The Evaluation on the Cadmium Net Concentration for Soil Ecosystems

Area of Science:

• Environmental Science
• Soil Science
• Ecotoxicology

Background:

• Yixing, the
• City of Ceramics
• faces a raw material crisis due to high soil cadmium (Cd) concentrations from industrial wastewater.
• Evaluating Cd bioavailability is crucial for managing soil contamination and crop selection.

Purpose of the Study:

• To assess and compare methods for predicting soil cadmium bioavailability in Yixing.
• To identify suitable cash crops with tolerance to cadmium contamination.

Main Methods:

• In situ diffusive gradients in thin film (DGT) and ex situ methods (HAc, EDTA, CaCl2) were used to measure labile soil Cd.
• Dissolved Cd in soil solution and microwave digestion were also employed.
• Cadmium accumulation in paddy and zizania aquatica was analyzed.

Main Results:

• Zizania aquatica showed high Cd accumulation but also high transfer to edible parts, making it unsuitable.
• Diffusive gradients in thin film (DGT) and soil solution measurements strongly correlated with plant Cd uptake.
• Ex situ methods and microwave digestion showed poor correlation with plant Cd accumulation.

Conclusions:

• Diffusive gradients in thin film (DGT) is a robust and effective tool for evaluating labile cadmium concentrations in Yixing soils.
• Plant biomass sensitivity reflected regional soil contamination differences.
• Zizania aquatica is not ideal due to high Cd transfer to edible parts.