ADSORPTION KINETICSOF Pb(II), Cd(lI) AND Cr(lII) ON ADSORBENT PRODUCEDBY PROTECTED-CROSSLINKINGOF HUMICACID-CHITOSAN Kinetika Adsorpsi Pb(II),Cd(lI)dan Cr(lII)pada Adsorben Produk Pengikatan-Silang Terproteksi Asam Humat - Perpustakaan UGM, i-lib ([Yogyakarta] : Universitas Gadjah Mada, 2009)