Effect of Nano Zeolite on the Transformation of Cadmium Speciation and Its Uptake by Tobacco in Cadmium-contaminated Soil

Abstract

Abstract The study was aimed at exploring the effects of applying ordinary and nano zeolite on the soil pH, soil available cadmium (Cd) content, soil Cd speciation and Cd uptakes by tobacco using pot experiment with simulated Cd contaminated soil indoors. The results showed that soil pH increased and available Cd content reduced with the amount of ordinary and nano zeolite increasing. Compared with the control, the application of ordinary and nano zeolite increased soil pH at 0.47 - 1.05 and 0.73 - 1.57, respectively, and reduced the available Cd contents at 19.3% - 32.7% and 23.2% - 40.5%, respectively. In addition, soil pH had significantly negative correlation with available Cd content in each treatment (p<0.05). Nano zeolite could more effectively reduce Cd contents of all parts of tobacco than ordinary zeolite with the same amount treatments, and Cd content in all parts of tobacco plants was positively correlated with soil available Cd content. The content of exchangeable Cd (EXE) in soil decreased to some extent with different zeolite treatments, application of nano zeolite was better than that of application of ordinary zeolite in reducing Cd bioavailability and transferability. Overall, application of nano zeolite has an advantage over ordinary zeolite in reducing available Cd content in soil and Cd content in tobacco.