Reversible Second Order Kinetics of Sorption-Desorption of Cr(VI) Ion on Activated Carbon from Palm Empty Fruit Bunches - Falah, Iip Izul; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara PO BOX BLS 21 Yogyakarta 55281 (Universitas Gadjah Mada, 2015)