不同提取剂提取酸性土壤有效态Cu和Cd的方法研究

The Study of Extraction Method for Available Copper and Cadmium in Acidity Soil with Different Extractants

选择HCl(1#)、HOAc(2#)、NaNO3(3#)和CaCl2(4#)、NH4OAc(5#)、NaOAc(6#)6种不同的提取剂提取某冶炼厂周边重金属污染水稻田土壤中有效态Cu和Cd。结果表明,对土壤有效态Cu,各提取剂按提取量排序为:1#>2#>5#>4#>3#>6#,对土壤有效态Cd,各提取剂按提取量排序为:1#>5#>2#≈4#>6#>3#,有效态Cu的提取量因提取剂种类不同差异较Cd大;4#、5#两种提取剂对土壤有效态Cu和Cd的提取结果变异范围较集中,实验结果相对较稳定;各提取剂提取土壤有效态Cu和Cd的量与其在土壤中全量都显著相关,仅5#提取剂的提取量与水稻籽粒中Cu、Cd的质量比显著相关。综合实验结果的稳定性与土壤重金属有效态的实际意义,NH4OAc(5#)为最适合提取该研究土壤中有效态Cu和Cd的提取剂。

The six extractants cbosed to extract available copper and cadmium from heavy metal polluted soils around a smelter. The extractants were HCl（1#） , HOAc（2#） , NaNO3（3#） and CaCl2（4#） , NH4OAc（5#） and NaOAc（6#）. The results showed that CaCl2（4#） , NH4OAc（5#） had lower coefficients of variation （CV） for both copper and cadmium. The sequence of extraction contents for copper was 1# 〉 2# 〉 5# 〉4# 〉 3# 〉 6#, andforcadmiumwasl# 〉5# 〉2#≈4# 〉6# 〉3#. The study also showed that the kinds of the extractions had rela- tively smaller influences on cadmium than copper. The contents of available copper and cadmium in soil extracted by all the six extractions had significant correlation with the total contents of copper and cadmium in soils, but only the contents of available copper and cadmium extracted by NH4OAc（5#）had significant correlations with the contents of Cu and Cd in rice grains. NH4OAc was the best extractant for available copper and cadmium from studied soils.