某冶炼厂周边土壤碳组分与铜形态的相关性

Relationship between organic carbon fractions and copper speciation in soil around the smelting area

研究了浙江某冶炼污染区农田土壤有机碳组分与铜(Cu)形态的相关关系.结果表明,研究区土壤Cu形态含量为铁锰氧化物结合态>残渣态>碳酸盐结合态>有机质结合态>可交换态,其中铁锰氧化物结合态Cu和残渣态Cu含量分别占全量的39.55%和39.19%.土壤p H值和碳组分对不同形态Cu含量存在一定程度的影响,其中p H值与碳酸盐结合态Cu和铁锰氧化物结合态Cu均呈显著正相关;溶解性有机碳(DOC)含量与可交换态Cu呈极显著正相关;富里酸(FA)含量与可交换态Cu呈极显著正相关,与有机结合态Cu呈显著正相关;胡敏酸(HA)含量分别与可交换态Cu和有机结合态Cu呈极显著正相关.土壤DOC、FA、HA的动态变化对这些在移动性上存在差异的Cu形态间的相互转化会带来一定程度的影响,从而改变土壤Cu的迁移能力和生物有效性.

The relationship between different organic carbon fractions and copper （Cu） speciation in soil around the smelting area was investigated. The results indicated that the average percentage of different Cu species decreased in the order of Fe-Mn oxide bound （FMO） 〉 Residual （RES） 〉 Carbonate bound （CAB） 〉 Organic bound （OM） 〉 Exchangeable （EX）. The FMO and RES fractions contribute 39.55% and 39.19% to the overall Cu spcciation, respectively. Cu speciation shows significant correlation with different carbon fractions such as dissolved organic carbon （DOC） , fulvic acid （FA） , and humic acid （HA）. DOC had a significantly positive correlation with EX. Both FA and HA were significantly positively correlated with EX and OM. The dynamic change of DOC, FA, and HA contents could dramatically influence the transformation of different Cu species, thus change the mobility and bioavailability of Cu in soil environment.