Adsorpsi Logam Pb pada Adsorbent Berbasis Karboksimetil Selulosa dan Hidroksipropil Metil Selulosa dengan Divinil Sulfon sebagai Agen Ikat Silang

Abstract

This study examines the adsorption process of Pb metal on adsorbents based on carboxymethyl cellulose (CMC) and hydroxypropyl methyl cellulose (HPMC) with divinyl sulfone (DVS) as a crosslinking agent. The adsorbent was prepared by mixing CMC and HPMC in a 7:1 ratio in a 4% polymer mixture, followed by the addition of DVS (0.04M) and KOH (1M) as a catalyst. The resulting material was a film that underwent tests for crosslinking degree, water absorption, and characterization using FTIR and DSC. Pb (II) adsorption was conducted statically and analyzed using Atomic Absorption Spectrophotometry. Results showed a crosslinking percentage of 80% and a maximum water absorption of 10.955%. FTIR confirmed the formation of the adsorbent with peaks at 3227 cm-1 and 2939 cm-1 (C-H and O-H bonds), as well as 1461 cm-1 and 954 cm-1 (–COO and C-O-C groups). The glass transition temperature (Tg) of the adsorbent was 125.39°C, indicating polymer interaction. The optimum contact time for Pb(II) adsorption was 20 minutes, with an adsorbed Pb concentration of 1.76 mg/L (35.2%). At a concentration of 100 mg/L, Pb adsorption was 4.25 mg/g. The Langmuir isotherm curve indicated a Pb adsorption capacity of 4.25 mg/g, with a regression coefficient of 0.9985 and an error percentage of 16.80%.