Dave Brogle of the Middlesex Water Company had a problem.
He’s the plant director of the 60-million-gallon-a-day water treatment facility in Edison, New Jersey, USA.
Dave faced challenges managing the amount of dissolved organic material from its water source. Its main supply of raw water is the Delaware Raritan Canal. Rain events cause runoff, compounding the problem.
“We get a lot of organics,” he said. “There's certain regulations we have to meet on organics removal and disinfection byproduct formations like THMs (trihalomethanes), which are formed when chlorine reacts with the organics. We were having a problem getting high numbers. So we were looking into how we can remove more of it and see what organics were causing the problem.”
The plant had to meet regulatory requirements regarding THMs. Most utilities just measured total organics, which is a combination of everything, Dave said. Middlesex began looking at fractions that make up those organics.
“The goal was to adjust the chemicals so we can remove more organics and reduce the formation of the disinfection byproducts,” he said.
Dave worked with an outside company to fractionate, or breakdown the THMs into smaller components, using fluorescence spectroscopy. But it was a slow, complicated process.
Dave met HORIBA around 2015. HORIBA offered the Aqualog®, which provides the fastest and most sensitive optical analysis of organics in water. It is the only instrument to simultaneously measure both absorbance spectra and fluorescence Excitation-Emission Matrices (A-TEEMs), which are acquired up to a 100 times faster than with other instruments.
HORIBA wanted to get into the water treatment business. The Middlesex Water Company and HORIBA decided to work together to make the Aqualog more useful for the industry.
“We started working on how we could use the data to come up with some real-time information so I can make changes in treatment,” Dave said. “We looked at increasing certain chemicals or decreasing or lowering the pH. We want it to be able to see results in real time. We have these organics going in. If we do this, then we should be reducing our organics going out and therefore the disinfection byproducts.”
Dave began feeding HORIBA data, which it would process and compare it to the actual formation potentials. HORIBA could look at the fluorescence and calculate what those formation potentials would be if the water had made it to the distribution system. The two companies then compared Dave’s results and that of HORIBA’s analysis.
Adam Gilmore, Ph.D., is HORIBA’S Aqualog Product Manager. He’s also Dave’s counterpart in the development of what eventually became the Datastream Dashboard.
Adam said the project came about as a collaborative effort with Middlesex Water primarily but also in consideration of many others.
“We simply realized after we successfully modeled and patented the algorithms for DOC (dissolved organic carbons) with the Aqualog, that we needed an operator level dashboard to eliminate the need for expertise in chemometrics,” Adam said. “Our main goal was to facilitate fingertip access to the vital parameters needed for monitoring and controlling organics and the issues associated with them.”
The ah-ha moment came for the pair when the calculations for the formation potential matched the samples the plant ran in parallel after a two-year period.
“(Adam) was within 99% accuracy on calculating the formation potentials,” Dave said. “So I think that was a ‘eureka’ moment. With any kind of research, it's the time it takes to get something done that's frustrating. It just takes a long time.“
The dashboard interface for the Datastream software works seamlessly with the Aqualog. It enables completely automated analysis and reporting of a wide range of organic matter parameters critical for managing and optimizing the drinking water treatment process. It delivers chemometrics without lengthy user calculations.
“We could get that data in more of a real-time basis and actually make changes at the treatment plant before the water gets out there,” he said.
Middlesex has its own in-house laboratory but also sends samples out to other labs. The company has an organics lab to analyze volatile organics.
“The Datastream software makes it so that we can get to the data we want quickly,” Dave said. “You run your samples and you get your results. Before that, you had to take your data and use software to do whatever they do with the data. Now we can just put the samples in and we get our numbers coming out. It has simplified the whole process.”
How much did it shorten it by?
“I would say probably by days” Dave said.
Middlesex plans to expand the treatment at the plant, switching to ozone as its primary disinfectant. Ozone, Dave said, is more expensive but also more effective at disinfecting the water supply.
“We're moving away from chlorine as a primary disinfectant. We're looking to reduce the organics even more. Ozone does a better job at that. It’s a stronger oxidant. Construction will start in June and take about two years to complete.”
In the meantime, Middlesex has been running a pilot study for the past year with an ozone pilot plant that is processing six gallons a minute. They have been running samples from the plant to study the process.
The online treatment process currently in operation requires sampling from various sources.
“We also sample up the canal, in certain areas,” Dave said. “That gives us like a two or three-day advanced notice of what's coming at us, so we can be prepared when it gets here. Because you can only treat the water once. Once it goes through the plant, we can't get it back.”
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