Study on the Nickel Adsorption Characteristics of Lake Sediments and Soil

Abstract

The test adopted the OECD (Organisation for Economic Co-operation and Development) guideine106 equilibrium adsorption method (Bian et al., 2016), to explore the Ni adsorption behavior of the bottom sediment and black soil of the lake. The isothermal adsorption curve of Ni on sediment and black soil retained an "S" shape, and the Freundlich model and D-R model could sufficiently fit the adsorption of Ni by sediment and soil, and the correlation coefficient r was 0.9859~0.9963; Within 120 min, the adsorption amount of nickel in the sediment and soil reached 99.57% and 99.84% of the total adsorption amount, respectively, and reached equilibrium after 720 min. The final desorption amounts of Ni in sediments and soil accounting for 1.26% and 1.35% of the adsorption amounts, respectively. The amount of Ni adsorbed in the sediment increases with rising temperature, and the adsorption coefficient changes in the following manner: Kf 15 °C < Kf 25 °C < Kf 35 °C, Δ G < 0. The adsorption process of nickel on sediment and soil is spontaneous and high temperature is beneficial to this process. The removal of organic matter from sediment and soil weakened the adsorption of nickel, indicating that organic matter could improve the interception of nickel.

Correlations between physico-chemical properties and nickel adsorption parameters in soils used in sanitary landfill liners

“…The Freundlich model is based on the adsorption of metals on heterogeneous surfaces, which is typical in soils, while the Langmuir model is based on adsorption on a homogeneous monolayer surface (JIANG et al, 2010). Ma, X et al (2019) had also achieved a better adjustment to the Freundlich model for the adsorption of nickel in soils. In addition, an increase in nickel adsorption was observed due to the presence of organic matter and the rise of temperature, obtaining adsorption rates of 99.57 and 99.84% for sediments of lake and soils, respectively.…”