P2EC.14 - Suspension Wien effect sensor method for distinguishing Zn2+ in inner and outer Helmholtz plane in electrical double layer of colloid particles
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- P-2 - Electrochemical Sensors
- Y. Wang, T. Fan, P. Cui, C. Li, D. Zhou - Institute of Soil Science, the Chinese Academy of Sciences, Nanjing (China)
- 727 - 727
The electrical double layer (EDL) is a central theory that shed light on the interaction between ions and charged soil colloid particles. A new approach based on the suspension Wien effect sensor method was established to verify the EDL theory and to determine the ion distribution in the soil-water interface. The new approach was applied to assessing Zn2+ distribution in the EDL of Zn-saturated soil colloids. The results showed that more than 84% of Zn2+ was adsorbed via chemical interaction and located in the inner Helmholtz plane (IHP) layer. The remaining Zn2+ fraction was 13 electrically adsorbed and distributed in the outer Helmholtz plane (OHP) layer (2.3% - 21.6 %) and the Gouy-Chapman (GC) diffuse layer (78.4% - 97.7 %). The proposed approach was employed to assess specific and non-specific adsorption and so to deepen the understanding of the metal sorption process in soils. Further, our findings reinforce the better adequacy of the Grahame-Stern-Gouy-Chapman (GSGC) EDL model to describe the ion distribution in the solid-water interface.