Dine Agustine Pengarang Siti Maftukhah Penguji 1 Hafid Arrizal Pengarang Sutresna Juhara Ketua Penguji Lily Arlianti Penguji 1

Chicken egg shells are waste generated from household activities and the food industry. Egg shell contains calcium carbonate (CaCO3) which can be used as a biosorbent. This study aims to determine the adsorption ability of chicken eggshell waste to manganese (Mn) and iron (Fe) in synthetic wastewater. The research method used a batch system with a stirring time of 30 minutes and variations in the concentration of biosorbent 5%, 10%, 15%. The results showed that the average absorption of manganese (Mn) was in the range of 77.54%-89.13%, 10% biosorbent concentration had the highest absorption efficiency, which was 89.13%. The conclusion of this study is that chicken egg shell biosorbent can reduce manganese (Mn) levels but has not been able to reduce iron (Fe) levels