Study of Pb (II) adsorption by Tannin Based Adsorbent from mangrove bark (Rhizopora mucronata)

Abstract

Mangrove bark (Rhizopora mucronata) is a potential adsorbent for heavy metals adsorption such as lead or Pb (II), because of its tannin content. Prior to be used as adsorbent, the extract of tannin should be polymerized using formaldehyde and produced Tannin Based adsorbent which was not dissolved in water. This research aimed to study the effect of temperature, adsorbent dose and contacting time to % removal of Pb (II). A series of batch adsorption was carried out using 250 mL Pb (II) solution with initial concentration 307.2mg/g. The variation of adsorbent mass was 1-5 gram, the variation of temperature was 30,40 and 50°C, and the variation of contact time was started at 10 minutes until reached the adsorption equilibrium. The obtained data were also required to determine the adsorption kinetic and adsorption isotherm. The maximum percentage(%) removal was 71.6% which was obtained at temperature 50°C, contact time 70 minutes and TBA dosage 4gram/250 mL solution. Study of adsorption kinetic determines that the pseudo-2 order fitted with this adsorption process. The adsorption coefficient was 0.0099 g/mg.min and the coefficient of determination (R 2) was 0.9976. In addition, Langmuir equation described adsorption isotherm better than Freundlich and Temkin equation. The maximum adsorption capacity (qe ) was 18.281 mg/g, Langmuir coefficient was 0.0017 L/mg. The research results can be applied to design and to scale-up the process.