Study On The Mechanism Of Cadmium And Benzo [a] Pyrene Interactions In Burozem And Phaeozem Of Northeast China

According to the characteristics of heavy metals and PAHs compound pollution in the soils of northeast China, we select the typical heavy metal-cadmium (Cd), representative PAHs-benzo [a] pyrene (BaP) as the research objects, to carry out cadmium and BaP in the northeast soils interaction, and mechanism research. It uses X-ray absorption fine structure (XAFS), infrared spectroscopy, soil suspension Wien effect method and combines with the traditional method of soil science technology. It will provide a scientific basis for soil environmental quality benchmark and composite soil bioremediation.(1) The batch experiment method is adopted for cadmium and benzo [a] pyrene in different types of soil in northeast China (brown soil and black soil) of adsorption experiments. The results indicate that the adsorption isotherm of cadmium in brown soil and black soil, belong to L and F. Langmuir model under the condition of not adding BaP, cadmium has higher model fitting correlation coefficient, and when adding different concentrations of BaP fitting correlation coefficient is low. With increasing of the concentration of cadmium in liquid, Cd adsorption in brown soil and black soil increases.(2) Black soil and brown soil light component accounted for9.99%to9.99%,29.37%to31.19%respectively. However the proportion of cadmium was17.16%-23.87%,49.30%-23.87%. With the increasing of benzo [a] pyrene, proportion of exchange state and carbonate state increase for light and heavy components of five kinds of morphological analysis, and proportion of the residue and organic states reduce.(3) Potential analysis shows that, with the increasing of benzene [a] pyrene, the black soil and brown soil are potential is moving, but the potential of the metal cadmium ion solution has not changed. Black soil of average free energy is greater than the brown soil. However joining benzene [a] pyrene, the average free energy of black soil and brown soil decreased respectively. Black soil adsorption free energy is less than brown soil adsorption free energy without benzene and [a] pyrene. With benzo [a] pyrene increasing, the absolute value of black soil and brown soil adsorption free energy decreases, and adsorption capacity decreased.