Morentera BG, Wahyuningsih S, Sudarni DHA. The Effect of Contact Time Variation and Dosage of NaOH-Activated Fly ash on Adsorption of Methylene Blue. Eksergi [Internet]. 2022 Nov. 15 [cited 2025 Jul. 18];19(3):104-9. Available from: https://jurnal.upnyk.ac.id/index.php/eksergi/article/view/7207