Cadmium Sorption Characteristics of Soil Amendments and its Relationship with the Cadmium Uptake by Hyperaccumulator and Normal Plants in Amended Soils

• Published in: International journal of phytoremediation Vol. 16; no. 5; pp. 496 - 508
• Main Authors: Sun, Yan, Wu, Qi-Tang, Lee, Charles C.C, Li, Baoqin, Long, Xinxian
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis Group 2014; Taylor & Francis Ltd; Taylor & Francis
• Subjects: Animals; Biodegradation, Environmental; Cadmium; Cadmium - analysis; Cadmium - metabolism; Chickens; clay minerals; corn; Correlation analysis; Flowers & plants; heavy metals; humic acids; Hydrogen-Ion Concentration; Maize; Manure; Mathematical analysis; Mica; montmorillonite; Mushrooms; organic materials; phytoremediation; polluted soils; Sedum; Sedum - drug effects; Sedum - growth & development; Sedum - metabolism; Sedum alfredii; Seeds; Soil (material); Soil - chemistry; soil amendments; Soil contamination; Soil Pollutants - analysis; Soil Pollutants - metabolism; Sorption; sorption constants; sorption isotherms; Stability constants; Swine; Uptakes; Zea mays; Zea mays - drug effects; Zea mays - growth & development; Zea mays - metabolism; zeolites; Zinc - analysis; Zinc - metabolism
• ISSN: 1549-7879; 1522-6514; 1549-7879
• DOI: 10.1080/15226514.2013.798617

In order to select appropriate amendments for cropping hyperaccumulator or normal plants on contaminated soils and establish the relationship between Cd sorption characteristics of soil amendments and their capacity to reduce Cd uptake by plants, batch sorption experiments with 11 different clay minerals and organic materials and a pot experiment with the same amendments were carried out. The pot experiment was conducted with Sedum alfredii and maize (Zea mays) in a co-cropping system. The results showed that the highest sorption amount was by montmorillonite at 40.82 mg/g, while mica was the lowest at only 1.83 mg/g. There was a significant negative correlation between the n value of Freundlich equation and Cd uptake by plants, and between the logarithm of the stability constant K of the Langmuir equation and plant uptake. Humic acids (HAs) and mushroom manure increased Cd uptake by S. alfredii, but not maize, thus they are suitable as soil amendments for the co-cropping S. alfredii and maize. The stability constant K in these cases was 0.14–0.16 L/mg and n values were 1.51–2.19. The alkaline zeolite and mica had the best fixation abilities and significantly decreased Cd uptake by the both plants, with K ≥ 1.49 L/mg and n ≥ 3.59.