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原文链接：

https://awwa.onlinelibrary.wiley.com/doi/epdf/10.1002/opfl.1650

原文作者：

PETER S. FISKE

原文出处：J Opflow

翻译：阮辰旼

Pack a One-Two Punch Against Lead

一箭双雕对付铅

Akron Ohio, known as the Rubber Capital of the World, has a long tradition of innovation and civic engagement. Municipal water service in Akron began on April 1, 1912, when the city took over the private water company that had been purveying low-quality water to the city’s residents. Today, the City of Akron Water Supply Bureau delivers roughly 35 mgd to nearly 300,000 customers in the city and surrounding areas.

俄亥俄州的阿克伦，被称为世界橡胶之都，有着悠久的创新和公民参与的传统。阿克伦市的市政供水服务始于1912年4月1日，当时该市接管了一家之前向居民提供低质量水的私营水务公司。今天，阿克伦市供水局向该市和周边地区的近30万用户提供大约每天3500万加仑的水。

Lead service lines (LSLs) were common-place at the turn of the 20th century, even though the risks that lead posed to human health were well-known at the time. Like those in many cities of the era, Akron builders often preferred LSLs to cast iron because the former were less expensive and easier to bend to conform to the contours of existing buildings and other structures.

在20世纪之初，尽管铅对人类健康造成的风险在当时是众所周知的，但含铅管道（LSL）还是很普遍的。像那个时代的许多城市一样，阿克伦的建筑商通常喜欢用含铅管道而不是铸铁管，因为前者价格较低，而且更容易弯曲以符合建筑物和其他结构的轮廓。

The City of Akron began to remove LSLs 60 years ago.

阿克伦市在60年前就开始淘汰含铅管道。

“Akron was way ahead of the curve,” says Matt Ebie, utilities chief operator for the city.

“阿克伦市走在了前头”，该市公用事业首席运营商马Matt Ebie说。

At the outset, there were more than 40,000 LSLs. Today, the city has fewer than 4,000, and more are removed every year.

在最开始，该市有超过40,000处含铅管道。到今天，只有不到4,000处，而且每年都有更多的含铅管道被淘汰。

The city also has maintained a proactive approach to ensuring water quality. Akron has been testing its water for lead at customers’ taps since 1992, when the first Lead and Copper Rule (LCR) came into effect. The city also maintains a US Environmental Protection Agency (EPA)–approved corrosion control process consisting of a constant dose of zinc orthophosphate and maintaining a system pH of around 7.3. As a result, Akron’s water has tested within the EPA limit.

该市还保持了一种积极主动的方法来确保水的水质。自1992年以来，阿克伦市一直有在客户的水龙头处检测到水的铅含量，当时正值第一版铅和铜规则（LCR）生效，该市还保持实施着美国环境保护署（EPA）批准的腐蚀控制过程，包括持续的正磷酸锌投加量和保持供水系统的pH值在7.3左右。因此，阿克伦市的水质检测结果得以保持在环保总署的限值范围内。

Many cities with this history of success would probably consider their “lead problem” solved. However, the team at the Akron Water Supply Bureau pursues water quality excellence far beyond the regulatory minimums. In 2019, the Akron team put that principle into practice when     it approached the tricky challenge of optimizing the city’s water quality for both disinfection byproducts (DBPs) and lead.

许多也已经取得了类似成功的城市可能会认为他们的“铅问题”已经得到了解决。然而，阿克伦供水局的团队对水质的追求远远超出了法规规定的最低标准。2019年，阿克伦团队在同时处理优化该市的消毒副产物（DBPs）和铅这一棘手的挑战时，将这一原则付诸于实践。

For surface water treatment plants like Akron’s that use chlorine as a primary and secondary disinfectant, different water quality objectives sometimes require conflicting treatment plant approaches. For example, to minimize DBPs, a water plant might choose to aggressively lower total organic carbon in the incoming water and keep distribution system pH as low as possible to minimize trihalomethane formation in the distribution system.

对于像阿克伦市这样使用氯气作为一级和二级消毒剂的地表水厂，不同的水质目标有时会对水厂提出采取相互矛盾的方法的需求。例如，为了尽量减少消毒副产物，水厂可能会选择积极降低进水的总有机碳，并尽可能保持输配系统的pH值，以减少输配系统中的三卤甲烷形成。

But lower pH in the distribution system raises corrosivity and can cause increases in dissolved lead levels in drinking water. As a result, operators are forced to strike a balance, but the complex interactions between lead solubility, organics, and other dissolved constituents such as manganese can leave operators wondering where the optimal balancing point is.

但输配系统中较低的pH值会提高腐蚀性，并可能导致饮用水中溶解的铅含量增加。因此，操作人员不得不寻求平衡，但铅的溶解度、有机物和其他溶解成分（如锰）之间复杂的相互作用关系会让操作人员不知道最佳平衡点在哪里。

In 2018, Akron Water Supply Bureau implemented Virtual Jar, a new software system developed by Fontus Blue (www. fontusblue.com), to optimize its organics removal as a strategy to lower DBPs in its distribution system. The software system uses treatment plant parameters, including settled turbidity and ultraviolet fluorescence measurements, to accurately predict the effectiveness of different levels of coagulant and powdered activated carbon. The system allowed Ebie and his team to try different combinations of alum and other chemicals on a computer and arrive at an optimal treatment strategy to simultaneously remove turbidity for filter performance and minimize DBPs.

2018年，阿克伦供水局部署了Virtual Jar，一个由Fontus Blue（www. fontusblue.com）开发的新软件系统，可以帮助优化有机物去除，作为降低输配系统中消毒副产物的策略。该软件系统基于水厂运行参数，包括沉淀后的浑浊度和紫外线荧光测量，以准确预测不同水平的混凝剂和粉末活性炭投加后的效果。该系统使Ebie和他的团队能够在计算机上尝试铝盐和其他化学品的不同组合，并得出一个最佳的处理策略，以同时满足滤池去除浑浊度的高性能和消毒副产物生成的最小化。

“The software tool predicted settled turbidity, DBPs, and cost,” Ebie explains. “That really impressed us.”

“该软件工具预测了沉淀后的浑浊度、消毒副产物浓度和成本”，Ebie解释说，“这真的让我们印象深刻。”

“Many of our operators started with a ‘we’ve already done it this way’ mentality,” he adds.

他补充道：“这让我们许多操作人员一开始就能抱有‘我们已经这样做了’的心态。”

At the outset, some team members were concerned that a software model would be used simply to shave alum dosing to save money.

但在最开始时，一些团队的成员担心软件模型只是会简单地为了节省资金而削减铝盐的投加量。

“There was a bit of fear that you’d just look at cost and sacrifice water quality,” Ebie says. “But at our treatment facility, quality comes first.”

“是会有一点担心，担心会只考虑成本而牺牲水质”，Ebie说，“但在我们的处理目标中，水质是第一位的。”

With their initial success in using the new software system to reduce DBPs and improve plant performance, Ebie and team were curious about the following questions: Why is the orthophosphate set at this level? Was there anything the utility could do to further improve lead performance in the distribution system?

随着他们在使用新的软件系统过程中，再减少消毒副产物和改善水厂性能方面取得的初步成功，Ebie和团队对以下问题感到好奇：为什么正磷酸盐被设定在这个水平？公用事业公司是否还有什么可以做的以进一步改善输配系统中的铅的问题？

“Ortho tends to be ‘set it and forget it,’ but would more be better?” Ebie says. “Would pH adjustment improve outcomes? We just didn’t know.”

“软件对参数的修正往往是‘设置它并忘记它’，但做更多的修正就会更好吗？”Ebie说，“pH值的调整会改善结果吗？我们只是不知道。”

The Fontus Blue team returned with a new tool, Corrosion Sentry, which uses advanced chemical models and proprietary insights to optimize orthophosphate addition and distribution system pH. The tool can be applied to systemwide analyses and be used to predict lead risk in premise plumbing.

Fontus Blue团队带着一个新的工具回来了——Corrosion Sentry，它使用先进的化学模型和独有见解来优化正磷酸盐的投加量和输配系统的pH值。该工具可应用于整个供水系统的分析，并可用于提前预测管道中的铅风险。

Ebie and team then discovered the power of simultaneous optimization. By combining the software tools for DBP management with the tools for optimizing corrosion control, the team discovered that there was a “sweet spot” in its treatment strategy that delivered improvements in both DBPs and lead.

Ebie和团队随后发现了同步优化的“力量”。通过将消毒产物管理的软件工具与优化腐蚀控制的工具相结合，该团队发现，在其处理策略中存在一个“甜蜜点”，可以同时改善消毒副产物和铅。

“It’s the best results we’ve ever had for lead,” Ebie notes.

“这是我们从未取得过的控制铅的最好的结果”，Ebie表示。

But the best news came in 2020. In an otherwise challenging year, the Akron team continued to refine its treatment operations using Fontus Blue’s Decision Blue toolbox for advanced water quality monitoring, analysis, treatment optimization, and compliance. As shown in Figure 1, the team reduced lead levels to a historic low and reduced DBPs, plus the team’s optimized use of chemicals saved the city $1.2 million and resulted in a 25% overall reduction in chemical cost of treatment per million gallons of water.

但最好的消息是在2020年取得的。在充满挑战的一年里，阿克伦团队继续在其工艺操作中使用Fontus Blue的Decision Blue工具用于先进的水质监测、分析、处理优化和合规达标等。如图1所示，该团队将铅含量降低到历史最低水平，并减少了消毒副产物，此外，该团队对化学药剂的优化使用为该市节省了120万美元，并使每百万加仑水的化学处理成本总体减少25%。