TRANSPORT OF Cr3+, Cd2+, Pb2+, AND Ag+ IONS THROUGH BULK LIQUID MEMBRANE CONTAINING p-tert-BUTYLCALIX[4]ARENE –TETRACARBOXYLIC ACID AS ION CARRIER - Maming, Maming; Chemistry Department , Faculty of Mathematics and Natural Science, Hasanuddin University, Jl. Perintis Kemedekaan KM.10 Makassar Indonesia (Universitas Gadjah Mada, 2010)