Effects of Mercapto-functionalized Nanosilica on Cd Stabilization and Uptake by Wheat Seedling (Triticum aestivum L.) in an Agricultural Soil.

In the present study, a pot-culture experiment was conducted to investigate the influences of mercapto-functionalized nanosilica (MPTS/nano-silica) on Cd stabilization and uptake by wheat seedling. Four different dosages of MPTS/nano-silica were applied: 0%, 0.3%, 0.6% and 1% (w/w), and the changes of DTPA-extractable Cd in soil, soil properties, wheat biomass, and uptake of Cd to wheat tissues (shoots and roots) were measured throughout the experiment. The results showed that the application of MPTS/nano-silica (at dose of 1%) reduced the DTPA-extractable Cd from 4.21 to 1.45 mg/kg in the soil. Whereas the addition of MPTS/nano-silica hardly changed soil properties and slightly decreased the biomass of wheat seedling. In addition, Cd concentration in wheat tissues decreased from 6.388 to 2.625 mg/kg for shoot, and from 18.622 to 6.368 mg/kg for root. These results indicated that MPTS/nano-silica is an ideal candidate for remediation of Cd contaminated agricultural soil.