Multimedium Interface Processes And Chemical Dynamics Of Cd In Contaminated Phaiozem By Cd And Chlorimuron-ethyl

Cadmium and chlorimuron-ethyl (CE) are two typical pollutants in phaiozem. Through carrying out the experiments of Cd-transferring behaviors between water-soil interfaces, sorption/desorption behaviors and chemical dynamics of Cd between root-soil interfaces and biochemical dynamics of Cd-CE, in particular, multimedium interface processes and chemical dynamics in phaiozem polluted by Cd and CE were studied, aiming to provide theoretical references for the prevention and treatment of Cd and CE pollution in the phaiozem area.Diffusion and sorption processes of Cd between water-soil interfaces were obviously affected by pH, and Cd2+ transferred more quickly in acidic solution than in alkaline solution. CE could affect the Cd transferred action, but Cd transferred action affected by pH between water-soil or soil-water interface was different.The best models for Cd2+ sorption/desorption kinetics were Elovich equation and two-constant equation, respectively. The amount of Cd sorbed on root-soil interfaces was much higher than that on non-root-soil interfaces, but it was on the contrary when Cd was desorbed. CE could restrain the sorption and desorption of Cd.The quantity of Cd absorbed by wheat plants increased with increasing soil Cd, and which was affected by CE. There was antagonistic interaction between Cd and CE in the process of absorbing Cd by wheat plants. The trend of carbonate-bound Cd and Fe-Mn oxide-bound Cd transformed to exchangeable Cd was weakened from root-center zone to non-rhizosphere, but the trend of two Cd forms transformed to residual Cd was strengthened. The result of correlation suggested that exchangeable Cd and organic-bound Cd nearby the root were the main Cd forms that could be absorbed by wheat. There was antagonistic interaction to the activity of urease, but shown synergistical effect to the activity of CAT and acidic phosphate.