| dc.description.abstract | Waste from chemical processes contains heavy metals. Chromium (Cr) is a heavy metal that is dangerous for the environment and health. This research was carried out using the adsorption method using a powder adsorbent from Medan orange peel which aims to develop active carbon that is effective in absorbing chromium (Cr) solution using Medan orange peel as the basic material. The advantages of the medan orange peel adsorbent are that it is able to remove heavy metals, can be applied at low concentrations, has low operational costs, does not require a complicated process, and is an easy to obtain and environmentally friendly raw material. Activation used 7.5% NaOH and a powder composite was made using sodium alginate to adsorb Cr metal. The adsorbent was characterized using FTIR (Fourier Transform Infrared) and GSA (Gas Sorption Analyzer). Adsorption is carried out using variations in mass, contact time, concentration and pH. The research results showed that the best Cr mass variation was I gram with a % adsorption of 99.95%. The best contact time variation for Cr was at 60 minutes with an adsorption of 99.72%. The best Cr concentration variation was at a concentration of 10 ppm with an adsorption % of 66.94%. The best pH variation is the pH with adsorption of 97.34%. Studies on adsorption equilibrium were also carried out using the Langmuir and Freundlich adsorption isotherm approach. The adsorption of Cr metal by medan orange peel adsorbent powder is in accordance with the Langmuir adsorption isotherm with a capacity of 3.573 mg/g. | en_US |
