PENGAMBILAN TANIN DARI KULIT KAYU BAKAU DAN PEMANFAATANNYA SEBAGAI ADSORBEN LOGAM BERAT CUPRUM (Cu) DAN TIMBAL (Pb)

Abstract

Mangrove bark contains tannins which can be modified into mangrove tannins based adsorbent (MTBA) for heavy metals removal. This research aims to study the performance of MTBA in removing lead (Pb) and copper (Cu). Mangrove barks was extracted using ethanol 70%w during a certain extraction time (1; 1.5; 2; 2.5; 3 hours) and temperature (50, 55, 60, 65, 70 ºC).  After removing the residue, the filtrate was then dried. The obtained dried tannins was dissolved in NaOH solution and formaldehyde 37% to form adsorbent structure.  In adsorption experiment, the tannin powder was mixed lead and copper solutions. The metal concentrations were analyzed by Atomic Adsorption Spectrophotometry (AAS). Based on experiment data, it was found that in extraction process, with the increasing of temperature and extraction time, the yield of tannins were higher. The obtained MTBA could adsorb 79.94% of lead metal and 43.75% of copper metal. The Langmuir’s equation was more suitable to describe the equilibrium absorption process which the constant equilibrium for lead (k_Pb) was 0.0289 with relative error percentage of 5.17%. Constant equilibrium of copper (k_Cu) was 0.0011 with relative error percentage of 7.57%.