Polymerization of the tannin extract from the leave of Acacia mangium and its application as an adsorbent for the removal of lead

Pollution of heavy metal ions in water is a hazardous environmental problem that requires specific methods for handling lead ion contamination. One of these methods involves the use of tannin adsorbent. Tannin adsorbents exhibit renewability, biodegradability, and natural abundance. In this study, the extract from the leaves of Acacia mangium was used as the raw material for the adsorbent. The tannin extract was polymerized by the addition of concentrated H₂SO₄ because the adsorbent was insoluble in water. The resin obtained from the polymerization of the tannin extract (hereafter referred to as PET) was characterized qualitatively by Fourier transform infrared spectroscopy and quantitatively by total organic carbon measurements. To determine its ability as an adsorbent, we estimated the adsorption parameters of PET. The optimum adsorption capacity of PET was 5.261 mg/g at a pH of 7 and a contact time of 120 min.