Emerging Threats

Nov. 4, 2016
Membrane technology aids in removal of contaminants both traditional & emerging

About the author: David Noble is communications director for Bluewater. Noble can be reached at [email protected].

This summer, the U.S. Geological Survey warned that research is “documenting with increasing frequency that many chemical and microbial constituents that have not historically been considered as contaminants are present in the environment on a global scale.” Noting these “contaminants of emerging concern” are commonly derived from municipal, agricultural and industrial wastewater sources, the agency said the newly recognized contaminants “represent a shift in traditional thinking as many are produced industrially yet are dispersed to the environment from domestic, commercial, and industrial uses.”

The contamination of the environment with pharmaceuticals such as antibiotics, as well as personal care products, could pose a threat to both aquatic life and human health. Mounting evidence suggests that antibiotic-resistant bacteria that survive on beaches, on plant surfaces and in soil, as well as other contaminants such as herbicides, pharmaceuticals and high-production-volume chemicals, can find their way into water destined for human consumption.

However, detecting pollution in water and removing it are two different things. As far back as 2008, the U.K. Royal Society of Chemistry (RSC) reported that studies in Europe and the U.S. had found traces of approximately 100 therapeutic drug compounds such as painkillers, antibiotics, antiseptics, contraceptive pills and beta blockers in surface water, groundwater, sewage, wastewater treatment plant effluent, and “more worryingly, tap water.” 

The problem, according to the RSC, is that many pharmaceuticals pass through treatment plants designed to remove traditional contaminants. A 2013 report by a joint U.S.-Canadian organization found not all prescription drugs and other chemicals are removed by water treatment plants. 

The International Joint Commission (IJC), which regulates shared water uses, raised concerns that the Great Lakes and other bodies of water “are being contaminated with so-called chemicals of emerging concern (CECs),” which eventually could show up in drinking water. The IJC said the chemicals often are used in household items, agriculture, personal care products, pharmaceuticals and flame retardants.

Treatment Options

Today, many treatment methods to remove these substances are being examined, including activated carbon and membrane filtration. According to the World Health Organization (WHO), while conventional water treatment processes can remove approximately 50% of CECs, more advanced treatment processes, such as ozonation, advanced oxidation, activated carbon, nanofiltration and reverse osmosis (RO), are needed to achieve higher removal rates.

WHO seems to view RO as a solution with great potential to help resolve contamination issues. For example, the organization noted RO can remove more than 99% of large pharmaceutical molecules.

In the U.S., most people believe they can drink tap water without worrying about getting sick. But that attitude may be changing in the wake of recent disasters such as the Flint, Mich., water crisis or the California drought. In Flint, where lead leached into the drinking water supply from pipe, people have been relying on water filters and bottled water.

The federal government defines CECs as synthetic or naturally occurring chemicals or microorganisms that have not been commonly monitored but are known to cause or are suspected of causing human health effects or environmental problems. Many water treatment plants were not designed to completely eliminate these trace contaminants. The exact effects CECs may have on human health and the environment are unknown. 

“These substances are called emerging contaminants partially because they can now be detected in the drinking water supply and because they are emerging as potential issues,” said Brent Alspach, environmental engineer for Arcadis, a Netherlands-based water treatment design and consulting company that operates in more than 70 countries.

“It includes compounds that are better known to science, but now we are detecting them in water supplies where we hadn’t previously,” Alspach said. “The difference between now and 15 to 20 years ago is that our analytical techniques are getting much, much better. The compounds are so numerous and in different combinations and concentrations, so we don’t know what the effects might be. It would be very difficult for any research study, as a broad brush, to say they aren’t hazardous.”

Bengt Rittri, founder and executive chairperson of Bluewater, a manufacturer of point-of-use RO systems, believes consumers and businesses in the U.S. and other areas of the world need to take greater individual responsibility for treating their own water.

“Using a reverse osmosis system means you are just about as protected as you can get,” Rittri said. According to Rittri, the company’s RO technology removes heavy metals such as lead, as well as chemicals, microorganisms and pharmaceutical byproducts. “Plus, by producing clean water on demand, we help consumers reduce their need to buy plastic bottles of water, which also contribute to polluting our environment,” he added.

Bluewater offers second generation, direct-flow RO technology that reduces the water wastage traditionally associated with RO systems by up to 82%. In January, the company donated lead-removing PRO models to two charities in Flint: the Catholic Charities’ North End Soup Kitchen and the Shelter of Flint, a program providing emergency shelter, transitional housing and outreach services.

The technologies capture contaminants down to 0.0001 µ (500,000 times smaller than the diameter of a human hair), and can deliver 1,248 gal of treated water per day.

Considering the Future

“Fixing our water supply system is not something we are going to do overnight,” said David Sedlak, professor for the University of California, Berkeley. “These are big publicly run and operated systems that are designed to last many, many decades, so change happens over decades unless an emergency happens.”

Sedlak looked at the effects of overpopulation, climate change and pollution on sources of clean, drinkable water in his 2014 book Water 4.0. These circumstances are leading to the next major change in how cities look to treat water for human consumption, including using seawater, storm water runoff and sewage.

“Modern reverse osmosis technology can remove nearly all contaminants from water and [produce] water that is ultrapure and clean,” said Sedlak, who also is co-director of the Berkeley Water Center and director of the Institute for Environmental Science and Engineering.

About the Author

David Noble