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The Other Scarce Resource

Water treatment firms help industry close the water loop

by Melody Voith
October 6, 2008 | A version of this story appeared in Volume 86, Issue 40

In the flow
Credit: Nalco
Nalco sales engineers and customers review the performance metrics of a cooling tower.
Credit: Nalco
Nalco sales engineers and customers review the performance metrics of a cooling tower.

CHEAP AND PLENTIFUL, water was for centuries a manufacturing tool that industry took for granted. But population growth, globalization, and climate change are shepherding in a new water-constrained era. Good, clean water just cannot be replaced—and it is getting harder to come by.

For big industrial companies such as Dow Chemical and General Electric, water presents both an operational challenge and an opportunity for growth. As manufacturers, they must manage their physical operations in a way that conserves and reuses water. As suppliers to other manufacturers, they are investing in new technologies to take advantage of the evolving demand for water treatment chemicals, services, and equipment.

Manufacturers have been keeping a keen eye on rising energy prices; their concerns about water, in contrast, are turning more and more to the risk of running out. "Everyone shares this water model where it's cheap, cheap, cheap—then unavailable," says Scott Noesen, director of sustainability and business integration at Dow Water Solutions. For Dow, water has become a major strategic issue. "It's huge because we're trying to grow around the world, and where we want to grow often has issues of fresh water," Noesen says.

Specialty chemical companies have long played a key role in ensuring that industry has high-quality water both for manufacturing products and for keeping plants running smoothly. When there was plenty of clean water, facilities could use as much as they wanted, treat it, and emit it as a waste stream. That "once through" pattern has changed. In dry areas manufacturers may have little or no access to clean water, and in some places where water is plentiful, regulations make wastewater discharge costly or impossible.

With access to clean water a growing worry to business, water treatment companies such as Dow, Nalco, Ashland, and GE have invested in research and development and acquisitions to expand the reach of their water product lines.

Their choices for investment have expanded well beyond standard chemical additives, and now even traditional chemical companies are positioning themselves as full-service providers. That means they have to offer expertise in a range of chemical, biological, and physical treatment options.

Chemistry is still the basis of many water treatment systems, including biocides that kill and prevent the growth of microbes, softening salts that remove magnesium and calcium, flocculants and coagulants that remove suspended particles, and resins that add or remove ions.

Other treatment solutions, such as semipermeable polymer membranes for filtration and purification, are the products of chemistry but don't involve the addition of chemicals. In micro- and ultrafiltration, porous membranes filter out suspended solids. Reverse osmosis and nanofiltration membranes do not have pores; they remove contaminant salts as the water diffuses through them.

Bug zapper
Credit: Ashland
Ashland's Sonoxide water treatment system uses ultrasound to disrupt the cellular structures of microbial contaminants.
Credit: Ashland
Ashland's Sonoxide water treatment system uses ultrasound to disrupt the cellular structures of microbial contaminants.

IF CUSTOMERS wish to further avoid adding chemicals, they can select systems that use energy in the form of electricity, ultraviolet light, or ultrasound to kill microbes and deionize water. Companies also offer biological control, which uses beneficial aerobic and anaerobic bacteria to break down dissolved organic material.

Steven Prod, vice president for marketing at Ashland Water Technology, estimates that the global water treatment business is worth between $300 billion and $350 billion per year. Prod says his company has set its sights on a $10 billion to $20 billion slice of the pie. To get there, Ashland is responding to customer demand for green technologies, some of which are nonchemical solutions, Prod says.

Ashland's planned acquisition of Hercules, announced in July, "signals that we believe very strongly about growth and viability of the water technology space," Prod says (C&EN, July 21, page 11). He points to Hercules' paper technology and Aqualon water polymers businesses as significant additions to Ashland's water investments.

Growth in the water treatment business stems from more than just concerns about scarcity. Most customers are aware that their use of water has an impact on their corporate reputation, according to Eric Meliton, a Frost & Sullivan research analyst who covers environmental technologies. "Major corporations like IBM and ExxonMobil all have sustainability objectives," he notes, adding that water, both in the amount used and in the amount discharged, is a big player in metrics of sustainability.

The United Nations warns that the world's use of water is not sustainable. Globally, agriculture claims 70% of the world's supply of fresh water, leaving little for industry. In the U.S. water is apportioned differently. Agriculture takes less than 40% of the 345 billion gal of fresh water used per day, and almost the same amount is used in power generation. Household and business use is the third-largest segment, at 12.5%, and industry uses 5.3%, according to the U.S. Geological Survey (USGS).

The shocking amount of water consumed in power generation in the U.S. is due to the use of surface water in cooling systems. Although these once-through systems are becoming less common, even closed-loop versions use large amounts of water to replace contaminated water and make up for evaporation and leakage.

Aside from power generation, the thirstiest water consumers are petroleum refineries, organic and inorganic chemical manufacturers, steel mills, and pulp and paper mills, according to USGS. These industries also use a great deal of water for utility purposes—heating and cooling—just as power plants do.

Pulp and paper mills, semiconductor manufacturers, and pharmaceutical makers have a special problem—they require ultrapure water. As the quality and quantity of water they bring into their facilities worsens because of either pollution or regulatory restrictions, their treatment costs increase, Frost & Sullivan's Meliton says.

According to Marilee A. Horn, a water specialist at USGS, water use by industry has actually declined since the 1970s. She attributes the decrease to the Clean Water Act, which raised the cost of discharging wastewater, and to the replacement of older industrial facilities. "Typically, newer facilities incorporate pollution controls that limit the amount of water used per unit of production," she explains.

ANOTHER REASON for the decrease is the significant migration of U.S. manufacturing overseas. Now, industry has to manage water use under two very different scenarios: at home in older facilities where local water and environmental rules are becoming more stringent and at new sites in developing regions where there may be little or no water allotment for industry at all.

In industrial water management, geography is destiny. "We've grown to understand that water is a local or regional issue. Each place will have unique issues around water," says Gena Leathers, global technology leader for water and wastewater for Dow's chemical operations. Her team stays busy doing studies of risk related to water availability at a particular location, either an existing facility or one where Dow might want to build.

The findings help the company choose among several possible strategies: retooling to use municipal wastewater rather than fresh water, recycling, new treatment technologies, or even simple solutions such as a waste reduction awards program. But these strategies have many possible constraints. "Where you don't have ability to discharge, that becomes the driver," Leathers says. "We look for opportunities to reduce waste at the source. But we also look at it from an economic perspective." In some new locations Dow avoids external water suppliers entirely by incorporating zero liquid discharge—by way of such tactics as distillation and reuse—into the plant design.

At Nalco, one of the chemical industry's few pure-play water treatment companies, assisting customers who expand overseas introduces a new level of complexity. "In the Middle East the petrochemical expansion has real water challenges that can differ from those facing microelectronics in Silicon Valley. Everyone wants to save water," says Mary K. Kaufmann, the firm's chief marketing officer.

Water shortages can happen anywhere and, according to the UN, they are increasing around the world in both rich and poor countries. In addition to the Middle East, the southwestern U.S., Mexico, parts of Africa, China, and India all suffer from physical water scarcity, meaning there are not sufficient water resources to meet the competing needs of population, agriculture, and industry.

In other areas of Africa, Central America, and Asia, water is abundant, but lack of infrastructure and regional poverty make it difficult for people to meet their daily needs. Long-term regional drought conditions—such as those found now in the southeastern U.S., parts of Europe, and Australia—are hard to predict and usually require water use reductions for industry and residents.

According to the UN, the big pressure on water supplies in the future will come from irrigation for food crops. Global population is expected to reach 8.1 billion by 2030, and the UN has called for the agriculture sector to find ways to grow more with less water. In the meantime, rising food consumption in developing regions will increasingly squeeze urban and industrial water users.

MANUFACTURERS THAT face water risk in existing facilities work closely with water treatment companies to find opportunities to decrease water use, according to Kaufmann. She says Nalco practices a service model that includes a close audit of where water comes from and where it goes.

Nalco's team focuses on the three biggest streams in an industrial facility: cooling water, wastewater, and boiler water. "The first thing we do is look at water minimization, ways the company can just use less," Kaufmann says. Any pipe that is going into the ground, she explains, is a sign that water is not being reused effectively.

According to Kaufmann, Nalco's experts find many opportunities to reuse water. "We can take water of one quality, put it in a production stream, and reuse it rather than get fresh water," she says. One example is using boiler wastewater in cooling towers. Each time a company reuses water, it has to remove contaminants before sending it to the next destination. Once those streams are optimized, the last and most expensive step is to recycle water from the waste stream back to the front end.

Spending on water technologies can create cost savings elsewhere in the business mix. Kaufmann gives the example of pretreating boiler water. If a customer installs a reverse-osmosis-based mineral removal system, it can save money twice; cleaner water does not need to be replaced as often, and hot water from the boiler can be used elsewhere in the plant without having to reheat it.

Other times, though, there is a financial trade-off between water and energy. Reverse osmosis is a much cheaper way to desalinate seawater than older distillation methods, but it is still too energy intensive to use in industry except where there is absolutely no clean water available, Kaufmann acknowledges.

Dow Water Solutions has made reverse osmosis desalination a focus of its business and is working to decrease energy costs, according to the business' global R&D director, David Klanecky. "Energy is definitely a component of any water treatment issue or facility," he says. "We are developing low-energy membranes that require less energy to remove contaminants and pump water through." Dow is also looking at ways to recover and reuse the latent energy in industrial water systems.

Nalco is betting that automation and control technologies will be the key to reducing water, energy, and chemical inputs at the same time. Its 3D Trasar cooling water treatment program was awarded the Environmental Protection Agency's 2008 Green Chemistry Challenge Award in the category of greener reaction conditions (C&EN, June 30, page 9). The system includes treatment chemicals, automation, and computer-modeling tools that monitor system water and adjust chemistry to minimize stress on a customer's cooling equipment.

Unmonitored water can result in poor heat transfer, wasted water and chemicals, and a shorter life span for cooling machinery. When cooling water goes bad, it causes corrosion, fouling from suspended solids, scaling, and insulation by microbial biofilms. At times the water used for cooling is actually process water from a manufacturing waste stream. Plant workers usually add treatment agents and biocides to keep the systems running, but over time, the heat exchangers stop working effectively.

In 3D Trasar case studies from the semiconductor and petrochemical industries, Nalco found that real-time monitoring helped workers compensate for the changing quality of cooling water.


The Nalco system also uses new chemistry. When a chemical such as an orthophosphate, which is used to control corrosion, reacts with calcium ions in the water, it forms tricalcium phosphate and leaves a hard scale on the copper walls of the heat exchanger.

The Nalco system uses a new corrosion inhibitor, phosphino succinic oligomer, that controls both corrosion and scale in highly variable water sources. As a result, Nalco says, its customers were able to cycle cooling tower water several times. At the petrochemical plant the result was an annual water savings of 65 million gal.

At Ashland the newest water treatment technology bypasses chemicals in favor of low-power, high-frequency, ultrasonic energy. The company claims that its Sonoxide equipment controls bacteria, biofilms, and algae, thereby reducing or eliminating the need for chemical biocides.

BUT THE COMPANY is not leaving chemistry behind. Prod says Ashland researchers are "investigating ways to switch out inorganic for organic chemistries in our formulations and testing new organic, environmentally friendly chemicals." Part of the test is to ensure that the new treatments are of the same high quality to protect customer infrastructure, he says.

Process chemistry changes won't help if the well goes dry. Frost & Sullivan's Meliton reports that companies operating in water-scarce areas have to go to painful lengths to secure new sources. "Plants in California are told they cannot exceed certain levels of withdrawal" from public sources, "and they need to find new ways to get water for manufacturing through desalination or shipping in water," Meliton says. Some counties in the state, he says, require industry to use municipal "gray" water, untreated wastewater that has not come into contact with toilet waste.

Michael S. Stadnyckyj, global marketing leader for GE Water & Process Technologies, says municipal wastewater is becoming a common source of water for business and industry. "In Tempe, Ariz., they are reusing 10 million gal of wastewater per day by sending it to the power plant for cooling towers, to the golf course for irrigation, and into a man-made lake," he says.

Indeed, Stadnyckyj sees big changes coming in how water will be reused: "In the future there is no question—there will be no other option than to use highly treated wastewater for regular daily uses."

Industries that rely on ultrapure water are already spending most of their water dollars on the front end of the water cycle, according to Meliton. In the U.S. the bill for a year of water treatment is up to $250 million for the pulp and paper industry and $350 million for the pharmaceutical industry. Because of extremely strict water quality standards, the pharmaceutical industry has led the world in pursuit of cutting-edge technologies. Its tool kit has grown to include reverse osmosis, ion exchange, electrodeionization, UV light, and ultra- and microfiltration.

In the 1990s, the pharmaceutical industry started shifting toward a new type of system called a microbioreactor (MBR). These days, material advances and cost reductions have led water experts to hail MBR as the technology of the future for wastewater recycling. The systems combine biological decomposition with state-of-the-art hollow-fiber filtration membranes.

Squeaky clean
Credit: Siemens
The pharmaceutical industry uses reverse osmosis to obtain ultrapure water.
Credit: Siemens
The pharmaceutical industry uses reverse osmosis to obtain ultrapure water.

The attractiveness of MBR is "universal," Meliton says. "Now, Siemens and GE are in an arms race with this technology, acquiring smaller companies to clear out the competition," he says. GE's 2006 acquisition of Zenon Environmental, a Canadian manufacturer of hollow-fiber ultrafiltration membranes, "jump-started MBR technology," Meliton adds.

Stadnyckyj says GE has developed the once-finicky MBR technology to the point where it can be used in such grungy locales as municipal wastewater plants and oil sands operations in Alberta. MBR can clean wastewater to the point where it is a valuable resource again. "For example, a food and beverage maker can take its wastewater and produce drinking-quality water that can be reused," Stadnyckyj says.

Dow is pilot testing its own MBR systems, according to Klanecky, and hopes to have a product on the market in 2009. Dow estimates that MBR equipment sales are growing 15 to 20% annually and predicts that by 2010 MBR technology for industrial and municipal wastewater treatment will have a global market value of more than $360 million.

Dow and its competitors will offer their own versions of the technology, but all the systems combine biological and physical treatment. In the first stage, water that has been filtered of large debris goes into a bioreactor. The two-part tank uses aerobic and anaerobic bacteria to break down and digest organic materials in the water.

The membrane portion takes over from there. It contains hollow, spaghetti-like fibers made of tough hydrophobic polymers, such as polyvinylidene fluoride, which contain billions of microscopic pores. A pump creates a gentle, low-energy vacuum to draw clean water through the membranes, up the tubes, and out to a storage facility.

As a new waste treatment technology, MBR faces two hurdles, according to Meliton: cost and inertia. "It's the wave of the future, but the price is still high and there is not enough reputation built behind it yet," he says. Also, some customers needing specialized applications—such as the ability to clean high-temperature water—will have to wait for the next generation of MBR.

Industrial firms dependent on clean water can be assured that innovation will continue to flow, Ashland's Prod says. "The market is looking for greener and more sustainable solutions for water treatment," he says. "We want to be ahead of those trends, so we have many irons in the fire."

GE's Stadnyckyj adds that policies and incentives will also drive development and adoption of new technologies: "If you look at what's happening right now in the states, there are no standards or policies for reuse across the board." He predicts that government incentives to reuse water will create a virtuous feedback loop that will bring technology costs down for everyone and lessen the competition for scarce resources. "We have to find a balance in managing where the water goes," he says.


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