Bai Weiyang, Gao Huanfang, Li Gang

（Department of Chemistry and Chemical Engineering, Chongqing University of Technology , Chongqing 400054，China）

Abstract: In order to find out the effect of non-bio chelating agent EDTA and bio-chelating agent NTA on soil heavy metals’ pollution, the effects of different ratios of chelating agent NTA and EDTA on soil heavy metals (Pb, Cu and Cd), the effects of chelating on contents of chlorophyll and vitamin C and the degree of soil nutrient loss were evaluated. Results show that the contents of Pb and Cd are the highest in the roots of chrysanthemum in the treatment (EDTA / NTA = 2: 1). The treatment (EDTA / NTA = 1: 1) is the best in chelating agent ratio for synergistic effect, which can significantly promote chrysanthemum on heavy metal Cu uptake and transport to aboveground. The chrysanthemum is inhibited by all chelating agents treatments, while the contents of chlorophyll and vitamin C of the chrysanthemum physiological indexes decrease. In the treatment (EDTA = 1), chlorophyll SPAD and vitamin C contents reach a minimum of 36 and 38mg•100g-1, respectively. The nutrient element TN in the leachate gradually decreases with the time, and in the tenth day is significantly lower than the leaching rate of the first day (p <0.05) in the treatments (NTA = 1, EDTA / NTA = 1: 2). The nutrient element TN decreases most, reaching 51.6%, and the activation effect decreases significantly in the fifteenth day in treatment (NTA = 1). Results show the order of treatment(EDTA / NTA = 1: 1)> treatment (EDTA = 1) >treatment (EDTA / NTA = 2: 1) >treatment (EDTA / NTA = 1: 2)> treatment (NTA = 1). Treatment (EDTA / NTA = 2: 1) is recommended for the chelating agent ratio with better physiological parameters, more heavy metal extraction and less nitrogen and phosphorus loss.

Key words: NTA；EDTA；Heavy metals; Chrysanthemum

EARTH AND ENVIRONMENT Vol.46, No.2, Tot No.322, 2018, Page 156-163