College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Engineering Research Center for Agricultural Water-Saving and Water Resources, Ministry of Education, Beijing 100083, China.
Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil.
Sci Total Environ. 2021 Dec 1;798:148900. doi: 10.1016/j.scitotenv.2021.148900. Epub 2021 Jul 8.
Fouling growth in brackish water distribution systems (BWDS), especially calcium-silica fouling, is inevitable issue in brackish water desalination, chemical and agricultural industry, eventually threaten the cleaner production process and environment. Magnetic Field (MF) has been a greener and effective technology to control calcium carbonate fouling. However, the effects of MF on composite calcium-silica fouling are still elusive. Therefore, this paper assessed the effect of MF on calcium and silica fouling. We found that MF not only significantly reduce the calcium carbonate fouling, but also obviously decreased the silica fouling. The MF reduced the calcite fouling reached 38.2%-64.3% by changing water quality parameters to trigger the transformation rate of CaCO crystal from compact calcite to looser aragonite, as well as increase the unit-cell parameters and chemical bond lengths of calcite and aragonite. The MF also decreased the content of silica fouling (silica and silicate) reached 22.4-46.3% by reducing the concentration of soluble silica and accelerating the flocculation settlement to form large size solid particles in BW. Furthermore, MF broke the synergistic interactions among calcium and silica fouling. In addition, the anti-fouling ability of permanent MF was higher by 12.3-35.1% than electric MF. Overall, these findings demonstrate that MF is an effective and chemical-free technology to control calcium-silica fouling in BWDS, and provide a new perspective for sustainable application of brackish water.
海水中配水系统（BWDS）中的结垢生长，尤其是硅钙结垢，是海水淡化、化工和农业等行业不可避免的问题，最终会威胁到清洁生产过程和环境。磁场（MF）是一种绿色且有效的控制碳酸钙结垢的技术。然而，MF 对复合硅钙结垢的影响仍不清楚。因此，本文评估了 MF 对钙和硅结垢的影响。我们发现，MF 不仅显著降低了碳酸钙结垢，而且明显降低了硅结垢。MF 通过改变水质参数来触发 CaCO 晶体的转化速率，从致密的方解石转变为较松散的文石，从而减少了方解石结垢，降幅达 38.2%-64.3%，同时增加了方解石和文石的晶胞参数和化学键长度。MF 还通过降低可溶性硅的浓度并加速絮体沉降，在 BW 中形成大尺寸的固体颗粒，从而减少了硅结垢（硅和硅酸盐）的含量，降幅达 22.4-46.3%。此外，MF 打破了钙和硅结垢之间的协同相互作用。此外，永久 MF 的抗结垢能力比电动 MF 高 12.3-35.1%。总之，这些发现表明，MF 是一种控制 BWDS 中硅钙结垢的有效且无化学物质的技术，为可持续利用海水提供了新的视角。
