Kuster Anthony C, Huser Brian J, Thongdamrongtham Somjate, Patra Santanu, Padungthon Surapol, Kuster Anootnara T
Department of Environmental Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, Thailand.
Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Water Res. 2023 Apr 1;232:119677. doi: 10.1016/j.watres.2023.119677. Epub 2023 Jan 31.
Drinking water treatment residual (DWTR) derived from flocculation and sedimentation of raw water using aluminum coagulants is a valuable environmental remediation byproduct capable of inactivating phosphorus (P). However, no generalizable model exists in the literature to describe reduction of releasable (mobile) P in lake sediment as a result of DWTR addition. The reduction of mobile P (sum of labile P and reductant soluble P) was investigated in over 100 sub-samples using five sediment samples from two lakes and three DWTRs from different water treatment plants. A consistent relationship was determined across a range of mobile P contents (0.23 g/m/cm to 0.92 g/m/cm, or 15.8 to 186.1 µg/g DW) and DWTRs. The relationship was best described as a function of the mobile P content of the sediment and the oxalate-extractable aluminum content of the DWTR. An empirical model was developed to predict the immediate reduction in mobile P following the addition of DWTR containing aluminum. This model was validated using two additional lake sediments and one additional DWTR (R² = 0.995). Thus, the immediate inactivation of P in lake sediment following DWTR addition can be predicted with this model, which can be used with internal P loading or other water quality goals to determine an appropriate DWTR dose. Further recommendations were made about dosing DWTRs for lake restoration, allowing practitioners to use DWTR to inactivate P in lake sediment without conducting individual sorption experiments.
利用铝混凝剂对原水进行絮凝和沉淀产生的饮用水处理残余物（DWTR）是一种有价值的环境修复副产品，能够使磷（P）失活。然而，文献中不存在可普遍适用的模型来描述添加DWTR后湖泊沉积物中可释放（可移动）磷的减少情况。使用来自两个湖泊的五个沉积物样本和来自不同水处理厂的三种DWTR，对100多个子样本中的可移动磷（不稳定磷和还原剂可溶性磷之和）的减少情况进行了研究。在一系列可移动磷含量（0.23 g/m/cm至0.92 g/m/cm，或15.8至186.1 µg/g DW）和DWTR之间确定了一种一致的关系。这种关系最好描述为沉积物中可移动磷含量和DWTR中草酸盐可提取铝含量的函数。开发了一个经验模型来预测添加含铝DWTR后可移动磷的即时减少情况。使用另外两个湖泊沉积物和一种额外的DWTR对该模型进行了验证（R² = 0.995）。因此，利用该模型可以预测添加DWTR后湖泊沉积物中磷的即时失活情况，该模型可与内部磷负荷或其他水质目标一起使用，以确定合适的DWTR剂量。还就湖泊修复中DWTR的投加量提出了进一步建议，使从业者无需进行单独的吸附实验就能使用DWTR使湖泊沉积物中的磷失活。
