The Financial Benefits of Water Treatment

Due to the rising costs of water use and disposal, improved treatment technologies make economic sense.

While chemical processors think of themselves as just that — makers of chemicals — they don’t often consider themselves players in the water industry. However, due to a combination of drivers, such as water scarcity and pressure to clean up discharge water coupled with improved water treatment technologies and tools, it may be time to consider water treatment as more than a necessary method to improve water quality for process or discharge. In fact, experts agree that water treatment can also be an integral part of the chemical processing business and a way to boost the bottom line.

“No matter what business you’re in, you’re also in the water business, simply because of the fact that you can’t manufacture anything without using water in the process industry,” says Justin Mattingly, research manager with the Water Environment & Reuse Foundation (WE&RF; Alexandria, Va.; www.werf.org), which recently completed a project — Framework for the Successful Implementation of On-Site Industrial Reuse — that provides tools for industry to identify, evaluate and implement onsite water conservation and reuse opportunities.

And, as large consumers of water, processors need to be aware that water is quickly becoming a scarce resource in many regions around the world. Nanette Hermsen, global marketing director for reverse osmosis at Dow Water & Process Solutions (Edina, Minn.; www.dowwaterandprocess.com), cites statistics from UN-Water (the United Nations interagency mechanism on freshwater-related issues; www.unwater.org), which suggest that over the course of 50 years, from 2000 to 2050, the global manufacturing demand for water is expected to increase by 400%. “The increasing demand for water in industry combined with water scarcity issues means we have to use water effectively and get more out of every cycle, every loop and every drop of water so there’s no waste,” she says. “As such, industry has begun using more wastewater and more challenging waters as feed water, so there’s been a strong push for designing technologies and processes to accommodate these more challenging streams, whether it’s on the front end or the back end, because they are looking more and more alike these days. Water treatment in a circular economy approach means that your back end often becomes your front end.”

THE FINANCIAL CASE FOR TREATMENT

Mattingly agrees, and adds that it is also possible for processors to financially benefit from water treatment and water reuse. “While drivers for water treatment, specifically water reuse, are usually water shortages or discharge restrictions, it’s becoming more important for industry to peel back the onion on water use and identify opportunities on investments that allow them to not only treat water for their needs, but also to reap some significant financial awards by doing so,” he explains.

How so? According to Eric Hoek, CEO of Water Planet (Los Angeles, Calif.; www.waterplanet.com), the cost of purchasing and disposing of water has gone up to the extent where water is a major expense for industry, but treating and reusing that water reduces those costs. “Due to water scarcity, the cost of sourcing fresh water for industrial purposes has increased. At the same time, the cost of disposing of water, either by treating wastewater to a very high level for sewer disposal or paying someone to accept it, has climbed. So we have a situation where going the traditional route of buying water from the local municipality and treating for disposal has become very burdensome,” explains Hoek. “However, today’s water-treatment technologies have gotten to the point where they are more effective and less expensive, which creates a situation where treating and recycling that water for reuse is a straight up reduction in costs.”

He says, in most cases, a return on investment for the technology needed to treat water for reuse can be seen in less than five years. “Even when there is a need for advanced treatment technologies, water reuse offsets the costs dramatically.”

As a matter of fact, WE&RF is working on a second project — Scorecard for Evaluating Opportunities in Industrial Water Reuse — which aims to develop a user-friendly return on investment (ROI) calculator for onsite water reuse. “We’re trying to make visible the full cost of water to help industry get a more accurate calculation of the cost of water, which includes how much you pay per gallon of water, the volume of water used, the energy needed to heat and treat that water for process, the energy used to treat that water for disposal and the cost to dispose of the water, as well as water supply availability and the costs associated with risk of water shortage,” explains Mattingly. “Only by understanding the full cost of water, can you get an accurate calculation for the ROI of onsite reuse technology and water efficiency.”

He adds, however, that initial capital investment is just one point that may deter facility decision makers. “We also need to educate them on today’s available treatment technologies and the concept of reuse because they need to have the confidence that the water being produced will be suitable for their needs.” In an effort to boost confidence in water-treatment technologies, the organization includes a section in its first report with a full survey of the available technologies, how they operate and their capabilities in meeting treatment needs.

Some of the newest technologies are discussed below.

WATER REUSE TECHNOLOGIES

Membrane technology has long been used for water treatment because it’s very compact and highly automated. However, until recently, available membrane technologies — polymeric and ceramic membranes — had drawbacks. Hoek says polymeric membranes foul quickly, requiring frequent cleaning, while ceramic membranes are more robust but extremely expensive. “It created a paradigm where everyone would like to use membranes, but found them too expensive or unreliable.”

To alleviate this problem, Water Planet created a membrane material that can handle fouling, is easy to clean and is more chemically and thermally robust than conventional polymeric materials, but is still a polymer. “The result is PolyCera, which offers polymer economics with ceramic performance,” says Hoek. “It is a low-cost alternative to ceramics, but reliable enough to be deployed in difficult-to-treat industrial wastewaters.”

Available as flat sheets or in spiral monolith elements, PolyCera membranes offer a ceramic-like combination of high hydrophilicity, permeability and robustness, but at 10 to 20 times lower cost. The spiral monolith elements leverage benefits in a ceramic-like crossflow, back-washable filtration module. “Our testing shows operating expense savings og up to 40% relative to commodity polymer membranes and 80% relative to ceramic membranes,” says Hoek. “It allows our customers to stop doing nothing and start choosing to recycle and reuse their water.”

In the water reuse space is an approach known as Minimal Liquid Discharge (MLD), an alternative to Zero Liquid Discharge (ZLD), which can be expensive and not always environmentally friendly because of the energy and resources required to get discharges down to zero. “Some industrial and municipal users are turning to MLD to achieve up to a 95% liquid-discharge recovery, but at a fraction of ZLD cost,” says Hermsen. “MLD is attractive because they aren’t paying for water intake and water disposal via the use of a combination of different technologies.” In an effort to promote MLD and reuse, one of Dow’s newest product lines, Filmtec Fortilife, consists of new elements designed to meet these needs. Fortilife XC70, XC80 and XC-N offer advantages for plants looking to reduce costly concentrate waste, lower operating expense and achieve MLD goals.

Dow’s IntegraFlux Ultrafiltration Modules with XP fibers are meant to handle the challenging demands of closed-loop water systems and are typically used in conjunction with reverse osmosis (RO) in systems using an MLD approach, says Hermsen.

Recognizing the systematic approach to cleaning up water for reuse, as well as treating river or alternative water sources for use, another player in the water treatment industry has also tweaked existing technologies to provide higher efficiencies. “As we look to alternative water sources, such as river water and resource recovery, we, as treatment providers, have invested in research to develop technologies that are more efficient and robust so that our users can employ alternative sources and reuse effluent to improve their own efficiencies,” says Ben Moore, business development manager with Veolia Water Technologies (High Wycombe, U.K.; www.veoliawatertechnologies.com.uk). As a result, the company has made improvements to many of its traditional treatment methods. For example, Veolia offers Actiflo, a high-rate, compact water-clarification process in which water is flocculated with microsand and polymer in a draft tube (Figure 4). The microsand enhances the formation of robust flocs and acts as a ballast, significantly increasing their settling velocity. The resulting microsand ballasted flocs allow for clarifier designs with very short retention times, high rise rates and extremely compact footprints. “On the back of that, our Rapide Strata twin-bed deionizers help produce high-purity water, while offering savings of up to 40% on running and effluent costs compared to conventional ion-exchange systems. The improved technology offers regeneration in 30 to 45 minutes, minimizes downtime, enhances bacterial control and improves chemical usage efficiencies,” notes Moore. He also cites improvements to the company’s Sirion Mega RO system for industrial process water, wastewater and water reuse applications. It can be used alone or in combination with processes such as ion exchange in applications where total dissolved solids (TDS) concentrations in water must be reduced. The RO membrane also acts as a very fine filter, removing 99% of suspended and colloidal solids, bacterial and organic molecules. This makes the process attractive in applications where treated water not only has to be low in TDS but also of high clarity and free from bacteria, such as in food processing and pharmaceutical manufacturing. “All these systems from deionizers to RO are becoming more and more efficient and can reliably recover more water to improve efficiencies and costs,” says Moore.

MORE EFFICIENT WATER TREATMENT

Thanks to technology adaptations, water treatment for applications other than reuse has also become more efficient and cost effective. For example, in the oil-and-gas industry, there are a number of problems associated with controlling microorganisms via chemicals. “Companies in this sector need to use a form of disinfection technology to avoid a range of negative consequences in the well, the equipment and the piping systems that can be caused by uncontrolled colonies of bacteria,” explains Paul Hennessey, oil, gas and energy business manager with atg UV Technology (Lancashire, U.K.; www.atguv.com). “For the last 30 or 40 years, that has been done using chemicals. However, there are not only transportation and storage issues associated with using chemicals in offshore applications, but also issues related to chemical-induced byproducts that have to be taken down to undetectable limits before wastewater can be discharged into the ocean. This required extra equipment, time and expense,” he says. “So it became necessary to take a holistic approach to avoid putting something in on the front end that has to be removed on the back end.”

The solution turned out to be ultraviolet (UV) technology — an existing technology with a new use (Figure 5). “We use the same technology that’s been used in municipal drinking and wastewater treatment for years, but packaged it in a different way and designed it to target oil field microorganisms,” says Hennessey. “It is chemical free, so there’s no toxicity, no need to transport, store or handle chemicals and it creates no residual byproducts that need treatment.”

Here, too, tweaks to an existing technology have created a solution that is not only more efficient, but also less expensive. “Treatment chemicals weren’t inexpensive and to properly treat these applications, you needed a whole cocktail of chemicals applied at different stages,” he says. “So when you take the whole chemical solution and treatment process and compare it to UV, UV is much less expensive.” He says one oil-and-gas major company used to spend£200,000 ($251,000) a year on treatment chemicals, but moved to UV technology, with a consumable cost of the UV system equipment and energy to run it of£15,000 ($18,800) a year. “That’s a savings of£185,000 ($232,200) a year when using UV as opposed to traditional chemical treatment,” says Hennessey.

Clearly, treatment technologies have improved, allowing users to see significant economic benefits. “A lot of these technologies have been available for decades, but they are more advanced, more energy efficient and cost effective than ever before,” says Dow’s Hermsen. “This provides significant advancements in water and wastewater treatment, recovery and reuse and affords users better sustainability and cost benefits, which is what we’re all striving for in a water-strapped environment.”

Source: Chemical Engineering

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Taxonomy

• Water
• Treatment
• Chemical Treatment