143 – 152 Received : Mar 26 th , 2023 Accepted : June 12 th , 2023 Web Published : July 31 st , 2023 Adsorption of Heavy Metal Cu(II) in Wastewater Using Adsorbents from Empty Oil Palm Bunches Indah Fitri 1* , Hafni Indriati Nasution 1 , Jasmidi 1 , Moondra Zubir 1,2 , Siti Rahmah 1,3 , Rini Selly 1 and Putri Faradilla 1 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, 20221, Indonesia 2 Research Initiative for Supra-Materials (RISM), Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Japan 3 Chemical Engineering Department, Faculty of Engineering, Tohoku University, Japan *Email: indahfitri12@mhs.unimed.ac.id ABSTRACT Heavy metal pollution has increased with increasing industrialization. To overcome this contamination, carried out by using the adsorption method. The adsorbents used are activated carbon and porous polymer composite carbon Cu(TAC). in liquid waste, one of which is Cu metal. This is evidenced by the existence of data showing the efficiency of activated carbon and porous polymer composite carbon Cu(TAC) above 90%. In addition, activated carbon and porous polymer composite carbon Cu(TAC) have an adsorption isotherm equation that is suitable for Cu(II) adsorption is the Langmuir isotherm with linear regression values of 0.9045 and 0.8912. Keywords: Adsorption, Isotherm, Copper (Cu), Wastewater 1. INTRODUCTION Oil palm is a group of plantation crops that have an important position in the agricultural and plantation sectors. This is because oil palm produces the largest economic value per hectare of the many plants that produce oil or fat in the world 1 . According to the Oil Palm Plantation Sector Data Base in Indonesia, the area of oil palm plantations in 2022 will be 15.38 million hectares, an increase of 4.5% from 2021. Meanwhile, oil palm production will increase by an average of 3% per year. The increase in area was factored in by the relatively stable nominal CPO price on the international market and providing income for producers, especially for farmers. The distribution of oil palm in several provinces in Indonesia contributes to the production of oil palm plants which is quite large. The number of oil palm plantations spread across