Adsorption of Lead and Copper Using Water Hyacinth Compost (Eichornia Crassipes)

Abstract

Adsorption of heavy metals, Pb and Cu, has been carried out using compost from plant water hyacinth (Eichornia crassipes). First step of the composting was fermentation of fresh hyacinth plants with molasses and water. Once formed, the compost was used as an adsorbent for the adsorption of Pb and Cu. The water hyacinth compost was then characterized to determine the humic acid content, as well as the functional groups Determination of optimum conditions on the adsorption of Pb and Cu was performed with adsorbent mass variations, variations in pH, and the concentration variation. Adsorption isotherm was also determined. The results showed that the adsorption of Pb optimally occurs using 1.2 g of adsorbent mass of 1.2 g at solution pH of 5. As for the adsorption of Cu, the optimum adsorption conditions occur in the adsorbent mass of 0.8 g at pH 6. At the optimum conditions, the compost could adsorb 95.13% Pb and up to 91.42% Cu. Pb and Cu adsorption using adsorbents of water hyacinth compost followed Langmuir model. INTRODUCTION Indonesian waters are now polluted by heavy metals, mostly due to industrial activities. If the waste from industrial activity is not treated and discharged directly into the water bodies such materials will contaminate the surrounding environment. Heavy metals into the water system will undergo by three processes namely precipitation, dilution and dispersion, then absorbed by organisms that live in these waters [1]. Mature leaf compost has the ability to reduce the dissolved heavy metals through cation exchange process [2]. Compost from garden waste mainly foliage has been shown to have a high ability to adsorb heavy metals, oils, fats, nutrients, and harmful organic substances from the water because of its high content of compost and the large of absorption surface area [3]. The compost consisting of humic acid, fulvic acid and humin has ability for forming metal complexes through cation exchange, chelate formation and the formation of electrostatic bonds [2].