长江口底质腐殖酸铜铅络合物的表观稳定常数

APPARENT STABILITY CONSTANT OF Cu-AND Pb-HUMIC ACID COMPLEXES FROM CHANGJIANG ESTUARY SURFACE SEDIMENT

采用差示脉冲阳极溶出极谱法测定了长江口底质腐殖酸每个分子中可键合金属位置的平均数,计算其平均分子量约为800,并估算出长江口底质腐殖酸-铜、铅络合物的表现稳定常数高达10^(11)-10^(12)数量级。

Humic acid was extracted from surface sediment in the Changjiang Estuary.The average potential bonding sites of each humic acid molecule were determined by DPASV and the average molecular weight(about 800)was estimated.The conditional stability constant of Cu-and Pb-humic acid complexes from the Changjiang Estuary surface sediment was evaluated(5.4×1011 and 2.1×1012 respectively).Humic acid-metal complexes and syecies complexed with other organic matters are inferred from the above results as the main existing species of the heavy metals in the sediment and interstitial water.