Devine Christina, Wang Fei, Edwards Marc
Virginia Tech, Civil and Environmental Engineering Department, Blacksburg, Virginia, USA.
Environ Eng Sci. 2021 Dec 1;38(12):1109-1119. doi: 10.1089/ees.2021.0047. Epub 2021 Dec 9.
Precipitation of calcium carbonate (i.e., scaling) can occur in both traditional tank (electric and gas) and "green" tankless hot water systems that have implications for public health, water and energy sustainability, infrastructure damage, and consumer esthetics. There are many scale reduction devices and technologies that aim to reduce or eliminate such problems, and several standardized methods have been proposed to research their performance with scientific rigor. All of the existing approaches were inherently nonreproducible or could not quantify important aspects of scale deposition, including quantity, location, and deposit durability. Here we develop and vet a Standardized Scaling Test Protocol that overcomes many of these deficiencies, using a laboratory-scale model premise plumbing system and a synthesized synthetic scaling water that could be reproduced in any laboratory. This approach produced 25.1 g of calcium carbonate scaling (95% confidence interval of 20.3-29.8 g, = 3) in ∼5 days. Illustrative scale reduction for a range of representative technologies, including cation exchange, electrochemical deionization, magnetism, electric field generator, media-induced precipitation, phosphate sacrificial media, and citric acid sacrificial media, ranged from 0% to 100% using the standardized protocol. The general approach was also applied to suitable local natural water with high scaling potential, and similar capabilities were observed.
碳酸钙沉淀（即结垢）可能发生在传统水箱（电热水器和燃气热水器）以及“绿色”即热式热水系统中，这对公众健康、水和能源的可持续性、基础设施损坏以及消费者美观都有影响。有许多旨在减少或消除此类问题的除垢设备和技术，并且已经提出了几种标准化方法来严格科学地研究它们的性能。所有现有的方法本质上都不可重复，或者无法量化结垢沉积的重要方面，包括数量、位置和沉积物耐久性。在这里，我们开发并验证了一种标准化结垢测试方案，该方案克服了许多这些缺陷，使用实验室规模模型的房屋管道系统和一种可以在任何实验室中重现的合成结垢水。这种方法在大约5天内产生了25.1克碳酸钙结垢（95%置信区间为20.3 - 29.8克，n = 3）。使用标准化方案，一系列代表性技术（包括阳离子交换、电化学去离子、磁、电场发生器、介质诱导沉淀、磷酸盐牺牲介质和柠檬酸牺牲介质）的除垢效果从0%到100%不等。该通用方法也应用于具有高结垢潜力的合适当地天然水，并观察到了类似的效果。
