Mahmud KN, Wen TH, Zakaria ZA. Activated carbon and biochar from pineapple waste biomass for the removal of methylene blue. ETM [Internet]. 2021 Apr. 30 [cited 2026 Aug. 9];1(1):30-6. Available from: https://journal2.unusa.ac.id/index.php/ETM/article/view/2036