ADSORPSI TIMBAL (Pb) DAN ZINK (Zn) DARI LARUTANNYA MENGGUNAKAN ARANG HAYATI (BIOCHARCOAL) KULIT PISANG KEPOK BERDASARKAN VARIASI pH (Adsorption of Plumbum (Pb) and Zinc (Zn) From Its The Solution by Using Biological Charcoal (Biocharcoal) of Kepok Banana) - Darmayanti, Darmayanti (Universitas Tadulako, 2012)