School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China.
Water Res. 2017 Mar 15;111:382-392. doi: 10.1016/j.watres.2017.01.021. Epub 2017 Jan 13.
This is the first study to systematically investigate the characteristics of the water obtained by dewatering cyanobacteria-containing sludge generated in the drinking water treatment plant, including formation of C- and N-disinfection by-products (DBPs). Results showed that this 'dewatering water' (DW) had different properties when the sludge was stored at different times. The content of dissolved organic matter (DOM) and microcystins (MCs) in the DW were low when the sludge was treated or disposed of within 4 days; correspondingly, the C-, N-DBP production was also low. However, due to the damage of algal cells to some extent, the DOM and MC levels increased significantly for storage time longer than 4 days; the production of C-, N-DBPs also increased. There were also obvious differences in the characteristics of the DW from sludges generated with different coagulant species. Due to the better protective effect of FeCl and polymeric aluminium ferric chloride (PAFC) flocs, the DOM and MC levels and the production of C-, N-DBPs in the DW with FeCl and PAFC coagulation were lower than those with AlCl coagulation, even though the sludges were stored for the same amount of time. Furthermore, because of the formation of Al and Fe hydroxides, precipitated onto the surface of flocs, the soluble Al and Fe in the DW decreased with increased storage time, especially in the first four days. Overall, this study revealed the trends in variation of DW quality for cyanobacteria-containing sludges formed with different coagulants, then FeCl and PAFC coagulants are recommended and sludge should be treated or disposed of within 4 days.
这是第一项系统研究从饮用水处理厂生成的含蓝藻污泥中脱水得到的水的特性的研究，包括 C 类和 N 类消毒副产物（DBP）的形成。结果表明，当污泥在不同时间储存时，这种“脱水水”（DW）具有不同的性质。当污泥在 4 天内处理或处置时，DW 中的溶解性有机物（DOM）和微囊藻毒素（MCs）含量较低；相应地，C 类、N 类 DBP 的生成也较低。然而，由于藻类细胞受到一定程度的破坏，DOM 和 MC 水平在储存时间超过 4 天时显著增加；C 类、N 类 DBP 的生成也增加。不同混凝剂生成的污泥 DW 的特性也有明显差异。由于 FeCl 和聚合铝铁（PAFC）絮体具有更好的保护作用，FeCl 和 PAFC 混凝生成的 DW 中的 DOM 和 MC 水平以及 C 类、N 类 DBP 的生成低于 AlCl 混凝生成的 DW，即使污泥储存的时间相同。此外，由于 Al 和 Fe 氢氧化物的形成，沉淀到絮体表面，DW 中的可溶性 Al 和 Fe 随储存时间的增加而减少，尤其是在前四天。总体而言，这项研究揭示了不同混凝剂形成的含蓝藻污泥 DW 质量随时间变化的趋势，建议使用 FeCl 和 PAFC 混凝剂，并在 4 天内处理或处置污泥。
