| 两种水体铜配合容量测试方法的适用性比较及应用 |
| 摘要点击 1418 全文点击 561 投稿时间：2016-11-15 修订日期：2016-12-31 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 配合容量 天然水体 铜 萃取动力学法 离子选择电极法 |
| 英文关键词 complexing capacity natural waters copper the extraction kinetics method the ion-selective electrodes method |
|
| 中文摘要 |
| 配合（络合）容量是影响重金属在水体中环境行为的重要指标.为比较两种测量方法测量值的差异及人为污染物对配合容量的影响，以乙二胺四乙酸（EDTA）和安赛蜜分别作为强、弱配体，对水体铜配合容量（CuCC）的双硫腙萃取动力学测试法（萃取法）和离子选择电极测试法（电极法）进行验证和比较.研究发现，萃取法更适合用于测定水体中强配体对CuCC的贡献，而电极法的测试结果与水溶液中强、弱配体的存在均有关联.两种方法对实际水体的测定结果显示，电极法对水库、排污河等地表水体CuCC的测定值（86.9~227.0 μmol·L-1）比萃取法（9.9~14.6 μmol·L-1）高约1个数量级，而对于垃圾渗沥液，电极法的测定值（6998.4~31005.8 μmol·L-1）比萃取法（89.6~109.1 μmol·L-1）高2个数量级.结果表明，污染受纳水体重金属络合容量的升高主要是由弱配体化合物增加导致，且弱配体的含量与水体氨氮和有机氮的总和具有显著的相关性（R=0.975，P<0.01）. |
| 英文摘要 |
| Complexing capacity (CC) is an important indicator affecting the environmental behavior of heavy metals in water, which can be determined by different methods based on different mechanisms. To validate and compare the applicability of different methods in CC determination, the complexing capacity of Cu2+ (CuCC) in solutions of ethylenediamine tetraacetic acid (EDTA) and acesulfame was determined by methods of dithizone extraction kinetics (DEK) and ion-selective electrodes (ISE), while EDTA and acesulfame were selected to represent strong and weak ligands in water, respectively. DEK method was found to be more suitable for determining the contribution of strong ligands to CuCC, while the results determined by ISE were related to both the strong and weak ligands in water. DEK and ISE methods were used to measure CuCC of several actual water samples, including samples from reservoir, discharge river, fishpond, and landfill leachates. CuCC in the water samples of the reservoir and discharge river measured by ISE were 86.9-227.0 μmol·L-1, which were about one order of magnitude higher than those measured by DEK (9.9-14.6 μmol·L-1). For the landfill leachates, CuCC measured by ISE were 6998.4-31005.8 μmol·L-1, which were 2 orders of magnitude higher than those by DEK (89.6-109.1 μmol·L-1). The increase of CuCC in the polluted water samples might be due to the weak ligands like pollutants. A positive correlation (R=0.975, P<0.01) was found between the CuCC related to the weak ligands (ΔCuCC) and the sum concentration of ammonia nitrogen and organic nitrogen in waters. |
|
|
|
