Abstract. Mangrove plant around Prigi beach has the potential to be used as biochar adsorbent to remove nickel content. The high Ni concentrations can cause water pollution problems, which is needed as adsorbent at this time. This study aims to characterize mangrove biochar using XRF, SEM, and FT-IR and determine the optimization of the size and contact time of mangrove biochar on the nickel ion in the adsorption process. The leaves, seeds and mangrove stems were collected and produced biochar using the pyrolysis method, and then characterized with XRF, FT-IR and SEM. The results of this XRF analysis of mangrove plants contained a content of 0.01% NiO. The FT-IR results show the presence of the main functional group O-H at a wave number of 3319.49 cm-1, and SEM magnification of 2500x found that biochar has a rough morphology and the presence of micropores with an average particle diameter of 2018 m. The adsorption test showed that the adsorbent in bulk size was able to absorb the highest nickel metal ion of 99.4% with a contact time of 48 hours.
Keywords: Mangrove, Biochar, Prigi Bay, Adsorption, Nickel
