Removal of Cadmium (II) by Adsorption Using Water Hyacinth (Eichhornia crassipes) Dried Biomass

Using water hyacinth as a phytoremediation agent produces abundant biomass due to periodic harvesting in the system. One of the alternative uses of water hyacinth biomass can be a bio-sorbent to absorb metal contamina-tion in the waters. This study aims to determine the quality of activated water hyacinth bio-sorbent, potentially reducing metal cadmium (Cd). The research was conducted from January to April 2022. The results showed that the parameters of water content, iodine absorption, and methylene blue in water hyacinth bio-sorbent had met the quality standard of activated carbon based on SNI No. 06-3730-1995. In contrast, the ash content still did not. In water, hyacinth stem bio-sorbents (stems + ZnCl2 and stems 300 degrees C + ZnCl2) obtained higher ash content (25.87 and 73.30%) than the ash content of water hyacinth root and leaf bio-sorbent with the same activation treatment. The optimum adsorption capacity (Qe) for the roots + ZnCl2 occurred at a contact time of 45 minutes which was 8.13 mg/g with an absorption efficiency (Ef) of 34.20%. For the root 300 degrees C + ZnCl2, the optimum adsorption capacity and absorption efficiency occurred at a contact time of 8 hours, namely 9.08 mg/g and 38.66%, respectively. The optimum adsorption capacity and absorption efficiency of the leaves + ZnCl2 occurred at a contact time of 4 hours, namely 7.63 mg/g and 32.12%, respectively. Meanwhile, at the leaves 300 degrees C + ZnCl2, the optimum adsorption capacity and absorption efficiency occurred at a contact time of 8 hours with a value of Qe = 11.84 mg/g and Ef = 49.35%.