earticle

영어

Contaminated sediments with hexavalent chromium (Cr(VI)) and naphthalene (NAP) have posed a significant risk to sediment environment. This study introduced an activated mulbbery biochar (MBK) with alkali (K2CO3) to stabilize Cr(VI) and NAP from sediment. Moreover, MBK exhibited remarkably large specific surface area of 2213 m2/g. and high sorption performances of Cr(VI) and NAP were 340.1 mg/g and 250 mg/g, respectively. Furthermore, sorption kinetics and thermodynamic sorption revealed fast sorption equilibrium, with higher temperatures favoring sorption of both Cr(VI) and NAP. Moreover, environmentally relevant concentrations of DOM significantly enhanced the sorption of both Cr(VI) and NAP onto MBK. While low levels of Cr(VI) (60 mg/L) did not affect NAP sorption, higher concentrations of Cr(VI) suppressed NAP sorption. Microcosm studies were conducted to evaluate the effectiveness of two different sediment amendment techniques, in-situ mechanical mixing (MIX) and in-situ capping (CAP), in stabilizing Cr(VI) and NAP. Both techniques demonstrated a 99% reduction in the flux of Cr(VI) and NAP from water to sediment. However, the in-situ MIX technique exhibited a higher reduction in Cr(VI) and NAP concentrations in pore water compared to the CAP technique. Moreover, MBK demonstrated higher stabilization efficiency for Cr(VI) and NAP compared to CAC, indicating the practicality of using MBK instead of CAC for Cr(VI) and NAP sediments. These findings offer valuable strategies for the in-situ stabilization of Cr(VI) and NAP in contaminated sediments using MBK.