Water Conservation Is Becoming a Sustainability Imperative

Pressure to reduce water consumption and switch to other, often lower-quality, sources is prompting a major rethink about how chemical companies manage and use their water resources. Optimization has become a corporate mantra.

"An increasing challenge is water scarcity and ensuring that the population has enough for their needs, so we are seeing increasing restrictions on where industry can get water -- plus increasing cost. Industry is also seeing significant increases in wastewater sewer fees -- disproportionately so compared with homes," notes Derek Miller, North American industrial water manager, Air Products and Chemicals, Allentown, Pa.

"Our customers are facing three pinches in terms of their water utility footprints," says Glen Messina, global business leader, chemical monitoring solutions business -- water and process technologies for GE Power & Water, Trevose, Pa.

First, global constraints on the supply of fresh water are growing: regulations now are beginning either to prevent companies from using municipal fresh water or taking more from rivers.

Second, companies face declining water quality -- for example, plants more and more must take discharge water from municipal treatment plants.

Third, increasingly stringent regulations worldwide govern discharges, even sometimes banning them. Traditional tailing ponds are being closed down, so new ways are needed to recondition the water.

"Between 2006 and 2010, we doubled our investment in the technologies in these areas and we expect this to double again in the next three to five years. We think we have a significant advantage here because of the breadth of our portfolio," notes Messina.

The company has launched an advanced system for cooling water. This comprises GenGard anti-fouling and anti-corrosion treatment coupled with the TrueSense automation and control platform that allows continuous monitoring and dosing of the cooling water.

GE also offers a broad portfolio of filtration systems, including basic paper cartridges, reverse osmosis (RO), ultrafiltration, membrane bioreactors (MBRs), electrodialysis, electrodialysis reversal and electrodeionization.

"These systems allow us to take a raw discharge and convert it into drinking water quality. Industrial users today want to meet regulatory standards for either discharge or recycling back into the front end of their processes," explains Messina.

In addition, the firm has established an integrated water solutions group to help customers look at the water utility footprint of existing plants and to offer engineering services for new plant construction. "…More than a dozen of the Fortune top 50 companies have approached us to carry out an evaluation of their existing water utility footprints," he notes.

GE Power & Water has dramatically decreased its own water usage. In 2008 the company set a goal of a 20% reduction (versus a 2006 baseline) by 2012. It achieved a 30% cut by the end of 2009 and is now working on the next benchmark.

"Each application is customized for each of our plants: there is no cookie-cutter solution. At the same time it is important to remember that some of these improvements are based on changing operations. For example, a simple re-routing of water pipes reduced usage at one site. So cold water flow redesign can be very important while not being a major capex [capital expenditure]."

Looking to the future, Messina points to the challenges posed by the need to remove heavy metals such as mercury. In some countries, the legal requirement is for five parts per trillion: "This is a very complex demand to deal with and there's no one magic solution: a combination of technologies will be needed to achieve this."

Dow Water & Process Solutions, Edina, Minn., is focused on the twin requirements of reduced costs and increased sustainability.

Energy Efficiency

Figure 1. Companies are paying increasing attention to the net energy footprint to treat water. Source: Dow.

"Industry generally will have to be very, very much more efficient so that water use can be focused on using it for drinking and food production. Reducing water use and then reusing it in the system is therefore becoming more important for the formation of long-term, sustainable enterprises," says Snehal Desai, global marketing director.

One major technology focus for the company is a new fouling-resistant (FR) series of filters for waste treatment centers. "This is particularly important in the production of chloralkalis, which requires a lot of water. Standard RO technology was used by one customer to recycle the water, but they wanted to increase the times between filter cleanings," notes Desai.

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