Speciation and Release Kinetics Simulation of Zn and Cd from River Sediment Contaminated by Gold Mining

Heavy metals release from contaminated sediments is one of the most important chemical processes affecting overlying water quality in river, lake, and ocean. The objective this study was to determine leaching properties, kinetic rate, amount zinc (Zn) cadmium (Cd) river sediment by gold mining. Speciation Zn Cd extracted a modified BCR extraction procedure. Release kinetics were studied simulated experiment using stirred-flow reactor two-site equilibrium-kinetic model. we significantly (620–5878 mg kg?1) (2–67 kg?1), both have high content weak acid extractable forms. There much more smaller particles on surface JH01 JH02 than JH03 JH04. model fits data well, it demonstrated as an effective tool describe sediments. Kinetic rates obtained curve fitting showed large variation among indicating different reaction mechanisms. rapid stage (before second stop-flow) controlled equilibrium sites sites, while slow (after mainly sites. total (27.1 kg?1, 0.4 (474 7.5 (320 7.6 JH04 (52.4 2.0 that can be leached into solution. Thus, measures should taken prevent heavy sediment.