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Geoscience ›› 2023, Vol. 37 ›› Issue (01): 197-207.DOI: 10.19657/j.geoscience.1000-8527.2023.01.21

• Geochemistry and Remote Sensing Geology • Previous Articles     Next Articles

Differences of Cadmium Mobility in Paddy Soils from Different Parent Materials in the Pearl River Delta and Its Influencing Factors

WANG Jiaxin(), HOU Qingye(), YE Danjun, YANG Zhongfang, YU Tao   

  1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
  • Received:2022-04-13 Revised:2022-09-07 Online:2023-02-10 Published:2023-03-20

Abstract:

With the rapid development of economy, heavy metals in soil exceed the environment standards more and more seriously, especially for Cd. The mobile fraction of Cd in soils is affected by various factors, but there are few reports about its influencing factors from the perspective of different parent materials. We collected and measured 235 paddy soil samples which were formed by Quaternary sediments, acid intrusive rocks and terrigenous clastic rocks in the Pearl River Delta. The physicochemical characteristics of paddy soils were summarized, and factors affecting total and the mobile fractions of Cd were discussed. The results showed that there were significant differences in physicochemical properties, total Cd concentrations of paddy soil formed by different parent materials. The average concentrations of CaO, K2O, Na2O, TFe2O3, cation exchange capacity (CEC), pH, organic matter and clay in paddy soil formed by Quaternary sediments are significantly higher than those of acid intrusive rocks and terrigenous clastic rocks. Cd in paddy soil developed from Quaternary sediments exceed the standard most seriously. Meanwhile, the concentration of Cd in mobile fractions extracted by different metho-ds in this type soil is also the highest. The correlation between the total Cd concentration and soil physicoche-mical parameters in paddy soil formed by terrigenous clastic rocks is stronger than that of the other two types of parent materials. The correlation between the total Cd concentration and soil physicochemical parameters in paddy soil formed by acid intrusive rock is weak. The total Cd concentration has an important impact on Cd in mobile fractions. In addition, the correlation between Cd in mobile fraction and pH, organic matter, TFe2O3 of paddy soils developed from Quaternary sediment is significantly higher than that of the other two types of parent materials. The correlation between Cd in mobile fraction and Tl, CEC, clay and Mn in paddy soil formed by terrigenous clastic rocks is significantly higher than that of the other two types of parent materials. Cd in mobile fraction is mainly affected by the total Cd,CEC, TFe2O3 and Mn in paddy soils formed by acid intrusive rocks.

Key words: the Pearl River Delta, paddy soil, cadmium, mobile fraction, parent material, influencingfactor

CLC Number: