原子荧光光谱法研究贝壳堤岛贝壳沙中As的空间分布特征

摘要

The present paper determined the As concentration in shell sand of the shell ridge islands by hydride generation atomic fluorescence spectrometry ,studied the distribution of As in shell sand of the shell ridge islands ,analysed the correlations of As with other nutrient elements ,and discussed the probably influencing factors affecting the As concentration and distribution in shell sand .The results showed that the range of the arsenic concentration in shell sand is between 0.78 and 8.76 mg · kg -1 ,the average concentration is 3.11 mg · kg -1 ,and this indicated that the As contamination of the shell ridge island is in clean level . The As concentration of the shell sand has a increasing trend followed by the increase with profile depth or the decrease with the particle size ,and the difference in As concentrations in shell sand of different particle sizes reached the significant level ( p≤0.05) .The As concentration in shell sand has a very significant positive correlation with the concentrations of Cu ,Zn and Mn as well as the TP and TK ,whereas the correlations between As and TN or Fe are not significant .The pollutant of As in the shell sand mainly comes from the absorption and fixation by shell sand from the environment but not the accumulation of the shell organism during their growing up .%用原子荧光光谱法测定了贝壳沙中As元素含量，研究了As在黄河三角洲贝壳堤岛贝壳沙中的空间分布规律，分析了贝壳沙中As与其他营养元素的相关性，并对影响其含量与空间分布的因素进行探讨。结果表明：贝壳沙样品中As的含量范围为0.78～8.76 mg · kg -1，平均值为3.11 mg · kg -1，整体上处于清洁的水平。贝壳沙中As含量有随剖面深度增加而增大的趋势，贝壳沙粒径大小也影响贝壳沙中As的含量，贝壳沙粒径越小，A s含量越高，且不同粒径贝壳沙中A s含量差异显著（ p≤0.05）。贝壳沙中A s与全磷（to-tal phosphor ，TP）和全钾（total potassium ，TK）以及Cu ，Zn ，Mn均具有极显著的正相关关系，与全氮（total nitrogen ，TN）和Fe的相关性不显著。综合分析认为，贝壳沙中As主要来自于风化后的贝壳沙对环境中As元素的吸附与固定而非贝壳形成过程中对该元素的富集作用。