AKIDA MULYANINGTYAS, MALIK MUSTHOFA AND TITIK SURYANI
Abstract
This study investigates the biosorption performance of Penicillium chrysogenum for the removal of Hg (II) under different chemical pretreatments and pH conditions. Untreated fungal biomass exhibited high intrinsic sorption efficiency, reaching 97.93%, indicating the presence of functional groups capable of binding mercury through ion exchange and surface complexation. Alkali pretreatment using alkali further enhanced Hg (II) removal and prevented the desorption. Biomass treated by 1N NaOH could reach 98.56% of removal, while 2N NaOH could achieve 98.62% of removal. This improvement is attributed to the deprotonation of acidic ligands and increased exposure of active sites resulting from partial cell wall disruption. In contrast, HCl 1 N pretreatment reduced sorption efficiency to 80â91%, likely due to protonation of binding groups and structural degradation of the fungal cell wall. Variation in solution pH revealed optimal biosorption at pH 6â8, while a significant decline at pH 9 suggested the formation of Hgâhydroxo complexes and partial desorption from negatively charged surfaces. These findings demonstrate that alkali-modified P. chrysogenum serves as an efficient biosorbent for mercury removal, with performance strongly influenced by surface chemistry and solution pH. This work provides mechanistic insights into fungal biomass modification and offers a promising approach for low-cost treatment of mercury contaminated wastewater.