Adaptation of Working Conditions of an Operating Drinking Water Treatment Plant to Remove Naturally Occurring Radionuclides
Adaptation of Working Conditions of an Operating Drinking Water Treatment Plant to Remove Naturally Occurring Radionuclides
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DOI：
10.1007/s11270-012-1258-6
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发表时间：
2012-09-01
影响因子：
2.9
通讯作者：
Guillen, J.
中科院分区：
文献类型：
--
作者：
Baeza, A.;Salas, A.;Guillen, J.
人类饮用的水中含有铀和镭等自然产生的放射性核素。有几种方法可以去除饮用水中的铀和（或）镭含量，尽管它们主要只用于实验室试验，只有少数情况在试验工厂中使用。在目前的工作中，选择了一个总α活性高于0.1 Bq L-1阈值的正在运行的饮用水处理厂（DWTP），水的铀含量是造成这一活性的主要原因。DWTP中使用的常规程序无法从饮用水中去除这种活性。对混凝-絮凝步骤中的程序进行了修改，成功地从人群最终消耗的饮用水中去除了50- 83%的铀，由此产生的总α活性降至0.1 Bq L-1以下。修改后的程序是可逆的——只要程序停止，铀就不会被移除。除去的铀最终浓缩在工厂产生的污泥中。对污泥进行的顺序萃取程序表明，大部分污泥附着在易还原和适度还原的馏分上，因此分别可以用羟胺和草酸铵提取。这是因为在混凝-絮凝过程中，铀基本上通过与氧化铝的结合而被去除。
Naturally occurring radionuclides such as uranium and radium are present in water used for human consumption. There are several procedures to remove the uranium and/or radium content in drinking water, although they have mainly been used just in laboratory tests, and in only a few cases in pilot plants. In the present work, an operating drinking water treatment plant (DWTP) with gross alpha activity above the 0.1 Bq L-1 threshold was selected, with the water's uranium content being principally responsible for this activity. The routine procedure used in the DWTP was incapable of removing this activity from the drinking water. A modification of the procedure in the coagulation-flocculation step successfully removed 50-83 % of the uranium from the drinking water finally consumed by the population, with the resulting gross alpha activity being reduced to below 0.1 Bq L-1. The modified procedure was reversible-whenever the procedure was halted, no uranium was removed. The uranium removed ended up concentrated in the sludge generated by the plant. A sequential extraction procedure applied to the sludge showed most of it to be attached to the easily and moderately reducible fractions and hence extractable with hydroxylamine and ammonium oxalate, respectively. This was because in the coagulation-flocculation process, the uranium was essentially removed by association with aluminium oxides.