Research on Cd-contaminated soil
Yuanming Xie
The project focus on Cadmium-contaminated soil which was starting from last year. The overall objective of this research is to determine the optimal limestone level by comparing six different levels of lime which are added into Cd- contaminated soil.
Cadmium, which is a kind of non-essential elements of human body, is gradually acknowledged as one of primary soil contaminants result from its strong toxicity and migration capability which can give rise to a long time and wide range pollution. About the soil sample: constraints challenge is not directly having access to highly contaminated cadmium soil, because there is no human or industrial activity that results in Cd-polluted soil in Truro, NS. So Cd concentrated soil will be prepared by adding cadmium into the soil deliberately by sprayer to produce Cd-contaminated soil at 15 mg Cd / kg soil. The experimental soil is natural acidic soil from Truro, NS.
Limestone is recognized as a valuable soil amendment, which can improve the quality of soil and decrease content of available cadmium. In terms of the types of limestone, the project used agricultural limestone, which was added into the Cd- contaminated soil at six different levels: 0g, 0.5g, 0.8g, 1.0g, 1.2g, 1.5g.
To determine the content of available cadmium the sample, all of samples were extracted with CaCl2 and filtered by Whatman #1 filter paper and then applied atomic absorption spectroscopy (AAS) method to measure the concentration of available cadmium.
Through the Tukey analysis, 1.0g level is the optimal limestone level after comparing it with other levels.
Soil is regarded as the main natural resources for human survival, which also play irreplaceable role in human development process. Soil cadmium pollution which is harmful to human development should arouse widely attention. The project can give some suggestions for farmers or gardeners about using agricultural limestone to neutralize the soil pH which is conductive to achieve high yield of the crops.